50 lines
1.7 KiB
LLVM
50 lines
1.7 KiB
LLVM
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; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
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; RUN: opt < %s -instcombine -S | FileCheck %s
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target datalayout = "p:32:32"
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%S = type { [2 x i32] }
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define i1 @test([0 x %S]* %p, i32 %n) {
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; CHECK-LABEL: @test(
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; CHECK-NEXT: [[CMP:%.*]] = icmp eq i32 [[N:%.*]], 1
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; CHECK-NEXT: ret i1 [[CMP]]
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;
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%start.cast = bitcast [0 x %S]* %p to %S*
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%end = getelementptr inbounds [0 x %S], [0 x %S]* %p, i32 0, i32 %n, i32 0, i32 0
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%end.cast = bitcast i32* %end to %S*
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%last = getelementptr inbounds %S, %S* %end.cast, i32 -1
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%cmp = icmp eq %S* %last, %start.cast
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ret i1 %cmp
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}
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; Same test using 64-bit indices.
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define i1 @test64([0 x %S]* %p, i64 %n) {
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; CHECK-LABEL: @test64(
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; CHECK-NEXT: [[TMP1:%.*]] = trunc i64 [[N:%.*]] to i32
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; CHECK-NEXT: [[CMP:%.*]] = icmp eq i32 [[TMP1]], 1
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; CHECK-NEXT: ret i1 [[CMP]]
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;
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%start.cast = bitcast [0 x %S]* %p to %S*
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%end = getelementptr inbounds [0 x %S], [0 x %S]* %p, i64 0, i64 %n, i32 0, i64 0
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%end.cast = bitcast i32* %end to %S*
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%last = getelementptr inbounds %S, %S* %end.cast, i64 -1
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%cmp = icmp eq %S* %last, %start.cast
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ret i1 %cmp
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}
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; Here the offset overflows and is treated modulo 2^32. This is UB.
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define i1 @test64_overflow([0 x %S]* %p, i64 %n) {
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; CHECK-LABEL: @test64_overflow(
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; CHECK-NEXT: [[TMP1:%.*]] = trunc i64 [[N:%.*]] to i32
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; CHECK-NEXT: [[CMP:%.*]] = icmp eq i32 [[TMP1]], 1
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; CHECK-NEXT: ret i1 [[CMP]]
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;
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%start.cast = bitcast [0 x %S]* %p to %S*
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%end = getelementptr inbounds [0 x %S], [0 x %S]* %p, i64 0, i64 %n, i32 0, i64 8589934592
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%end.cast = bitcast i32* %end to %S*
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%last = getelementptr inbounds %S, %S* %end.cast, i64 -1
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%cmp = icmp eq %S* %last, %start.cast
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ret i1 %cmp
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}
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