/
Trampoline-x64.cpp
executable file
·1242 lines (1036 loc) · 42 KB
/
Trampoline-x64.cpp
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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
* vim: set ts=8 sts=4 et sw=4 tw=99:
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "jit/Bailouts.h"
#include "jit/JitCompartment.h"
#include "jit/JitFrames.h"
#include "jit/Linker.h"
#ifdef JS_ION_PERF
# include "jit/PerfSpewer.h"
#endif
#include "jit/VMFunctions.h"
#include "jit/x64/BaselineHelpers-x64.h"
using namespace js;
using namespace js::jit;
// All registers to save and restore. This includes the stack pointer, since we
// use the ability to reference register values on the stack by index.
static const RegisterSet AllRegs =
RegisterSet(GeneralRegisterSet(Registers::AllMask),
FloatRegisterSet(FloatRegisters::AllMask));
// Generates a trampoline for calling Jit compiled code from a C++ function.
// The trampoline use the EnterJitCode signature, with the standard x64 fastcall
// calling convention.
JitCode*
JitRuntime::generateEnterJIT(JSContext* cx, EnterJitType type)
{
MacroAssembler masm(cx);
masm.assertStackAlignment(ABIStackAlignment, -int32_t(sizeof(uintptr_t)) /* return address */);
const Register reg_code = IntArgReg0;
const Register reg_argc = IntArgReg1;
const Register reg_argv = IntArgReg2;
MOZ_ASSERT(OsrFrameReg == IntArgReg3);
#if defined(_WIN64)
const Operand token = Operand(rbp, 16 + ShadowStackSpace);
const Operand scopeChain = Operand(rbp, 24 + ShadowStackSpace);
const Operand numStackValuesAddr = Operand(rbp, 32 + ShadowStackSpace);
const Operand result = Operand(rbp, 40 + ShadowStackSpace);
#else
const Register token = IntArgReg4;
const Register scopeChain = IntArgReg5;
const Operand numStackValuesAddr = Operand(rbp, 16 + ShadowStackSpace);
const Operand result = Operand(rbp, 24 + ShadowStackSpace);
#endif
// Save old stack frame pointer, set new stack frame pointer.
masm.push(rbp);
masm.mov(rsp, rbp);
// Save non-volatile registers. These must be saved by the trampoline, rather
// than by the JIT'd code, because they are scanned by the conservative scanner.
masm.push(rbx);
masm.push(r12);
masm.push(r13);
masm.push(r14);
masm.push(r15);
#if defined(_WIN64)
masm.push(rdi);
masm.push(rsi);
// 16-byte aligment for vmovdqa
masm.subq(Imm32(16 * 10 + 8), rsp);
masm.vmovdqa(xmm6, Operand(rsp, 16 * 0));
masm.vmovdqa(xmm7, Operand(rsp, 16 * 1));
masm.vmovdqa(xmm8, Operand(rsp, 16 * 2));
masm.vmovdqa(xmm9, Operand(rsp, 16 * 3));
masm.vmovdqa(xmm10, Operand(rsp, 16 * 4));
masm.vmovdqa(xmm11, Operand(rsp, 16 * 5));
masm.vmovdqa(xmm12, Operand(rsp, 16 * 6));
masm.vmovdqa(xmm13, Operand(rsp, 16 * 7));
masm.vmovdqa(xmm14, Operand(rsp, 16 * 8));
masm.vmovdqa(xmm15, Operand(rsp, 16 * 9));
#endif
// Save arguments passed in registers needed after function call.
masm.push(result);
// Remember stack depth without padding and arguments.
masm.mov(rsp, r14);
// Remember number of bytes occupied by argument vector
masm.mov(reg_argc, r13);
masm.shll(Imm32(3), r13); // r13 = argc * sizeof(Value)
static_assert(sizeof(Value) == 1 << 3, "Constant is baked in assembly code");
// Guarantee stack alignment of Jit frames.
//
// This code compensates for the offset created by the copy of the vector of
// arguments, such that the jit frame will be aligned once the return
// address is pushed on the stack.
//
// In the computation of the offset, we omit the size of the JitFrameLayout
// which is pushed on the stack, as the JitFrameLayout size is a multiple of
// the JitStackAlignment.
masm.mov(rsp, r12);
masm.subq(r13, r12);
static_assert(sizeof(JitFrameLayout) % JitStackAlignment == 0,
"No need to consider the JitFrameLayout for aligning the stack");
masm.andl(Imm32(JitStackAlignment - 1), r12);
masm.subq(r12, rsp);
/***************************************************************
Loop over argv vector, push arguments onto stack in reverse order
***************************************************************/
// r13 still stores the number of bytes in the argument vector.
masm.addq(reg_argv, r13); // r13 points above last argument.
// while r13 > rdx, push arguments.
{
Label header, footer;
masm.bind(&header);
masm.cmpPtr(r13, reg_argv);
masm.j(AssemblerX86Shared::BelowOrEqual, &footer);
masm.subq(Imm32(8), r13);
masm.push(Operand(r13, 0));
masm.jmp(&header);
masm.bind(&footer);
}
// Push the number of actual arguments. |result| is used to store the
// actual number of arguments without adding an extra argument to the enter
// JIT.
masm.movq(result, reg_argc);
masm.unboxInt32(Operand(reg_argc, 0), reg_argc);
masm.push(reg_argc);
// Push the callee token.
masm.push(token);
/*****************************************************************
Push the number of bytes we've pushed so far on the stack and call
*****************************************************************/
masm.subq(rsp, r14);
// Create a frame descriptor.
masm.makeFrameDescriptor(r14, JitFrame_Entry);
masm.push(r14);
CodeLabel returnLabel;
if (type == EnterJitBaseline) {
// Handle OSR.
GeneralRegisterSet regs(GeneralRegisterSet::All());
regs.takeUnchecked(OsrFrameReg);
regs.take(rbp);
regs.take(reg_code);
// Ensure that |scratch| does not end up being JSReturnOperand.
// Do takeUnchecked because on Win64/x64, reg_code (IntArgReg0) and JSReturnOperand are
// the same (rcx). See bug 849398.
regs.takeUnchecked(JSReturnOperand);
Register scratch = regs.takeAny();
Label notOsr;
masm.branchTestPtr(Assembler::Zero, OsrFrameReg, OsrFrameReg, ¬Osr);
Register numStackValues = regs.takeAny();
masm.movq(numStackValuesAddr, numStackValues);
// Push return address
masm.mov(returnLabel.dest(), scratch);
masm.push(scratch);
// Push previous frame pointer.
masm.push(rbp);
// Reserve frame.
Register framePtr = rbp;
masm.subPtr(Imm32(BaselineFrame::Size()), rsp);
masm.mov(rsp, framePtr);
#ifdef XP_WIN
// Can't push large frames blindly on windows. Touch frame memory incrementally.
masm.mov(numStackValues, scratch);
masm.lshiftPtr(Imm32(3), scratch);
masm.subPtr(scratch, framePtr);
{
masm.movePtr(rsp, scratch);
masm.subPtr(Imm32(WINDOWS_BIG_FRAME_TOUCH_INCREMENT), scratch);
Label touchFrameLoop;
Label touchFrameLoopEnd;
masm.bind(&touchFrameLoop);
masm.branchPtr(Assembler::Below, scratch, framePtr, &touchFrameLoopEnd);
masm.store32(Imm32(0), Address(scratch, 0));
masm.subPtr(Imm32(WINDOWS_BIG_FRAME_TOUCH_INCREMENT), scratch);
masm.jump(&touchFrameLoop);
masm.bind(&touchFrameLoopEnd);
}
masm.mov(rsp, framePtr);
#endif
// Reserve space for locals and stack values.
Register valuesSize = regs.takeAny();
masm.mov(numStackValues, valuesSize);
masm.shll(Imm32(3), valuesSize);
masm.subPtr(valuesSize, rsp);
// Enter exit frame.
masm.addPtr(Imm32(BaselineFrame::Size() + BaselineFrame::FramePointerOffset), valuesSize);
masm.makeFrameDescriptor(valuesSize, JitFrame_BaselineJS);
masm.push(valuesSize);
masm.push(Imm32(0)); // Fake return address.
// No GC things to mark, push a bare token.
masm.enterFakeExitFrame(ExitFrameLayout::BareToken());
regs.add(valuesSize);
masm.push(framePtr);
masm.push(reg_code);
masm.setupUnalignedABICall(3, scratch);
masm.passABIArg(framePtr); // BaselineFrame
masm.passABIArg(OsrFrameReg); // InterpreterFrame
masm.passABIArg(numStackValues);
masm.callWithABI(JS_FUNC_TO_DATA_PTR(void*, jit::InitBaselineFrameForOsr));
masm.pop(reg_code);
masm.pop(framePtr);
MOZ_ASSERT(reg_code != ReturnReg);
Label error;
masm.addPtr(Imm32(ExitFrameLayout::SizeWithFooter()), rsp);
masm.addPtr(Imm32(BaselineFrame::Size()), framePtr);
masm.branchIfFalseBool(ReturnReg, &error);
// If OSR-ing, then emit instrumentation for setting lastProfilerFrame
// if profiler instrumentation is enabled.
{
Label skipProfilingInstrumentation;
Register realFramePtr = numStackValues;
AbsoluteAddress addressOfEnabled(cx->runtime()->spsProfiler.addressOfEnabled());
masm.branch32(Assembler::Equal, addressOfEnabled, Imm32(0),
&skipProfilingInstrumentation);
masm.lea(Operand(framePtr, sizeof(void*)), realFramePtr);
masm.profilerEnterFrame(realFramePtr, scratch);
masm.bind(&skipProfilingInstrumentation);
}
masm.jump(reg_code);
// OOM: load error value, discard return address and previous frame
// pointer and return.
masm.bind(&error);
masm.mov(framePtr, rsp);
masm.addPtr(Imm32(2 * sizeof(uintptr_t)), rsp);
masm.moveValue(MagicValue(JS_ION_ERROR), JSReturnOperand);
masm.mov(returnLabel.dest(), scratch);
masm.jump(scratch);
masm.bind(¬Osr);
masm.movq(scopeChain, R1.scratchReg());
}
// The call will push the return address on the stack, thus we check that
// the stack would be aligned once the call is complete.
masm.assertStackAlignment(JitStackAlignment, sizeof(uintptr_t));
// Call function.
masm.call(reg_code);
if (type == EnterJitBaseline) {
// Baseline OSR will return here.
masm.bind(returnLabel.src());
masm.addCodeLabel(returnLabel);
}
// Pop arguments and padding from stack.
masm.pop(r14); // Pop and decode descriptor.
masm.shrq(Imm32(FRAMESIZE_SHIFT), r14);
masm.addq(r14, rsp); // Remove arguments.
/*****************************************************************
Place return value where it belongs, pop all saved registers
*****************************************************************/
masm.pop(r12); // vp
masm.storeValue(JSReturnOperand, Operand(r12, 0));
// Restore non-volatile registers.
#if defined(_WIN64)
masm.vmovdqa(Operand(rsp, 16 * 0), xmm6);
masm.vmovdqa(Operand(rsp, 16 * 1), xmm7);
masm.vmovdqa(Operand(rsp, 16 * 2), xmm8);
masm.vmovdqa(Operand(rsp, 16 * 3), xmm9);
masm.vmovdqa(Operand(rsp, 16 * 4), xmm10);
masm.vmovdqa(Operand(rsp, 16 * 5), xmm11);
masm.vmovdqa(Operand(rsp, 16 * 6), xmm12);
masm.vmovdqa(Operand(rsp, 16 * 7), xmm13);
masm.vmovdqa(Operand(rsp, 16 * 8), xmm14);
masm.vmovdqa(Operand(rsp, 16 * 9), xmm15);
masm.addq(Imm32(16 * 10 + 8), rsp);
masm.pop(rsi);
masm.pop(rdi);
#endif
masm.pop(r15);
masm.pop(r14);
masm.pop(r13);
masm.pop(r12);
masm.pop(rbx);
// Restore frame pointer and return.
masm.pop(rbp);
masm.ret();
Linker linker(masm);
JitCode* code = linker.newCode<NoGC>(cx, OTHER_CODE);
#ifdef JS_ION_PERF
writePerfSpewerJitCodeProfile(code, "EnterJIT");
#endif
return code;
}
JitCode*
JitRuntime::generateInvalidator(JSContext* cx)
{
AutoJitContextAlloc ajca(cx);
MacroAssembler masm(cx);
// See explanatory comment in x86's JitRuntime::generateInvalidator.
masm.addq(Imm32(sizeof(uintptr_t)), rsp);
// Push registers such that we can access them from [base + code].
masm.PushRegsInMask(AllRegs);
masm.movq(rsp, rax); // Argument to jit::InvalidationBailout.
// Make space for InvalidationBailout's frameSize outparam.
masm.reserveStack(sizeof(size_t));
masm.movq(rsp, rbx);
// Make space for InvalidationBailout's bailoutInfo outparam.
masm.reserveStack(sizeof(void*));
masm.movq(rsp, r9);
masm.setupUnalignedABICall(3, rdx);
masm.passABIArg(rax);
masm.passABIArg(rbx);
masm.passABIArg(r9);
masm.callWithABI(JS_FUNC_TO_DATA_PTR(void*, InvalidationBailout));
masm.pop(r9); // Get the bailoutInfo outparam.
masm.pop(rbx); // Get the frameSize outparam.
// Pop the machine state and the dead frame.
masm.lea(Operand(rsp, rbx, TimesOne, sizeof(InvalidationBailoutStack)), rsp);
// Jump to shared bailout tail. The BailoutInfo pointer has to be in r9.
JitCode* bailoutTail = cx->runtime()->jitRuntime()->getBailoutTail();
masm.jmp(bailoutTail);
Linker linker(masm);
JitCode* code = linker.newCode<NoGC>(cx, OTHER_CODE);
#ifdef JS_ION_PERF
writePerfSpewerJitCodeProfile(code, "Invalidator");
#endif
return code;
}
JitCode*
JitRuntime::generateArgumentsRectifier(JSContext* cx, void** returnAddrOut)
{
// Do not erase the frame pointer in this function.
MacroAssembler masm(cx);
// Caller:
// [arg2] [arg1] [this] [[argc] [callee] [descr] [raddr]] <- rsp
// '--- #r8 ---'
// ArgumentsRectifierReg contains the |nargs| pushed onto the current frame.
// Including |this|, there are (|nargs| + 1) arguments to copy.
MOZ_ASSERT(ArgumentsRectifierReg == r8);
// Add |this|, in the counter of known arguments.
masm.addl(Imm32(1), r8);
// Load |nformals| into %rcx.
masm.loadPtr(Address(rsp, RectifierFrameLayout::offsetOfCalleeToken()), rax);
masm.mov(rax, rcx);
masm.andq(Imm32(uint32_t(CalleeTokenMask)), rcx);
masm.movzwl(Operand(rcx, JSFunction::offsetOfNargs()), rcx);
// Including |this|, there are (|nformals| + 1) arguments to push to the
// stack. Then we push a JitFrameLayout. We compute the padding expressed
// in the number of extra |undefined| values to push on the stack.
static_assert(sizeof(JitFrameLayout) % JitStackAlignment == 0,
"No need to consider the JitFrameLayout for aligning the stack");
static_assert(JitStackAlignment % sizeof(Value) == 0,
"Ensure that we can pad the stack by pushing extra UndefinedValue");
const uint32_t alignment = JitStackAlignment / sizeof(Value);
MOZ_ASSERT(IsPowerOfTwo(alignment));
masm.addl(Imm32(alignment - 1 /* for padding */ + 1 /* for |this| */), rcx);
masm.andl(Imm32(~(alignment - 1)), rcx);
// Load the number of |undefined|s to push into %rcx.
masm.subq(r8, rcx);
// Caller:
// [arg2] [arg1] [this] [[argc] [callee] [descr] [raddr]] <- rsp <- r9
// '------ #r8 -------'
//
// Rectifier frame:
// [undef] [undef] [undef] [arg2] [arg1] [this] [[argc] [callee] [descr] [raddr]]
// '------- #rcx --------' '------ #r8 -------'
// Copy the number of actual arguments
masm.loadPtr(Address(rsp, RectifierFrameLayout::offsetOfNumActualArgs()), rdx);
masm.moveValue(UndefinedValue(), r10);
masm.movq(rsp, r9); // Save %rsp.
// Push undefined. (including the padding)
{
Label undefLoopTop;
masm.bind(&undefLoopTop);
masm.push(r10);
masm.subl(Imm32(1), rcx);
masm.j(Assembler::NonZero, &undefLoopTop);
}
// Get the topmost argument.
static_assert(sizeof(Value) == 8, "TimesEight is used to skip arguments");
// | - sizeof(Value)| is used to put rcx such that we can read the last
// argument, and not the value which is after.
BaseIndex b = BaseIndex(r9, r8, TimesEight, sizeof(RectifierFrameLayout) - sizeof(Value));
masm.lea(Operand(b), rcx);
// Copy & Push arguments, |nargs| + 1 times (to include |this|).
{
Label copyLoopTop;
masm.bind(©LoopTop);
masm.push(Operand(rcx, 0x0));
masm.subq(Imm32(sizeof(Value)), rcx);
masm.subl(Imm32(1), r8);
masm.j(Assembler::NonZero, ©LoopTop);
}
// Caller:
// [arg2] [arg1] [this] [[argc] [callee] [descr] [raddr]] <- r9
//
//
// Rectifier frame:
// [undef] [undef] [undef] [arg2] [arg1] [this] <- rsp [[argc] [callee] [descr] [raddr]]
//
// Construct descriptor.
masm.subq(rsp, r9);
masm.makeFrameDescriptor(r9, JitFrame_Rectifier);
// Construct JitFrameLayout.
masm.push(rdx); // numActualArgs
masm.push(rax); // callee token
masm.push(r9); // descriptor
// Call the target function.
// Note that this code assumes the function is JITted.
masm.andq(Imm32(uint32_t(CalleeTokenMask)), rax);
masm.loadPtr(Address(rax, JSFunction::offsetOfNativeOrScript()), rax);
masm.loadBaselineOrIonRaw(rax, rax, nullptr);
masm.call(rax);
uint32_t returnOffset = masm.currentOffset();
// Remove the rectifier frame.
masm.pop(r9); // r9 <- descriptor with FrameType.
masm.shrq(Imm32(FRAMESIZE_SHIFT), r9);
masm.pop(r11); // Discard calleeToken.
masm.pop(r11); // Discard numActualArgs.
masm.addq(r9, rsp); // Discard pushed arguments.
masm.ret();
Linker linker(masm);
JitCode* code = linker.newCode<NoGC>(cx, OTHER_CODE);
#ifdef JS_ION_PERF
writePerfSpewerJitCodeProfile(code, "ArgumentsRectifier");
#endif
CodeOffsetLabel returnLabel(returnOffset);
returnLabel.fixup(&masm);
if (returnAddrOut)
*returnAddrOut = (void*) (code->raw() + returnLabel.offset());
return code;
}
static void
PushBailoutFrame(MacroAssembler& masm, Register spArg)
{
// Push registers such that we can access them from [base + code].
if (JitSupportsSimd()) {
masm.PushRegsInMask(AllRegs);
} else {
// When SIMD isn't supported, PushRegsInMask reduces the set of float
// registers to be double-sized, while the RegisterDump expects each of
// the float registers to have the maximal possible size
// (Simd128DataSize). To work around this, we just spill the double
// registers by hand here, using the register dump offset directly.
RegisterSet set = AllRegs;
for (GeneralRegisterBackwardIterator iter(set.gprs()); iter.more(); iter++)
masm.Push(*iter);
masm.reserveStack(sizeof(RegisterDump::FPUArray));
for (FloatRegisterBackwardIterator iter(set.fpus()); iter.more(); iter++) {
FloatRegister reg = *iter;
Address spillAddress(StackPointer, reg.getRegisterDumpOffsetInBytes());
masm.storeDouble(reg, spillAddress);
}
}
// Get the stack pointer into a register, pre-alignment.
masm.movq(rsp, spArg);
}
static void
GenerateBailoutThunk(JSContext* cx, MacroAssembler& masm, uint32_t frameClass)
{
PushBailoutFrame(masm, r8);
// Make space for Bailout's bailoutInfo outparam.
masm.reserveStack(sizeof(void*));
masm.movq(rsp, r9);
// Call the bailout function.
masm.setupUnalignedABICall(2, rax);
masm.passABIArg(r8);
masm.passABIArg(r9);
masm.callWithABI(JS_FUNC_TO_DATA_PTR(void*, Bailout));
masm.pop(r9); // Get the bailoutInfo outparam.
// Stack is:
// [frame]
// snapshotOffset
// frameSize
// [bailoutFrame]
//
// Remove both the bailout frame and the topmost Ion frame's stack.
static const uint32_t BailoutDataSize = sizeof(RegisterDump);
masm.addq(Imm32(BailoutDataSize), rsp);
masm.pop(rcx);
masm.lea(Operand(rsp, rcx, TimesOne, sizeof(void *)), rsp);
// Jump to shared bailout tail. The BailoutInfo pointer has to be in r9.
JitCode* bailoutTail = cx->runtime()->jitRuntime()->getBailoutTail();
masm.jmp(bailoutTail);
}
JitCode*
JitRuntime::generateBailoutTable(JSContext* cx, uint32_t frameClass)
{
MOZ_CRASH("x64 does not use bailout tables");
}
JitCode*
JitRuntime::generateBailoutHandler(JSContext* cx)
{
MacroAssembler masm;
GenerateBailoutThunk(cx, masm, NO_FRAME_SIZE_CLASS_ID);
Linker linker(masm);
JitCode* code = linker.newCode<NoGC>(cx, OTHER_CODE);
#ifdef JS_ION_PERF
writePerfSpewerJitCodeProfile(code, "BailoutHandler");
#endif
return code;
}
JitCode*
JitRuntime::generateVMWrapper(JSContext* cx, const VMFunction& f)
{
MOZ_ASSERT(functionWrappers_);
MOZ_ASSERT(functionWrappers_->initialized());
VMWrapperMap::AddPtr p = functionWrappers_->lookupForAdd(&f);
if (p)
return p->value();
// Generate a separated code for the wrapper.
MacroAssembler masm;
// Avoid conflicts with argument registers while discarding the result after
// the function call.
GeneralRegisterSet regs = GeneralRegisterSet(Register::Codes::WrapperMask);
// Wrapper register set is a superset of Volatile register set.
JS_STATIC_ASSERT((Register::Codes::VolatileMask & ~Register::Codes::WrapperMask) == 0);
// The context is the first argument.
Register cxreg = IntArgReg0;
regs.take(cxreg);
// Stack is:
// ... frame ...
// +12 [args]
// +8 descriptor
// +0 returnAddress
//
// We're aligned to an exit frame, so link it up.
masm.enterExitFrame(&f);
masm.loadJSContext(cxreg);
// Save the current stack pointer as the base for copying arguments.
Register argsBase = InvalidReg;
if (f.explicitArgs) {
argsBase = r10;
regs.take(argsBase);
masm.lea(Operand(rsp, ExitFrameLayout::SizeWithFooter()), argsBase);
}
// Reserve space for the outparameter.
Register outReg = InvalidReg;
switch (f.outParam) {
case Type_Value:
outReg = regs.takeAny();
masm.reserveStack(sizeof(Value));
masm.movq(esp, outReg);
break;
case Type_Handle:
outReg = regs.takeAny();
masm.PushEmptyRooted(f.outParamRootType);
masm.movq(esp, outReg);
break;
case Type_Int32:
case Type_Bool:
outReg = regs.takeAny();
masm.reserveStack(sizeof(int32_t));
masm.movq(esp, outReg);
break;
case Type_Double:
outReg = regs.takeAny();
masm.reserveStack(sizeof(double));
masm.movq(esp, outReg);
break;
case Type_Pointer:
outReg = regs.takeAny();
masm.reserveStack(sizeof(uintptr_t));
masm.movq(esp, outReg);
break;
default:
MOZ_ASSERT(f.outParam == Type_Void);
break;
}
masm.setupUnalignedABICall(f.argc(), regs.getAny());
masm.passABIArg(cxreg);
size_t argDisp = 0;
// Copy arguments.
for (uint32_t explicitArg = 0; explicitArg < f.explicitArgs; explicitArg++) {
MoveOperand from;
switch (f.argProperties(explicitArg)) {
case VMFunction::WordByValue:
if (f.argPassedInFloatReg(explicitArg))
masm.passABIArg(MoveOperand(argsBase, argDisp), MoveOp::DOUBLE);
else
masm.passABIArg(MoveOperand(argsBase, argDisp), MoveOp::GENERAL);
argDisp += sizeof(void*);
break;
case VMFunction::WordByRef:
masm.passABIArg(MoveOperand(argsBase, argDisp, MoveOperand::EFFECTIVE_ADDRESS),
MoveOp::GENERAL);
argDisp += sizeof(void*);
break;
case VMFunction::DoubleByValue:
case VMFunction::DoubleByRef:
MOZ_CRASH("NYI: x64 callVM should not be used with 128bits values.");
}
}
// Copy the implicit outparam, if any.
if (outReg != InvalidReg)
masm.passABIArg(outReg);
masm.callWithABI(f.wrapped);
// Test for failure.
switch (f.failType()) {
case Type_Object:
masm.branchTestPtr(Assembler::Zero, rax, rax, masm.failureLabel());
break;
case Type_Bool:
masm.testb(rax, rax);
masm.j(Assembler::Zero, masm.failureLabel());
break;
default:
MOZ_CRASH("unknown failure kind");
}
// Load the outparam and free any allocated stack.
switch (f.outParam) {
case Type_Handle:
masm.popRooted(f.outParamRootType, ReturnReg, JSReturnOperand);
break;
case Type_Value:
masm.loadValue(Address(esp, 0), JSReturnOperand);
masm.freeStack(sizeof(Value));
break;
case Type_Int32:
masm.load32(Address(esp, 0), ReturnReg);
masm.freeStack(sizeof(int32_t));
break;
case Type_Bool:
masm.load8ZeroExtend(Address(esp, 0), ReturnReg);
masm.freeStack(sizeof(int32_t));
break;
case Type_Double:
MOZ_ASSERT(cx->runtime()->jitSupportsFloatingPoint);
masm.loadDouble(Address(esp, 0), ReturnDoubleReg);
masm.freeStack(sizeof(double));
break;
case Type_Pointer:
masm.loadPtr(Address(esp, 0), ReturnReg);
masm.freeStack(sizeof(uintptr_t));
break;
default:
MOZ_ASSERT(f.outParam == Type_Void);
break;
}
masm.leaveExitFrame();
masm.retn(Imm32(sizeof(ExitFrameLayout) +
f.explicitStackSlots() * sizeof(void*) +
f.extraValuesToPop * sizeof(Value)));
Linker linker(masm);
JitCode* wrapper = linker.newCode<NoGC>(cx, OTHER_CODE);
if (!wrapper)
return nullptr;
#ifdef JS_ION_PERF
writePerfSpewerJitCodeProfile(wrapper, "VMWrapper");
#endif
// linker.newCode may trigger a GC and sweep functionWrappers_ so we have to
// use relookupOrAdd instead of add.
if (!functionWrappers_->relookupOrAdd(p, &f, wrapper))
return nullptr;
return wrapper;
}
JitCode*
JitRuntime::generatePreBarrier(JSContext* cx, MIRType type)
{
MacroAssembler masm;
RegisterSet regs = RegisterSet(GeneralRegisterSet(Registers::VolatileMask),
FloatRegisterSet(FloatRegisters::VolatileMask));
masm.PushRegsInMask(regs);
MOZ_ASSERT(PreBarrierReg == rdx);
masm.mov(ImmPtr(cx->runtime()), rcx);
masm.setupUnalignedABICall(2, rax);
masm.passABIArg(rcx);
masm.passABIArg(rdx);
masm.callWithABI(IonMarkFunction(type));
masm.PopRegsInMask(regs);
masm.ret();
Linker linker(masm);
JitCode* code = linker.newCode<NoGC>(cx, OTHER_CODE);
#ifdef JS_ION_PERF
writePerfSpewerJitCodeProfile(code, "PreBarrier");
#endif
return code;
}
typedef bool (*HandleDebugTrapFn)(JSContext*, BaselineFrame*, uint8_t*, bool*);
static const VMFunction HandleDebugTrapInfo = FunctionInfo<HandleDebugTrapFn>(HandleDebugTrap);
JitCode*
JitRuntime::generateDebugTrapHandler(JSContext* cx)
{
MacroAssembler masm;
Register scratch1 = rax;
Register scratch2 = rcx;
Register scratch3 = rdx;
// Load the return address in scratch1.
masm.loadPtr(Address(rsp, 0), scratch1);
// Load BaselineFrame pointer in scratch2.
masm.mov(rbp, scratch2);
masm.subPtr(Imm32(BaselineFrame::Size()), scratch2);
// Enter a stub frame and call the HandleDebugTrap VM function. Ensure
// the stub frame has a nullptr ICStub pointer, since this pointer is marked
// during GC.
masm.movePtr(ImmPtr(nullptr), BaselineStubReg);
EmitEnterStubFrame(masm, scratch3);
JitCode* code = cx->runtime()->jitRuntime()->getVMWrapper(HandleDebugTrapInfo);
if (!code)
return nullptr;
masm.push(scratch1);
masm.push(scratch2);
EmitCallVM(code, masm);
EmitLeaveStubFrame(masm);
// If the stub returns |true|, we have to perform a forced return
// (return from the JS frame). If the stub returns |false|, just return
// from the trap stub so that execution continues at the current pc.
Label forcedReturn;
masm.branchTest32(Assembler::NonZero, ReturnReg, ReturnReg, &forcedReturn);
masm.ret();
masm.bind(&forcedReturn);
masm.loadValue(Address(ebp, BaselineFrame::reverseOffsetOfReturnValue()),
JSReturnOperand);
masm.mov(rbp, rsp);
masm.pop(rbp);
// Before returning, if profiling is turned on, make sure that lastProfilingFrame
// is set to the correct caller frame.
{
Label skipProfilingInstrumentation;
AbsoluteAddress addressOfEnabled(cx->runtime()->spsProfiler.addressOfEnabled());
masm.branch32(Assembler::Equal, addressOfEnabled, Imm32(0), &skipProfilingInstrumentation);
masm.profilerExitFrame();
masm.bind(&skipProfilingInstrumentation);
}
masm.ret();
Linker linker(masm);
JitCode* codeDbg = linker.newCode<NoGC>(cx, OTHER_CODE);
#ifdef JS_ION_PERF
writePerfSpewerJitCodeProfile(codeDbg, "DebugTrapHandler");
#endif
return codeDbg;
}
JitCode*
JitRuntime::generateExceptionTailStub(JSContext* cx, void* handler)
{
MacroAssembler masm;
masm.handleFailureWithHandlerTail(handler);
Linker linker(masm);
JitCode* code = linker.newCode<NoGC>(cx, OTHER_CODE);
#ifdef JS_ION_PERF
writePerfSpewerJitCodeProfile(code, "ExceptionTailStub");
#endif
return code;
}
JitCode*
JitRuntime::generateBailoutTailStub(JSContext* cx)
{
MacroAssembler masm;
masm.generateBailoutTail(rdx, r9);
Linker linker(masm);
JitCode* code = linker.newCode<NoGC>(cx, OTHER_CODE);
#ifdef JS_ION_PERF
writePerfSpewerJitCodeProfile(code, "BailoutTailStub");
#endif
return code;
}
JitCode*
JitRuntime::generateProfilerExitFrameTailStub(JSContext* cx)
{
MacroAssembler masm;
Register scratch1 = r8;
Register scratch2 = r9;
Register scratch3 = r10;
Register scratch4 = r11;
//
// The code generated below expects that the current stack pointer points
// to an Ion or Baseline frame, at the state it would be immediately
// before a ret(). Thus, after this stub's business is done, it executes
// a ret() and returns directly to the caller script, on behalf of the
// callee script that jumped to this code.
//
// Thus the expected stack is:
//
// StackPointer ----+
// v
// ..., ActualArgc, CalleeToken, Descriptor, ReturnAddr
// MEM-HI MEM-LOW
//
//
// The generated jitcode is responsible for overwriting the
// jitActivation->lastProfilingFrame field with a pointer to the previous
// Ion or Baseline jit-frame that was pushed before this one. It is also
// responsible for overwriting jitActivation->lastProfilingCallSite with
// the return address into that frame. The frame could either be an
// immediate "caller" frame, or it could be a frame in a previous
// JitActivation (if the current frame was entered from C++, and the C++
// was entered by some caller jit-frame further down the stack).
//
// So this jitcode is responsible for "walking up" the jit stack, finding
// the previous Ion or Baseline JS frame, and storing its address and the
// return address into the appropriate fields on the current jitActivation.
//
// There are a fixed number of different path types that can lead to the
// current frame, which is either a baseline or ion frame:
//
// <Baseline-Or-Ion>
// ^
// |
// ^--- Ion
// |
// ^--- Baseline Stub <---- Baseline
// |
// ^--- Argument Rectifier
// | ^
// | |
// | ^--- Ion
// | |
// | ^--- Baseline Stub <---- Baseline
// |
// ^--- Entry Frame (From C++)
//
Register actReg = scratch4;
AbsoluteAddress activationAddr(GetJitContext()->runtime->addressOfProfilingActivation());
masm.loadPtr(activationAddr, actReg);
Address lastProfilingFrame(actReg, JitActivation::offsetOfLastProfilingFrame());
Address lastProfilingCallSite(actReg, JitActivation::offsetOfLastProfilingCallSite());
#ifdef DEBUG
// Ensure that frame we are exiting is current lastProfilingFrame
{
masm.loadPtr(lastProfilingFrame, scratch1);
Label checkOk;
masm.branchPtr(Assembler::Equal, scratch1, ImmWord(0), &checkOk);
masm.branchPtr(Assembler::Equal, StackPointer, scratch1, &checkOk);
masm.assumeUnreachable(
"Mismatch between stored lastProfilingFrame and current stack pointer.");
masm.bind(&checkOk);
}
#endif
// Load the frame descriptor into |scratch1|, figure out what to do depending on its type.
masm.loadPtr(Address(StackPointer, JitFrameLayout::offsetOfDescriptor()), scratch1);
// Going into the conditionals, we will have:
// FrameDescriptor.size in scratch1
// FrameDescriptor.type in scratch2
masm.movePtr(scratch1, scratch2);
masm.rshiftPtr(Imm32(FRAMESIZE_SHIFT), scratch1);
masm.and32(Imm32((1 << FRAMETYPE_BITS) - 1), scratch2);
// Handling of each case is dependent on FrameDescriptor.type
Label handle_IonJS;
Label handle_BaselineStub;
Label handle_Rectifier;