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gflow.d
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gflow.d
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/**
* Compiler implementation of the
* $(LINK2 http://www.dlang.org, D programming language).
*
* Copyright: Copyright (C) 1985-1998 by Symantec
* Copyright (C) 2000-2019 by The D Language Foundation, All Rights Reserved
* Authors: $(LINK2 http://www.digitalmars.com, Walter Bright)
* License: $(LINK2 http://www.boost.org/LICENSE_1_0.txt, Boost License 1.0)
* Source: $(LINK2 https://github.com/dlang/dmd/blob/master/src/dmd/backend/gflow.d, backend/gflow.d)
* Coverage: https://codecov.io/gh/dlang/dmd/src/master/src/dmd/backend/gflow.d
*/
module dmd.backend.gflow;
version (SCPP)
version = COMPILE;
version (MARS)
version = COMPILE;
version (COMPILE)
{
import core.stdc.stdio;
import core.stdc.stdlib;
import core.stdc.string;
import dmd.backend.cc;
import dmd.backend.cdef;
import dmd.backend.code_x86;
import dmd.backend.oper;
import dmd.backend.global;
import dmd.backend.goh;
import dmd.backend.el;
import dmd.backend.outbuf;
import dmd.backend.ty;
import dmd.backend.type;
import dmd.backend.barray;
import dmd.backend.dlist;
import dmd.backend.dvec;
void vec_setclear(size_t b, vec_t vs, vec_t vc) { vec_setbit(b, vs); vec_clearbit(b, vc); }
bool Eunambig(elem* e) { return OTassign(e.Eoper) && e.EV.E1.Eoper == OPvar; }
char symbol_isintab(Symbol *s) { return sytab[s.Sclass] & SCSS; }
void util_free(void* p) { if (p) free(p); }
void *util_calloc(uint n, uint size) { void* p = calloc(n, size); assert(!(n * size) || p); return p; }
void *util_realloc(void* p, uint n, uint size) { void* q = realloc(p, n * size); assert(!(n * size) || q); return q; }
extern (C++):
/* Since many routines are nearly identical, we can combine them with */
/* this flag: */
enum
{
AE = 1,
CP,
VBE
}
private __gshared
{
int flowxx; // one of the above values
vec_t ambigsym = null;
}
/***************** REACHING DEFINITIONS *********************/
/************************************
* Compute reaching definitions (RDs).
* That is, for each block B and each program variable X
* find all elems that could be the last elem that defines
* X along some path to B.
* Binrd = the set of defs reaching the beginning of B.
* Boutrd = the set of defs reaching the end of B.
* Bkillrd = set of defs that are killed by some def in B.
* Bgenrd = set of defs in B that reach the end of B.
*/
void flowrd()
{
rdgenkill(); /* Compute Bgen and Bkill for RDs */
if (go.defnod.length == 0) /* if no definition elems */
return; /* no analysis to be done */
/* The transfer equation is: */
/* Bin = union of Bouts of all predecessors of B. */
/* Bout = (Bin - Bkill) | Bgen */
/* Using Ullman's algorithm: */
foreach (b; dfo[])
vec_copy(b.Boutrd, b.Bgen);
bool anychng;
vec_t tmp = vec_calloc(go.defnod.length);
do
{
anychng = false;
foreach (b; dfo[]) // for each block
{
/* Binrd = union of Boutrds of all predecessors of b */
vec_clear(b.Binrd);
if (b.BC != BCcatch /*&& b.BC != BCjcatch*/)
{
/* Set Binrd to 0 to account for:
* i = 0;
* try { i = 1; throw; } catch () { x = i; }
*/
foreach (bp; ListRange(b.Bpred))
vec_orass(b.Binrd,list_block(bp).Boutrd);
}
/* Bout = (Bin - Bkill) | Bgen */
vec_sub(tmp,b.Binrd,b.Bkill);
vec_orass(tmp,b.Bgen);
if (!anychng)
anychng = !vec_equal(tmp,b.Boutrd);
vec_copy(b.Boutrd,tmp);
}
} while (anychng); /* while any changes to Boutrd */
vec_free(tmp);
static if (0)
{
dbg_printf("Reaching definitions\n");
foreach (i, b; dfo[]) // for each block
{
assert(vec_numbits(b.Binrd) == go.defnod.length);
dbg_printf("B%d Bin ", cast(int)i); vec_println(b.Binrd);
dbg_printf(" Bgen "); vec_println(b.Bgen);
dbg_printf(" Bkill "); vec_println(b.Bkill);
dbg_printf(" Bout "); vec_println(b.Boutrd);
}
}
}
/***************************
* Compute Bgen and Bkill for RDs.
*/
private void rdgenkill()
{
/* Compute number of definition elems. */
uint num_unambig_def = 0;
uint deftop = 0;
foreach (b; dfo[]) // for each block
if (b.Belem)
{
deftop += numdefelems(b.Belem, &num_unambig_def);
}
/* Allocate array of pointers to all definition elems */
/* The elems are in dfo order. */
/* go.defnod[]s consist of a elem pointer and a pointer */
/* to the enclosing block. */
go.defnod.setLength(deftop);
if (deftop == 0)
return;
/* Allocate buffer for the DNunambig vectors
*/
const size_t dim = (deftop + (VECBITS - 1)) >> VECSHIFT;
const sz = (dim + 2) * num_unambig_def;
go.dnunambig.setLength(sz);
go.dnunambig[] = 0;
go.defnod.setLength(0);
foreach (b; dfo[]) // for each block
if (b.Belem)
asgdefelems(b, b.Belem); // fill in go.defnod[]
assert(go.defnod.length == deftop);
initDNunambigVectors();
foreach (b; dfo[]) // for each block
{
/* dump any existing vectors */
vec_free(b.Bgen);
vec_free(b.Bkill);
vec_free(b.Binrd);
vec_free(b.Boutrd);
/* calculate and create new vectors */
rdelem(&(b.Bgen),&(b.Bkill),b.Belem);
if (b.BC == BCasm)
{
vec_clear(b.Bkill); // KILL nothing
vec_set(b.Bgen); // GEN everything
}
b.Binrd = vec_calloc(deftop);
b.Boutrd = vec_calloc(deftop);
}
}
/**********************
* Compute and return # of definition elems in e.
*/
private uint numdefelems(elem *e, uint *pnum_unambig_def)
{
uint n = 0;
while (1)
{
assert(e);
if (OTdef(e.Eoper))
{
++n;
if (OTassign(e.Eoper) && e.EV.E1.Eoper == OPvar)
++*pnum_unambig_def;
}
if (OTbinary(e.Eoper))
{
n += numdefelems(e.EV.E1, pnum_unambig_def);
e = e.EV.E2;
}
else if (OTunary(e.Eoper))
{
e = e.EV.E1;
}
else
break;
}
return n;
}
/**************************
* Load go.defnod[] array.
* Loaded in order of execution of the elems. Not sure if this is
* necessary.
*/
private void asgdefelems(block *b,elem *n)
{
assert(b && n);
const uint op = n.Eoper;
if (ERTOL(n))
{
asgdefelems(b,n.EV.E2);
asgdefelems(b,n.EV.E1);
}
else if (OTbinary(op))
{
asgdefelems(b,n.EV.E1);
asgdefelems(b,n.EV.E2);
}
else if (OTunary(op))
asgdefelems(b,n.EV.E1);
if (OTdef(op))
{
n.Edef = cast(uint)go.defnod.length;
go.defnod.push(DefNode(n, b, null));
}
else
n.Edef = ~0; // just to ensure it is not in the array
}
/*************************************
* Allocate and initialize DNumambig vectors in go.defnod[]
*/
private void initDNunambigVectors()
{
//printf("initDNunambigVectors()\n");
const size_t numbits = go.defnod.length;
const size_t dim = (numbits + (VECBITS - 1)) >> VECSHIFT;
uint j = 0;
foreach (const i; 0 .. go.defnod.length)
{
elem *e = go.defnod[i].DNelem;
if (OTassign(e.Eoper) && e.EV.E1.Eoper == OPvar)
{
vec_t v = &go.dnunambig[j] + 2;
assert(vec_dim(v) == 0);
vec_dim(v) = dim;
vec_numbits(v) = numbits;
j += dim + 2;
fillInDNunambig(v, e);
go.defnod[i].DNunambig = v;
}
}
assert(j <= go.dnunambig.length);
}
/*************************************
* Allocate and compute rd GEN and KILL.
*/
private void rdelem(vec_t *pgen,vec_t *pkill, /* where to put result */
elem *n) /* tree to evaluate for GEN and KILL */
{
*pgen = vec_calloc(go.defnod.length);
*pkill = vec_calloc(go.defnod.length);
if (n)
accumrd(*pgen,*pkill,n);
}
/**************************************
* Accumulate GEN and KILL vectors for this elem.
*/
private void accumrd(vec_t GEN,vec_t KILL,elem *n)
{
assert(GEN && KILL && n);
const uint op = n.Eoper;
if (OTunary(op))
accumrd(GEN,KILL,n.EV.E1);
else if (OTbinary(op))
{
if (op == OPcolon || op == OPcolon2)
{
vec_t Gl,Kl,Gr,Kr;
rdelem(&Gl,&Kl,n.EV.E1);
rdelem(&Gr,&Kr,n.EV.E2);
switch (el_returns(n.EV.E1) * 2 | int(el_returns(n.EV.E2)))
{
case 3: // E1 and E2 return
/* GEN = (GEN - Kl) | Gl |
* (GEN - Kr) | Gr
* KILL |= Kl & Kr
* This simplifies to:
* GEN = GEN | (Gl | Gr) | (GEN - (Kl & Kr)
* KILL |= Kl & Kr
*/
vec_andass(Kl,Kr);
vec_orass(KILL,Kl);
vec_orass(Gl,Gr);
vec_sub(Gr,GEN,Kl); // (GEN - (Kl & Kr)
vec_or(GEN,Gl,Gr);
break;
case 2: // E1 returns
/* GEN = (GEN - Kl) | Gl
* KILL |= Kl
*/
vec_subass(GEN,Kl);
vec_orass(GEN,Gl);
vec_orass(KILL,Kl);
break;
case 1: // E2 returns
/* GEN = (GEN - Kr) | Gr
* KILL |= Kr
*/
vec_subass(GEN,Kr);
vec_orass(GEN,Gr);
vec_orass(KILL,Kr);
break;
case 0: // neither returns
break;
default:
assert(0);
}
vec_free(Gl);
vec_free(Kl);
vec_free(Gr);
vec_free(Kr);
}
else if (op == OPandand || op == OPoror)
{
vec_t Gr,Kr;
accumrd(GEN,KILL,n.EV.E1);
rdelem(&Gr,&Kr,n.EV.E2);
if (el_returns(n.EV.E2))
vec_orass(GEN,Gr); // GEN |= Gr
vec_free(Gr);
vec_free(Kr);
}
else if (OTrtol(op) && ERTOL(n))
{
accumrd(GEN,KILL,n.EV.E2);
accumrd(GEN,KILL,n.EV.E1);
}
else
{
accumrd(GEN,KILL,n.EV.E1);
accumrd(GEN,KILL,n.EV.E2);
}
}
if (OTdef(op)) /* if definition elem */
updaterd(n,GEN,KILL);
}
/******************** AVAILABLE EXPRESSIONS ***********************/
/************************************
* Compute available expressions (AEs).
* That is, expressions whose result is still current.
* Bin = the set of AEs reaching the beginning of B.
* Bout = the set of AEs reaching the end of B.
*/
void flowae()
{
flowxx = AE;
flowaecp();
}
/**************************** COPY PROPAGATION ************************/
/***************************************
* Compute copy propagation info (CPs).
* Very similar to AEs (the same code is used).
* Using RDs for copy propagation is WRONG!
* That is, set of copy statements still valid.
* Bin = the set of CPs reaching the beginning of B.
* Bout = the set of CPs reaching the end of B.
*/
void flowcp()
{
flowxx = CP;
flowaecp();
}
/*****************************************
* Common flow analysis routines for Available Expressions and
* Copy Propagation.
* Input:
* flowxx
*/
private void flowaecp()
{
aecpgenkill(); /* Compute Bgen and Bkill for AEs or CPs */
if (go.exptop <= 1) /* if no expressions */
return;
/* The transfer equation is: */
/* Bin = & Bout(all predecessors P of B) */
/* Bout = (Bin - Bkill) | Bgen */
/* Using Ullman's algorithm: */
vec_clear(startblock.Bin);
vec_copy(startblock.Bout,startblock.Bgen); /* these never change */
if (startblock.BC == BCiftrue)
vec_copy(startblock.Bout2,startblock.Bgen2); // these never change
/* For all blocks except startblock */
foreach (b; dfo[1 .. $])
{
vec_set(b.Bin); /* Bin = all expressions */
/* Bout = (Bin - Bkill) | Bgen */
vec_sub(b.Bout,b.Bin,b.Bkill);
vec_orass(b.Bout,b.Bgen);
if (b.BC == BCiftrue)
{
vec_sub(b.Bout2,b.Bin,b.Bkill2);
vec_orass(b.Bout2,b.Bgen2);
}
}
vec_t tmp = vec_calloc(go.exptop);
bool anychng;
do
{
anychng = false;
// For all blocks except startblock
foreach (b; dfo[1 .. $])
{
// Bin = & of Bout of all predecessors
// Bout = (Bin - Bkill) | Bgen
bool first = true;
foreach (bl; ListRange(b.Bpred))
{
block* bp = list_block(bl);
if (bp.BC == BCiftrue && bp.nthSucc(0) != b)
{
if (first)
vec_copy(b.Bin,bp.Bout2);
else
vec_andass(b.Bin,bp.Bout2);
}
else
{
if (first)
vec_copy(b.Bin,bp.Bout);
else
vec_andass(b.Bin,bp.Bout);
}
first = false;
}
assert(!first); // it must have had predecessors
if (anychng)
{
vec_sub(b.Bout,b.Bin,b.Bkill);
vec_orass(b.Bout,b.Bgen);
}
else
{
vec_sub(tmp,b.Bin,b.Bkill);
vec_orass(tmp,b.Bgen);
if (!vec_equal(tmp,b.Bout))
{ // Swap Bout and tmp instead of
// copying tmp over Bout
vec_t v = tmp;
tmp = b.Bout;
b.Bout = v;
anychng = true;
}
}
if (b.BC == BCiftrue)
{ // Bout2 = (Bin - Bkill2) | Bgen2
if (anychng)
{
vec_sub(b.Bout2,b.Bin,b.Bkill2);
vec_orass(b.Bout2,b.Bgen2);
}
else
{
vec_sub(tmp,b.Bin,b.Bkill2);
vec_orass(tmp,b.Bgen2);
if (!vec_equal(tmp,b.Bout2))
{ // Swap Bout and tmp instead of
// copying tmp over Bout2
vec_t v = tmp;
tmp = b.Bout2;
b.Bout2 = v;
anychng = true;
}
}
}
}
} while (anychng);
vec_free(tmp);
}
/******************************
* A variable to avoid parameter overhead to asgexpelems().
*/
private __gshared block *this_block;
/***********************************
* Compute Bgen and Bkill for AEs, CPs, and VBEs.
*/
private void aecpgenkill()
{
go.expnod.setLength(0); // dump any existing one
/* Compute number of expressions */
go.exptop = 1; /* start at 1 */
foreach (b; dfo[])
if (b.Belem)
{
if (flowxx == CP)
go.exptop += numcpelems(b.Belem);
else // AE || VBE
numaeelems(b.Belem);
}
if (go.exptop <= 1) /* if no expressions */
return;
/* Allocate array of pointers to all expression elems. */
/* (The elems are in order. Also, these expressions must not */
/* have any side effects, and possibly should not be machine */
/* dependent primitive addressing modes.) */
go.expnod.setLength(go.exptop);
go.expnod[0] = null;
go.expblk.setLength(flowxx == VBE ? go.exptop : 0);
const uint exptopsave = go.exptop;
go.exptop = 1;
foreach (b; dfo[])
{
this_block = b; /* so asgexpelems knows about this */
if (b.Belem)
asgexpelems(b.Belem);
}
assert(go.exptop == exptopsave);
defstarkill(); /* compute go.defkill and go.starkill */
static if (0)
{
assert(vec_numbits(go.defkill) == go.exptop);
assert(vec_numbits(go.starkill) == go.exptop);
assert(vec_numbits(go.vptrkill) == go.exptop);
dbg_printf("defkill "); vec_println(go.defkill);
if (go.starkill)
{ dbg_printf("starkill "); vec_println(go.starkill);}
if (go.vptrkill)
{ dbg_printf("vptrkill "); vec_println(go.vptrkill); }
}
foreach (i, b; dfo[])
{
/* dump any existing vectors */
vec_free(b.Bin);
vec_free(b.Bout);
vec_free(b.Bgen);
vec_free(b.Bkill);
b.Bgen = vec_calloc(go.exptop);
b.Bkill = vec_calloc(go.exptop);
switch (b.BC)
{
case BCiftrue:
vec_free(b.Bout2);
vec_free(b.Bgen2);
vec_free(b.Bkill2);
elem* e;
for (e = b.Belem; e.Eoper == OPcomma; e = e.EV.E2)
accumaecp(b.Bgen,b.Bkill,e);
if (e.Eoper == OPandand || e.Eoper == OPoror)
{
accumaecp(b.Bgen,b.Bkill,e.EV.E1);
vec_t Kr = vec_calloc(go.exptop);
vec_t Gr = vec_calloc(go.exptop);
accumaecp(Gr,Kr,e.EV.E2);
// We might or might not have executed E2
// KILL1 = KILL | Kr
// GEN1 = GEN & ((GEN - Kr) | Gr)
// We definitely executed E2
// KILL2 = (KILL - Gr) | Kr
// GEN2 = (GEN - Kr) | Gr
const uint dim = cast(uint)vec_dim(Kr);
vec_t KILL = b.Bkill;
vec_t GEN = b.Bgen;
foreach (j; 0 .. dim)
{
vec_base_t KILL1 = KILL[j] | Kr[j];
vec_base_t GEN1 = GEN[j] & ((GEN[j] & ~Kr[j]) | Gr[j]);
vec_base_t KILL2 = (KILL[j] & ~Gr[j]) | Kr[j];
vec_base_t GEN2 = (GEN[j] & ~Kr[j]) | Gr[j];
KILL[j] = KILL1;
GEN[j] = GEN1;
Kr[j] = KILL2;
Gr[j] = GEN2;
}
if (e.Eoper == OPandand)
{ b.Bkill = Kr;
b.Bgen = Gr;
b.Bkill2 = KILL;
b.Bgen2 = GEN;
}
else
{ b.Bkill = KILL;
b.Bgen = GEN;
b.Bkill2 = Kr;
b.Bgen2 = Gr;
}
}
else
{
accumaecp(b.Bgen,b.Bkill,e);
b.Bgen2 = vec_clone(b.Bgen);
b.Bkill2 = vec_clone(b.Bkill);
}
b.Bout2 = vec_calloc(go.exptop);
break;
case BCasm:
vec_set(b.Bkill); // KILL everything
vec_clear(b.Bgen); // GEN nothing
break;
default:
// calculate GEN & KILL vectors
if (b.Belem)
accumaecp(b.Bgen,b.Bkill,b.Belem);
break;
}
static if (0)
{
printf("block %d Bgen ",i); vec_println(b.Bgen);
printf(" Bkill "); vec_println(b.Bkill);
}
b.Bin = vec_calloc(go.exptop);
b.Bout = vec_calloc(go.exptop);
}
}
/*****************************
* Accumulate number of expressions in go.exptop.
* Set NFLaecp as a flag indicating an AE elem.
* Returns:
* true if this elem is a possible AE elem.
*/
private int numaeelems(elem *n)
{
uint ae;
assert(n);
const uint op = n.Eoper;
if (OTunary(op))
{
ae = numaeelems(n.EV.E1);
// Disallow starred references to avoid problems with VBE's
// being hoisted before tests of an invalid pointer.
if (flowxx == VBE && op == OPind)
goto L1;
}
else if (OTbinary(op))
ae = numaeelems(n.EV.E1) & numaeelems(n.EV.E2);
else
ae = true;
if (ae && OTae(op) && !(n.Ety & mTYvolatile) &&
// Disallow struct AEs, because we can't handle CSEs that are structs
tybasic(n.Ety) != TYstruct)
{
n.Nflags |= NFLaecp; /* remember for asgexpelems() */
go.exptop++;
}
else
L1:
n.Nflags &= ~NFLaecp;
return n.Nflags & NFLaecp;
}
/****************************
* Compute number of cp (copy propagation) elems.
* Mark cp elems by setting NFLaecp flag.
* Returns:
* number of cp elems
*/
private int numcpelems(elem *n)
{
while (1)
{
const op = n.Eoper;
if (OTunary(op))
{
n.Nflags &= ~NFLaecp;
n = n.EV.E1;
continue;
}
else if (OTbinary(op))
{
/* look for elem of the form OPvar=OPvar, where they aren't the */
/* same variable. */
if ((op == OPeq || op == OPstreq) &&
n.EV.E1.Eoper == OPvar &&
n.EV.E2.Eoper == OPvar &&
!((n.EV.E1.Ety | n.EV.E2.Ety) & mTYvolatile) &&
n.EV.E1.EV.Vsym != n.EV.E2.EV.Vsym)
{
n.Nflags |= NFLaecp;
return numcpelems(n.EV.E1) +
numcpelems(n.EV.E2) +
1;
}
n.Nflags &= ~NFLaecp;
int num = numcpelems(n.EV.E2);
if (num)
return num + numcpelems(n.EV.E1);
n = n.EV.E1;
continue;
}
else
{
n.Nflags &= ~NFLaecp;
return 0;
}
}
}
/********************************
* Assign ae (or cp) elems to go.expnod[] (in order of evaluation).
*/
private void asgexpelems(elem *n)
{
assert(n);
if (OTunary(n.Eoper))
asgexpelems(n.EV.E1);
else if (ERTOL(n))
{
asgexpelems(n.EV.E2);
asgexpelems(n.EV.E1);
}
else if (OTbinary(n.Eoper))
{
asgexpelems(n.EV.E1);
asgexpelems(n.EV.E2);
}
if (n.Nflags & NFLaecp) /* if an ae, cp or vbe elem */
{
n.Eexp = go.exptop; /* remember index into go.expnod[] */
go.expnod[go.exptop] = n;
if (go.expblk.length)
go.expblk[go.exptop] = this_block;
go.exptop++;
}
else
n.Eexp = 0;
}
/********************************
* Compute defkill, starkill and vptrkill vectors.
* starkill: set of expressions killed when a variable is
* changed that somebody could be pointing to.
* (not needed for cp)
* starkill is a subset of defkill.
* defkill: set of expressions killed by an ambiguous
* definition.
* vptrkill: set of expressions killed by an access to a vptr.
*/
private void defstarkill()
{
vec_free(go.vptrkill);
vec_free(go.defkill);
vec_free(go.starkill); /* dump any existing ones */
go.defkill = vec_calloc(go.exptop);
if (flowxx != CP)
{
go.starkill = vec_calloc(go.exptop); /* and create new ones */
go.vptrkill = vec_calloc(go.exptop); /* and create new ones */
}
else /* CP */
{
go.starkill = null;
go.vptrkill = null;
}
if (!go.exptop)
return;
if (flowxx == CP)
{
foreach (uint i; 1 .. go.exptop)
{
elem *n = go.expnod[i];
const uint op = n.Eoper;
assert(op == OPeq || op == OPstreq);
assert(n.EV.E1.Eoper==OPvar && n.EV.E2.Eoper==OPvar);
// Set bit in defkill if either the left or the
// right variable is killed by an ambiguous def.
Symbol *s1 = n.EV.E1.EV.Vsym;
if (!(s1.Sflags & SFLunambig) ||
!(n.EV.E2.EV.Vsym.Sflags & SFLunambig))
{
vec_setbit(i,go.defkill);
}
}
}
else
{
foreach (uint i; 1 .. go.exptop)
{
elem *n = go.expnod[i];
const uint op = n.Eoper;
switch (op)
{
case OPvar:
if (!(n.EV.Vsym.Sflags & SFLunambig))
vec_setbit(i,go.defkill);
break;
case OPind: // if a 'starred' ref
static if (1)
{
/* The following program fails for this:
import core.stdc.stdio;
class Foo
{
string foo = "abc";
size_t i = 0;
void bar()
{
printf("%c\n", foo[i]);
i++;
printf("%c\n", foo[i]);
}
}
void main()
{
auto f = new Foo();
f.bar();
}
*/
// For C/C++, casting to 'const' doesn't mean it
// actually is const,
// but immutable really doesn't change
if ((n.Ety & (mTYimmutable | mTYvolatile)) == mTYimmutable &&
n.EV.E1.Eoper == OPvar &&
n.EV.E1.EV.Vsym.Sflags & SFLunambig
)
break;
}
goto case OPstrlen;
case OPstrlen:
case OPstrcmp:
case OPmemcmp:
case OPbt: // OPbt is like OPind
vec_setbit(i,go.defkill);
vec_setbit(i,go.starkill);
break;
case OPvp_fp:
case OPcvp_fp:
vec_setbit(i,go.vptrkill);
goto Lunary;
default:
if (OTunary(op))
{
Lunary:
if (vec_testbit(n.EV.E1.Eexp,go.defkill))
vec_setbit(i,go.defkill);
if (vec_testbit(n.EV.E1.Eexp,go.starkill))
vec_setbit(i,go.starkill);
}
else if (OTbinary(op))
{
if (vec_testbit(n.EV.E1.Eexp,go.defkill) ||
vec_testbit(n.EV.E2.Eexp,go.defkill))
vec_setbit(i,go.defkill);
if (vec_testbit(n.EV.E1.Eexp,go.starkill) ||
vec_testbit(n.EV.E2.Eexp,go.starkill))
vec_setbit(i,go.starkill);
}
break;
}
}
}
}
/********************************
* Compute GEN and KILL vectors only for AEs.
* defkill and starkill are assumed to be already set up correctly.
* go.expnod[] is assumed to be set up correctly.
*/
void genkillae()
{
flowxx = AE;
assert(go.exptop > 1);
foreach (b; dfo[])
{
assert(b);
vec_clear(b.Bgen);
vec_clear(b.Bkill);
if (b.Belem)
accumaecp(b.Bgen,b.Bkill,b.Belem);
else if (b.BC == BCasm)
{
vec_set(b.Bkill); // KILL everything
vec_clear(b.Bgen); // GEN nothing
}
}
}
/************************************
* Allocate and compute KILL and GEN vectors for a elem.
*/
private void aecpelem(vec_t *pgen,vec_t *pkill, elem *n)
{
*pgen = vec_calloc(go.exptop);
*pkill = vec_calloc(go.exptop);
if (n)
{
if (flowxx == VBE)
accumvbe(*pgen,*pkill,n);
else
accumaecp(*pgen,*pkill,n);
}
}