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| author | Evgeniy Stepanov <eugeni.stepanov@gmail.com> | 2012-12-06 11:41:03 +0000 |
|---|---|---|
| committer | Evgeniy Stepanov <eugeni.stepanov@gmail.com> | 2012-12-06 11:41:03 +0000 |
| commit | 4031b194acd50f35b75658f66ee3bb1b4afcfd25 (patch) | |
| tree | bbcccc2a3fe47d96d3c8d974da061ca8c2f8acc2 /test/Instrumentation/MemorySanitizer | |
| parent | 6afe478e005bf9f112b32b7ec25879475adc1915 (diff) | |
| download | external_llvm-4031b194acd50f35b75658f66ee3bb1b4afcfd25.zip external_llvm-4031b194acd50f35b75658f66ee3bb1b4afcfd25.tar.gz external_llvm-4031b194acd50f35b75658f66ee3bb1b4afcfd25.tar.bz2 | |
[msan] Do not store origin for clean values.
Instead of unconditionally storing origin with every application store,
only do this when the shadow of the stored value is != 0.
This change also delays instrumentation of stores until after the walk over
function's instructions, because adding new basic blocks confuses InstVisitor.
We only keep 1 origin value per 4 bytes of application memory. This change
fixes the bug when a store of a single clean byte wiped the origin for the
whole 4-byte area.
Since stores of uninitialized values are relatively uncommon, this change
improves performance of track-origins mode by 5% median and by up to 47% on
specs.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169490 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'test/Instrumentation/MemorySanitizer')
| -rw-r--r-- | test/Instrumentation/MemorySanitizer/msan_basic.ll | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/test/Instrumentation/MemorySanitizer/msan_basic.ll b/test/Instrumentation/MemorySanitizer/msan_basic.ll index a62b600..3228863 100644 --- a/test/Instrumentation/MemorySanitizer/msan_basic.ll +++ b/test/Instrumentation/MemorySanitizer/msan_basic.ll @@ -1,4 +1,5 @@ ; RUN: opt < %s -msan -S | FileCheck %s +; RUN: opt < %s -msan -msan-track-origins=1 -S | FileCheck -check-prefix=CHECK-ORIGINS %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" ; Check the presence of __msan_init @@ -7,6 +8,31 @@ target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f3 ; Check the presence and the linkage type of __msan_track_origins ; CHECK: @__msan_track_origins = weak_odr constant i32 0 +; Check instrumentation of stores +define void @Store(i32* nocapture %p, i32 %x) nounwind uwtable { +entry: + store i32 %x, i32* %p, align 4 + ret void +} + +; CHECK: @Store +; CHECK: load {{.*}} @__msan_param_tls +; CHECK: store +; CHECK: store +; CHECK: ret void +; CHECK-ORIGINS: @Store +; CHECK-ORIGINS: load {{.*}} @__msan_param_tls +; CHECK-ORIGINS: store +; CHECK-ORIGINS: icmp +; CHECK-ORIGINS: br i1 +; CHECK-ORIGINS: <label> +; CHECK-ORIGINS: store +; CHECK-ORIGINS: br label +; CHECK-ORIGINS: <label> +; CHECK-ORIGINS: store +; CHECK-ORIGINS: ret void + + ; load followed by cmp: check that we load the shadow and call __msan_warning. define void @LoadAndCmp(i32* nocapture %a) nounwind uwtable { entry: |