[Mlir-commits] [mlir] [mlir][spirv] Add folding for SNegate, [Logical]Not (PR #74992)

[Jakub Kuderski]

================
@@ -643,6 +643,45 @@ OpFoldResult spirv::UModOp::fold(FoldAdaptor adaptor) {
   return div0 ? Attribute() : res;
 }
 
+//===----------------------------------------------------------------------===//
+// spirv.SNegate
+//===----------------------------------------------------------------------===//
+
+OpFoldResult spirv::SNegateOp::fold(FoldAdaptor adaptor) {
+  // -(-x) = 0 - (0 - x) = x
+  auto op = getOperand();
+  if (auto negateOp = op.getDefiningOp<spirv::SNegateOp>())
+    return negateOp->getOperand(0);
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kuhar wrote:

I wasn't sure if this works for INT_MIN, it should check out like that:
- `- INT_MIN == INT_MIN`
- `- (- INT_MIN) == - INT_MIN = INT_MIN`

which looks fine

https://github.com/llvm/llvm-project/pull/74992