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CelluleCellule
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On x86 for int64 compare, we need to compare the low bits using unsigned comparisons.
This removes the need for the hack to prevent cmp src swapping.
1 parent a7ebceb commit 6279ead

4 files changed

Lines changed: 33 additions & 20 deletions

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‎lib/Backend/IR.h‎

Lines changed: 1 addition & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -736,7 +736,6 @@ class BranchInstr : public Instr
736736
bool m_isAirlock : 1;
737737
bool m_isSwitchBr : 1;
738738
bool m_isOrphanedLeave : 1; // A Leave in a loop body in a try, most likely generated because of a return statement.
739-
bool m_areCmpRegisterFlagsUsedLater : 1; // Indicate that this branch is not the only instr using the register flags set by cmp
740739
#if DBG
741740
bool m_isMultiBranch;
742741
bool m_isHelperToNonHelperBranch;
@@ -748,7 +747,7 @@ class BranchInstr : public Instr
748747
static BranchInstr * New(Js::OpCode opcode, Opnd* destOpnd, LabelInstr * branchTarget, Opnd *srcOpnd, Func *func);
749748
static BranchInstr * New(Js::OpCode opcode, LabelInstr * branchTarget, Opnd *src1Opnd, Opnd *src2Opnd, Func *func);
750749

751-
BranchInstr(bool hasBailOutInfo = false) : Instr(hasBailOutInfo), m_branchTarget(nullptr), m_isAirlock(false), m_isSwitchBr(false), m_isOrphanedLeave(false), m_areCmpRegisterFlagsUsedLater(false)
750+
BranchInstr(bool hasBailOutInfo = false) : Instr(hasBailOutInfo), m_branchTarget(nullptr), m_isAirlock(false), m_isSwitchBr(false), m_isOrphanedLeave(false)
752751
{
753752
#if DBG
754753
m_isMultiBranch = false;

‎lib/Backend/LowerMDShared.cpp‎

Lines changed: 30 additions & 16 deletions
Original file line numberDiff line numberDiff line change
@@ -2856,22 +2856,6 @@ void LowererMD::GenerateFastCmXx(IR::Instr *instr)
28562856
done->InsertBefore(newInstr);
28572857
}
28582858

2859-
#ifndef _M_X64
2860-
if (isInt64Src)
2861-
{
2862-
IR::LabelInstr* skipLow = IR::LabelInstr::New(Js::OpCode::Label, m_func);
2863-
newInstr = IR::BranchInstr::New(Js::OpCode::JNE, skipLow, this->m_func);
2864-
newInstr->AsBranchInstr()->m_areCmpRegisterFlagsUsedLater = true;
2865-
done->InsertBefore(newInstr);
2866-
2867-
newInstr = IR::Instr::New(cmpOp, this->m_func);
2868-
newInstr->SetSrc1(src1Pair.low);
2869-
newInstr->SetSrc2(src2Pair.low);
2870-
done->InsertBefore(newInstr);
2871-
done->InsertBefore(skipLow);
2872-
}
2873-
#endif
2874-
28752859
if (!isIntDst)
28762860
{
28772861
opnd = this->m_lowerer->LoadLibraryValueOpnd(instr, LibraryValue::ValueFalse);
@@ -2950,6 +2934,36 @@ void LowererMD::GenerateFastCmXx(IR::Instr *instr)
29502934
}
29512935
done->InsertBefore(newInstr);
29522936

2937+
#ifndef _M_X64
2938+
if (isInt64Src)
2939+
{
2940+
IR::LabelInstr* skipLow = IR::LabelInstr::New(Js::OpCode::Label, m_func);
2941+
newInstr = IR::BranchInstr::New(Js::OpCode::JNE, skipLow, this->m_func);
2942+
done->InsertBefore(newInstr);
2943+
2944+
newInstr = IR::Instr::New(cmpOp, this->m_func);
2945+
newInstr->SetSrc1(src1Pair.low);
2946+
newInstr->SetSrc2(src2Pair.low);
2947+
done->InsertBefore(newInstr);
2948+
2949+
Js::OpCode lowUseCC = useCC;
2950+
// Need to do an unsigned compare for the lower part
2951+
switch (instr->m_opcode)
2952+
{
2953+
case Js::OpCode::CmGe_I4: lowUseCC = Js::OpCode::SETAE; break;
2954+
case Js::OpCode::CmGt_I4: lowUseCC = Js::OpCode::SETA; break;
2955+
case Js::OpCode::CmLe_I4: lowUseCC = Js::OpCode::SETBE; break;
2956+
case Js::OpCode::CmLt_I4: lowUseCC = Js::OpCode::SETB; break;
2957+
}
2958+
2959+
// tmp.i8 = SetCC tmp.i8
2960+
IR::Opnd *tmp_i8 = tmp->UseWithNewType(TyInt8, this->m_func);
2961+
newInstr = IR::Instr::New(lowUseCC, tmp_i8, tmp_i8, this->m_func);
2962+
done->InsertBefore(newInstr);
2963+
done->InsertBefore(skipLow);
2964+
}
2965+
#endif
2966+
29532967
if (tmp != dst)
29542968
{
29552969
newInstr = IR::Instr::New(Js::OpCode::MOV, dst, tmp, this->m_func);

‎lib/Backend/amd64/EncoderMD.cpp‎

Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -1885,7 +1885,7 @@ bool EncoderMD::TryFold(IR::Instr *instr, IR::RegOpnd *regOpnd)
18851885
{
18861886
IR::Instr *instrNext = instr->GetNextRealInstrOrLabel();
18871887

1888-
if (instrNext->IsBranchInstr() && instrNext->AsBranchInstr()->IsConditional() && !instrNext->AsBranchInstr()->m_areCmpRegisterFlagsUsedLater)
1888+
if (instrNext->IsBranchInstr() && instrNext->AsBranchInstr()->IsConditional())
18891889
{
18901890
// Swap src and reverse branch
18911891
src2 = instr->UnlinkSrc1();

‎lib/Backend/i386/EncoderMD.cpp‎

Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -1700,7 +1700,7 @@ bool EncoderMD::TryFold(IR::Instr *instr, IR::RegOpnd *regOpnd)
17001700
{
17011701
IR::Instr *instrNext = instr->GetNextRealInstrOrLabel();
17021702

1703-
if (instrNext->IsBranchInstr() && instrNext->AsBranchInstr()->IsConditional() && !instrNext->AsBranchInstr()->m_areCmpRegisterFlagsUsedLater)
1703+
if (instrNext->IsBranchInstr() && instrNext->AsBranchInstr()->IsConditional())
17041704
{
17051705
// Swap src and reverse branch
17061706
src2 = instr->UnlinkSrc1();

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