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x86/x64: Don't fuse loads across IR_NEWREF.

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Reported by Peter Cawley. #1117
This commit is contained in:
Mike Pall 2023-11-14 22:50:21 +01:00
parent d854d00ce9
commit 644723649e
1 changed files with 9 additions and 7 deletions
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16
src/lj_asm_x86.h
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@ -93,7 +93,7 @@ static int asm_isk32(ASMState *as, IRRef ref, int32_t *k)
/* Check if there's no conflicting instruction between curins and ref.
** Also avoid fusing loads if there are multiple references.
*/
static int noconflict(ASMState *as, IRRef ref, IROp conflict, int noload)
static int noconflict(ASMState *as, IRRef ref, IROp conflict, int check)
{
IRIns *ir = as->ir;
IRRef i = as->curins;
@ -102,7 +102,9 @@ static int noconflict(ASMState *as, IRRef ref, IROp conflict, int noload)
while (--i > ref) {
if (ir[i].o == conflict)
return 0; /* Conflict found. */
else if (!noload && (ir[i].op1 == ref || ir[i].op2 == ref))
else if ((check & 1) && ir[i].o == IR_NEWREF)
return 0;
else if ((check & 2) && (ir[i].op1 == ref || ir[i].op2 == ref))
return 0;
}
return 1; /* Ok, no conflict. */
@ -118,7 +120,7 @@ static IRRef asm_fuseabase(ASMState *as, IRRef ref)
lua_assert(irb->op2 == IRFL_TAB_ARRAY);
/* We can avoid the FLOAD of t->array for colocated arrays. */
if (ira->o == IR_TNEW && ira->op1 <= LJ_MAX_COLOSIZE &&
!neverfuse(as) && noconflict(as, irb->op1, IR_NEWREF, 1)) {
!neverfuse(as) && noconflict(as, irb->op1, IR_NEWREF, 0)) {
as->mrm.ofs = (int32_t)sizeof(GCtab); /* Ofs to colocated array. */
return irb->op1; /* Table obj. */
}
@ -337,7 +339,7 @@ static Reg asm_fuseload(ASMState *as, IRRef ref, RegSet allow)
RegSet xallow = (allow & RSET_GPR) ? allow : RSET_GPR;
if (ir->o == IR_SLOAD) {
if (!(ir->op2 & (IRSLOAD_PARENT|IRSLOAD_CONVERT)) &&
noconflict(as, ref, IR_RETF, 0)) {
noconflict(as, ref, IR_RETF, 2)) {
as->mrm.base = (uint8_t)ra_alloc1(as, REF_BASE, xallow);
as->mrm.ofs = 8*((int32_t)ir->op1-1) + ((ir->op2&IRSLOAD_FRAME)?4:0);
as->mrm.idx = RID_NONE;
@ -346,12 +348,12 @@ static Reg asm_fuseload(ASMState *as, IRRef ref, RegSet allow)
} else if (ir->o == IR_FLOAD) {
/* Generic fusion is only ok for 32 bit operand (but see asm_comp). */
if ((irt_isint(ir->t) || irt_isu32(ir->t) || irt_isaddr(ir->t)) &&
noconflict(as, ref, IR_FSTORE, 0)) {
noconflict(as, ref, IR_FSTORE, 2)) {
asm_fusefref(as, ir, xallow);
return RID_MRM;
}
} else if (ir->o == IR_ALOAD || ir->o == IR_HLOAD || ir->o == IR_ULOAD) {
if (noconflict(as, ref, ir->o + IRDELTA_L2S, 0)) {
if (noconflict(as, ref, ir->o + IRDELTA_L2S, 2+(ir->o != IR_ULOAD))) {
asm_fuseahuref(as, ir->op1, xallow);
return RID_MRM;
}
@ -360,7 +362,7 @@ static Reg asm_fuseload(ASMState *as, IRRef ref, RegSet allow)
** Fusing unaligned memory operands is ok on x86 (except for SIMD types).
*/
if ((!irt_typerange(ir->t, IRT_I8, IRT_U16)) &&
noconflict(as, ref, IR_XSTORE, 0)) {
noconflict(as, ref, IR_XSTORE, 2)) {
asm_fusexref(as, ir->op1, xallow);
return RID_MRM;
}