[Mlir-commits] [mlir] [mlir][spirv] Add folding for Bitwise[Or|And|Xor] (PR #74193)

[Jakub Kuderski]

================
@@ -356,6 +356,92 @@ OpFoldResult spirv::LogicalOrOp::fold(FoldAdaptor adaptor) {
   return Attribute();
 }
 
+//===----------------------------------------------------------------------===//
+// spirv.BitwiseAndOp
+//===----------------------------------------------------------------------===//
+
+OpFoldResult
+spirv::BitwiseAndOp::fold(spirv::BitwiseAndOp::FoldAdaptor adaptor) {
+  APInt rhsMask;
+  if (matchPattern(adaptor.getOperand2(), m_ConstantInt(&rhsMask))) {
+    // x & 0 -> 0
+    if (rhsMask.isZero())
+      return getOperand2();
+
+    // x & <all ones> -> x
+    if (rhsMask.isAllOnes())
+      return getOperand1();
+
+    // (UConvert x : iN to iK) & <mask with N low bits set> -> UConvert x
+    if (auto zext = getOperand1().getDefiningOp<spirv::UConvertOp>()) {
+      int valueBits =
+          getElementTypeOrSelf(zext.getOperand()).getIntOrFloatBitWidth();
+      if (rhsMask.zextOrTrunc(valueBits).isAllOnes())
+        return getOperand1();
+    }
+  }
+
+  // According to the SPIR-V spec:
+  //
+  // Type is a scalar or vector of integer type.
+  // Results are computed per component, and within each component, per bit.
+  // So we can use the APInt & method.
+  return constFoldBinaryOp<IntegerAttr>(
+      adaptor.getOperands(),
+      [](const APInt &a, const APInt &b) { return a & b; });
+}
+
+//===----------------------------------------------------------------------===//
+// spirv.BitwiseOrOp
+//===----------------------------------------------------------------------===//
+
+OpFoldResult spirv::BitwiseOrOp::fold(spirv::BitwiseOrOp::FoldAdaptor adaptor) {
+  APInt rhsMask;
+  if (matchPattern(adaptor.getOperand2(), m_ConstantInt(&rhsMask))) {
----------------
kuhar wrote:

Also here: `x | x => x`.

https://github.com/llvm/llvm-project/pull/74193