forked from OSchip/llvm-project
291 lines
7.8 KiB
LLVM
291 lines
7.8 KiB
LLVM
; RUN: opt < %s -S -early-cse | FileCheck %s
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; RUN: opt < %s -S -passes=early-cse | FileCheck %s
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declare {}* @llvm.invariant.start.p0i8(i64, i8* nocapture) nounwind readonly
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declare void @llvm.invariant.end.p0i8({}*, i64, i8* nocapture) nounwind
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; Check that we do load-load forwarding over invariant.start, since it does not
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; clobber memory
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define i8 @test_bypass1(i8 *%P) {
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; CHECK-LABEL: @test_bypass1(
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; CHECK-NEXT: %V1 = load i8, i8* %P
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; CHECK-NEXT: %i = call {}* @llvm.invariant.start.p0i8(i64 1, i8* %P)
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; CHECK-NEXT: ret i8 0
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%V1 = load i8, i8* %P
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%i = call {}* @llvm.invariant.start.p0i8(i64 1, i8* %P)
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%V2 = load i8, i8* %P
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%Diff = sub i8 %V1, %V2
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ret i8 %Diff
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}
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; Trivial Store->load forwarding over invariant.start
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define i8 @test_bypass2(i8 *%P) {
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; CHECK-LABEL: @test_bypass2(
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; CHECK-NEXT: store i8 42, i8* %P
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; CHECK-NEXT: %i = call {}* @llvm.invariant.start.p0i8(i64 1, i8* %P)
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; CHECK-NEXT: ret i8 42
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store i8 42, i8* %P
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%i = call {}* @llvm.invariant.start.p0i8(i64 1, i8* %P)
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%V1 = load i8, i8* %P
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ret i8 %V1
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}
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; We can DSE over invariant.start calls, since the first store to
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; %P is valid, and the second store is actually unreachable based on semantics
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; of invariant.start.
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define void @test_bypass3(i8* %P) {
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; CHECK-LABEL: @test_bypass3(
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; CHECK-NEXT: %i = call {}* @llvm.invariant.start.p0i8(i64 1, i8* %P)
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; CHECK-NEXT: store i8 60, i8* %P
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store i8 50, i8* %P
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%i = call {}* @llvm.invariant.start.p0i8(i64 1, i8* %P)
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store i8 60, i8* %P
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ret void
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}
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; FIXME: Now the first store can actually be eliminated, since there is no read within
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; the invariant region, between start and end.
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define void @test_bypass4(i8* %P) {
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; CHECK-LABEL: @test_bypass4(
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; CHECK-NEXT: store i8 50, i8* %P
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; CHECK-NEXT: %i = call {}* @llvm.invariant.start.p0i8(i64 1, i8* %P)
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; CHECK-NEXT: call void @llvm.invariant.end.p0i8({}* %i, i64 1, i8* %P)
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; CHECK-NEXT: store i8 60, i8* %P
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store i8 50, i8* %P
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%i = call {}* @llvm.invariant.start.p0i8(i64 1, i8* %P)
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call void @llvm.invariant.end.p0i8({}* %i, i64 1, i8* %P)
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store i8 60, i8* %P
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ret void
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}
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declare void @clobber()
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declare {}* @llvm.invariant.start.p0i32(i64 %size, i32* nocapture %ptr)
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declare void @llvm.invariant.end.p0i32({}*, i64, i32* nocapture) nounwind
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define i32 @test_before_load(i32* %p) {
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; CHECK-LABEL: @test_before_load
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; CHECK: ret i32 0
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call {}* @llvm.invariant.start.p0i32(i64 4, i32* %p)
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%v1 = load i32, i32* %p
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call void @clobber()
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%v2 = load i32, i32* %p
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%sub = sub i32 %v1, %v2
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ret i32 %sub
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}
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define i32 @test_before_clobber(i32* %p) {
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; CHECK-LABEL: @test_before_clobber
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; CHECK: ret i32 0
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%v1 = load i32, i32* %p
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call {}* @llvm.invariant.start.p0i32(i64 4, i32* %p)
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call void @clobber()
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%v2 = load i32, i32* %p
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%sub = sub i32 %v1, %v2
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ret i32 %sub
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}
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define i32 @test_duplicate_scope(i32* %p) {
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; CHECK-LABEL: @test_duplicate_scope
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; CHECK: ret i32 0
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%v1 = load i32, i32* %p
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call {}* @llvm.invariant.start.p0i32(i64 4, i32* %p)
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call void @clobber()
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call {}* @llvm.invariant.start.p0i32(i64 4, i32* %p)
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%v2 = load i32, i32* %p
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%sub = sub i32 %v1, %v2
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ret i32 %sub
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}
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define i32 @test_unanalzyable_load(i32* %p) {
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; CHECK-LABEL: @test_unanalzyable_load
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; CHECK: ret i32 0
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call {}* @llvm.invariant.start.p0i32(i64 4, i32* %p)
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call void @clobber()
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%v1 = load i32, i32* %p
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call void @clobber()
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%v2 = load i32, i32* %p
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%sub = sub i32 %v1, %v2
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ret i32 %sub
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}
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define i32 @test_negative_after_clobber(i32* %p) {
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; CHECK-LABEL: @test_negative_after_clobber
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; CHECK: ret i32 %sub
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%v1 = load i32, i32* %p
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call void @clobber()
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call {}* @llvm.invariant.start.p0i32(i64 4, i32* %p)
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%v2 = load i32, i32* %p
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%sub = sub i32 %v1, %v2
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ret i32 %sub
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}
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define i32 @test_merge(i32* %p, i1 %cnd) {
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; CHECK-LABEL: @test_merge
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; CHECK: ret i32 0
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%v1 = load i32, i32* %p
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call {}* @llvm.invariant.start.p0i32(i64 4, i32* %p)
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br i1 %cnd, label %merge, label %taken
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taken:
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call void @clobber()
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br label %merge
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merge:
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%v2 = load i32, i32* %p
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%sub = sub i32 %v1, %v2
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ret i32 %sub
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}
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define i32 @test_negative_after_mergeclobber(i32* %p, i1 %cnd) {
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; CHECK-LABEL: @test_negative_after_mergeclobber
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; CHECK: ret i32 %sub
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%v1 = load i32, i32* %p
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br i1 %cnd, label %merge, label %taken
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taken:
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call void @clobber()
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br label %merge
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merge:
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call {}* @llvm.invariant.start.p0i32(i64 4, i32* %p)
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%v2 = load i32, i32* %p
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%sub = sub i32 %v1, %v2
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ret i32 %sub
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}
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; In theory, this version could work, but earlycse is incapable of
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; merging facts along distinct paths.
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define i32 @test_false_negative_merge(i32* %p, i1 %cnd) {
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; CHECK-LABEL: @test_false_negative_merge
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; CHECK: ret i32 %sub
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%v1 = load i32, i32* %p
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br i1 %cnd, label %merge, label %taken
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taken:
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call {}* @llvm.invariant.start.p0i32(i64 4, i32* %p)
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call void @clobber()
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br label %merge
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merge:
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%v2 = load i32, i32* %p
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%sub = sub i32 %v1, %v2
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ret i32 %sub
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}
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define i32 @test_merge_unanalyzable_load(i32* %p, i1 %cnd) {
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; CHECK-LABEL: @test_merge_unanalyzable_load
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; CHECK: ret i32 0
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call {}* @llvm.invariant.start.p0i32(i64 4, i32* %p)
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call void @clobber()
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%v1 = load i32, i32* %p
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br i1 %cnd, label %merge, label %taken
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taken:
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call void @clobber()
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br label %merge
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merge:
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%v2 = load i32, i32* %p
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%sub = sub i32 %v1, %v2
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ret i32 %sub
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}
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define void @test_dse_before_load(i32* %p, i1 %cnd) {
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; CHECK-LABEL: @test_dse_before_load
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; CHECK-NOT: store
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call {}* @llvm.invariant.start.p0i32(i64 4, i32* %p)
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%v1 = load i32, i32* %p
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call void @clobber()
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store i32 %v1, i32* %p
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ret void
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}
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define void @test_dse_after_load(i32* %p, i1 %cnd) {
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; CHECK-LABEL: @test_dse_after_load
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; CHECK-NOT: store
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%v1 = load i32, i32* %p
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call {}* @llvm.invariant.start.p0i32(i64 4, i32* %p)
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call void @clobber()
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store i32 %v1, i32* %p
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ret void
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}
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; In this case, we have a false negative since MemoryLocation is implicitly
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; typed due to the user of a Value to represent the address. Note that other
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; passes will canonicalize away the bitcasts in this example.
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define i32 @test_false_negative_types(i32* %p) {
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; CHECK-LABEL: @test_false_negative_types
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; CHECK: ret i32 %sub
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call {}* @llvm.invariant.start.p0i32(i64 4, i32* %p)
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%v1 = load i32, i32* %p
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call void @clobber()
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%pf = bitcast i32* %p to float*
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%v2f = load float, float* %pf
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%v2 = bitcast float %v2f to i32
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%sub = sub i32 %v1, %v2
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ret i32 %sub
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}
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define i32 @test_negative_size1(i32* %p) {
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; CHECK-LABEL: @test_negative_size1
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; CHECK: ret i32 %sub
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call {}* @llvm.invariant.start.p0i32(i64 3, i32* %p)
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%v1 = load i32, i32* %p
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call void @clobber()
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%v2 = load i32, i32* %p
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%sub = sub i32 %v1, %v2
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ret i32 %sub
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}
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define i32 @test_negative_size2(i32* %p) {
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; CHECK-LABEL: @test_negative_size2
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; CHECK: ret i32 %sub
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call {}* @llvm.invariant.start.p0i32(i64 0, i32* %p)
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%v1 = load i32, i32* %p
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call void @clobber()
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%v2 = load i32, i32* %p
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%sub = sub i32 %v1, %v2
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ret i32 %sub
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}
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define i32 @test_negative_scope(i32* %p) {
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; CHECK-LABEL: @test_negative_scope
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; CHECK: ret i32 %sub
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%scope = call {}* @llvm.invariant.start.p0i32(i64 4, i32* %p)
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call void @llvm.invariant.end.p0i32({}* %scope, i64 4, i32* %p)
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%v1 = load i32, i32* %p
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call void @clobber()
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%v2 = load i32, i32* %p
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%sub = sub i32 %v1, %v2
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ret i32 %sub
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}
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define i32 @test_false_negative_scope(i32* %p) {
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; CHECK-LABEL: @test_false_negative_scope
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; CHECK: ret i32 %sub
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%scope = call {}* @llvm.invariant.start.p0i32(i64 4, i32* %p)
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%v1 = load i32, i32* %p
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call void @clobber()
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%v2 = load i32, i32* %p
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call void @llvm.invariant.end.p0i32({}* %scope, i64 4, i32* %p)
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%sub = sub i32 %v1, %v2
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ret i32 %sub
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}
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; Invariant load defact starts an invariant.start scope of the appropriate size
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define i32 @test_invariant_load_scope(i32* %p) {
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; CHECK-LABEL: @test_invariant_load_scope
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; CHECK: ret i32 0
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%v1 = load i32, i32* %p, !invariant.load !{}
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call void @clobber()
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%v2 = load i32, i32* %p
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%sub = sub i32 %v1, %v2
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ret i32 %sub
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}
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