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| author | Kostya Serebryany <kcc@google.com> | 2012-04-10 18:18:56 +0000 |
|---|---|---|
| committer | Kostya Serebryany <kcc@google.com> | 2012-04-10 18:18:56 +0000 |
| commit | 2076af0184bd38185a719ea07cb10a90e8565a89 (patch) | |
| tree | 539c661f5cf55768452c59ba10992183d7f88fed /test/Instrumentation/ThreadSanitizer | |
| parent | 18112d83e7d54597bcd5870fb411c7997e02bc1e (diff) | |
[tsan] compile-time instrumentation: do not instrument a read if
a write to the same temp follows in the same BB.
Also add stats printing.
On Spec CPU2006 this optimization saves roughly 4% of instrumented reads
(which is 3% of all instrumented accesses):
Writes : 161216
Reads : 446458
Reads-before-write: 18295
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154418 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'test/Instrumentation/ThreadSanitizer')
| -rw-r--r-- | test/Instrumentation/ThreadSanitizer/read_before_write.ll | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/test/Instrumentation/ThreadSanitizer/read_before_write.ll b/test/Instrumentation/ThreadSanitizer/read_before_write.ll new file mode 100644 index 0000000000..482362aa7d --- /dev/null +++ b/test/Instrumentation/ThreadSanitizer/read_before_write.ll @@ -0,0 +1,32 @@ +; RUN: opt < %s -tsan -S | FileCheck %s + +target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128" + +define void @IncrementMe(i32* nocapture %ptr) nounwind uwtable { +entry: + %0 = load i32* %ptr, align 4 + %inc = add nsw i32 %0, 1 + store i32 %inc, i32* %ptr, align 4 + ret void +} +; CHECK: define void @IncrementMe +; CHECK-NOT: __tsan_read +; CHECK: __tsan_write +; CHECK: ret void + +define void @IncrementMeWithCallInBetween(i32* nocapture %ptr) nounwind uwtable { +entry: + %0 = load i32* %ptr, align 4 + %inc = add nsw i32 %0, 1 + call void @foo() + store i32 %inc, i32* %ptr, align 4 + ret void +} + +; CHECK: define void @IncrementMeWithCallInBetween +; CHECK: __tsan_read +; CHECK: __tsan_write +; CHECK: ret void + +declare void @foo() + |