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[SimplifyCFG] Fix value enumeration of a full range #166379

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Merged
merged 1 commit into from
Nov 4, 2025
+40 −1
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[SimplifyCFG] Fix value enumeration of a full range #166379

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4 changes: 3 additions & 1 deletion llvm/lib/Transforms/Utils/SimplifyCFG.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -778,8 +778,10 @@ struct ConstantComparesGatherer {
return false;

// Add all values from the range to the set
for (APInt Tmp = Span.getLower(); Tmp != Span.getUpper(); ++Tmp)
APInt Tmp = Span.getLower();
do
Vals.push_back(ConstantInt::get(I->getContext(), Tmp));
while (++Tmp != Span.getUpper());

UsedICmps++;
return true;
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37 changes: 37 additions & 0 deletions llvm/test/Transforms/SimplifyCFG/pr166369.ll
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Original file line number Diff line number Diff line change
@@ -0,0 +1,37 @@
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 6
; RUN: opt -S -passes=simplifycfg < %s | FileCheck %s

; Make sure we handle full-set ranges correctly.
define void @test_i1() {
; CHECK-LABEL: define void @test_i1() {
; CHECK-NEXT: [[BB:.*:]]
; CHECK-NEXT: ret void
;
bb:
%icmp = icmp ugt i1 false, true
br label %bb5

bb5:
%select = select i1 %icmp, i1 %icmp, i1 false
br i1 %select, label %bb5, label %bb6

bb6:
ret void
}

define void @test_i3() {
; CHECK-LABEL: define void @test_i3() {
; CHECK-NEXT: [[BB:.*:]]
; CHECK-NEXT: ret void
;
bb:
%icmp = icmp ugt i3 0, 7
br label %bb5

bb5:
%select = select i1 %icmp, i1 %icmp, i1 false
br i1 %select, label %bb5, label %bb6

bb6:
ret void
}