From 57dafd26307942fbacd64f4be7a9c73638a47ec1 Mon Sep 17 00:00:00 2001
From: Evgeniy Stepanov <eugeni.stepanov@gmail.com>
Date: Mon, 14 Oct 2013 09:52:09 +0000
Subject: [PATCH] [msan] Fix handling of scalar select of vectors.

llvm-svn: 192575
---
 .../Instrumentation/MemorySanitizer.cpp       |  8 ++++----
 .../MemorySanitizer/msan_basic.ll             | 19 +++++++++++++++++++
 2 files changed, 23 insertions(+), 4 deletions(-)

diff --git a/lib/Transforms/Instrumentation/MemorySanitizer.cpp b/lib/Transforms/Instrumentation/MemorySanitizer.cpp
index 65db206e570..f158ceee1e8 100644
--- a/lib/Transforms/Instrumentation/MemorySanitizer.cpp
+++ b/lib/Transforms/Instrumentation/MemorySanitizer.cpp
@@ -1233,15 +1233,15 @@ struct MemorySanitizerVisitor : public InstVisitor<MemorySanitizerVisitor> {
   Value *CreateShadowCast(IRBuilder<> &IRB, Value *V, Type *dstTy) {
     Type *srcTy = V->getType();
     if (dstTy->isIntegerTy() && srcTy->isIntegerTy())
-      return IRB.CreateIntCast(V, dstTy, false);
+      return IRB.CreateIntCast(V, dstTy, true);
     if (dstTy->isVectorTy() && srcTy->isVectorTy() &&
         dstTy->getVectorNumElements() == srcTy->getVectorNumElements())
-      return IRB.CreateIntCast(V, dstTy, false);
+      return IRB.CreateIntCast(V, dstTy, true);
     size_t srcSizeInBits = VectorOrPrimitiveTypeSizeInBits(srcTy);
     size_t dstSizeInBits = VectorOrPrimitiveTypeSizeInBits(dstTy);
     Value *V1 = IRB.CreateBitCast(V, Type::getIntNTy(*MS.C, srcSizeInBits));
     Value *V2 =
-      IRB.CreateIntCast(V1, Type::getIntNTy(*MS.C, dstSizeInBits), false);
+      IRB.CreateIntCast(V1, Type::getIntNTy(*MS.C, dstSizeInBits), true);
     return IRB.CreateBitCast(V2, dstTy);
     // TODO: handle struct types.
   }
@@ -1899,7 +1899,7 @@ struct MemorySanitizerVisitor : public InstVisitor<MemorySanitizerVisitor> {
     } else {
       // Sa = (sext Sb) | (select b, Sc, Sd)
       S = IRB.CreateOr(
-          S, IRB.CreateSExt(getShadow(I.getCondition()), S->getType()),
+          S, CreateShadowCast(IRB, getShadow(I.getCondition()), S->getType()),
           "_msprop_select");
     }
     setShadow(&I, S);
diff --git a/test/Instrumentation/MemorySanitizer/msan_basic.ll b/test/Instrumentation/MemorySanitizer/msan_basic.ll
index 02c03ef8976..ad9c5d7df3d 100644
--- a/test/Instrumentation/MemorySanitizer/msan_basic.ll
+++ b/test/Instrumentation/MemorySanitizer/msan_basic.ll
@@ -290,6 +290,25 @@ entry:
 ; CHECK-ORIGINS: ret <8 x i16>
 
 
+; Check that we propagate origin for "select" with scalar condition and vector
+; arguments. Select condition shadow is sign-extended to the vector type and
+; mixed into the result shadow.
+
+define <8 x i16> @SelectVector2(<8 x i16> %a, <8 x i16> %b, i1 %c) nounwind uwtable readnone sanitize_memory {
+entry:
+  %cond = select i1 %c, <8 x i16> %a, <8 x i16> %b
+  ret <8 x i16> %cond
+}
+
+; CHECK: @SelectVector2
+; CHECK: select i1
+; CHECK: sext i1 {{.*}} to i128
+; CHECK: bitcast i128 {{.*}} to <8 x i16>
+; CHECK: or <8 x i16>
+; CHECK: select i1
+; CHECK: ret <8 x i16>
+
+
 define { i64, i64 } @SelectStruct(i1 zeroext %x, { i64, i64 } %a, { i64, i64 } %b) readnone sanitize_memory {
 entry:
   %c = select i1 %x, { i64, i64 } %a, { i64, i64 } %b