[msan] Handle x86 vector pack intrinsics.

llvm-svn: 210020

1 files changed, 36 insertions, 0 deletions

diff --git a/llvm/lib/Transforms/Instrumentation/MemorySanitizer.cpp b/llvm/lib/Transforms/Instrumentation/MemorySanitizer.cpp
index 2323a8c5755..b05138ac986 100644
--- a/llvm/lib/Transforms/Instrumentation/MemorySanitizer.cpp
+++ b/llvm/lib/Transforms/Instrumentation/MemorySanitizer.cpp
@@ -1944,6 +1944,28 @@ struct MemorySanitizerVisitor : public InstVisitor<MemorySanitizerVisitor> {
     setOriginForNaryOp(I);
   }
 
+  // \brief Instrument vector shift instrinsic.
+  //
+  // This function instruments intrinsics like x86_mmx_packsswb, that
+  // packs elements of 2 input vectors into half as much bits with saturation.
+  // Shadow is propagated with the same intrinsic applied to
+  // sext(Sa != zeroinitializer), sext(Sb != zeroinitializer).
+  void handleVectorPackIntrinsic(IntrinsicInst &I) {
+    assert(I.getNumArgOperands() == 2);
+    IRBuilder<> IRB(&I);
+    Value *S1 = getShadow(&I, 0);
+    Value *S2 = getShadow(&I, 1);
+    Type *T = S1->getType();
+    Value *S1_ext = IRB.CreateSExt(
+        IRB.CreateICmpNE(S1, llvm::Constant::getNullValue(T)), T);
+    Value *S2_ext = IRB.CreateSExt(
+        IRB.CreateICmpNE(S2, llvm::Constant::getNullValue(T)), T);
+    Value *S = IRB.CreateCall2(I.getCalledValue(), S1_ext, S2_ext,
+                               "_msprop_vector_pack");
+    setShadow(&I, S);
+    setOriginForNaryOp(I);
+  }
+
   void visitIntrinsicInst(IntrinsicInst &I) {
     switch (I.getIntrinsicID()) {
     case llvm::Intrinsic::bswap:
@@ -2060,6 +2082,20 @@ struct MemorySanitizerVisitor : public InstVisitor<MemorySanitizerVisitor> {
     // case llvm::Intrinsic::x86_sse2_psll_dq_bs:
     // case llvm::Intrinsic::x86_sse2_psrl_dq_bs:
 
+    case llvm::Intrinsic::x86_sse2_packsswb_128:
+    case llvm::Intrinsic::x86_sse2_packssdw_128:
+    case llvm::Intrinsic::x86_sse2_packuswb_128:
+    case llvm::Intrinsic::x86_sse41_packusdw:
+    case llvm::Intrinsic::x86_avx2_packsswb:
+    case llvm::Intrinsic::x86_avx2_packssdw:
+    case llvm::Intrinsic::x86_avx2_packuswb:
+    case llvm::Intrinsic::x86_avx2_packusdw:
+    case llvm::Intrinsic::x86_mmx_packsswb:
+    case llvm::Intrinsic::x86_mmx_packssdw:
+    case llvm::Intrinsic::x86_mmx_packuswb:
+      handleVectorPackIntrinsic(I);
+      break;
+
     default:
       if (!handleUnknownIntrinsic(I))
         visitInstruction(I);