[Mlir-commits] [mlir] [mlir] Add `arith-int-range-narrowing` pass (PR #112404)

[Ivan Butygin]

================
@@ -214,6 +455,32 @@ struct IntRangeOptimizationsPass
       signalPassFailure();
   }
 };
+
+struct IntRangeNarrowingPass final
+    : arith::impl::ArithIntRangeNarrowingBase<IntRangeNarrowingPass> {
+  using ArithIntRangeNarrowingBase::ArithIntRangeNarrowingBase;
+
+  void runOnOperation() override {
+    Operation *op = getOperation();
+    MLIRContext *ctx = op->getContext();
+    DataFlowSolver solver;
+    solver.load<DeadCodeAnalysis>();
+    solver.load<IntegerRangeAnalysis>();
+    if (failed(solver.initializeAndRun(op)))
+      return signalPassFailure();
+
+    DataFlowListener listener(solver);
+
+    RewritePatternSet patterns(ctx);
+    populateIntRangeNarrowingPatterns(patterns, solver, bitwidthsSupported);
+
+    GreedyRewriteConfig config;
+    config.listener = &listener;
+
+    if (failed(applyPatternsAndFoldGreedily(op, std::move(patterns), config)))
+      signalPassFailure();
----------------
Hardcode84 wrote:

The problem is in code
```
func.func @test_add_cmpi() -> i1 {
  ...
  %4 = arith.addi %0, %1 : index
  %5 = arith.cmpi slt, %3, %4 : index
  return %5 : i1
}
```
`arith.cmpi` must be matched before `arith.addi`

The missing folders is not a big problem by itself (and I'm planning to run these patterns in greedy driver anyway in prod), but it makes test code matching more annoying as trunc/ext casts are not removed.

https://github.com/llvm/llvm-project/pull/112404