[clang] [InstCombine] Add combines/simplifications for `llvm.ptrmask` (PR #67166)

[via cfe-commits]

================
@@ -6411,6 +6411,41 @@ static Value *simplifyBinaryIntrinsic(Function *F, Value *Op0, Value *Op1,
       return Constant::getNullValue(ReturnType);
     break;
   }
+  case Intrinsic::ptrmask: {
+    if (isa<PoisonValue>(Op0) || isa<PoisonValue>(Op1))
+      return PoisonValue::get(Op0->getType());
+
+    // NOTE: We can't apply this simplifications based on the value of Op1
+    // because we need to preserve provenance.
+    if (Q.isUndefValue(Op0) || match(Op0, m_Zero()))
+      return Constant::getNullValue(Op0->getType());
+
+    if (Op1->getType()->getScalarSizeInBits() ==
+        Q.DL.getPointerTypeSizeInBits(Op0->getType())) {
+      if (match(Op1, m_PtrToInt(m_Specific(Op0))))
+        return Op0;
+
+      // NOTE: We may have attributes associated with the return value of the
+      // llvm.ptrmask intrinsic that will be lost when we just return the
+      // operand. We should try to preserve them.
+      if (match(Op1, m_AllOnes()) || Q.isUndefValue(Op1))
+        return Op0;
+
+      Constant *C;
+      if (match(Op1, m_ImmConstant(C))) {
+        KnownBits PtrKnown =
+            computeKnownBits(Op0, Q.DL, /*Depth=*/0, Q.AC, Q.CxtI, Q.DT);
----------------
goldsteinn wrote:

Done

https://github.com/llvm/llvm-project/pull/67166