271deb17b0
Memory transfer instructions take two pointers. It is not defined to which of those a noalias annotation applies. To ensure correctness, do not add noalias annotations to memcpy/memmove instructions anymore. The caused a miscompile with test-suite's MultiSource/Applications/obsequi. Since r321138, the MemCpyOpt pass would remove memcpy/memmove calls if known to copy uninitialized memory. In that case, it was initialized by another memcpy, but the annotation for the target pointer said it would not alias. The annotation was actually meant for the source pointer, which was was an alloca and could not alias with the target pointer. llvm-svn: 321371
42 lines
929 B
LLVM
42 lines
929 B
LLVM
; RUN: opt %loadPolly -polly-codegen -S < %s | FileCheck %s
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;
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; Verify that @llvm.memcpy does not get a !alias.scope annotation.
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; @llvm.memcpy takes two pointers, it is ambiguous to which the
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; annotation applies.
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;
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; for (int j = 0; j < n; j += 1) {
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; memcpy(A, B, 8);
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; }
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;
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declare void @llvm.memcpy.p0i8.p0i8.i64(i8* nocapture writeonly, i8* nocapture readonly, i64, i32, i1)
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define void @func(i32 %n, i8* noalias nonnull %A, i8* noalias nonnull %B) {
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entry:
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br label %for
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for:
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%j = phi i32 [0, %entry], [%j.inc, %inc]
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%j.cmp = icmp slt i32 %j, %n
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br i1 %j.cmp, label %body, label %exit
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body:
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call void @llvm.memcpy.p0i8.p0i8.i64(i8* nonnull %A, i8* %B, i64 8, i32 4, i1 false)
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br label %inc
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inc:
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%j.inc = add nuw nsw i32 %j, 1
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br label %for
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exit:
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br label %return
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return:
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ret void
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}
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; CHECK-LABEL: polly.start:
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; CHECK: call void @llvm.memcpy
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; CHECK-NOT: !alias.scope
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