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…ead to fields

Currently, for data moving, we generate an msanread of the source,
followed by an msanwrite of the destination. msanread checks
the source is initialized.

This has a problem: if the source is an aggregate type containing
alignment paddings, the padding bytes may not be thought as
initialized by MSAN. If we copy the aggregate type by value, if
it counts as a read, MSAN reports using uninitialized data. This
CL changes it to use __msan_memmove for data copying, which tells
MSAN to propagate initialized-ness but not check for it.

Caveat: technically __msan_memmove is not a public API of MSAN,
although the C compiler does generate direct calls to it.

Also, when instrumenting a load of a struct, split the
instrumentation to fields, instead of generating an msanread for
the whole struct. This skips padding bytes, which may not be
considered initialized in MSAN.

Fixes #42820.

Change-Id: Id861c8bbfd94cfcccefcc58eaf9e4eb43b4d85c6
Reviewed-on: https://go-review.googlesource.com/c/go/+/270859
Trust: Cherry Zhang <cherryyz@google.com>
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
74 contributors

Users who have contributed to this file

@randall77 @josharian @dr2chase @mdempsky @cherrymui @tzneal @aclements @mundaym @mvdan @griesemer @cuonglm @ianlancetaylor
7231 lines (6593 sloc) 236 KB
// Copyright 2015 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package gc
import (
"encoding/binary"
"fmt"
"html"
"os"
"path/filepath"
"sort"
"bufio"
"bytes"
"cmd/compile/internal/ssa"
"cmd/compile/internal/types"
"cmd/internal/obj"
"cmd/internal/obj/x86"
"cmd/internal/objabi"
"cmd/internal/src"
"cmd/internal/sys"
)
var ssaConfig *ssa.Config
var ssaCaches []ssa.Cache
var ssaDump string // early copy of $GOSSAFUNC; the func name to dump output for
var ssaDir string // optional destination for ssa dump file
var ssaDumpStdout bool // whether to dump to stdout
var ssaDumpCFG string // generate CFGs for these phases
const ssaDumpFile = "ssa.html"
// The max number of defers in a function using open-coded defers. We enforce this
// limit because the deferBits bitmask is currently a single byte (to minimize code size)
const maxOpenDefers = 8
// ssaDumpInlined holds all inlined functions when ssaDump contains a function name.
var ssaDumpInlined []*Node
func initssaconfig() {
types_ := ssa.NewTypes()
if thearch.SoftFloat {
softfloatInit()
}
// Generate a few pointer types that are uncommon in the frontend but common in the backend.
// Caching is disabled in the backend, so generating these here avoids allocations.
_ = types.NewPtr(types.Types[TINTER]) // *interface{}
_ = types.NewPtr(types.NewPtr(types.Types[TSTRING])) // **string
_ = types.NewPtr(types.NewSlice(types.Types[TINTER])) // *[]interface{}
_ = types.NewPtr(types.NewPtr(types.Bytetype)) // **byte
_ = types.NewPtr(types.NewSlice(types.Bytetype)) // *[]byte
_ = types.NewPtr(types.NewSlice(types.Types[TSTRING])) // *[]string
_ = types.NewPtr(types.NewPtr(types.NewPtr(types.Types[TUINT8]))) // ***uint8
_ = types.NewPtr(types.Types[TINT16]) // *int16
_ = types.NewPtr(types.Types[TINT64]) // *int64
_ = types.NewPtr(types.Errortype) // *error
types.NewPtrCacheEnabled = false
ssaConfig = ssa.NewConfig(thearch.LinkArch.Name, *types_, Ctxt, Debug.N == 0)
ssaConfig.SoftFloat = thearch.SoftFloat
ssaConfig.Race = flag_race
ssaCaches = make([]ssa.Cache, nBackendWorkers)
// Set up some runtime functions we'll need to call.
assertE2I = sysfunc("assertE2I")
assertE2I2 = sysfunc("assertE2I2")
assertI2I = sysfunc("assertI2I")
assertI2I2 = sysfunc("assertI2I2")
deferproc = sysfunc("deferproc")
deferprocStack = sysfunc("deferprocStack")
Deferreturn = sysfunc("deferreturn")
Duffcopy = sysfunc("duffcopy")
Duffzero = sysfunc("duffzero")
gcWriteBarrier = sysfunc("gcWriteBarrier")
goschedguarded = sysfunc("goschedguarded")
growslice = sysfunc("growslice")
msanread = sysfunc("msanread")
msanwrite = sysfunc("msanwrite")
msanmove = sysfunc("msanmove")
newobject = sysfunc("newobject")
newproc = sysfunc("newproc")
panicdivide = sysfunc("panicdivide")
panicdottypeE = sysfunc("panicdottypeE")
panicdottypeI = sysfunc("panicdottypeI")
panicnildottype = sysfunc("panicnildottype")
panicoverflow = sysfunc("panicoverflow")
panicshift = sysfunc("panicshift")
raceread = sysfunc("raceread")
racereadrange = sysfunc("racereadrange")
racewrite = sysfunc("racewrite")
racewriterange = sysfunc("racewriterange")
x86HasPOPCNT = sysvar("x86HasPOPCNT") // bool
x86HasSSE41 = sysvar("x86HasSSE41") // bool
x86HasFMA = sysvar("x86HasFMA") // bool
armHasVFPv4 = sysvar("armHasVFPv4") // bool
arm64HasATOMICS = sysvar("arm64HasATOMICS") // bool
typedmemclr = sysfunc("typedmemclr")
typedmemmove = sysfunc("typedmemmove")
Udiv = sysvar("udiv") // asm func with special ABI
writeBarrier = sysvar("writeBarrier") // struct { bool; ... }
zerobaseSym = sysvar("zerobase")
// asm funcs with special ABI
if thearch.LinkArch.Name == "amd64" {
GCWriteBarrierReg = map[int16]*obj.LSym{
x86.REG_AX: sysfunc("gcWriteBarrier"),
x86.REG_CX: sysfunc("gcWriteBarrierCX"),
x86.REG_DX: sysfunc("gcWriteBarrierDX"),
x86.REG_BX: sysfunc("gcWriteBarrierBX"),
x86.REG_BP: sysfunc("gcWriteBarrierBP"),
x86.REG_SI: sysfunc("gcWriteBarrierSI"),
x86.REG_R8: sysfunc("gcWriteBarrierR8"),
x86.REG_R9: sysfunc("gcWriteBarrierR9"),
}
}
if thearch.LinkArch.Family == sys.Wasm {
BoundsCheckFunc[ssa.BoundsIndex] = sysfunc("goPanicIndex")
BoundsCheckFunc[ssa.BoundsIndexU] = sysfunc("goPanicIndexU")
BoundsCheckFunc[ssa.BoundsSliceAlen] = sysfunc("goPanicSliceAlen")
BoundsCheckFunc[ssa.BoundsSliceAlenU] = sysfunc("goPanicSliceAlenU")
BoundsCheckFunc[ssa.BoundsSliceAcap] = sysfunc("goPanicSliceAcap")
BoundsCheckFunc[ssa.BoundsSliceAcapU] = sysfunc("goPanicSliceAcapU")
BoundsCheckFunc[ssa.BoundsSliceB] = sysfunc("goPanicSliceB")
BoundsCheckFunc[ssa.BoundsSliceBU] = sysfunc("goPanicSliceBU")
BoundsCheckFunc[ssa.BoundsSlice3Alen] = sysfunc("goPanicSlice3Alen")
BoundsCheckFunc[ssa.BoundsSlice3AlenU] = sysfunc("goPanicSlice3AlenU")
BoundsCheckFunc[ssa.BoundsSlice3Acap] = sysfunc("goPanicSlice3Acap")
BoundsCheckFunc[ssa.BoundsSlice3AcapU] = sysfunc("goPanicSlice3AcapU")
BoundsCheckFunc[ssa.BoundsSlice3B] = sysfunc("goPanicSlice3B")
BoundsCheckFunc[ssa.BoundsSlice3BU] = sysfunc("goPanicSlice3BU")
BoundsCheckFunc[ssa.BoundsSlice3C] = sysfunc("goPanicSlice3C")
BoundsCheckFunc[ssa.BoundsSlice3CU] = sysfunc("goPanicSlice3CU")
} else {
BoundsCheckFunc[ssa.BoundsIndex] = sysfunc("panicIndex")
BoundsCheckFunc[ssa.BoundsIndexU] = sysfunc("panicIndexU")
BoundsCheckFunc[ssa.BoundsSliceAlen] = sysfunc("panicSliceAlen")
BoundsCheckFunc[ssa.BoundsSliceAlenU] = sysfunc("panicSliceAlenU")
BoundsCheckFunc[ssa.BoundsSliceAcap] = sysfunc("panicSliceAcap")
BoundsCheckFunc[ssa.BoundsSliceAcapU] = sysfunc("panicSliceAcapU")
BoundsCheckFunc[ssa.BoundsSliceB] = sysfunc("panicSliceB")
BoundsCheckFunc[ssa.BoundsSliceBU] = sysfunc("panicSliceBU")
BoundsCheckFunc[ssa.BoundsSlice3Alen] = sysfunc("panicSlice3Alen")
BoundsCheckFunc[ssa.BoundsSlice3AlenU] = sysfunc("panicSlice3AlenU")
BoundsCheckFunc[ssa.BoundsSlice3Acap] = sysfunc("panicSlice3Acap")
BoundsCheckFunc[ssa.BoundsSlice3AcapU] = sysfunc("panicSlice3AcapU")
BoundsCheckFunc[ssa.BoundsSlice3B] = sysfunc("panicSlice3B")
BoundsCheckFunc[ssa.BoundsSlice3BU] = sysfunc("panicSlice3BU")
BoundsCheckFunc[ssa.BoundsSlice3C] = sysfunc("panicSlice3C")
BoundsCheckFunc[ssa.BoundsSlice3CU] = sysfunc("panicSlice3CU")
}
if thearch.LinkArch.PtrSize == 4 {
ExtendCheckFunc[ssa.BoundsIndex] = sysvar("panicExtendIndex")
ExtendCheckFunc[ssa.BoundsIndexU] = sysvar("panicExtendIndexU")
ExtendCheckFunc[ssa.BoundsSliceAlen] = sysvar("panicExtendSliceAlen")
ExtendCheckFunc[ssa.BoundsSliceAlenU] = sysvar("panicExtendSliceAlenU")
ExtendCheckFunc[ssa.BoundsSliceAcap] = sysvar("panicExtendSliceAcap")
ExtendCheckFunc[ssa.BoundsSliceAcapU] = sysvar("panicExtendSliceAcapU")
ExtendCheckFunc[ssa.BoundsSliceB] = sysvar("panicExtendSliceB")
ExtendCheckFunc[ssa.BoundsSliceBU] = sysvar("panicExtendSliceBU")
ExtendCheckFunc[ssa.BoundsSlice3Alen] = sysvar("panicExtendSlice3Alen")
ExtendCheckFunc[ssa.BoundsSlice3AlenU] = sysvar("panicExtendSlice3AlenU")
ExtendCheckFunc[ssa.BoundsSlice3Acap] = sysvar("panicExtendSlice3Acap")
ExtendCheckFunc[ssa.BoundsSlice3AcapU] = sysvar("panicExtendSlice3AcapU")
ExtendCheckFunc[ssa.BoundsSlice3B] = sysvar("panicExtendSlice3B")
ExtendCheckFunc[ssa.BoundsSlice3BU] = sysvar("panicExtendSlice3BU")
ExtendCheckFunc[ssa.BoundsSlice3C] = sysvar("panicExtendSlice3C")
ExtendCheckFunc[ssa.BoundsSlice3CU] = sysvar("panicExtendSlice3CU")
}
// Wasm (all asm funcs with special ABIs)
WasmMove = sysvar("wasmMove")
WasmZero = sysvar("wasmZero")
WasmDiv = sysvar("wasmDiv")
WasmTruncS = sysvar("wasmTruncS")
WasmTruncU = sysvar("wasmTruncU")
SigPanic = sysfunc("sigpanic")
}
// getParam returns the Field of ith param of node n (which is a
// function/method/interface call), where the receiver of a method call is
// considered as the 0th parameter. This does not include the receiver of an
// interface call.
func getParam(n *Node, i int) *types.Field {
t := n.Left.Type
if n.Op == OCALLMETH {
if i == 0 {
return t.Recv()
}
return t.Params().Field(i - 1)
}
return t.Params().Field(i)
}
// dvarint writes a varint v to the funcdata in symbol x and returns the new offset
func dvarint(x *obj.LSym, off int, v int64) int {
if v < 0 || v > 1e9 {
panic(fmt.Sprintf("dvarint: bad offset for funcdata - %v", v))
}
if v < 1<<7 {
return duint8(x, off, uint8(v))
}
off = duint8(x, off, uint8((v&127)|128))
if v < 1<<14 {
return duint8(x, off, uint8(v>>7))
}
off = duint8(x, off, uint8(((v>>7)&127)|128))
if v < 1<<21 {
return duint8(x, off, uint8(v>>14))
}
off = duint8(x, off, uint8(((v>>14)&127)|128))
if v < 1<<28 {
return duint8(x, off, uint8(v>>21))
}
off = duint8(x, off, uint8(((v>>21)&127)|128))
return duint8(x, off, uint8(v>>28))
}
// emitOpenDeferInfo emits FUNCDATA information about the defers in a function
// that is using open-coded defers. This funcdata is used to determine the active
// defers in a function and execute those defers during panic processing.
//
// The funcdata is all encoded in varints (since values will almost always be less than
// 128, but stack offsets could potentially be up to 2Gbyte). All "locations" (offsets)
// for stack variables are specified as the number of bytes below varp (pointer to the
// top of the local variables) for their starting address. The format is:
//
// - Max total argument size among all the defers
// - Offset of the deferBits variable
// - Number of defers in the function
// - Information about each defer call, in reverse order of appearance in the function:
// - Total argument size of the call
// - Offset of the closure value to call
// - Number of arguments (including interface receiver or method receiver as first arg)
// - Information about each argument
// - Offset of the stored defer argument in this function's frame
// - Size of the argument
// - Offset of where argument should be placed in the args frame when making call
func (s *state) emitOpenDeferInfo() {
x := Ctxt.Lookup(s.curfn.Func.lsym.Name + ".opendefer")
s.curfn.Func.lsym.Func().OpenCodedDeferInfo = x
off := 0
// Compute maxargsize (max size of arguments for all defers)
// first, so we can output it first to the funcdata
var maxargsize int64
for i := len(s.openDefers) - 1; i >= 0; i-- {
r := s.openDefers[i]
argsize := r.n.Left.Type.ArgWidth()
if argsize > maxargsize {
maxargsize = argsize
}
}
off = dvarint(x, off, maxargsize)
off = dvarint(x, off, -s.deferBitsTemp.Xoffset)
off = dvarint(x, off, int64(len(s.openDefers)))
// Write in reverse-order, for ease of running in that order at runtime
for i := len(s.openDefers) - 1; i >= 0; i-- {
r := s.openDefers[i]
off = dvarint(x, off, r.n.Left.Type.ArgWidth())
off = dvarint(x, off, -r.closureNode.Xoffset)
numArgs := len(r.argNodes)
if r.rcvrNode != nil {
// If there's an interface receiver, treat/place it as the first
// arg. (If there is a method receiver, it's already included as
// first arg in r.argNodes.)
numArgs++
}
off = dvarint(x, off, int64(numArgs))
if r.rcvrNode != nil {
off = dvarint(x, off, -r.rcvrNode.Xoffset)
off = dvarint(x, off, s.config.PtrSize)
off = dvarint(x, off, 0)
}
for j, arg := range r.argNodes {
f := getParam(r.n, j)
off = dvarint(x, off, -arg.Xoffset)
off = dvarint(x, off, f.Type.Size())
off = dvarint(x, off, f.Offset)
}
}
}
// buildssa builds an SSA function for fn.
// worker indicates which of the backend workers is doing the processing.
func buildssa(fn *Node, worker int) *ssa.Func {
name := fn.funcname()
printssa := false
if ssaDump != "" { // match either a simple name e.g. "(*Reader).Reset", or a package.name e.g. "compress/gzip.(*Reader).Reset"
printssa = name == ssaDump || myimportpath+"."+name == ssaDump
}
var astBuf *bytes.Buffer
if printssa {
astBuf = &bytes.Buffer{}
fdumplist(astBuf, "buildssa-enter", fn.Func.Enter)
fdumplist(astBuf, "buildssa-body", fn.Nbody)
fdumplist(astBuf, "buildssa-exit", fn.Func.Exit)
if ssaDumpStdout {
fmt.Println("generating SSA for", name)
fmt.Print(astBuf.String())
}
}
var s state
s.pushLine(fn.Pos)
defer s.popLine()
s.hasdefer = fn.Func.HasDefer()
if fn.Func.Pragma&CgoUnsafeArgs != 0 {
s.cgoUnsafeArgs = true
}
fe := ssafn{
curfn: fn,
log: printssa && ssaDumpStdout,
}
s.curfn = fn
s.f = ssa.NewFunc(&fe)
s.config = ssaConfig
s.f.Type = fn.Type
s.f.Config = ssaConfig
s.f.Cache = &ssaCaches[worker]
s.f.Cache.Reset()
s.f.Name = name
s.f.DebugTest = s.f.DebugHashMatch("GOSSAHASH")
s.f.PrintOrHtmlSSA = printssa
if fn.Func.Pragma&Nosplit != 0 {
s.f.NoSplit = true
}
s.panics = map[funcLine]*ssa.Block{}
s.softFloat = s.config.SoftFloat
// Allocate starting block
s.f.Entry = s.f.NewBlock(ssa.BlockPlain)
s.f.Entry.Pos = fn.Pos
if printssa {
ssaDF := ssaDumpFile
if ssaDir != "" {
ssaDF = filepath.Join(ssaDir, myimportpath+"."+name+".html")
ssaD := filepath.Dir(ssaDF)
os.MkdirAll(ssaD, 0755)
}
s.f.HTMLWriter = ssa.NewHTMLWriter(ssaDF, s.f, ssaDumpCFG)
// TODO: generate and print a mapping from nodes to values and blocks
dumpSourcesColumn(s.f.HTMLWriter, fn)
s.f.HTMLWriter.WriteAST("AST", astBuf)
}
// Allocate starting values
s.labels = map[string]*ssaLabel{}
s.labeledNodes = map[*Node]*ssaLabel{}
s.fwdVars = map[*Node]*ssa.Value{}
s.startmem = s.entryNewValue0(ssa.OpInitMem, types.TypeMem)
s.hasOpenDefers = Debug.N == 0 && s.hasdefer && !s.curfn.Func.OpenCodedDeferDisallowed()
switch {
case s.hasOpenDefers && (Ctxt.Flag_shared || Ctxt.Flag_dynlink) && thearch.LinkArch.Name == "386":
// Don't support open-coded defers for 386 ONLY when using shared
// libraries, because there is extra code (added by rewriteToUseGot())
// preceding the deferreturn/ret code that is generated by gencallret()
// that we don't track correctly.
s.hasOpenDefers = false
}
if s.hasOpenDefers && s.curfn.Func.Exit.Len() > 0 {
// Skip doing open defers if there is any extra exit code (likely
// copying heap-allocated return values or race detection), since
// we will not generate that code in the case of the extra
// deferreturn/ret segment.
s.hasOpenDefers = false
}
if s.hasOpenDefers &&
s.curfn.Func.numReturns*s.curfn.Func.numDefers > 15 {
// Since we are generating defer calls at every exit for
// open-coded defers, skip doing open-coded defers if there are
// too many returns (especially if there are multiple defers).
// Open-coded defers are most important for improving performance
// for smaller functions (which don't have many returns).
s.hasOpenDefers = false
}
s.sp = s.entryNewValue0(ssa.OpSP, types.Types[TUINTPTR]) // TODO: use generic pointer type (unsafe.Pointer?) instead
s.sb = s.entryNewValue0(ssa.OpSB, types.Types[TUINTPTR])
s.startBlock(s.f.Entry)
s.vars[&memVar] = s.startmem
if s.hasOpenDefers {
// Create the deferBits variable and stack slot. deferBits is a
// bitmask showing which of the open-coded defers in this function
// have been activated.
deferBitsTemp := tempAt(src.NoXPos, s.curfn, types.Types[TUINT8])
s.deferBitsTemp = deferBitsTemp
// For this value, AuxInt is initialized to zero by default
startDeferBits := s.entryNewValue0(ssa.OpConst8, types.Types[TUINT8])
s.vars[&deferBitsVar] = startDeferBits
s.deferBitsAddr = s.addr(deferBitsTemp)
s.store(types.Types[TUINT8], s.deferBitsAddr, startDeferBits)
// Make sure that the deferBits stack slot is kept alive (for use
// by panics) and stores to deferBits are not eliminated, even if
// all checking code on deferBits in the function exit can be
// eliminated, because the defer statements were all
// unconditional.
s.vars[&memVar] = s.newValue1Apos(ssa.OpVarLive, types.TypeMem, deferBitsTemp, s.mem(), false)
}
// Generate addresses of local declarations
s.decladdrs = map[*Node]*ssa.Value{}
var args []ssa.Param
var results []ssa.Param
for _, n := range fn.Func.Dcl {
switch n.Class() {
case PPARAM:
s.decladdrs[n] = s.entryNewValue2A(ssa.OpLocalAddr, types.NewPtr(n.Type), n, s.sp, s.startmem)
args = append(args, ssa.Param{Type: n.Type, Offset: int32(n.Xoffset)})
case PPARAMOUT:
s.decladdrs[n] = s.entryNewValue2A(ssa.OpLocalAddr, types.NewPtr(n.Type), n, s.sp, s.startmem)
results = append(results, ssa.Param{Type: n.Type, Offset: int32(n.Xoffset)})
if s.canSSA(n) {
// Save ssa-able PPARAMOUT variables so we can
// store them back to the stack at the end of
// the function.
s.returns = append(s.returns, n)
}
case PAUTO:
// processed at each use, to prevent Addr coming
// before the decl.
case PAUTOHEAP:
// moved to heap - already handled by frontend
case PFUNC:
// local function - already handled by frontend
default:
s.Fatalf("local variable with class %v unimplemented", n.Class())
}
}
// Populate SSAable arguments.
for _, n := range fn.Func.Dcl {
if n.Class() == PPARAM && s.canSSA(n) {
v := s.newValue0A(ssa.OpArg, n.Type, n)
s.vars[n] = v
s.addNamedValue(n, v) // This helps with debugging information, not needed for compilation itself.
}
}
// Convert the AST-based IR to the SSA-based IR
s.stmtList(fn.Func.Enter)
s.stmtList(fn.Nbody)
// fallthrough to exit
if s.curBlock != nil {
s.pushLine(fn.Func.Endlineno)
s.exit()
s.popLine()
}
for _, b := range s.f.Blocks {
if b.Pos != src.NoXPos {
s.updateUnsetPredPos(b)
}
}
s.insertPhis()
// Main call to ssa package to compile function
ssa.Compile(s.f)
if s.hasOpenDefers {
s.emitOpenDeferInfo()
}
return s.f
}
func dumpSourcesColumn(writer *ssa.HTMLWriter, fn *Node) {
// Read sources of target function fn.
fname := Ctxt.PosTable.Pos(fn.Pos).Filename()
targetFn, err := readFuncLines(fname, fn.Pos.Line(), fn.Func.Endlineno.Line())
if err != nil {
writer.Logf("cannot read sources for function %v: %v", fn, err)
}
// Read sources of inlined functions.
var inlFns []*ssa.FuncLines
for _, fi := range ssaDumpInlined {
var elno src.XPos
if fi.Name.Defn == nil {
// Endlineno is filled from exported data.
elno = fi.Func.Endlineno
} else {
elno = fi.Name.Defn.Func.Endlineno
}
fname := Ctxt.PosTable.Pos(fi.Pos).Filename()
fnLines, err := readFuncLines(fname, fi.Pos.Line(), elno.Line())
if err != nil {
writer.Logf("cannot read sources for inlined function %v: %v", fi, err)
continue
}
inlFns = append(inlFns, fnLines)
}
sort.Sort(ssa.ByTopo(inlFns))
if targetFn != nil {
inlFns = append([]*ssa.FuncLines{targetFn}, inlFns...)
}
writer.WriteSources("sources", inlFns)
}
func readFuncLines(file string, start, end uint) (*ssa.FuncLines, error) {
f, err := os.Open(os.ExpandEnv(file))
if err != nil {
return nil, err
}
defer f.Close()
var lines []string
ln := uint(1)
scanner := bufio.NewScanner(f)
for scanner.Scan() && ln <= end {
if ln >= start {
lines = append(lines, scanner.Text())
}
ln++
}
return &ssa.FuncLines{Filename: file, StartLineno: start, Lines: lines}, nil
}
// updateUnsetPredPos propagates the earliest-value position information for b
// towards all of b's predecessors that need a position, and recurs on that
// predecessor if its position is updated. B should have a non-empty position.
func (s *state) updateUnsetPredPos(b *ssa.Block) {
if b.Pos == src.NoXPos {
s.Fatalf("Block %s should have a position", b)
}
bestPos := src.NoXPos
for _, e := range b.Preds {
p := e.Block()
if !p.LackingPos() {
continue
}
if bestPos == src.NoXPos {
bestPos = b.Pos
for _, v := range b.Values {
if v.LackingPos() {
continue
}
if v.Pos != src.NoXPos {
// Assume values are still in roughly textual order;
// TODO: could also seek minimum position?
bestPos = v.Pos
break
}
}
}
p.Pos = bestPos
s.updateUnsetPredPos(p) // We do not expect long chains of these, thus recursion is okay.
}
}
// Information about each open-coded defer.
type openDeferInfo struct {
// The ODEFER node representing the function call of the defer
n *Node
// If defer call is closure call, the address of the argtmp where the
// closure is stored.
closure *ssa.Value
// The node representing the argtmp where the closure is stored - used for
// function, method, or interface call, to store a closure that panic
// processing can use for this defer.
closureNode *Node
// If defer call is interface call, the address of the argtmp where the
// receiver is stored
rcvr *ssa.Value
// The node representing the argtmp where the receiver is stored
rcvrNode *Node
// The addresses of the argtmps where the evaluated arguments of the defer
// function call are stored.
argVals []*ssa.Value
// The nodes representing the argtmps where the args of the defer are stored
argNodes []*Node
}
type state struct {
// configuration (arch) information
config *ssa.Config
// function we're building
f *ssa.Func
// Node for function
curfn *Node
// labels and labeled control flow nodes (OFOR, OFORUNTIL, OSWITCH, OSELECT) in f
labels map[string]*ssaLabel
labeledNodes map[*Node]*ssaLabel
// unlabeled break and continue statement tracking
breakTo *ssa.Block // current target for plain break statement
continueTo *ssa.Block // current target for plain continue statement
// current location where we're interpreting the AST
curBlock *ssa.Block
// variable assignments in the current block (map from variable symbol to ssa value)
// *Node is the unique identifier (an ONAME Node) for the variable.
// TODO: keep a single varnum map, then make all of these maps slices instead?
vars map[*Node]*ssa.Value
// fwdVars are variables that are used before they are defined in the current block.
// This map exists just to coalesce multiple references into a single FwdRef op.
// *Node is the unique identifier (an ONAME Node) for the variable.
fwdVars map[*Node]*ssa.Value
// all defined variables at the end of each block. Indexed by block ID.
defvars []map[*Node]*ssa.Value
// addresses of PPARAM and PPARAMOUT variables.
decladdrs map[*Node]*ssa.Value
// starting values. Memory, stack pointer, and globals pointer
startmem *ssa.Value
sp *ssa.Value
sb *ssa.Value
// value representing address of where deferBits autotmp is stored
deferBitsAddr *ssa.Value
deferBitsTemp *Node
// line number stack. The current line number is top of stack
line []src.XPos
// the last line number processed; it may have been popped
lastPos src.XPos
// list of panic calls by function name and line number.
// Used to deduplicate panic calls.
panics map[funcLine]*ssa.Block
// list of PPARAMOUT (return) variables.
returns []*Node
cgoUnsafeArgs bool
hasdefer bool // whether the function contains a defer statement
softFloat bool
hasOpenDefers bool // whether we are doing open-coded defers
// If doing open-coded defers, list of info about the defer calls in
// scanning order. Hence, at exit we should run these defers in reverse
// order of this list
openDefers []*openDeferInfo
// For open-coded defers, this is the beginning and end blocks of the last
// defer exit code that we have generated so far. We use these to share
// code between exits if the shareDeferExits option (disabled by default)
// is on.
lastDeferExit *ssa.Block // Entry block of last defer exit code we generated
lastDeferFinalBlock *ssa.Block // Final block of last defer exit code we generated
lastDeferCount int // Number of defers encountered at that point
prevCall *ssa.Value // the previous call; use this to tie results to the call op.
}
type funcLine struct {
f *obj.LSym
base *src.PosBase
line uint
}
type ssaLabel struct {
target *ssa.Block // block identified by this label
breakTarget *ssa.Block // block to break to in control flow node identified by this label
continueTarget *ssa.Block // block to continue to in control flow node identified by this label
}
// label returns the label associated with sym, creating it if necessary.
func (s *state) label(sym *types.Sym) *ssaLabel {
lab := s.labels[sym.Name]
if lab == nil {
lab = new(ssaLabel)
s.labels[sym.Name] = lab
}
return lab
}
func (s *state) Logf(msg string, args ...interface{}) { s.f.Logf(msg, args...) }
func (s *state) Log() bool { return s.f.Log() }
func (s *state) Fatalf(msg string, args ...interface{}) {
s.f.Frontend().Fatalf(s.peekPos(), msg, args...)
}
func (s *state) Warnl(pos src.XPos, msg string, args ...interface{}) { s.f.Warnl(pos, msg, args...) }
func (s *state) Debug_checknil() bool { return s.f.Frontend().Debug_checknil() }
var (
// dummy node for the memory variable
memVar = Node{Op: ONAME, Sym: &types.Sym{Name: "mem"}}
// dummy nodes for temporary variables
ptrVar = Node{Op: ONAME, Sym: &types.Sym{Name: "ptr"}}
lenVar = Node{Op: ONAME, Sym: &types.Sym{Name: "len"}}
newlenVar = Node{Op: ONAME, Sym: &types.Sym{Name: "newlen"}}
capVar = Node{Op: ONAME, Sym: &types.Sym{Name: "cap"}}
typVar = Node{Op: ONAME, Sym: &types.Sym{Name: "typ"}}
okVar = Node{Op: ONAME, Sym: &types.Sym{Name: "ok"}}
deferBitsVar = Node{Op: ONAME, Sym: &types.Sym{Name: "deferBits"}}
)
// startBlock sets the current block we're generating code in to b.
func (s *state) startBlock(b *ssa.Block) {
if s.curBlock != nil {
s.Fatalf("starting block %v when block %v has not ended", b, s.curBlock)
}
s.curBlock = b
s.vars = map[*Node]*ssa.Value{}
for n := range s.fwdVars {
delete(s.fwdVars, n)
}
}
// endBlock marks the end of generating code for the current block.
// Returns the (former) current block. Returns nil if there is no current
// block, i.e. if no code flows to the current execution point.
func (s *state) endBlock() *ssa.Block {
b := s.curBlock
if b == nil {
return nil
}
for len(s.defvars) <= int(b.ID) {
s.defvars = append(s.defvars, nil)
}
s.defvars[b.ID] = s.vars
s.curBlock = nil
s.vars = nil
if b.LackingPos() {
// Empty plain blocks get the line of their successor (handled after all blocks created),
// except for increment blocks in For statements (handled in ssa conversion of OFOR),
// and for blocks ending in GOTO/BREAK/CONTINUE.
b.Pos = src.NoXPos
} else {
b.Pos = s.lastPos
}
return b
}
// pushLine pushes a line number on the line number stack.
func (s *state) pushLine(line src.XPos) {
if !line.IsKnown() {
// the frontend may emit node with line number missing,
// use the parent line number in this case.
line = s.peekPos()
if Debug.K != 0 {
Warn("buildssa: unknown position (line 0)")
}
} else {
s.lastPos = line
}
s.line = append(s.line, line)
}
// popLine pops the top of the line number stack.
func (s *state) popLine() {
s.line = s.line[:len(s.line)-1]
}
// peekPos peeks the top of the line number stack.
func (s *state) peekPos() src.XPos {
return s.line[len(s.line)-1]
}
// newValue0 adds a new value with no arguments to the current block.
func (s *state) newValue0(op ssa.Op, t *types.Type) *ssa.Value {
return s.curBlock.NewValue0(s.peekPos(), op, t)
}
// newValue0A adds a new value with no arguments and an aux value to the current block.
func (s *state) newValue0A(op ssa.Op, t *types.Type, aux interface{}) *ssa.Value {
return s.curBlock.NewValue0A(s.peekPos(), op, t, aux)
}
// newValue0I adds a new value with no arguments and an auxint value to the current block.
func (s *state) newValue0I(op ssa.Op, t *types.Type, auxint int64) *ssa.Value {
return s.curBlock.NewValue0I(s.peekPos(), op, t, auxint)
}
// newValue1 adds a new value with one argument to the current block.
func (s *state) newValue1(op ssa.Op, t *types.Type, arg *ssa.Value) *ssa.Value {
return s.curBlock.NewValue1(s.peekPos(), op, t, arg)
}
// newValue1A adds a new value with one argument and an aux value to the current block.
func (s *state) newValue1A(op ssa.Op, t *types.Type, aux interface{}, arg *ssa.Value) *ssa.Value {
return s.curBlock.NewValue1A(s.peekPos(), op, t, aux, arg)
}
// newValue1Apos adds a new value with one argument and an aux value to the current block.
// isStmt determines whether the created values may be a statement or not
// (i.e., false means never, yes means maybe).
func (s *state) newValue1Apos(op ssa.Op, t *types.Type, aux interface{}, arg *ssa.Value, isStmt bool) *ssa.Value {
if isStmt {
return s.curBlock.NewValue1A(s.peekPos(), op, t, aux, arg)
}
return s.curBlock.NewValue1A(s.peekPos().WithNotStmt(), op, t, aux, arg)
}
// newValue1I adds a new value with one argument and an auxint value to the current block.
func (s *state) newValue1I(op ssa.Op, t *types.Type, aux int64, arg *ssa.Value) *ssa.Value {
return s.curBlock.NewValue1I(s.peekPos(), op, t, aux, arg)
}
// newValue2 adds a new value with two arguments to the current block.
func (s *state) newValue2(op ssa.Op, t *types.Type, arg0, arg1 *ssa.Value) *ssa.Value {
return s.curBlock.NewValue2(s.peekPos(), op, t, arg0, arg1)
}
// newValue2A adds a new value with two arguments and an aux value to the current block.
func (s *state) newValue2A(op ssa.Op, t *types.Type, aux interface{}, arg0, arg1 *ssa.Value) *ssa.Value {
return s.curBlock.NewValue2A(s.peekPos(), op, t, aux, arg0, arg1)
}
// newValue2Apos adds a new value with two arguments and an aux value to the current block.
// isStmt determines whether the created values may be a statement or not
// (i.e., false means never, yes means maybe).
func (s *state) newValue2Apos(op ssa.Op, t *types.Type, aux interface{}, arg0, arg1 *ssa.Value, isStmt bool) *ssa.Value {
if isStmt {
return s.curBlock.NewValue2A(s.peekPos(), op, t, aux, arg0, arg1)
}
return s.curBlock.NewValue2A(s.peekPos().WithNotStmt(), op, t, aux, arg0, arg1)
}
// newValue2I adds a new value with two arguments and an auxint value to the current block.
func (s *state) newValue2I(op ssa.Op, t *types.Type, aux int64, arg0, arg1 *ssa.Value) *ssa.Value {
return s.curBlock.NewValue2I(s.peekPos(), op, t, aux, arg0, arg1)
}
// newValue3 adds a new value with three arguments to the current block.
func (s *state) newValue3(op ssa.Op, t *types.Type, arg0, arg1, arg2 *ssa.Value) *ssa.Value {
return s.curBlock.NewValue3(s.peekPos(), op, t, arg0, arg1, arg2)
}
// newValue3I adds a new value with three arguments and an auxint value to the current block.
func (s *state) newValue3I(op ssa.Op, t *types.Type, aux int64, arg0, arg1, arg2 *ssa.Value) *ssa.Value {
return s.curBlock.NewValue3I(s.peekPos(), op, t, aux, arg0, arg1, arg2)
}
// newValue3A adds a new value with three arguments and an aux value to the current block.
func (s *state) newValue3A(op ssa.Op, t *types.Type, aux interface{}, arg0, arg1, arg2 *ssa.Value) *ssa.Value {
return s.curBlock.NewValue3A(s.peekPos(), op, t, aux, arg0, arg1, arg2)
}
// newValue3Apos adds a new value with three arguments and an aux value to the current block.
// isStmt determines whether the created values may be a statement or not
// (i.e., false means never, yes means maybe).
func (s *state) newValue3Apos(op ssa.Op, t *types.Type, aux interface{}, arg0, arg1, arg2 *ssa.Value, isStmt bool) *ssa.Value {
if isStmt {
return s.curBlock.NewValue3A(s.peekPos(), op, t, aux, arg0, arg1, arg2)
}
return s.curBlock.NewValue3A(s.peekPos().WithNotStmt(), op, t, aux, arg0, arg1, arg2)
}
// newValue4 adds a new value with four arguments to the current block.
func (s *state) newValue4(op ssa.Op, t *types.Type, arg0, arg1, arg2, arg3 *ssa.Value) *ssa.Value {
return s.curBlock.NewValue4(s.peekPos(), op, t, arg0, arg1, arg2, arg3)
}
// newValue4 adds a new value with four arguments and an auxint value to the current block.
func (s *state) newValue4I(op ssa.Op, t *types.Type, aux int64, arg0, arg1, arg2, arg3 *ssa.Value) *ssa.Value {
return s.curBlock.NewValue4I(s.peekPos(), op, t, aux, arg0, arg1, arg2, arg3)
}
// entryNewValue0 adds a new value with no arguments to the entry block.
func (s *state) entryNewValue0(op ssa.Op, t *types.Type) *ssa.Value {
return s.f.Entry.NewValue0(src.NoXPos, op, t)
}
// entryNewValue0A adds a new value with no arguments and an aux value to the entry block.
func (s *state) entryNewValue0A(op ssa.Op, t *types.Type, aux interface{}) *ssa.Value {
return s.f.Entry.NewValue0A(src.NoXPos, op, t, aux)
}
// entryNewValue1 adds a new value with one argument to the entry block.
func (s *state) entryNewValue1(op ssa.Op, t *types.Type, arg *ssa.Value) *ssa.Value {
return s.f.Entry.NewValue1(src.NoXPos, op, t, arg)
}
// entryNewValue1 adds a new value with one argument and an auxint value to the entry block.
func (s *state) entryNewValue1I(op ssa.Op, t *types.Type, auxint int64, arg *ssa.Value) *ssa.Value {
return s.f.Entry.NewValue1I(src.NoXPos, op, t, auxint, arg)
}
// entryNewValue1A adds a new value with one argument and an aux value to the entry block.
func (s *state) entryNewValue1A(op ssa.Op, t *types.Type, aux interface{}, arg *ssa.Value) *ssa.Value {
return s.f.Entry.NewValue1A(src.NoXPos, op, t, aux, arg)
}
// entryNewValue2 adds a new value with two arguments to the entry block.
func (s *state) entryNewValue2(op ssa.Op, t *types.Type, arg0, arg1 *ssa.Value) *ssa.Value {
return s.f.Entry.NewValue2(src.NoXPos, op, t, arg0, arg1)
}
// entryNewValue2A adds a new value with two arguments and an aux value to the entry block.
func (s *state) entryNewValue2A(op ssa.Op, t *types.Type, aux interface{}, arg0, arg1 *ssa.Value) *ssa.Value {
return s.f.Entry.NewValue2A(src.NoXPos, op, t, aux, arg0, arg1)
}
// const* routines add a new const value to the entry block.
func (s *state) constSlice(t *types.Type) *ssa.Value {
return s.f.ConstSlice(t)
}
func (s *state) constInterface(t *types.Type) *ssa.Value {
return s.f.ConstInterface(t)
}
func (s *state) constNil(t *types.Type) *ssa.Value { return s.f.ConstNil(t) }
func (s *state) constEmptyString(t *types.Type) *ssa.Value {
return s.f.ConstEmptyString(t)
}
func (s *state) constBool(c bool) *ssa.Value {
return s.f.ConstBool(types.Types[TBOOL], c)
}
func (s *state) constInt8(t *types.Type, c int8) *ssa.Value {
return s.f.ConstInt8(t, c)
}
func (s *state) constInt16(t *types.Type, c int16) *ssa.Value {
return s.f.ConstInt16(t, c)
}
func (s *state) constInt32(t *types.Type, c int32) *ssa.Value {
return s.f.ConstInt32(t, c)
}
func (s *state) constInt64(t *types.Type, c int64) *ssa.Value {
return s.f.ConstInt64(t, c)
}
func (s *state) constFloat32(t *types.Type, c float64) *ssa.Value {
return s.f.ConstFloat32(t, c)
}
func (s *state) constFloat64(t *types.Type, c float64) *ssa.Value {
return s.f.ConstFloat64(t, c)
}
func (s *state) constInt(t *types.Type, c int64) *ssa.Value {
if s.config.PtrSize == 8 {
return s.constInt64(t, c)
}
if int64(int32(c)) != c {
s.Fatalf("integer constant too big %d", c)
}
return s.constInt32(t, int32(c))
}
func (s *state) constOffPtrSP(t *types.Type, c int64) *ssa.Value {
return s.f.ConstOffPtrSP(t, c, s.sp)
}
// newValueOrSfCall* are wrappers around newValue*, which may create a call to a
// soft-float runtime function instead (when emitting soft-float code).
func (s *state) newValueOrSfCall1(op ssa.Op, t *types.Type, arg *ssa.Value) *ssa.Value {
if s.softFloat {
if c, ok := s.sfcall(op, arg); ok {
return c
}
}
return s.newValue1(op, t, arg)
}
func (s *state) newValueOrSfCall2(op ssa.Op, t *types.Type, arg0, arg1 *ssa.Value) *ssa.Value {
if s.softFloat {
if c, ok := s.sfcall(op, arg0, arg1); ok {
return c
}
}
return s.newValue2(op, t, arg0, arg1)
}
type instrumentKind uint8
const (
instrumentRead = iota
instrumentWrite
instrumentMove
)
func (s *state) instrument(t *types.Type, addr *ssa.Value, kind instrumentKind) {
s.instrument2(t, addr, nil, kind)
}
// instrumentFields instruments a read/write operation on addr.
// If it is instrumenting for MSAN and t is a struct type, it instruments
// operation for each field, instead of for the whole struct.
func (s *state) instrumentFields(t *types.Type, addr *ssa.Value, kind instrumentKind) {
if !flag_msan || !t.IsStruct() {
s.instrument(t, addr, kind)
return
}
for _, f := range t.Fields().Slice() {
if f.Sym.IsBlank() {
continue
}
offptr := s.newValue1I(ssa.OpOffPtr, types.NewPtr(f.Type), f.Offset, addr)
s.instrumentFields(f.Type, offptr, kind)
}
}
func (s *state) instrumentMove(t *types.Type, dst, src *ssa.Value) {
if flag_msan {
s.instrument2(t, dst, src, instrumentMove)
} else {
s.instrument(t, src, instrumentRead)
s.instrument(t, dst, instrumentWrite)
}
}
func (s *state) instrument2(t *types.Type, addr, addr2 *ssa.Value, kind instrumentKind) {
if !s.curfn.Func.InstrumentBody() {
return
}
w := t.Size()
if w == 0 {
return // can't race on zero-sized things
}
if ssa.IsSanitizerSafeAddr(addr) {
return
}
var fn *obj.LSym
needWidth := false
if addr2 != nil && kind != instrumentMove {
panic("instrument2: non-nil addr2 for non-move instrumentation")
}
if flag_msan {
switch kind {
case instrumentRead:
fn = msanread
case instrumentWrite:
fn = msanwrite
case instrumentMove:
fn = msanmove
default:
panic("unreachable")
}
needWidth = true
} else if flag_race && t.NumComponents(types.CountBlankFields) > 1 {
// for composite objects we have to write every address
// because a write might happen to any subobject.
// composites with only one element don't have subobjects, though.
switch kind {
case instrumentRead:
fn = racereadrange
case instrumentWrite:
fn = racewriterange
default:
panic("unreachable")
}
needWidth = true
} else if flag_race {
// for non-composite objects we can write just the start
// address, as any write must write the first byte.
switch kind {
case instrumentRead:
fn = raceread
case instrumentWrite:
fn = racewrite
default:
panic("unreachable")
}
} else {
panic("unreachable")
}
args := []*ssa.Value{addr}
if addr2 != nil {
args = append(args, addr2)
}
if needWidth {
args = append(args, s.constInt(types.Types[TUINTPTR], w))
}
s.rtcall(fn, true, nil, args...)
}
func (s *state) load(t *types.Type, src *ssa.Value) *ssa.Value {
s.instrumentFields(t, src, instrumentRead)
return s.rawLoad(t, src)
}
func (s *state) rawLoad(t *types.Type, src *ssa.Value) *ssa.Value {
return s.newValue2(ssa.OpLoad, t, src, s.mem())
}
func (s *state) store(t *types.Type, dst, val *ssa.Value) {
s.vars[&memVar] = s.newValue3A(ssa.OpStore, types.TypeMem, t, dst, val, s.mem())
}
func (s *state) zero(t *types.Type, dst *ssa.Value) {
s.instrument(t, dst, instrumentWrite)
store := s.newValue2I(ssa.OpZero, types.TypeMem, t.Size(), dst, s.mem())
store.Aux = t
s.vars[&memVar] = store
}
func (s *state) move(t *types.Type, dst, src *ssa.Value) {
s.instrumentMove(t, dst, src)
store := s.newValue3I(ssa.OpMove, types.TypeMem, t.Size(), dst, src, s.mem())
store.Aux = t
s.vars[&memVar] = store
}
// stmtList converts the statement list n to SSA and adds it to s.
func (s *state) stmtList(l Nodes) {
for _, n := range l.Slice() {
s.stmt(n)
}
}
// stmt converts the statement n to SSA and adds it to s.
func (s *state) stmt(n *Node) {
if !(n.Op == OVARKILL || n.Op == OVARLIVE || n.Op == OVARDEF) {
// OVARKILL, OVARLIVE, and OVARDEF are invisible to the programmer, so we don't use their line numbers to avoid confusion in debugging.
s.pushLine(n.Pos)
defer s.popLine()
}
// If s.curBlock is nil, and n isn't a label (which might have an associated goto somewhere),
// then this code is dead. Stop here.
if s.curBlock == nil && n.Op != OLABEL {
return
}
s.stmtList(n.Ninit)
switch n.Op {
case OBLOCK:
s.stmtList(n.List)
// No-ops
case OEMPTY, ODCLCONST, ODCLTYPE, OFALL:
// Expression statements
case OCALLFUNC:
if isIntrinsicCall(n) {
s.intrinsicCall(n)
return
}
fallthrough
case OCALLMETH, OCALLINTER:
s.callResult(n, callNormal)
if n.Op == OCALLFUNC && n.Left.Op == ONAME && n.Left.Class() == PFUNC {
if fn := n.Left.Sym.Name; compiling_runtime && fn == "throw" ||
n.Left.Sym.Pkg == Runtimepkg && (fn == "throwinit" || fn == "gopanic" || fn == "panicwrap" || fn == "block" || fn == "panicmakeslicelen" || fn == "panicmakeslicecap") {
m := s.mem()
b := s.endBlock()
b.Kind = ssa.BlockExit
b.SetControl(m)
// TODO: never rewrite OPANIC to OCALLFUNC in the
// first place. Need to wait until all backends
// go through SSA.
}
}
case ODEFER:
if Debug_defer > 0 {
var defertype string
if s.hasOpenDefers {
defertype = "open-coded"
} else if n.Esc == EscNever {
defertype = "stack-allocated"
} else {
defertype = "heap-allocated"
}
Warnl(n.Pos, "%s defer", defertype)
}
if s.hasOpenDefers {
s.openDeferRecord(n.Left)
} else {
d := callDefer
if n.Esc == EscNever {
d = callDeferStack
}
s.callResult(n.Left, d)
}
case OGO:
s.callResult(n.Left, callGo)
case OAS2DOTTYPE:
res, resok := s.dottype(n.Right, true)
deref := false
if !canSSAType(n.Right.Type) {
if res.Op != ssa.OpLoad {
s.Fatalf("dottype of non-load")
}
mem := s.mem()
if mem.Op == ssa.OpVarKill {
mem = mem.Args[0]
}
if res.Args[1] != mem {
s.Fatalf("memory no longer live from 2-result dottype load")
}
deref = true
res = res.Args[0]
}
s.assign(n.List.First(), res, deref, 0)
s.assign(n.List.Second(), resok, false, 0)
return
case OAS2FUNC:
// We come here only when it is an intrinsic call returning two values.
if !isIntrinsicCall(n.Right) {
s.Fatalf("non-intrinsic AS2FUNC not expanded %v", n.Right)
}
v := s.intrinsicCall(n.Right)
v1 := s.newValue1(ssa.OpSelect0, n.List.First().Type, v)
v2 := s.newValue1(ssa.OpSelect1, n.List.Second().Type, v)
s.assign(n.List.First(), v1, false, 0)
s.assign(n.List.Second(), v2, false, 0)
return
case ODCL:
if n.Left.Class() == PAUTOHEAP {
s.Fatalf("DCL %v", n)
}
case OLABEL:
sym := n.Sym
lab := s.label(sym)
// Associate label with its control flow node, if any
if ctl := n.labeledControl(); ctl != nil {
s.labeledNodes[ctl] = lab
}
// The label might already have a target block via a goto.
if lab.target == nil {
lab.target = s.f.NewBlock(ssa.BlockPlain)
}
// Go to that label.
// (We pretend "label:" is preceded by "goto label", unless the predecessor is unreachable.)
if s.curBlock != nil {
b := s.endBlock()
b.AddEdgeTo(lab.target)
}
s.startBlock(lab.target)
case OGOTO:
sym := n.Sym
lab := s.label(sym)
if lab.target == nil {
lab.target = s.f.NewBlock(ssa.BlockPlain)
}
b := s.endBlock()
b.Pos = s.lastPos.WithIsStmt() // Do this even if b is an empty block.
b.AddEdgeTo(lab.target)
case OAS:
if n.Left == n.Right && n.Left.Op == ONAME {
// An x=x assignment. No point in doing anything
// here. In addition, skipping this assignment
// prevents generating:
// VARDEF x
// COPY x -> x
// which is bad because x is incorrectly considered
// dead before the vardef. See issue #14904.
return
}
// Evaluate RHS.
rhs := n.Right
if rhs != nil {
switch rhs.Op {
case OSTRUCTLIT, OARRAYLIT, OSLICELIT:
// All literals with nonzero fields have already been
// rewritten during walk. Any that remain are just T{}
// or equivalents. Use the zero value.
if !isZero(rhs) {
s.Fatalf("literal with nonzero value in SSA: %v", rhs)
}
rhs = nil
case OAPPEND:
// Check whether we're writing the result of an append back to the same slice.
// If so, we handle it specially to avoid write barriers on the fast
// (non-growth) path.
if !samesafeexpr(n.Left, rhs.List.First()) || Debug.N != 0 {
break
}
// If the slice can be SSA'd, it'll be on the stack,
// so there will be no write barriers,
// so there's no need to attempt to prevent them.
if s.canSSA(n.Left) {
if Debug_append > 0 { // replicating old diagnostic message
Warnl(n.Pos, "append: len-only update (in local slice)")
}
break
}
if Debug_append > 0 {
Warnl(n.Pos, "append: len-only update")
}
s.append(rhs, true)
return
}
}
if n.Left.isBlank() {
// _ = rhs
// Just evaluate rhs for side-effects.
if rhs != nil {
s.expr(rhs)
}
return
}
var t *types.Type
if n.Right != nil {
t = n.Right.Type
} else {
t = n.Left.Type
}
var r *ssa.Value
deref := !canSSAType(t)
if deref {
if rhs == nil {
r = nil // Signal assign to use OpZero.
} else {
r = s.addr(rhs)
}
} else {
if rhs == nil {
r = s.zeroVal(t)
} else {
r = s.expr(rhs)
}
}
var skip skipMask
if rhs != nil && (rhs.Op == OSLICE || rhs.Op == OSLICE3 || rhs.Op == OSLICESTR) && samesafeexpr(rhs.Left, n.Left) {
// We're assigning a slicing operation back to its source.
// Don't write back fields we aren't changing. See issue #14855.
i, j, k := rhs.SliceBounds()
if i != nil && (i.Op == OLITERAL && i.Val().Ctype() == CTINT && i.Int64Val() == 0) {
// [0:...] is the same as [:...]
i = nil
}
// TODO: detect defaults for len/cap also.
// Currently doesn't really work because (*p)[:len(*p)] appears here as:
// tmp = len(*p)
// (*p)[:tmp]
//if j != nil && (j.Op == OLEN && samesafeexpr(j.Left, n.Left)) {
// j = nil
//}
//if k != nil && (k.Op == OCAP && samesafeexpr(k.Left, n.Left)) {
// k = nil
//}
if i == nil {
skip |= skipPtr
if j == nil {
skip |= skipLen
}
if k == nil {
skip |= skipCap
}
}
}
s.assign(n.Left, r, deref, skip)
case OIF:
if Isconst(n.Left, CTBOOL) {
s.stmtList(n.Left.Ninit)
if n.Left.BoolVal() {
s.stmtList(n.Nbody)
} else {
s.stmtList(n.Rlist)
}
break
}
bEnd := s.f.NewBlock(ssa.BlockPlain)
var likely int8
if n.Likely() {
likely = 1
}
var bThen *ssa.Block
if n.Nbody.Len() != 0 {
bThen = s.f.NewBlock(ssa.BlockPlain)
} else {
bThen = bEnd
}
var bElse *ssa.Block
if n.Rlist.Len() != 0 {
bElse = s.f.NewBlock(ssa.BlockPlain)
} else {
bElse = bEnd
}
s.condBranch(n.Left, bThen, bElse, likely)
if n.Nbody.Len() != 0 {
s.startBlock(bThen)
s.stmtList(n.Nbody)
if b := s.endBlock(); b != nil {
b.AddEdgeTo(bEnd)
}
}
if n.Rlist.Len() != 0 {
s.startBlock(bElse)
s.stmtList(n.Rlist)
if b := s.endBlock(); b != nil {
b.AddEdgeTo(bEnd)
}
}
s.startBlock(bEnd)
case ORETURN:
s.stmtList(n.List)
b := s.exit()
b.Pos = s.lastPos.WithIsStmt()
case ORETJMP:
s.stmtList(n.List)
b := s.exit()
b.Kind = ssa.BlockRetJmp // override BlockRet
b.Aux = n.Sym.Linksym()
case OCONTINUE, OBREAK:
var to *ssa.Block
if n.Sym == nil {
// plain break/continue
switch n.Op {
case OCONTINUE:
to = s.continueTo
case OBREAK:
to = s.breakTo
}
} else {
// labeled break/continue; look up the target
sym := n.Sym
lab := s.label(sym)
switch n.Op {
case OCONTINUE:
to = lab.continueTarget
case OBREAK:
to = lab.breakTarget
}
}
b := s.endBlock()
b.Pos = s.lastPos.WithIsStmt() // Do this even if b is an empty block.
b.AddEdgeTo(to)
case OFOR, OFORUNTIL:
// OFOR: for Ninit; Left; Right { Nbody }
// cond (Left); body (Nbody); incr (Right)
//
// OFORUNTIL: for Ninit; Left; Right; List { Nbody }
// => body: { Nbody }; incr: Right; if Left { lateincr: List; goto body }; end:
bCond := s.f.NewBlock(ssa.BlockPlain)
bBody := s.f.NewBlock(ssa.BlockPlain)
bIncr := s.f.NewBlock(ssa.BlockPlain)
bEnd := s.f.NewBlock(ssa.BlockPlain)
// ensure empty for loops have correct position; issue #30167
bBody.Pos = n.Pos
// first, jump to condition test (OFOR) or body (OFORUNTIL)
b := s.endBlock()
if n.Op == OFOR {
b.AddEdgeTo(bCond)
// generate code to test condition
s.startBlock(bCond)
if n.Left != nil {
s.condBranch(n.Left, bBody, bEnd, 1)
} else {
b := s.endBlock()
b.Kind = ssa.BlockPlain
b.AddEdgeTo(bBody)
}
} else {
b.AddEdgeTo(bBody)
}
// set up for continue/break in body
prevContinue := s.continueTo
prevBreak := s.breakTo
s.continueTo = bIncr
s.breakTo = bEnd
lab := s.labeledNodes[n]
if lab != nil {
// labeled for loop
lab.continueTarget = bIncr
lab.breakTarget = bEnd
}
// generate body
s.startBlock(bBody)
s.stmtList(n.Nbody)
// tear down continue/break
s.continueTo = prevContinue
s.breakTo = prevBreak
if lab != nil {
lab.continueTarget = nil
lab.breakTarget = nil
}
// done with body, goto incr
if b := s.endBlock(); b != nil {
b.AddEdgeTo(bIncr)
}
// generate incr (and, for OFORUNTIL, condition)
s.startBlock(bIncr)
if n.Right != nil {
s.stmt(n.Right)
}
if n.Op == OFOR {
if b := s.endBlock(); b != nil {
b.AddEdgeTo(bCond)
// It can happen that bIncr ends in a block containing only VARKILL,
// and that muddles the debugging experience.
if n.Op != OFORUNTIL && b.Pos == src.NoXPos {
b.Pos = bCond.Pos
}
}
} else {
// bCond is unused in OFORUNTIL, so repurpose it.
bLateIncr := bCond
// test condition
s.condBranch(n.Left, bLateIncr, bEnd, 1)
// generate late increment
s.startBlock(bLateIncr)
s.stmtList(n.List)
s.endBlock().AddEdgeTo(bBody)
}
s.startBlock(bEnd)
case OSWITCH, OSELECT:
// These have been mostly rewritten by the front end into their Nbody fields.
// Our main task is to correctly hook up any break statements.
bEnd := s.f.NewBlock(ssa.BlockPlain)
prevBreak := s.breakTo
s.breakTo = bEnd
lab := s.labeledNodes[n]
if lab != nil {
// labeled
lab.breakTarget = bEnd
}
// generate body code
s.stmtList(n.Nbody)
s.breakTo = prevBreak
if lab != nil {
lab.breakTarget = nil
}
// walk adds explicit OBREAK nodes to the end of all reachable code paths.
// If we still have a current block here, then mark it unreachable.
if s.curBlock != nil {
m := s.mem()
b := s.endBlock()
b.Kind = ssa.BlockExit
b.SetControl(m)
}
s.startBlock(bEnd)
case OVARDEF:
if !s.canSSA(n.Left) {
s.vars[&memVar] = s.newValue1Apos(ssa.OpVarDef, types.TypeMem, n.Left, s.mem(), false)
}
case OVARKILL:
// Insert a varkill op to record that a variable is no longer live.
// We only care about liveness info at call sites, so putting the
// varkill in the store chain is enough to keep it correctly ordered
// with respect to call ops.
if !s.canSSA(n.Left) {
s.vars[&memVar] = s.newValue1Apos(ssa.OpVarKill, types.TypeMem, n.Left, s.mem(), false)
}
case OVARLIVE:
// Insert a varlive op to record that a variable is still live.
if !n.Left.Name.Addrtaken() {
s.Fatalf("VARLIVE variable %v must have Addrtaken set", n.Left)
}
switch n.Left.Class() {
case PAUTO, PPARAM, PPARAMOUT:
default:
s.Fatalf("VARLIVE variable %v must be Auto or Arg", n.Left)
}
s.vars[&memVar] = s.newValue1A(ssa.OpVarLive, types.TypeMem, n.Left, s.mem())
case OCHECKNIL:
p := s.expr(n.Left)
s.nilCheck(p)
case OINLMARK:
s.newValue1I(ssa.OpInlMark, types.TypeVoid, n.Xoffset, s.mem())
default:
s.Fatalf("unhandled stmt %v", n.Op)
}
}
// If true, share as many open-coded defer exits as possible (with the downside of
// worse line-number information)
const shareDeferExits = false
// exit processes any code that needs to be generated just before returning.
// It returns a BlockRet block that ends the control flow. Its control value
// will be set to the final memory state.
func (s *state) exit() *ssa.Block {
if s.hasdefer {
if s.hasOpenDefers {
if shareDeferExits && s.lastDeferExit != nil && len(s.openDefers) == s.lastDeferCount {
if s.curBlock.Kind != ssa.BlockPlain {
panic("Block for an exit should be BlockPlain")
}
s.curBlock.AddEdgeTo(s.lastDeferExit)
s.endBlock()
return s.lastDeferFinalBlock
}
s.openDeferExit()
} else {
s.rtcall(Deferreturn, true, nil)
}
}
// Run exit code. Typically, this code copies heap-allocated PPARAMOUT
// variables back to the stack.
s.stmtList(s.curfn.Func.Exit)
// Store SSAable PPARAMOUT variables back to stack locations.
for _, n := range s.returns {
addr := s.decladdrs[n]
val := s.variable(n, n.Type)
s.vars[&memVar] = s.newValue1A(ssa.OpVarDef, types.TypeMem, n, s.mem())
s.store(n.Type, addr, val)
// TODO: if val is ever spilled, we'd like to use the
// PPARAMOUT slot for spilling it. That won't happen
// currently.
}
// Do actual return.
m := s.mem()
b := s.endBlock()
b.Kind = ssa.BlockRet
b.SetControl(m)
if s.hasdefer && s.hasOpenDefers {
s.lastDeferFinalBlock = b
}
return b
}
type opAndType struct {
op Op
etype types.EType
}
var opToSSA = map[opAndType]ssa.Op{
opAndType{OADD, TINT8}: ssa.OpAdd8,
opAndType{OADD, TUINT8}: ssa.OpAdd8,
opAndType{OADD, TINT16}: ssa.OpAdd16,
opAndType{OADD, TUINT16}: ssa.OpAdd16,
opAndType{OADD, TINT32}: ssa.OpAdd32,
opAndType{OADD, TUINT32}: ssa.OpAdd32,
opAndType{OADD, TINT64}: ssa.OpAdd64,
opAndType{OADD, TUINT64}: ssa.OpAdd64,
opAndType{OADD, TFLOAT32}: ssa.OpAdd32F,
opAndType{OADD, TFLOAT64}: ssa.OpAdd64F,
opAndType{OSUB, TINT8}: ssa.OpSub8,
opAndType{OSUB, TUINT8}: ssa.OpSub8,
opAndType{OSUB, TINT16}: ssa.OpSub16,
opAndType{OSUB, TUINT16}: ssa.OpSub16,
opAndType{OSUB, TINT32}: ssa.OpSub32,
opAndType{OSUB, TUINT32}: ssa.OpSub32,
opAndType{OSUB, TINT64}: ssa.OpSub64,
opAndType{OSUB, TUINT64}: ssa.OpSub64,
opAndType{OSUB, TFLOAT32}: ssa.OpSub32F,
opAndType{OSUB, TFLOAT64}: ssa.OpSub64F,
opAndType{ONOT, TBOOL}: ssa.OpNot,
opAndType{ONEG, TINT8}: ssa.OpNeg8,
opAndType{ONEG, TUINT8}: ssa.OpNeg8,
opAndType{ONEG, TINT16}: ssa.OpNeg16,
opAndType{ONEG, TUINT16}: ssa.OpNeg16,
opAndType{ONEG, TINT32}: ssa.OpNeg32,
opAndType{ONEG, TUINT32}: ssa.OpNeg32,
opAndType{ONEG, TINT64}: ssa.OpNeg64,
opAndType{ONEG, TUINT64}: ssa.OpNeg64,
opAndType{ONEG, TFLOAT32}: ssa.OpNeg32F,
opAndType{ONEG, TFLOAT64}: ssa.OpNeg64F,
opAndType{OBITNOT, TINT8}: ssa.OpCom8,
opAndType{OBITNOT, TUINT8}: ssa.OpCom8,
opAndType{OBITNOT, TINT16}: ssa.OpCom16,
opAndType{OBITNOT, TUINT16}: ssa.OpCom16,
opAndType{OBITNOT, TINT32}: ssa.OpCom32,
opAndType{OBITNOT, TUINT32}: ssa.OpCom32,
opAndType{OBITNOT, TINT64}: ssa.OpCom64,
opAndType{OBITNOT, TUINT64}: ssa.OpCom64,
opAndType{OIMAG, TCOMPLEX64}: ssa.OpComplexImag,
opAndType{OIMAG, TCOMPLEX128}: ssa.OpComplexImag,
opAndType{OREAL, TCOMPLEX64}: ssa.OpComplexReal,
opAndType{OREAL, TCOMPLEX128}: ssa.OpComplexReal,
opAndType{OMUL, TINT8}: ssa.OpMul8,
opAndType{OMUL, TUINT8}: ssa.OpMul8,
opAndType{OMUL, TINT16}: ssa.OpMul16,
opAndType{OMUL, TUINT16}: ssa.OpMul16,
opAndType{OMUL, TINT32}: ssa.OpMul32,
opAndType{OMUL, TUINT32}: ssa.OpMul32,
opAndType{OMUL, TINT64}: ssa.OpMul64,
opAndType{OMUL, TUINT64}: ssa.OpMul64,
opAndType{OMUL, TFLOAT32}: ssa.OpMul32F,
opAndType{OMUL, TFLOAT64}: ssa.OpMul64F,
opAndType{ODIV, TFLOAT32}: ssa.OpDiv32F,
opAndType{ODIV, TFLOAT64}: ssa.OpDiv64F,
opAndType{ODIV, TINT8}: ssa.OpDiv8,
opAndType{ODIV, TUINT8}: ssa.OpDiv8u,
opAndType{ODIV, TINT16}: ssa.OpDiv16,
opAndType{ODIV, TUINT16}: ssa.OpDiv16u,
opAndType{ODIV, TINT32}: ssa.OpDiv32,
opAndType{ODIV, TUINT32}: ssa.OpDiv32u,
opAndType{ODIV, TINT64}: ssa.OpDiv64,
opAndType{ODIV, TUINT64}: ssa.OpDiv64u,
opAndType{OMOD, TINT8}: ssa.OpMod8,
opAndType{OMOD, TUINT8}: ssa.OpMod8u,
opAndType{OMOD, TINT16}: ssa.OpMod16,
opAndType{OMOD, TUINT16}: ssa.OpMod16u,
opAndType{OMOD, TINT32}: ssa.OpMod32,
opAndType{OMOD, TUINT32}: ssa.OpMod32u,
opAndType{OMOD, TINT64}: ssa.OpMod64,
opAndType{OMOD, TUINT64}: ssa.OpMod64u,
opAndType{OAND, TINT8}: ssa.OpAnd8,
opAndType{OAND, TUINT8}: ssa.OpAnd8,
opAndType{OAND, TINT16}: ssa.OpAnd16,
opAndType{OAND, TUINT16}: ssa.OpAnd16,
opAndType{OAND, TINT32}: ssa.OpAnd32,
opAndType{OAND, TUINT32}: ssa.OpAnd32,
opAndType{OAND, TINT64}: ssa.OpAnd64,
opAndType{OAND, TUINT64}: ssa.OpAnd64,
opAndType{OOR, TINT8}: ssa.OpOr8,
opAndType{OOR, TUINT8}: ssa.OpOr8,
opAndType{OOR, TINT16}: ssa.OpOr16,
opAndType{OOR, TUINT16}: ssa.OpOr16,
opAndType{OOR, TINT32}: ssa.OpOr32,
opAndType{OOR, TUINT32}: ssa.OpOr32,
opAndType{OOR, TINT64}: ssa.OpOr64,
opAndType{OOR, TUINT64}: ssa.OpOr64,
opAndType{OXOR, TINT8}: ssa.OpXor8,
opAndType{OXOR, TUINT8}: ssa.OpXor8,
opAndType{OXOR, TINT16}: ssa.OpXor16,
opAndType{OXOR, TUINT16}: ssa.OpXor16,
opAndType{OXOR, TINT32}: ssa.OpXor32,
opAndType{OXOR, TUINT32}: ssa.OpXor32,
opAndType{OXOR, TINT64}: ssa.OpXor64,
opAndType{OXOR, TUINT64}: ssa.OpXor64,
opAndType{OEQ, TBOOL}: ssa.OpEqB,
opAndType{OEQ, TINT8}: ssa.OpEq8,
opAndType{OEQ, TUINT8}: ssa.OpEq8,
opAndType{OEQ, TINT16}: ssa.OpEq16,
opAndType{OEQ, TUINT16}: ssa.OpEq16,
opAndType{OEQ, TINT32}: ssa.OpEq32,
opAndType{OEQ, TUINT32}: ssa.OpEq32,
opAndType{OEQ, TINT64}: ssa.OpEq64,
opAndType{OEQ, TUINT64}: ssa.OpEq64,
opAndType{OEQ, TINTER}: ssa.OpEqInter,
opAndType{OEQ, TSLICE}: ssa.OpEqSlice,
opAndType{OEQ, TFUNC}: ssa.OpEqPtr,
opAndType{OEQ, TMAP}: ssa.OpEqPtr,
opAndType{OEQ, TCHAN}: ssa.OpEqPtr,
opAndType{OEQ, TPTR}: ssa.OpEqPtr,
opAndType{OEQ, TUINTPTR}: ssa.OpEqPtr,
opAndType{OEQ, TUNSAFEPTR}: ssa.OpEqPtr,
opAndType{OEQ, TFLOAT64}: ssa.OpEq64F,
opAndType{OEQ, TFLOAT32}: ssa.OpEq32F,
opAndType{ONE, TBOOL}: ssa.OpNeqB,
opAndType{ONE, TINT8}: ssa.OpNeq8,
opAndType{ONE, TUINT8}: ssa.OpNeq8,
opAndType{ONE, TINT16}: ssa.OpNeq16,
opAndType{ONE, TUINT16}: ssa.OpNeq16,
opAndType{ONE, TINT32}: ssa.OpNeq32,
opAndType{ONE, TUINT32}: ssa.OpNeq32,
opAndType{ONE, TINT64}: ssa.OpNeq64,
opAndType{ONE, TUINT64}: ssa.OpNeq64,
opAndType{ONE, TINTER}: ssa.OpNeqInter,
opAndType{ONE, TSLICE}: ssa.OpNeqSlice,
opAndType{ONE, TFUNC}: ssa.OpNeqPtr,
opAndType{ONE, TMAP}: ssa.OpNeqPtr,
opAndType{ONE, TCHAN}: ssa.OpNeqPtr,
opAndType{ONE, TPTR}: ssa.OpNeqPtr,
opAndType{ONE, TUINTPTR}: ssa.OpNeqPtr,
opAndType{ONE, TUNSAFEPTR}: ssa.OpNeqPtr,
opAndType{ONE, TFLOAT64}: ssa.OpNeq64F,
opAndType{ONE, TFLOAT32}: ssa.OpNeq32F,
opAndType{OLT, TINT8}: ssa.OpLess8,
opAndType{OLT, TUINT8}: ssa.OpLess8U,
opAndType{OLT, TINT16}: ssa.OpLess16,
opAndType{OLT, TUINT16}: ssa.OpLess16U,
opAndType{OLT, TINT32}: ssa.OpLess32,
opAndType{OLT, TUINT32}: ssa.OpLess32U,
opAndType{OLT, TINT64}: ssa.OpLess64,
opAndType{OLT, TUINT64}: ssa.OpLess64U,
opAndType{OLT, TFLOAT64}: ssa.OpLess64F,
opAndType{OLT, TFLOAT32}: ssa.OpLess32F,
opAndType{OLE, TINT8}: ssa.OpLeq8,
opAndType{OLE, TUINT8}: ssa.OpLeq8U,
opAndType{OLE, TINT16}: ssa.OpLeq16,
opAndType{OLE, TUINT16}: ssa.OpLeq16U,
opAndType{OLE, TINT32}: ssa.OpLeq32,
opAndType{OLE, TUINT32}: ssa.OpLeq32U,
opAndType{OLE, TINT64}: ssa.OpLeq64,
opAndType{OLE, TUINT64}: ssa.OpLeq64U,
opAndType{OLE, TFLOAT64}: ssa.OpLeq64F,
opAndType{OLE, TFLOAT32}: ssa.OpLeq32F,
}
func (s *state) concreteEtype(t *types.Type) types.EType {
e := t.Etype
switch e {
default:
return e
case TINT:
if s.config.PtrSize == 8 {
return TINT64
}
return TINT32
case TUINT:
if s.config.PtrSize == 8 {
return TUINT64
}
return TUINT32
case TUINTPTR:
if s.config.PtrSize == 8 {
return TUINT64
}
return TUINT32
}
}
func (s *state) ssaOp(op Op, t *types.Type) ssa.Op {
etype := s.concreteEtype(t)
x, ok := opToSSA[opAndType{op, etype}]
if !ok {
s.Fatalf("unhandled binary op %v %s", op, etype)
}
return x
}
func floatForComplex(t *types.Type) *types.Type {
switch t.Etype {
case TCOMPLEX64:
return types.Types[TFLOAT32]
case TCOMPLEX128:
return types.Types[TFLOAT64]
}
Fatalf("unexpected type: %v", t)
return nil
}
func complexForFloat(t *types.Type) *types.Type {
switch t.Etype {
case TFLOAT32:
return types.Types[TCOMPLEX64]
case TFLOAT64:
return types.Types[TCOMPLEX128]
}
Fatalf("unexpected type: %v", t)
return nil
}
type opAndTwoTypes struct {
op Op
etype1 types.EType
etype2 types.EType
}
type twoTypes struct {
etype1 types.EType
etype2 types.EType
}
type twoOpsAndType struct {
op1 ssa.Op
op2 ssa.Op
intermediateType types.EType
}
var fpConvOpToSSA = map[twoTypes]twoOpsAndType{
twoTypes{TINT8, TFLOAT32}: twoOpsAndType{ssa.OpSignExt8to32, ssa.OpCvt32to32F, TINT32},
twoTypes{TINT16, TFLOAT32}: twoOpsAndType{ssa.OpSignExt16to32, ssa.OpCvt32to32F, TINT32},
twoTypes{TINT32, TFLOAT32}: twoOpsAndType{ssa.OpCopy, ssa.OpCvt32to32F, TINT32},
twoTypes{TINT64, TFLOAT32}: twoOpsAndType{ssa.OpCopy, ssa.OpCvt64to32F, TINT64},
twoTypes{TINT8, TFLOAT64}: twoOpsAndType{ssa.OpSignExt8to32, ssa.OpCvt32to64F, TINT32},
twoTypes{TINT16, TFLOAT64}: twoOpsAndType{ssa.OpSignExt16to32, ssa.OpCvt32to64F, TINT32},
twoTypes{TINT32, TFLOAT64}: twoOpsAndType{ssa.OpCopy, ssa.OpCvt32to64F, TINT32},
twoTypes{TINT64, TFLOAT64}: twoOpsAndType{ssa.OpCopy, ssa.OpCvt64to64F, TINT64},
twoTypes{TFLOAT32, TINT8}: twoOpsAndType{ssa.OpCvt32Fto32, ssa.OpTrunc32to8, TINT32},
twoTypes{TFLOAT32, TINT16}: twoOpsAndType{ssa.OpCvt32Fto32, ssa.OpTrunc32to16, TINT32},
twoTypes{TFLOAT32, TINT32}: twoOpsAndType{ssa.OpCvt32Fto32, ssa.OpCopy, TINT32},
twoTypes{TFLOAT32, TINT64}: twoOpsAndType{ssa.OpCvt32Fto64, ssa.OpCopy, TINT64},
twoTypes{TFLOAT64, TINT8}: twoOpsAndType{ssa.OpCvt64Fto32, ssa.OpTrunc32to8, TINT32},
twoTypes{TFLOAT64, TINT16}: twoOpsAndType{ssa.OpCvt64Fto32, ssa.OpTrunc32to16, TINT32},
twoTypes{TFLOAT64, TINT32}: twoOpsAndType{ssa.OpCvt64Fto32, ssa.OpCopy, TINT32},
twoTypes{TFLOAT64, TINT64}: twoOpsAndType{ssa.OpCvt64Fto64, ssa.OpCopy, TINT64},
// unsigned
twoTypes{TUINT8, TFLOAT32}: twoOpsAndType{ssa.OpZeroExt8to32, ssa.OpCvt32to32F, TINT32},
twoTypes{TUINT16, TFLOAT32}: twoOpsAndType{ssa.OpZeroExt16to32, ssa.OpCvt32to32F, TINT32},
twoTypes{TUINT32, TFLOAT32}: twoOpsAndType{ssa.OpZeroExt32to64, ssa.OpCvt64to32F, TINT64}, // go wide to dodge unsigned
twoTypes{TUINT64, TFLOAT32}: twoOpsAndType{ssa.OpCopy, ssa.OpInvalid, TUINT64}, // Cvt64Uto32F, branchy code expansion instead
twoTypes{TUINT8, TFLOAT64}: twoOpsAndType{ssa.OpZeroExt8to32, ssa.OpCvt32to64F, TINT32},
twoTypes{TUINT16, TFLOAT64}: twoOpsAndType{ssa.OpZeroExt16to32, ssa.OpCvt32to64F, TINT32},
twoTypes{TUINT32, TFLOAT64}: twoOpsAndType{ssa.OpZeroExt32to64, ssa.OpCvt64to64F, TINT64}, // go wide to dodge unsigned
twoTypes{TUINT64, TFLOAT64}: twoOpsAndType{ssa.OpCopy, ssa.OpInvalid, TUINT64}, // Cvt64Uto64F, branchy code expansion instead
twoTypes{TFLOAT32, TUINT8}: twoOpsAndType{ssa.OpCvt32Fto32, ssa.OpTrunc32to8, TINT32},
twoTypes{TFLOAT32, TUINT16}: twoOpsAndType{ssa.OpCvt32Fto32, ssa.OpTrunc32to16, TINT32},
twoTypes{TFLOAT32, TUINT32}: twoOpsAndType{ssa.OpCvt32Fto64, ssa.OpTrunc64to32, TINT64}, // go wide to dodge unsigned
twoTypes{TFLOAT32, TUINT64}: twoOpsAndType{ssa.OpInvalid, ssa.OpCopy, TUINT64}, // Cvt32Fto64U, branchy code expansion instead
twoTypes{TFLOAT64, TUINT8}: twoOpsAndType{ssa.OpCvt64Fto32, ssa.OpTrunc32to8, TINT32},
twoTypes{TFLOAT64, TUINT16}: twoOpsAndType{ssa.OpCvt64Fto32, ssa.OpTrunc32to16, TINT32},
twoTypes{TFLOAT64, TUINT32}: twoOpsAndType{ssa.OpCvt64Fto64, ssa.OpTrunc64to32, TINT64}, // go wide to dodge unsigned
twoTypes{TFLOAT64, TUINT64}: twoOpsAndType{ssa.OpInvalid, ssa.OpCopy, TUINT64}, // Cvt64Fto64U, branchy code expansion instead
// float
twoTypes{TFLOAT64, TFLOAT32}: twoOpsAndType{ssa.OpCvt64Fto32F, ssa.OpCopy, TFLOAT32},
twoTypes{TFLOAT64, TFLOAT64}: twoOpsAndType{ssa.OpRound64F, ssa.OpCopy, TFLOAT64},
twoTypes{TFLOAT32, TFLOAT32}: twoOpsAndType{ssa.OpRound32F, ssa.OpCopy, TFLOAT32},
twoTypes{TFLOAT32, TFLOAT64}: twoOpsAndType{ssa.OpCvt32Fto64F, ssa.OpCopy, TFLOAT64},
}
// this map is used only for 32-bit arch, and only includes the difference
// on 32-bit arch, don't use int64<->float conversion for uint32
var fpConvOpToSSA32 = map[twoTypes]twoOpsAndType{
twoTypes{TUINT32, TFLOAT32}: twoOpsAndType{ssa.OpCopy, ssa.OpCvt32Uto32F, TUINT32},
twoTypes{TUINT32, TFLOAT64}: twoOpsAndType{ssa.OpCopy, ssa.OpCvt32Uto64F, TUINT32},
twoTypes{TFLOAT32, TUINT32}: twoOpsAndType{ssa.OpCvt32Fto32U, ssa.OpCopy, TUINT32},
twoTypes{TFLOAT64, TUINT32}: twoOpsAndType{ssa.OpCvt64Fto32U, ssa.OpCopy, TUINT32},
}
// uint64<->float conversions, only on machines that have instructions for that
var uint64fpConvOpToSSA = map[twoTypes]twoOpsAndType{
twoTypes{TUINT64, TFLOAT32}: twoOpsAndType{ssa.OpCopy, ssa.OpCvt64Uto32F, TUINT64},
twoTypes{TUINT64, TFLOAT64}: twoOpsAndType{ssa.OpCopy, ssa.OpCvt64Uto64F, TUINT64},
twoTypes{TFLOAT32, TUINT64}: twoOpsAndType{ssa.OpCvt32Fto64U, ssa.OpCopy, TUINT64},
twoTypes{TFLOAT64, TUINT64}: twoOpsAndType{ssa.OpCvt64Fto64U, ssa.OpCopy, TUINT64},
}
var shiftOpToSSA = map[opAndTwoTypes]ssa.Op{
opAndTwoTypes{OLSH, TINT8, TUINT8}: ssa.OpLsh8x8,
opAndTwoTypes{OLSH, TUINT8, TUINT8}: ssa.OpLsh8x8,
opAndTwoTypes{OLSH, TINT8, TUINT16}: ssa.OpLsh8x16,
opAndTwoTypes{OLSH, TUINT8, TUINT16}: ssa.OpLsh8x16,
opAndTwoTypes{OLSH, TINT8, TUINT32}: ssa.OpLsh8x32,
opAndTwoTypes{OLSH, TUINT8, TUINT32}: ssa.OpLsh8x32,
opAndTwoTypes{OLSH, TINT8, TUINT64}: ssa.OpLsh8x64,
opAndTwoTypes{OLSH, TUINT8, TUINT64}: ssa.OpLsh8x64,
opAndTwoTypes{OLSH, TINT16, TUINT8}: ssa.OpLsh16x8,
opAndTwoTypes{OLSH, TUINT16, TUINT8}: ssa.OpLsh16x8,
opAndTwoTypes{OLSH, TINT16, TUINT16}: ssa.OpLsh16x16,
opAndTwoTypes{OLSH, TUINT16, TUINT16}: ssa.OpLsh16x16,
opAndTwoTypes{OLSH, TINT16, TUINT32}: ssa.OpLsh16x32,
opAndTwoTypes{OLSH, TUINT16, TUINT32}: ssa.OpLsh16x32,
opAndTwoTypes{OLSH, TINT16, TUINT64}: ssa.OpLsh16x64,
opAndTwoTypes{OLSH, TUINT16, TUINT64}: ssa.OpLsh16x64,
opAndTwoTypes{OLSH, TINT32, TUINT8}: ssa.OpLsh32x8,
opAndTwoTypes{OLSH, TUINT32, TUINT8}: ssa.OpLsh32x8,
opAndTwoTypes{OLSH, TINT32, TUINT16}: ssa.OpLsh32x16,
opAndTwoTypes{OLSH, TUINT32, TUINT16}: ssa.OpLsh32x16,
opAndTwoTypes{OLSH, TINT32, TUINT32}: ssa.OpLsh32x32,
opAndTwoTypes{OLSH, TUINT32, TUINT32}: ssa.OpLsh32x32,
opAndTwoTypes{OLSH, TINT32, TUINT64}: ssa.OpLsh32x64,
opAndTwoTypes{OLSH, TUINT32, TUINT64}: ssa.OpLsh32x64,
opAndTwoTypes{OLSH, TINT64, TUINT8}: ssa.OpLsh64x8,
opAndTwoTypes{OLSH, TUINT64, TUINT8}: ssa.OpLsh64x8,
opAndTwoTypes{OLSH, TINT64, TUINT16}: ssa.OpLsh64x16,
opAndTwoTypes{OLSH, TUINT64, TUINT16}: ssa.OpLsh64x16,
opAndTwoTypes{OLSH, TINT64, TUINT32}: ssa.OpLsh64x32,
opAndTwoTypes{OLSH, TUINT64, TUINT32}: ssa.OpLsh64x32,
opAndTwoTypes{OLSH, TINT64, TUINT64}: ssa.OpLsh64x64,
opAndTwoTypes{OLSH, TUINT64, TUINT64}: ssa.OpLsh64x64,
opAndTwoTypes{ORSH, TINT8, TUINT8}: ssa.OpRsh8x8,
opAndTwoTypes{ORSH, TUINT8, TUINT8}: ssa.OpRsh8Ux8,
opAndTwoTypes{ORSH, TINT8, TUINT16}: ssa.OpRsh8x16,
opAndTwoTypes{ORSH, TUINT8, TUINT16}: ssa.OpRsh8Ux16,
opAndTwoTypes{ORSH, TINT8, TUINT32}: ssa.OpRsh8x32,
opAndTwoTypes{ORSH, TUINT8, TUINT32}: ssa.OpRsh8Ux32,
opAndTwoTypes{ORSH, TINT8, TUINT64}: ssa.OpRsh8x64,
opAndTwoTypes{ORSH, TUINT8, TUINT64}: ssa.OpRsh8Ux64,
opAndTwoTypes{ORSH, TINT16, TUINT8}: ssa.OpRsh16x8,
opAndTwoTypes{ORSH, TUINT16, TUINT8}: ssa.OpRsh16Ux8,
opAndTwoTypes{ORSH, TINT16, TUINT16}: ssa.OpRsh16x16,
opAndTwoTypes{ORSH, TUINT16, TUINT16}: ssa.OpRsh16Ux16,
opAndTwoTypes{ORSH, TINT16, TUINT32}: ssa.OpRsh16x32,
opAndTwoTypes{ORSH, TUINT16, TUINT32}: ssa.OpRsh16Ux32,
opAndTwoTypes{ORSH, TINT16, TUINT64}: ssa.OpRsh16x64,
opAndTwoTypes{ORSH, TUINT16, TUINT64}: ssa.OpRsh16Ux64,
opAndTwoTypes{ORSH, TINT32, TUINT8}: ssa.OpRsh32x8,
opAndTwoTypes{ORSH, TUINT32, TUINT8}: ssa.OpRsh32Ux8,
opAndTwoTypes{ORSH, TINT32, TUINT16}: ssa.OpRsh32x16,
opAndTwoTypes{ORSH, TUINT32, TUINT16}: ssa.OpRsh32Ux16,
opAndTwoTypes{ORSH, TINT32, TUINT32}: ssa.OpRsh32x32,
opAndTwoTypes{ORSH, TUINT32, TUINT32}: ssa.OpRsh32Ux32,
opAndTwoTypes{ORSH, TINT32, TUINT64}: ssa.OpRsh32x64,
opAndTwoTypes{ORSH, TUINT32, TUINT64}: ssa.OpRsh32Ux64,
opAndTwoTypes{ORSH, TINT64, TUINT8}: ssa.OpRsh64x8,
opAndTwoTypes{ORSH, TUINT64, TUINT8}: ssa.OpRsh64Ux8,
opAndTwoTypes{ORSH, TINT64, TUINT16}: ssa.OpRsh64x16,
opAndTwoTypes{ORSH, TUINT64, TUINT16}: ssa.OpRsh64Ux16,
opAndTwoTypes{ORSH, TINT64, TUINT32}: ssa.OpRsh64x32,
opAndTwoTypes{ORSH, TUINT64, TUINT32}: ssa.OpRsh64Ux32,
opAndTwoTypes{ORSH, TINT64, TUINT64}: ssa.OpRsh64x64,
opAndTwoTypes{ORSH, TUINT64, TUINT64}: ssa.OpRsh64Ux64,
}
func (s *state) ssaShiftOp(op Op, t *types.Type, u *types.Type) ssa.Op {
etype1 := s.concreteEtype(t)
etype2 := s.concreteEtype(u)
x, ok := shiftOpToSSA[opAndTwoTypes{op, etype1, etype2}]
if !ok {
s.Fatalf("unhandled shift op %v etype=%s/%s", op, etype1, etype2)
}
return x
}
// expr converts the expression n to ssa, adds it to s and returns the ssa result.
func (s *state) expr(n *Node) *ssa.Value {
if !(n.Op == ONAME || n.Op == OLITERAL && n.Sym != nil) {
// ONAMEs and named OLITERALs have the line number
// of the decl, not the use. See issue 14742.
s.pushLine(n.Pos)
defer s.popLine()
}
s.stmtList(n.Ninit)
switch n.Op {
case OBYTES2STRTMP:
slice := s.expr(n.Left)
ptr := s.newValue1(ssa.OpSlicePtr, s.f.Config.Types.BytePtr, slice)
len := s.newValue1(ssa.OpSliceLen, types.Types[TINT], slice)
return s.newValue2(ssa.OpStringMake, n.Type, ptr, len)
case OSTR2BYTESTMP:
str := s.expr(n.Left)
ptr := s.newValue1(ssa.OpStringPtr, s.f.Config.Types.BytePtr, str)
len := s.newValue1(ssa.OpStringLen, types.Types[TINT], str)
return s.newValue3(ssa.OpSliceMake, n.Type, ptr, len, len)
case OCFUNC:
aux := n.Left.Sym.Linksym()
return s.entryNewValue1A(ssa.OpAddr, n.Type, aux, s.sb)
case ONAME:
if n.Class() == PFUNC {
// "value" of a function is the address of the function's closure
sym := funcsym(n.Sym).Linksym()
return s.entryNewValue1A(ssa.OpAddr, types.NewPtr(n.Type), sym, s.sb)
}
if s.canSSA(n) {
return s.variable(n, n.Type)
}
addr := s.addr(n)
return s.load(n.Type, addr)
case OCLOSUREVAR:
addr := s.addr(n)
return s.load(n.Type, addr)
case OLITERAL:
switch u := n.Val().U.(type) {
case *Mpint:
i := u.Int64()
switch n.Type.Size() {
case 1:
return s.constInt8(n.Type, int8(i))
case 2:
return s.constInt16(n.Type, int16(i))
case 4:
return s.constInt32(n.Type, int32(i))
case 8:
return s.constInt64(n.Type, i)
default:
s.Fatalf("bad integer size %d", n.Type.Size())
return nil
}
case string:
if u == "" {
return s.constEmptyString(n.Type)
}
return s.entryNewValue0A(ssa.OpConstString, n.Type, u)
case bool:
return s.constBool(u)
case *NilVal:
t := n.Type
switch {
case t.IsSlice():
return s.constSlice(t)
case t.IsInterface():
return s.constInterface(t)
default:
return s.constNil(t)
}
case *Mpflt:
switch n.Type.Size() {
case 4:
return s.constFloat32(n.Type, u.Float32())
case 8:
return s.constFloat64(n.Type, u.Float64())
default:
s.Fatalf("bad float size %d", n.Type.Size())
return nil
}
case *Mpcplx:
r := &u.Real
i := &u.Imag
switch n.Type.Size() {
case 8:
pt := types.Types[TFLOAT32]
return s.newValue2(ssa.OpComplexMake, n.Type,
s.constFloat32(pt, r.Float32()),
s.constFloat32(pt, i.Float32()))
case 16:
pt := types.Types[TFLOAT64]
return s.newValue2(ssa.OpComplexMake, n.Type,
s.constFloat64(pt, r.Float64()),
s.constFloat64(pt, i.Float64()))
default:
s.Fatalf("bad float size %d", n.Type.Size())
return nil
}
default:
s.Fatalf("unhandled OLITERAL %v", n.Val().Ctype())
return nil
}
case OCONVNOP:
to := n.Type
from := n.Left.Type
// Assume everything will work out, so set up our return value.
// Anything interesting that happens from here is a fatal.
x := s.expr(n.Left)
// Special case for not confusing GC and liveness.
// We don't want pointers accidentally classified
// as not-pointers or vice-versa because of copy
// elision.
if to.IsPtrShaped() != from.IsPtrShaped() {
return s.newValue2(ssa.OpConvert, to, x, s.mem())
}
v := s.newValue1(ssa.OpCopy, to, x) // ensure that v has the right type
// CONVNOP closure
if to.Etype == TFUNC && from.IsPtrShaped() {
return v
}
// named <--> unnamed type or typed <--> untyped const
if from.Etype == to.Etype {
return v
}
// unsafe.Pointer <--> *T
if to.IsUnsafePtr() && from.IsPtrShaped() || from.IsUnsafePtr() && to.IsPtrShaped() {
return v
}
// map <--> *hmap
if to.Etype == TMAP && from.IsPtr() &&
to.MapType().Hmap == from.Elem() {
return v
}
dowidth(from)
dowidth(to)
if from.Width != to.Width {
s.Fatalf("CONVNOP width mismatch %v (%d) -> %v (%d)\n", from, from.Width, to, to.Width)
return nil
}
if etypesign(from.Etype) != etypesign(to.Etype) {
s.Fatalf("CONVNOP sign mismatch %v (%s) -> %v (%s)\n", from, from.Etype, to, to.Etype)
return nil
}
if instrumenting {
// These appear to be fine, but they fail the
// integer constraint below, so okay them here.
// Sample non-integer conversion: map[string]string -> *uint8
return v
}
if etypesign(from.Etype) == 0 {
s.Fatalf("CONVNOP unrecognized non-integer %v -> %v\n", from, to)
return nil
}
// integer, same width, same sign
return v
case OCONV:
x := s.expr(n.Left)
ft := n.Left.Type // from type
tt := n.Type // to type
if ft.IsBoolean() && tt.IsKind(TUINT8) {
// Bool -> uint8 is generated internally when indexing into runtime.staticbyte.
return s.newValue1(ssa.OpCopy, n.Type, x)
}
if ft.IsInteger() && tt.IsInteger() {
var op ssa.Op
if tt.Size() == ft.Size() {
op = ssa.OpCopy
} else if tt.Size() < ft.Size() {
// truncation
switch 10*ft.Size() + tt.Size() {
case 21:
op = ssa.OpTrunc16to8
case 41:
op = ssa.OpTrunc32to8
case 42:
op = ssa.OpTrunc32to16
case 81:
op = ssa.OpTrunc64to8
case 82:
op = ssa.OpTrunc64to16
case 84:
op = ssa.OpTrunc64to32
default:
s.Fatalf("weird integer truncation %v -> %v", ft, tt)
}
} else if ft.IsSigned() {
// sign extension
switch 10*ft.Size() + tt.Size() {
case 12:
op = ssa.OpSignExt8to16
case 14:
op = ssa.OpSignExt8to32
case 18:
op = ssa.OpSignExt8to64
case 24:
op = ssa.OpSignExt16to32
case 28:
op = ssa.OpSignExt16to64
case 48:
op = ssa.OpSignExt32to64
default:
s.Fatalf("bad integer sign extension %v -> %v", ft, tt)
}
} else {
// zero extension
switch 10*ft.Size() + tt.Size() {
case 12:
op = ssa.OpZeroExt8to16
case 14:
op = ssa.OpZeroExt8to32
case 18:
op = ssa.OpZeroExt8to64
case 24:
op = ssa.OpZeroExt16to32
case 28:
op = ssa.OpZeroExt16to64
case 48:
op = ssa.OpZeroExt32to64
default:
s.Fatalf("weird integer sign extension %v -> %v", ft, tt)
}
}
return s.newValue1(op, n.Type, x)
}
if ft.IsFloat() || tt.IsFloat() {
conv, ok := fpConvOpToSSA[twoTypes{s.concreteEtype(ft), s.concreteEtype(tt)}]
if s.config.RegSize == 4 && thearch.LinkArch.Family != sys.MIPS && !s.softFloat {
if conv1, ok1 := fpConvOpToSSA32[twoTypes{s.concreteEtype(ft), s.concreteEtype(tt)}]; ok1 {
conv = conv1
}
}
if thearch.LinkArch.Family == sys.ARM64 || thearch.LinkArch.Family == sys.Wasm || thearch.LinkArch.Family == sys.S390X || s.softFloat {
if conv1, ok1 := uint64fpConvOpToSSA[twoTypes{s.concreteEtype(ft), s.concreteEtype(tt)}]; ok1 {
conv = conv1
}
}
if thearch.LinkArch.Family == sys.MIPS && !s.softFloat {
if ft.Size() == 4 && ft.IsInteger() && !ft.IsSigned() {
// tt is float32 or float64, and ft is also unsigned
if tt.Size() == 4 {
return s.uint32Tofloat32(n, x, ft, tt)
}
if tt.Size() == 8 {
return s.uint32Tofloat64(n, x, ft, tt)
}
} else if tt.Size() == 4 && tt.IsInteger() && !tt.IsSigned() {
// ft is float32 or float64, and tt is unsigned integer
if ft.Size() == 4 {
return s.float32ToUint32(n, x, ft, tt)
}
if ft.Size() == 8 {
return s.float64ToUint32(n, x, ft, tt)
}
}
}
if !ok {
s.Fatalf("weird float conversion %v -> %v", ft, tt)
}
op1, op2, it := conv.op1, conv.op2, conv.intermediateType
if op1 != ssa.OpInvalid && op2 != ssa.OpInvalid {
// normal case, not tripping over unsigned 64
if op1 == ssa.OpCopy {
if op2 == ssa.OpCopy {
return x
}
return s.newValueOrSfCall1(op2, n.Type, x)
}
if op2 == ssa.OpCopy {
return s.newValueOrSfCall1(op1, n.Type, x)
}
return s.newValueOrSfCall1(op2, n.Type, s.newValueOrSfCall1(op1, types.Types[it], x))
}
// Tricky 64-bit unsigned cases.
if ft.IsInteger() {
// tt is float32 or float64, and ft is also unsigned
if tt.Size() == 4 {
return s.uint64Tofloat32(n, x, ft, tt)
}
if tt.Size() == 8 {
return s.uint64Tofloat64(n, x, ft, tt)
}
s.Fatalf("weird unsigned integer to float conversion %v -> %v", ft, tt)
}
// ft is float32 or float64, and tt is unsigned integer
if ft.Size() == 4 {
return s.float32ToUint64(n, x, ft, tt)
}
if ft.Size() == 8 {
return s.float64ToUint64(n, x, ft, tt)
}
s.Fatalf("weird float to unsigned integer conversion %v -> %v", ft, tt)
return nil
}
if ft.IsComplex() && tt.IsComplex() {
var op ssa.Op
if ft.Size() == tt.Size() {
switch ft.Size() {
case 8:
op = ssa.OpRound32F
case 16:
op = ssa.OpRound64F
default:
s.Fatalf("weird complex conversion %v -> %v", ft, tt)
}
} else if ft.Size() == 8 && tt.Size() == 16 {
op = ssa.OpCvt32Fto64F
} else if ft.Size() == 16 && tt.Size() == 8 {
op = ssa.OpCvt64Fto32F
} else {
s.Fatalf("weird complex conversion %v -> %v", ft, tt)
}
ftp := floatForComplex(ft)
ttp := floatForComplex(tt)
return s.newValue2(ssa.OpComplexMake, tt,
s.newValueOrSfCall1(op, ttp, s.newValue1(ssa.OpComplexReal, ftp, x)),
s.newValueOrSfCall1(op, ttp, s.newValue1(ssa.OpComplexImag, ftp, x)))
}
s.Fatalf("unhandled OCONV %s -> %s", n.Left.Type.Etype, n.Type.Etype)
return nil
case ODOTTYPE:
res, _ := s.dottype(n, false)
return res
// binary ops
case OLT, OEQ, ONE, OLE, OGE, OGT:
a := s.expr(n.Left)
b := s.expr(n.Right)
if n.Left.Type.IsComplex() {
pt := floatForComplex(n.Left.Type)
op := s.ssaOp(OEQ, pt)
r := s.newValueOrSfCall2(op, types.Types[TBOOL], s.newValue1(ssa.OpComplexReal, pt, a), s.newValue1(ssa.OpComplexReal, pt, b))
i := s.newValueOrSfCall2(op, types.Types[TBOOL], s.newValue1(ssa.OpComplexImag, pt, a), s.newValue1(ssa.OpComplexImag, pt, b))
c := s.newValue2(ssa.OpAndB, types.Types[TBOOL], r, i)
switch n.Op {
case OEQ:
return c
case ONE:
return s.newValue1(ssa.OpNot, types.Types[TBOOL], c)
default:
s.Fatalf("ordered complex compare %v", n.Op)
}
}
// Convert OGE and OGT into OLE and OLT.
op := n.Op
switch op {
case OGE:
op, a, b = OLE, b, a
case OGT:
op, a, b = OLT, b, a
}
if n.Left.Type.IsFloat() {
// float comparison
return s.newValueOrSfCall2(s.ssaOp(op, n.Left.Type), types.Types[TBOOL], a, b)
}
// integer comparison
return s.newValue2(s.ssaOp(op, n.Left.Type), types.Types[TBOOL], a, b)
case OMUL:
a := s.expr(n.Left)
b := s.expr(n.Right)
if n.Type.IsComplex() {
mulop := ssa.OpMul64F
addop := ssa.OpAdd64F
subop := ssa.OpSub64F
pt := floatForComplex(n.Type) // Could be Float32 or Float64
wt := types.Types[TFLOAT64] // Compute in Float64 to minimize cancellation error
areal := s.newValue1(ssa.OpComplexReal, pt, a)
breal := s.newValue1(ssa.OpComplexReal, pt, b)
aimag := s.newValue1(ssa.OpComplexImag, pt, a)
bimag := s.newValue1(ssa.OpComplexImag, pt, b)
if pt != wt { // Widen for calculation
areal = s.newValueOrSfCall1(ssa.OpCvt32Fto64F, wt, areal)
breal = s.newValueOrSfCall1(ssa.OpCvt32Fto64F, wt, breal)
aimag = s.newValueOrSfCall1(ssa.OpCvt32Fto64F, wt, aimag)
bimag = s.newValueOrSfCall1(ssa.OpCvt32Fto64F, wt, bimag)
}
xreal := s.newValueOrSfCall2(subop, wt, s.newValueOrSfCall2(mulop, wt, areal, breal), s.newValueOrSfCall2(mulop, wt, aimag, bimag))
ximag := s.newValueOrSfCall2(addop, wt, s.newValueOrSfCall2(mulop, wt, areal, bimag), s.newValueOrSfCall2(mulop, wt, aimag, breal))
if pt != wt { // Narrow to store back
xreal = s.newValueOrSfCall1(ssa.OpCvt64Fto32F, pt, xreal)
ximag = s.newValueOrSfCall1(ssa.OpCvt64Fto32F, pt, ximag)
}
return s.newValue2(ssa.OpComplexMake, n.Type, xreal, ximag)
}
if n.Type.IsFloat() {
return s.newValueOrSfCall2(s.ssaOp(n.Op, n.Type), a.Type, a, b)
}
return s.newValue2(s.ssaOp(n.Op, n.Type), a.Type, a, b)
case ODIV:
a := s.expr(n.Left)
b := s.expr(n.Right)
if n.Type.IsComplex() {
// TODO this is not executed because the front-end substitutes a runtime call.
// That probably ought to change; with modest optimization the widen/narrow
// conversions could all be elided in larger expression trees.
mulop := ssa.OpMul64F
addop := ssa.OpAdd64F
subop := ssa.OpSub64F
divop := ssa.OpDiv64F
pt := floatForComplex(n.Type) // Could be Float32 or Float64
wt := types.Types[TFLOAT64] // Compute in Float64 to minimize cancellation error
areal := s.newValue1(ssa.OpComplexReal, pt, a)
breal := s.newValue1(ssa.OpComplexReal, pt, b)
aimag := s.newValue1(ssa.OpComplexImag, pt, a)
bimag := s.newValue1(ssa.OpComplexImag, pt, b)
if pt != wt { // Widen for calculation
areal = s.newValueOrSfCall1(ssa.OpCvt32Fto64F, wt, areal)
breal = s.newValueOrSfCall1(ssa.OpCvt32Fto64F, wt, breal)
aimag = s.newValueOrSfCall1(ssa.OpCvt32Fto64F, wt, aimag)
bimag = s.newValueOrSfCall1(ssa.OpCvt32Fto64F, wt, bimag)
}
denom := s.newValueOrSfCall2(addop, wt, s.newValueOrSfCall2(mulop, wt, breal, breal), s.newValueOrSfCall2(mulop, wt, bimag, bimag))
xreal := s.newValueOrSfCall2(addop, wt, s.newValueOrSfCall2(mulop, wt, areal, breal), s.newValueOrSfCall2(mulop, wt, aimag, bimag))
ximag := s.newValueOrSfCall2(subop, wt, s.newValueOrSfCall2(mulop, wt, aimag, breal), s.newValueOrSfCall2(mulop, wt, areal, bimag))
// TODO not sure if this is best done in wide precision or narrow
// Double-rounding might be an issue.
// Note that the pre-SSA implementation does the entire calculation
// in wide format, so wide is compatible.
xreal = s.newValueOrSfCall2(divop, wt, xreal, denom)
ximag = s.newValueOrSfCall2(divop, wt, ximag, denom)
if pt != wt { // Narrow to store back
xreal = s.newValueOrSfCall1(ssa.OpCvt64Fto32F, pt, xreal)
ximag = s.newValueOrSfCall1(ssa.OpCvt64Fto32F, pt, ximag)
}
return s.newValue2(ssa.OpComplexMake, n.Type, xreal, ximag)
}
if n.Type.IsFloat() {
return s.newValueOrSfCall2(s.ssaOp(n.Op, n.Type), a.Type, a, b)
}
return s.intDivide(n, a, b)
case OMOD:
a := s.expr(n.Left)
b := s.expr(n.Right)
return s.intDivide(n, a, b)
case OADD, OSUB:
a := s.expr(n.Left)
b := s.expr(n.Right)
if n.Type.IsComplex() {
pt := floatForComplex(n.Type)
op := s.ssaOp(n.Op, pt)
return s.newValue2(ssa.OpComplexMake, n.Type,
s.newValueOrSfCall2(op, pt, s.newValue1(ssa.OpComplexReal, pt, a), s.newValue1(ssa.OpComplexReal, pt, b)),
s.newValueOrSfCall2(op, pt, s.newValue1(ssa.OpComplexImag, pt, a), s.newValue1(ssa.OpComplexImag, pt, b)))
}
if n.Type.IsFloat() {
return s.newValueOrSfCall2(s.ssaOp(n.Op, n.Type), a.Type, a, b)
}
return s.newValue2(s.ssaOp(n.Op, n.Type), a.Type, a, b)
case OAND, OOR, OXOR:
a := s.expr(n.Left)
b := s.expr(n.Right)
return s.newValue2(s.ssaOp(n.Op, n.Type), a.Type, a, b)
case OANDNOT:
a := s.expr(n.Left)
b := s.expr(n.Right)
b = s.newValue1(s.ssaOp(OBITNOT, b.Type), b.Type, b)
return s.newValue2(s.ssaOp(OAND, n.Type), a.Type, a, b)
case OLSH, ORSH:
a := s.expr(n.Left)
b := s.expr(n.Right)
bt := b.Type
if bt.IsSigned() {
cmp := s.newValue2(s.ssaOp(OLE, bt), types.Types[TBOOL], s.zeroVal(bt), b)
s.check(cmp, panicshift)
bt = bt.ToUnsigned()
}
return s.newValue2(s.ssaShiftOp(n.Op, n.Type, bt), a.Type, a, b)
case OANDAND, OOROR:
// To implement OANDAND (and OOROR), we introduce a
// new temporary variable to hold the result. The
// variable is associated with the OANDAND node in the
// s.vars table (normally variables are only
// associated with ONAME nodes). We convert
// A && B
// to
// var = A
// if var {
// var = B
// }
// Using var in the subsequent block introduces the
// necessary phi variable.
el := s.expr(n.Left)
s.vars[n] = el
b := s.endBlock()
b.Kind = ssa.BlockIf
b.SetControl(el)
// In theory, we should set b.Likely here based on context.
// However, gc only gives us likeliness hints
// in a single place, for plain OIF statements,
// and passing around context is finnicky, so don't bother for now.
bRight := s.f.NewBlock(ssa.BlockPlain)
bResult := s.f.NewBlock(ssa.BlockPlain)
if n.Op == OANDAND {
b.AddEdgeTo(bRight)
b.AddEdgeTo(bResult)
} else if n.Op == OOROR {
b.AddEdgeTo(bResult)
b.AddEdgeTo(bRight)
}
s.startBlock(bRight)
er := s.expr(n.Right)
s.vars[n] = er
b = s.endBlock()
b.AddEdgeTo(bResult)
s.startBlock(bResult)
return s.variable(n, types.Types[TBOOL])
case OCOMPLEX:
r := s.expr(n.Left)
i := s.expr(n.Right)
return s.newValue2(ssa.OpComplexMake, n.Type, r, i)
// unary ops
case ONEG:
a := s.expr(n.Left)
if n.Type.IsComplex() {
tp := floatForComplex(n.Type)
negop := s.ssaOp(n.Op, tp)
return s.newValue2(ssa.OpComplexMake, n.Type,
s.newValue1(negop, tp, s.newValue1(ssa.OpComplexReal, tp, a)),
s.newValue1(negop, tp, s.newValue1(ssa.OpComplexImag, tp, a)))
}
return s.newValue1(s.ssaOp(n.Op, n.Type), a.Type, a)
case ONOT, OBITNOT:
a := s.expr(n.Left)
return s.newValue1(s.ssaOp(n.Op, n.Type), a.Type, a)
case OIMAG, OREAL:
a := s.expr(n.Left)
return s.newValue1(s.ssaOp(n.Op, n.Left.Type), n.Type, a)
case OPLUS:
return s.expr(n.Left)
case OADDR:
return s.addr(n.Left)
case ORESULT:
if s.prevCall == nil || s.prevCall.Op != ssa.OpStaticLECall && s.prevCall.Op != ssa.OpInterLECall && s.prevCall.Op != ssa.OpClosureLECall {
// Do the old thing
addr := s.constOffPtrSP(types.NewPtr(n.Type), n.Xoffset)
return s.rawLoad(n.Type, addr)
}
which := s.prevCall.Aux.(*ssa.AuxCall).ResultForOffset(n.Xoffset)
if which == -1 {
// Do the old thing // TODO: Panic instead.
addr := s.constOffPtrSP(types.NewPtr(n.Type), n.Xoffset)
return s.rawLoad(n.Type, addr)
}
if canSSAType(n.Type) {
return s.newValue1I(ssa.OpSelectN, n.Type, which, s.prevCall)
} else {
addr := s.newValue1I(ssa.OpSelectNAddr, types.NewPtr(n.Type), which, s.prevCall)
return s.rawLoad(n.Type, addr)
}
case ODEREF:
p := s.exprPtr(n.Left, n.Bounded(), n.Pos)
return s.load(n.Type, p)
case ODOT:
if n.Left.Op == OSTRUCTLIT {
// All literals with nonzero fields have already been
// rewritten during walk. Any that remain are just T{}
// or equivalents. Use the zero value.
if !isZero(n.Left) {
s.Fatalf("literal with nonzero value in SSA: %v", n.Left)
}
return s.zeroVal(n.Type)
}
// If n is addressable and can't be represented in
// SSA, then load just the selected field. This
// prevents false memory dependencies in race/msan
// instrumentation.
if islvalue(n) && !s.canSSA(n) {
p := s.addr(n)
return s.load(n.Type, p)
}
v := s.expr(n.Left)
return s.newValue1I(ssa.OpStructSelect, n.Type, int64(fieldIdx(n)), v)
case ODOTPTR:
p := s.exprPtr(n.Left, n.Bounded(), n.Pos)
p = s.newValue1I(ssa.OpOffPtr, types.NewPtr(n.Type), n.Xoffset, p)
return s.load(n.Type, p)
case OINDEX:
switch {
case n.Left.Type.IsString():
if n.Bounded() && Isconst(n.Left, CTSTR) && Isconst(n.Right, CTINT) {
// Replace "abc"[1] with 'b'.
// Delayed until now because "abc"[1] is not an ideal constant.
// See test/fixedbugs/issue11370.go.
return s.newValue0I(ssa.OpConst8, types.Types[TUINT8], int64(int8(n.Left.StringVal()[n.Right.Int64Val()])))
}
a := s.expr(n.Left)
i := s.expr(n.Right)
len := s.newValue1(ssa.OpStringLen, types.Types[TINT], a)
i = s.boundsCheck(i, len, ssa.BoundsIndex, n.Bounded())
ptrtyp := s.f.Config.Types.BytePtr
ptr := s.newValue1(ssa.OpStringPtr, ptrtyp, a)
if Isconst(n.Right, CTINT) {
ptr = s.newValue1I(ssa.OpOffPtr, ptrtyp, n.Right.Int64Val(), ptr)
} else {
ptr = s.newValue2(ssa.OpAddPtr, ptrtyp, ptr, i)
}
return s.load(types.Types[TUINT8], ptr)
case n.Left.Type.IsSlice():
p := s.addr(n)
return s.load(n.Left.Type.Elem(), p)
case n.Left.Type.IsArray():
if canSSAType(n.Left.Type) {
// SSA can handle arrays of length at most 1.
bound := n.Left.Type.NumElem()
a := s.expr(n.Left)
i := s.expr(n.Right)
if bound == 0 {
// Bounds check will never succeed. Might as well
// use constants for the bounds check.
z := s.constInt(types.Types[TINT], 0)
s.boundsCheck(z, z, ssa.BoundsIndex, false)
// The return value won't be live, return junk.
return s.newValue0(ssa.OpUnknown, n.Type)
}
len := s.constInt(types.Types[TINT], bound)
s.boundsCheck(i, len, ssa.BoundsIndex, n.Bounded()) // checks i == 0
return s.newValue1I(ssa.OpArraySelect, n.Type, 0, a)
}
p := s.addr(n)
return s.load(n.Left.Type.Elem(), p)
default:
s.Fatalf("bad type for index %v", n.Left.Type)
return nil
}
case OLEN, OCAP:
switch {
case n.Left.Type.IsSlice():
op := ssa.OpSliceLen
if n.Op == OCAP {
op = ssa.OpSliceCap
}
return s.newValue1(op, types.Types[TINT], s.expr(n.Left))
case n.Left.Type.IsString(): // string; not reachable for OCAP
return s.newValue1(ssa.OpStringLen, types.Types[TINT], s.expr(n.Left))
case n.Left.Type.IsMap(), n.Left.Type.IsChan():
return s.referenceTypeBuiltin(n, s.expr(n.Left))
default: // array
return s.constInt(types.Types[TINT], n.Left.Type.NumElem())
}
case OSPTR:
a := s.expr(n.Left)
if n.Left.Type.IsSlice() {
return s.newValue1(ssa.OpSlicePtr, n.Type, a)
} else {
return s.newValue1(ssa.OpStringPtr, n.Type, a)
}
case OITAB:
a := s.expr(n.Left)
return s.newValue1(ssa.OpITab, n.Type, a)
case OIDATA:
a := s.expr(n.Left)
return s.newValue1(ssa.OpIData, n.Type, a)
case OEFACE:
tab := s.expr(n.Left)
data := s.expr(n.Right)
return s.newValue2(ssa.OpIMake, n.Type, tab, data)
case OSLICEHEADER:
p := s.expr(n.Left)
l := s.expr(n.List.First())
c := s.expr(n.List.Second())
return s.newValue3(ssa.OpSliceMake, n.Type, p, l, c)
case OSLICE, OSLICEARR, OSLICE3, OSLICE3ARR:
v := s.expr(n.Left)
var i, j, k *ssa.Value
low, high, max := n.SliceBounds()
if low != nil {
i = s.expr(low)
}
if high != nil {
j = s.expr(high)
}
if max != nil {
k = s.expr(max)
}
p, l, c := s.slice(v, i, j, k, n.Bounded())
return s.newValue3(ssa.OpSliceMake, n.Type, p, l, c)
case OSLICESTR:
v := s.expr(n.Left)
var i, j *ssa.Value
low, high, _ := n.SliceBounds()
if low != nil {
i = s.expr(low)
}
if high != nil {
j = s.expr(high)
}
p, l, _ := s.slice(v, i, j, nil, n.Bounded())
return s.newValue2(ssa.OpStringMake, n.Type, p, l)
case OCALLFUNC:
if isIntrinsicCall(n) {
return s.intrinsicCall(n)
}
fallthrough
case OCALLINTER, OCALLMETH:
return s.callResult(n, callNormal)
case OGETG:
return s.newValue1(ssa.OpGetG, n.Type, s.mem())
case OAPPEND:
return s.append(n, false)
case OSTRUCTLIT, OARRAYLIT:
// All literals with nonzero fields have already been
// rewritten during walk. Any that remain are just T{}
// or equivalents. Use the zero value.
if !isZero(n) {
s.Fatalf("literal with nonzero value in SSA: %v", n)
}
return s.zeroVal(n.Type)
case ONEWOBJ:
if n.Type.Elem().Size() == 0 {
return s.newValue1A(ssa.OpAddr, n.Type, zerobaseSym, s.sb)
}
typ := s.expr(n.Left)
vv := s.rtcall(newobject, true, []*types.Type{n.Type}, typ)
return vv[0]
default:
s.Fatalf("unhandled expr %v", n.Op)
return nil
}
}
// append converts an OAPPEND node to SSA.
// If inplace is false, it converts the OAPPEND expression n to an ssa.Value,
// adds it to s, and returns the Value.
// If inplace is true, it writes the result of the OAPPEND expression n
// back to the slice being appended to, and returns nil.
// inplace MUST be set to false if the slice can be SSA'd.
func (s *state) append(n *Node, inplace bool) *ssa.Value {
// If inplace is false, process as expression "append(s, e1, e2, e3)":
//
// ptr, len, cap := s
// newlen := len + 3
// if newlen > cap {
// ptr, len, cap = growslice(s, newlen)
// newlen = len + 3 // recalculate to avoid a spill
// }
// // with write barriers, if needed:
// *(ptr+len) = e1
// *(ptr+len+1) = e2
// *(ptr+len+2) = e3
// return makeslice(ptr, newlen, cap)
//
//
// If inplace is true, process as statement "s = append(s, e1, e2, e3)":
//
// a := &s
// ptr, len, cap := s
// newlen := len + 3
// if uint(newlen) > uint(cap) {
// newptr, len, newcap = growslice(ptr, len, cap, newlen)
// vardef(a) // if necessary, advise liveness we are writing a new a
// *a.cap = newcap // write before ptr to avoid a spill
// *a.ptr = newptr // with write barrier
// }
// newlen = len + 3 // recalculate to avoid a spill
// *a.len = newlen
// // with write barriers, if needed:
// *(ptr+len) = e1
// *(ptr+len+1) = e2
// *(ptr+len+2) = e3
et := n.Type.Elem()
pt := types.NewPtr(et)
// Evaluate slice
sn := n.List.First() // the slice node is the first in the list
var slice, addr *ssa.Value
if inplace {
addr = s.addr(sn)
slice = s.load(n.Type, addr)
} else {
slice = s.expr(sn)
}
// Allocate new blocks
grow := s.f.NewBlock(ssa.BlockPlain)
assign := s.f.NewBlock(ssa.BlockPlain)
// Decide if we need to grow
nargs := int64(n.List.Len() - 1)
p := s.newValue1(ssa.OpSlicePtr, pt, slice)
l := s.newValue1(ssa.OpSliceLen, types.Types[TINT], slice)
c := s.newValue1(ssa.OpSliceCap, types.Types[TINT], slice)
nl := s.newValue2(s.ssaOp(OADD, types.Types[TINT]), types.Types[TINT], l, s.constInt(types.Types[TINT], nargs))
cmp := s.newValue2(s.ssaOp(OLT, types.Types[TUINT]), types.Types[TBOOL], c, nl)
s.vars[&ptrVar] = p
if !inplace {
s.vars[&newlenVar] = nl
s.vars[&capVar] = c
} else {
s.vars[&lenVar] = l
}
b := s.endBlock()
b.Kind = ssa.BlockIf
b.Likely = ssa.BranchUnlikely
b.SetControl(cmp)
b.AddEdgeTo(grow)
b.AddEdgeTo(assign)
// Call growslice
s.startBlock(grow)
taddr := s.expr(n.Left)
r := s.rtcall(growslice, true, []*types.Type{pt, types.Types[TINT], types.Types[TINT]}, taddr, p, l, c, nl)
if inplace {
if sn.Op == ONAME && sn.Class() != PEXTERN {
// Tell liveness we're about to build a new slice
s.vars[&memVar] = s.newValue1A(ssa.OpVarDef, types.TypeMem, sn, s.mem())
}
capaddr := s.newValue1I(ssa.OpOffPtr, s.f.Config.Types.IntPtr, sliceCapOffset, addr)