232698dc17
Handle !noundef metadata in comhineMetadata. The behavior of violating !noundef metadata is undefined behavior. So if K dominates J, we can preserve it uncontionally, otherwise, we preserve it if both K and J have !noundef metadata been set. This patch also makes !noundef metadata added in KnownIDs when doing instruction combine for phi node or global value numbering for loads. Reviewed By: nikic Differential Revision: https://reviews.llvm.org/D142801
29 lines
826 B
LLVM
29 lines
826 B
LLVM
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
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; RUN: opt -passes=gvn -S %s | FileCheck %s
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;
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;Check that !noundef metadata is combined.
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define i32 @one_noundef(ptr %p) {
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; CHECK-LABEL: @one_noundef(
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; CHECK-NEXT: [[A:%.*]] = load i32, ptr [[P:%.*]], align 4, !noundef !0
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; CHECK-NEXT: [[C:%.*]] = add i32 [[A]], [[A]]
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; CHECK-NEXT: ret i32 [[C]]
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;
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%a = load i32, ptr %p, !noundef !0
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%b = load i32, ptr %p
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%c = add i32 %a, %b
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ret i32 %c
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}
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define i32 @both_noundef(ptr %p) {
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; CHECK-LABEL: @both_noundef(
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; CHECK-NEXT: [[A:%.*]] = load i32, ptr [[P:%.*]], align 4, !noundef !0
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; CHECK-NEXT: [[C:%.*]] = add i32 [[A]], [[A]]
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; CHECK-NEXT: ret i32 [[C]]
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;
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%a = load i32, ptr %p, !noundef !0
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%b = load i32, ptr %p, !noundef !0
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%c = add i32 %a, %b
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ret i32 %c
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}
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!0 = !{}
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