Thread sanitizer instrumentation fails to skip all loads and stores to
profile counters. This can happen if profile counter updates are merged:
%.sink = phi i64* ...
%pgocount5 = load i64, i64* %.sink
%27 = add i64 %pgocount5, 1
%28 = bitcast i64* %.sink to i8*
call void @__tsan_write8(i8* %28)
store i64 %27, i64* %.sink
To suppress TSan diagnostics about racy counter updates, make the
counter updates atomic when TSan is enabled. If there's general interest
in this mode it can be surfaced as a clang/swift driver option.
Testing: check-{llvm,clang,profile}
rdar://40477803
Differential Revision: https://reviews.llvm.org/D50867
llvm-svn: 339955
15 lines
563 B
LLVM
15 lines
563 B
LLVM
; RUN: opt < %s -S -instrprof -instrprof-atomic-counter-update-all | FileCheck %s
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target triple = "x86_64-apple-macosx10.10.0"
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@__profn_foo = hidden constant [3 x i8] c"foo"
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; CHECK-LABEL: define void @foo
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; CHECK-NEXT: atomicrmw add i64* getelementptr inbounds ([1 x i64], [1 x i64]* @__profc_foo, i64 0, i64 0), i64 1 monotonic
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define void @foo() {
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call void @llvm.instrprof.increment(i8* getelementptr inbounds ([3 x i8], [3 x i8]* @__profn_foo, i32 0, i32 0), i64 0, i32 1, i32 0)
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ret void
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}
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declare void @llvm.instrprof.increment(i8*, i64, i32, i32)
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