[llvm] [msan] Add handler for llvm.x86.avx512.mask.cvtps2dq.512 (PR #147377)

[Florian Mayer via llvm-commits]

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@@ -4342,6 +4342,61 @@ struct MemorySanitizerVisitor : public InstVisitor<MemorySanitizerVisitor> {
     setOriginForNaryOp(I);
   }
 
+  // e.g., call <16 x i32> @llvm.x86.avx512.mask.cvtps2dq.512
+  //                           (<16 x float> a, <16 x i32> writethru, i16 mask,
+  //                           i32 rounding)
+  //
+  // dst[i] = mask[i] ? convert(a[i]) : writethru[i]
+  // dst_shadow[i] = mask[i] ? all_or_nothing(a_shadow[i]) : writethru_shadow[i]
+  //    where all_or_nothing(x) is fully uninitialized if x has any
+  //    uninitialized bits
+  void handleAVX512VectorConvertFPToInt(IntrinsicInst &I) {
+    IRBuilder<> IRB(&I);
+
+    assert(I.arg_size() == 4);
+    Value *A = I.getOperand(0);
+    Value *WriteThrough = I.getOperand(1);
+    Value *Mask = I.getOperand(2);
+    [[maybe_unused]] Value *RoundingMode = I.getOperand(3);
+
+    assert(isa<FixedVectorType>(A->getType()));
+    assert(A->getType()->isFPOrFPVectorTy());
+
+    assert(isa<FixedVectorType>(WriteThrough->getType()));
+    assert(WriteThrough->getType()->isIntOrIntVectorTy());
+
+    unsigned ANumElements =
+        cast<FixedVectorType>(A->getType())->getNumElements();
+    assert(ANumElements ==
+           cast<FixedVectorType>(WriteThrough->getType())->getNumElements());
+
+    assert(Mask->getType()->isIntegerTy());
+    assert(Mask->getType()->getScalarSizeInBits() == ANumElements);
+
+    assert(RoundingMode->getType()->isIntegerTy());
+
+    assert(I.getType() == WriteThrough->getType());
+
+    // Convert i16 mask to <16 x i1>
+    Mask = IRB.CreateBitCast(
+        Mask, FixedVectorType::get(IRB.getInt1Ty(), ANumElements));
+
+    Value *AShadow = getShadow(A);
+    /// For scalars:
+    /// Since they are converting from floating-point, the output is:
+    /// - fully uninitialized if *any* bit of the input is uninitialized
+    /// - fully ininitialized if all bits of the input are ininitialized
+    /// We apply the same principle on a per-field basis for vectors.
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fmayer wrote:

per-element?

https://github.com/llvm/llvm-project/pull/147377