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Differential D133469

[X86] Fold SUB(SBB(X,0,W), Y) -> SBB(X,Y,W)
AbandonedPublic

Authored by craig.topper on Sep 7 2022, 9:26 PM.

Details

Reviewers
RKSimon
spatel
Summary

Fixes PR57576.

Diff Detail

Unit TestsFailed

TimeTest
60,090 msx64 debian > MLIR.Examples/standalone::test.toy

Event Timeline

craig.topper created this revision.Sep 7 2022, 9:26 PM
Herald added a project: Restricted Project. · View Herald TranscriptSep 7 2022, 9:26 PM
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craig.topper requested review of this revision.Sep 7 2022, 9:26 PM
Herald added a project: Restricted Project. · View Herald TranscriptSep 7 2022, 9:26 PM
Harbormaster completed remote builds in B185557: Diff 458637.Sep 7 2022, 9:57 PM
craig.topper abandoned this revision.Sep 7 2022, 10:11 PM

Replaced by D133471

Revision Contents

PathSize
llvm/
lib/
Target/
X86/
8 lines
test/
CodeGen/
X86/
3 lines

Diff 458637

llvm/lib/Target/X86/X86ISelLowering.cpp

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// Fold SUB(X,ADC(Y,0,W)) -> SBB(X,Y,W) // Fold SUB(X,ADC(Y,0,W)) -> SBB(X,Y,W)
if (Op1.getOpcode() == X86ISD::ADC && Op1->hasOneUse() && if (Op1.getOpcode() == X86ISD::ADC && Op1->hasOneUse() &&
X86::isZeroNode(Op1.getOperand(1))) { X86::isZeroNode(Op1.getOperand(1))) {
assert(!Op1->hasAnyUseOfValue(1) && "Overflow bit in use"); assert(!Op1->hasAnyUseOfValue(1) && "Overflow bit in use");
return DAG.getNode(X86ISD::SBB, SDLoc(Op1), Op1->getVTList(), Op0, return DAG.getNode(X86ISD::SBB, SDLoc(Op1), Op1->getVTList(), Op0,
Op1.getOperand(0), Op1.getOperand(2)); Op1.getOperand(0), Op1.getOperand(2));
} }
// Fold SUB(SBB(X,0,W), Y) -> SBB(X,Y,W)
if (Op0.getOpcode() == X86ISD::SBB && Op0->hasOneUse() &&
X86::isZeroNode(Op0.getOperand(1))) {
assert(!Op0->hasAnyUseOfValue(1) && "Overflow bit in use");
return DAG.getNode(X86ISD::SBB, SDLoc(Op1), Op0->getVTList(),
Op0.getOperand(0), Op1, Op0.getOperand(2));
}
// Fold SUB(X,SBB(Y,Z,W)) -> SUB(ADC(X,Z,W),Y) // Fold SUB(X,SBB(Y,Z,W)) -> SUB(ADC(X,Z,W),Y)
// Don't fold to ADC(0,0,W)/SETCC_CARRY pattern which will prevent more folds. // Don't fold to ADC(0,0,W)/SETCC_CARRY pattern which will prevent more folds.
if (Op1.getOpcode() == X86ISD::SBB && Op1->hasOneUse() && if (Op1.getOpcode() == X86ISD::SBB && Op1->hasOneUse() &&
!(X86::isZeroNode(Op0) && X86::isZeroNode(Op1.getOperand(1)))) { !(X86::isZeroNode(Op0) && X86::isZeroNode(Op1.getOperand(1)))) {
assert(!Op1->hasAnyUseOfValue(1) && "Overflow bit in use"); assert(!Op1->hasAnyUseOfValue(1) && "Overflow bit in use");
SDValue ADC = DAG.getNode(X86ISD::ADC, SDLoc(Op1), Op1->getVTList(), Op0, SDValue ADC = DAG.getNode(X86ISD::ADC, SDLoc(Op1), Op1->getVTList(), Op0,
Op1.getOperand(1), Op1.getOperand(2)); Op1.getOperand(1), Op1.getOperand(2));
return DAG.getNode(ISD::SUB, SDLoc(N), Op0.getValueType(), ADC.getValue(0), return DAG.getNode(ISD::SUB, SDLoc(N), Op0.getValueType(), ADC.getValue(0),
▲ Show 20 Lines • Show All 2,699 Lines • Show Last 20 Lines

llvm/test/CodeGen/X86/pr57576.ll

; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py ; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
; RUN: llc < %s -mtriple=x86_64-unknown-linux-gnu | FileCheck %s ; RUN: llc < %s -mtriple=x86_64-unknown-linux-gnu | FileCheck %s
define { i64, i64 } @sub(i64 noundef %0, i64 noundef %1, i64 noundef %2, i64 noundef %3) { define { i64, i64 } @sub(i64 noundef %0, i64 noundef %1, i64 noundef %2, i64 noundef %3) {
; CHECK-LABEL: sub: ; CHECK-LABEL: sub:
; CHECK: # %bb.0: ; CHECK: # %bb.0:
; CHECK-NEXT: movq %rdi, %rax ; CHECK-NEXT: movq %rdi, %rax
; CHECK-NEXT: subq %rdx, %rax ; CHECK-NEXT: subq %rdx, %rax
; CHECK-NEXT: sbbq $0, %rsi ; CHECK-NEXT: sbbq %rcx, %rsi
; CHECK-NEXT: subq %rcx, %rsi
; CHECK-NEXT: movq %rsi, %rdx ; CHECK-NEXT: movq %rsi, %rdx
; CHECK-NEXT: retq ; CHECK-NEXT: retq
%5 = zext i64 %1 to i128 %5 = zext i64 %1 to i128
%6 = shl nuw i128 %5, 64 %6 = shl nuw i128 %5, 64
%7 = zext i64 %0 to i128 %7 = zext i64 %0 to i128
%8 = zext i64 %3 to i128 %8 = zext i64 %3 to i128
%9 = mul i128 %8, -18446744073709551616 %9 = mul i128 %8, -18446744073709551616
%10 = zext i64 %2 to i128 %10 = zext i64 %2 to i128
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