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
71 lines
2.1 KiB
LLVM
71 lines
2.1 KiB
LLVM
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
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; RUN: opt -passes=instcombine -S < %s | FileCheck %s
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declare void @bar()
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declare void @baz()
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; Check that !noundef metadata is combined
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define ptr @test_phi_combine_load_metadata(i1 %c, ptr dereferenceable(8) %p1, ptr dereferenceable(8) %p2) {
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; CHECK-LABEL: @test_phi_combine_load_metadata(
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; CHECK-NEXT: br i1 [[C:%.*]], label [[T:%.*]], label [[F:%.*]]
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; CHECK: t:
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; CHECK-NEXT: call void @bar()
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; CHECK-NEXT: br label [[CONT:%.*]]
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; CHECK: f:
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; CHECK-NEXT: call void @baz()
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; CHECK-NEXT: br label [[CONT]]
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; CHECK: cont:
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; CHECK-NEXT: [[RES_IN:%.*]] = phi ptr [ [[P1:%.*]], [[T]] ], [ [[P2:%.*]], [[F]] ]
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; CHECK-NEXT: [[RES:%.*]] = load ptr, ptr [[RES_IN]], align 8, !noundef !0
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; CHECK-NEXT: ret ptr [[RES]]
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;
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br i1 %c, label %t, label %f
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t:
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call void @bar()
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%v1 = load ptr, ptr %p1, align 8, !noundef !0
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br label %cont
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f:
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call void @baz()
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%v2 = load ptr, ptr %p2, align 8, !noundef !0
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br label %cont
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cont:
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%res = phi ptr [ %v1, %t ], [ %v2, %f ]
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ret ptr %res
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}
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; Check that !noundef metadata is not combined as a result of
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; there is a load don't have a noundef metadata.
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define ptr @test_phi_combine_load_metadata_negative(i1 %c, ptr dereferenceable(8) %p1, ptr dereferenceable(8) %p2) {
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; CHECK-LABEL: @test_phi_combine_load_metadata_negative(
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; CHECK-NEXT: br i1 [[C:%.*]], label [[T:%.*]], label [[F:%.*]]
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; CHECK: t:
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; CHECK-NEXT: call void @bar()
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; CHECK-NEXT: br label [[CONT:%.*]]
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; CHECK: f:
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; CHECK-NEXT: call void @baz()
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; CHECK-NEXT: br label [[CONT]]
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; CHECK: cont:
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; CHECK-NEXT: [[RES_IN:%.*]] = phi ptr [ [[P1:%.*]], [[T]] ], [ [[P2:%.*]], [[F]] ]
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; CHECK-NEXT: [[RES:%.*]] = load ptr, ptr [[RES_IN]], align 8
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; CHECK-NEXT: ret ptr [[RES]]
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;
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br i1 %c, label %t, label %f
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t:
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call void @bar()
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%v1 = load ptr, ptr %p1, align 8, !noundef !0
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br label %cont
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f:
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call void @baz()
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%v2 = load ptr, ptr %p2, align 8
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br label %cont
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cont:
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%res = phi ptr [ %v1, %t ], [ %v2, %f ]
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ret ptr %res
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}
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!0 = !{}
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