From 63cca4e2fd4dd70e54055c4d34d858f810e0bd44 Mon Sep 17 00:00:00 2001
From: Evgeniy Stepanov <eugeni.stepanov@gmail.com>
Date: Fri, 14 Dec 2012 13:43:11 +0000
Subject: [msan] Origin stores and loads do not need explicit alignment.

Origin address is always 4 byte aligned, and the access type is always i32.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@170199 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Transforms/Instrumentation/MemorySanitizer.cpp | 17 ++++++------
 test/Instrumentation/MemorySanitizer/msan_basic.ll | 30 ++++++++++++++++++++++
 2 files changed, 38 insertions(+), 9 deletions(-)

diff --git a/lib/Transforms/Instrumentation/MemorySanitizer.cpp b/lib/Transforms/Instrumentation/MemorySanitizer.cpp
index 0d9739d..db8e684 100644
--- a/lib/Transforms/Instrumentation/MemorySanitizer.cpp
+++ b/lib/Transforms/Instrumentation/MemorySanitizer.cpp
@@ -421,7 +421,7 @@ struct MemorySanitizerVisitor : public InstVisitor<MemorySanitizerVisitor> {
 
       if (ClTrackOrigins) {
         if (ClStoreCleanOrigin || isa<StructType>(Shadow->getType())) {
-          IRB.CreateAlignedStore(getOrigin(Val), getOriginPtr(Addr, IRB), I.getAlignment());
+          IRB.CreateStore(getOrigin(Val), getOriginPtr(Addr, IRB));
         } else {
           Value *ConvertedShadow = convertToShadowTyNoVec(Shadow, IRB);
 
@@ -435,10 +435,10 @@ struct MemorySanitizerVisitor : public InstVisitor<MemorySanitizerVisitor> {
           Value *Cmp = IRB.CreateICmpNE(ConvertedShadow,
               getCleanShadow(ConvertedShadow), "_mscmp");
           Instruction *CheckTerm =
-            SplitBlockAndInsertIfThen(cast<Instruction>(Cmp), false, MS.OriginStoreWeights);
-          IRBuilder<> IRBNewBlock(CheckTerm);
-          IRBNewBlock.CreateAlignedStore(getOrigin(Val),
-              getOriginPtr(Addr, IRBNewBlock), I.getAlignment());
+            SplitBlockAndInsertIfThen(cast<Instruction>(Cmp), false,
+                                      MS.OriginStoreWeights);
+          IRBuilder<> IRBNew(CheckTerm);
+          IRBNew.CreateStore(getOrigin(Val), getOriginPtr(Addr, IRBNew));
         }
       }
     }
@@ -787,7 +787,7 @@ struct MemorySanitizerVisitor : public InstVisitor<MemorySanitizerVisitor> {
       insertCheck(I.getPointerOperand(), &I);
 
     if (ClTrackOrigins)
-      setOrigin(&I, IRB.CreateAlignedLoad(getOriginPtr(Addr, IRB), I.getAlignment()));
+      setOrigin(&I, IRB.CreateLoad(getOriginPtr(Addr, IRB)));
   }
 
   /// \brief Instrument StoreInst
@@ -1296,9 +1296,8 @@ struct MemorySanitizerVisitor : public InstVisitor<MemorySanitizerVisitor> {
                                        kShadowTLSAlignment);
       }
       if (ClTrackOrigins)
-        IRB.CreateAlignedStore(getOrigin(A),
-                               getOriginPtrForArgument(A, IRB, ArgOffset),
-                               kShadowTLSAlignment);
+        IRB.CreateStore(getOrigin(A),
+                        getOriginPtrForArgument(A, IRB, ArgOffset));
       assert(Size != 0 && Store != 0);
       DEBUG(dbgs() << "  Param:" << *Store << "\n");
       ArgOffset += DataLayout::RoundUpAlignment(Size, 8);
diff --git a/test/Instrumentation/MemorySanitizer/msan_basic.ll b/test/Instrumentation/MemorySanitizer/msan_basic.ll
index 3228863..b6dcd16 100644
--- a/test/Instrumentation/MemorySanitizer/msan_basic.ll
+++ b/test/Instrumentation/MemorySanitizer/msan_basic.ll
@@ -8,7 +8,9 @@ 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
@@ -33,6 +35,34 @@ entry:
 ; CHECK-ORIGINS: ret void
 
 
+; Check instrumentation of aligned stores
+; Shadow store has the same alignment as the original store; origin store
+; does not specify explicit alignment.
+
+define void @AlignedStore(i32* nocapture %p, i32 %x) nounwind uwtable {
+entry:
+  store i32 %x, i32* %p, align 32
+  ret void
+}
+
+; CHECK: @AlignedStore
+; CHECK: load {{.*}} @__msan_param_tls
+; CHECK: store {{.*}} align 32
+; CHECK: store {{.*}} align 32
+; CHECK: ret void
+; CHECK-ORIGINS: @AlignedStore
+; CHECK-ORIGINS: load {{.*}} @__msan_param_tls
+; CHECK-ORIGINS: store {{.*}} align 32
+; CHECK-ORIGINS: icmp
+; CHECK-ORIGINS: br i1
+; CHECK-ORIGINS: <label>
+; CHECK-ORIGINS-NOT: store {{.*}} align
+; CHECK-ORIGINS: br label
+; CHECK-ORIGINS: <label>
+; CHECK-ORIGINS: store {{.*}} align 32
+; 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:
-- 
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