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[ConstraintElimination] Fix transfer info from SGT to unsigned system #627

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[ConstraintElimination] Fix transfer info from SGT to unsigned system #627

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c48d857
[ConstraintElimination] Add pre-commit test for Fix transfer info fro…
vladimirradosavljevic Jun 18, 2024
09624e9
[ConstraintElimination] Fix transfer info from SGT to unsigned system
vladimirradosavljevic Jun 18, 2024
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5 changes: 4 additions & 1 deletion llvm/lib/Transforms/Scalar/ConstraintElimination.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -746,7 +746,10 @@ void ConstraintInfo::transferToOtherSystem(
addFact(CmpInst::ICMP_ULT, A, B, NumIn, NumOut, DFSInStack);
break;
case CmpInst::ICMP_SGT: {
if (doesHold(CmpInst::ICMP_SGE, B, ConstantInt::get(B->getType(), -1)))
// EraVM local begin
if (doesHold(CmpInst::ICMP_SGE, B,
ConstantInt::get(B->getType(), -1, true)))
// EraVM local end
addFact(CmpInst::ICMP_UGE, A, ConstantInt::get(B->getType(), 0), NumIn,
NumOut, DFSInStack);
if (doesHold(CmpInst::ICMP_SGE, B, ConstantInt::get(B->getType(), 0)))
Expand Down
40 changes: 40 additions & 0 deletions llvm/test/Transforms/ConstraintElimination/transfer-sgt-to-unsigned-wrong-optimization.ll
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@@ -0,0 +1,40 @@
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 2
; RUN: opt -passes=constraint-elimination -S %s | FileCheck %s

declare void @llvm.assume(i1)

define i1 @dont_optimize(i256 %a, i256 %b) {
; CHECK-LABEL: define i1 @dont_optimize
; CHECK-SAME: (i256 [[A:%.*]], i256 [[B:%.*]]) {
; CHECK-NEXT: [[A_POS:%.*]] = icmp sge i256 [[B]], 18446744073709551615
; CHECK-NEXT: call void @llvm.assume(i1 [[A_POS]])
; CHECK-NEXT: [[C:%.*]] = icmp sgt i256 [[A]], [[B]]
; CHECK-NEXT: call void @llvm.assume(i1 [[C]])
; CHECK-NEXT: [[RES:%.*]] = icmp uge i256 [[A]], 0
; CHECK-NEXT: ret i1 [[RES]]
;
%a.pos = icmp sge i256 %b, 18446744073709551615
call void @llvm.assume(i1 %a.pos)
%c = icmp sgt i256 %a, %b
call void @llvm.assume(i1 %c)
%res = icmp uge i256 %a, 0
ret i1 %res
}

define i1 @optimize(i256 %a, i256 %b) {
; CHECK-LABEL: define i1 @optimize
; CHECK-SAME: (i256 [[A:%.*]], i256 [[B:%.*]]) {
; CHECK-NEXT: [[A_POS:%.*]] = icmp sge i256 [[B]], -1
; CHECK-NEXT: call void @llvm.assume(i1 [[A_POS]])
; CHECK-NEXT: [[C:%.*]] = icmp sgt i256 [[A]], [[B]]
; CHECK-NEXT: call void @llvm.assume(i1 [[C]])
; CHECK-NEXT: [[RES:%.*]] = icmp uge i256 [[A]], 0
; CHECK-NEXT: ret i1 true
;
%a.pos = icmp sge i256 %b, -1
call void @llvm.assume(i1 %a.pos)
%c = icmp sgt i256 %a, %b
call void @llvm.assume(i1 %c)
%res = icmp uge i256 %a, 0
ret i1 %res
}