[msan] Fix handling of select with vector condition.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171069 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Transforms/Instrumentation/MemorySanitizer.cpp

@@ -1566,9 +1566,18 @@ struct MemorySanitizerVisitor : public InstVisitor<MemorySanitizerVisitor> {
     setShadow(&I,  IRB.CreateSelect(I.getCondition(),
               getShadow(I.getTrueValue()), getShadow(I.getFalseValue()),
               "_msprop"));
-    if (MS.TrackOrigins)
+    if (MS.TrackOrigins) {
-      setOrigin(&I, IRB.CreateSelect(I.getCondition(),
+      // Origins are always i32, so any vector conditions must be flattened.
+      // FIXME: consider tracking vector origins for app vectors?
+      Value *Cond = I.getCondition();
+      if (Cond->getType()->isVectorTy()) {
+        Value *ConvertedShadow = convertToShadowTyNoVec(Cond, IRB);
+        Cond = IRB.CreateICmpNE(ConvertedShadow,
+                                getCleanShadow(ConvertedShadow), "_mso_select");
+      }
+      setOrigin(&I, IRB.CreateSelect(Cond,
                 getOrigin(I.getTrueValue()), getOrigin(I.getFalseValue())));
+    }
   }
 
   void visitLandingPadInst(LandingPadInst &I) {

test/Instrumentation/MemorySanitizer/msan_basic.ll

@@ -251,6 +251,23 @@ entry:
 ; CHECK: ret i32
 
 
+; Check that we propagate origin for "select" with vector condition.
+; Select condition is flattened to i1, which is then used to select one of the
+; argument origins.
+
+define <8 x i16> @SelectVector(<8 x i16> %a, <8 x i16> %b, <8 x i1> %c) nounwind uwtable readnone {
+entry:
+  %cond = select <8 x i1> %c, <8 x i16> %a, <8 x i16> %b
+  ret <8 x i16> %cond
+}
+
+; CHECK-ORIGINS: @SelectVector
+; CHECK-ORIGINS: bitcast <8 x i1> {{.*}} to i8
+; CHECK-ORIGINS: icmp ne i8
+; CHECK-ORIGINS: select i1
+; CHECK-ORIGINS: ret <8 x i16>
+
+
 define i8* @IntToPtr(i64 %x) nounwind uwtable readnone {
 entry:
   %0 = inttoptr i64 %x to i8*