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authorVedant Kumar <vsk@apple.com>2018-08-16 22:24:47 +0000
committerVedant Kumar <vsk@apple.com>2018-08-16 22:24:47 +0000
commitee6c233ae045f36f5bb5c7a8d14cfc9d41c634d0 (patch)
treef743e5d472f7bd629ce33757b8b837644a976f07 /clang/lib/CodeGen/BackendUtil.cpp
parentada3f77e4420d30e7bf39e215763a66e1ebdbe97 (diff)
downloadbcm5719-llvm-ee6c233ae045f36f5bb5c7a8d14cfc9d41c634d0.tar.gz
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[InstrProf] Use atomic profile counter updates for TSan
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
Diffstat (limited to 'clang/lib/CodeGen/BackendUtil.cpp')
-rw-r--r--clang/lib/CodeGen/BackendUtil.cpp5
1 files changed, 5 insertions, 0 deletions
diff --git a/clang/lib/CodeGen/BackendUtil.cpp b/clang/lib/CodeGen/BackendUtil.cpp
index 415bd962622..826ac267c68 100644
--- a/clang/lib/CodeGen/BackendUtil.cpp
+++ b/clang/lib/CodeGen/BackendUtil.cpp
@@ -653,6 +653,11 @@ void EmitAssemblyHelper::CreatePasses(legacy::PassManager &MPM,
InstrProfOptions Options;
Options.NoRedZone = CodeGenOpts.DisableRedZone;
Options.InstrProfileOutput = CodeGenOpts.InstrProfileOutput;
+
+ // TODO: Surface the option to emit atomic profile counter increments at
+ // the driver level.
+ Options.Atomic = LangOpts.Sanitize.has(SanitizerKind::Thread);
+
MPM.add(createInstrProfilingLegacyPass(Options));
}
if (CodeGenOpts.hasProfileIRInstr()) {
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