[llvm] [msan] Handle AVX512 vector down convert (non-mem) intrinsics (PR #147606)

[Thurston Dang via llvm-commits]

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@@ -4592,6 +4592,91 @@ struct MemorySanitizerVisitor : public InstVisitor<MemorySanitizerVisitor> {
                                     ConstantInt::get(IRB.getInt32Ty(), 0));
   }
 
+  // Handle llvm.x86.avx512.mask.pmov{,s,us}.*.512
+  //
+  // e.g., call <16 x i8> @llvm.x86.avx512.mask.pmov.qb.512
+  //         (<8 x i64>, <16 x i8>, i8)
+  //          A           WriteThru  Mask
+  //
+  //       call <16 x i8> @llvm.x86.avx512.mask.pmovs.db.512
+  //         (<16 x i32>, <16 x i8>, i16)
+  //
+  // Dst[i]        = Mask[i] ? truncate_or_saturate(A[i]) : WriteThru[i]
+  // Dst_shadow[i] = Mask[i] ? truncate(A_shadow[i])      : WriteThru_shadow[i]
+  //
+  // If Dst has more elements than A, the excess elements are zeroed (and the
+  // corresponding shadow is initialized).
+  //
+  // Note: for PMOV (truncation), handleIntrinsicByApplyingToShadow is precise
+  //       and is much faster than this handler.
+  void handleAVX512VectorDownConvert(IntrinsicInst &I) {
+    IRBuilder<> IRB(&I);
+
+    assert(I.arg_size() == 3);
+    Value *A = I.getOperand(0);
+    Value *WriteThrough = I.getOperand(1);
+    Value *Mask = I.getOperand(2);
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thurstond wrote:

Done

https://github.com/llvm/llvm-project/pull/147606