[mlir] Enable decoupling two kinds of greedy behavior. (#104649)

The greedy rewriter is used in many different flows and it has a lot of
convenience (work list management, debugging actions, tracing, etc). But
it combines two kinds of greedy behavior 1) how ops are matched, 2)
folding wherever it can.

These are independent forms of greedy and leads to inefficiency. E.g.,
cases where one need to create different phases in lowering and is
required to applying patterns in specific order split across different
passes. Using the driver one ends up needlessly retrying folding/having
multiple rounds of folding attempts, where one final run would have
sufficed.

Of course folks can locally avoid this behavior by just building their
own, but this is also a common requested feature that folks keep on
working around locally in suboptimal ways.

For downstream users, there should be no behavioral change. Updating
from the deprecated should just be a find and replace (e.g., `find ./
-type f -exec sed -i
's|applyPatternsAndFoldGreedily|applyPatternsGreedily|g' {} \;` variety)
as the API arguments hasn't changed between the two.

Author: jpienaar

flang/lib/Optimizer/HLFIR/Transforms/InlineElementals.cpp

@@ -125,7 +125,7 @@ class InlineElementalsPass
     mlir::RewritePatternSet patterns(context);
     patterns.insert<InlineElementalConversion>(context);
 
-    if (mlir::failed(mlir::applyPatternsAndFoldGreedily(
+    if (mlir::failed(mlir::applyPatternsGreedily(
             getOperation(), std::move(patterns), config))) {
       mlir::emitError(getOperation()->getLoc(),
                       "failure in HLFIR elemental inlining");

flang/lib/Optimizer/HLFIR/Transforms/LowerHLFIRIntrinsics.cpp

@@ -520,8 +520,8 @@ class LowerHLFIRIntrinsics
     config.enableRegionSimplification =
         mlir::GreedySimplifyRegionLevel::Disabled;
 
-    if (mlir::failed(mlir::applyPatternsAndFoldGreedily(
-            module, std::move(patterns), config))) {
+    if (mlir::failed(
+            mlir::applyPatternsGreedily(module, std::move(patterns), config))) {
       mlir::emitError(mlir::UnknownLoc::get(context),
                       "failure in HLFIR intrinsic lowering");
       signalPassFailure();

flang/lib/Optimizer/HLFIR/Transforms/OptimizedBufferization.cpp

@@ -1372,7 +1372,7 @@ class OptimizedBufferizationPass
     // patterns.insert<ReductionMaskConversion<hlfir::MaxvalOp>>(context);
     // patterns.insert<ReductionMaskConversion<hlfir::MinvalOp>>(context);
 
-    if (mlir::failed(mlir::applyPatternsAndFoldGreedily(
+    if (mlir::failed(mlir::applyPatternsGreedily(
             getOperation(), std::move(patterns), config))) {
       mlir::emitError(getOperation()->getLoc(),
                       "failure in HLFIR optimized bufferization");

flang/lib/Optimizer/HLFIR/Transforms/SimplifyHLFIRIntrinsics.cpp

@@ -491,7 +491,7 @@ class SimplifyHLFIRIntrinsics
     patterns.insert<SumAsElementalConversion>(context);
     patterns.insert<CShiftAsElementalConversion>(context);
 
-    if (mlir::failed(mlir::applyPatternsAndFoldGreedily(
+    if (mlir::failed(mlir::applyPatternsGreedily(
             getOperation(), std::move(patterns), config))) {
       mlir::emitError(getOperation()->getLoc(),
                       "failure in HLFIR intrinsic simplification");

flang/lib/Optimizer/Transforms/AlgebraicSimplification.cpp

@@ -39,8 +39,7 @@ struct AlgebraicSimplification
 void AlgebraicSimplification::runOnOperation() {
   RewritePatternSet patterns(&getContext());
   populateMathAlgebraicSimplificationPatterns(patterns);
-  (void)applyPatternsAndFoldGreedily(getOperation(), std::move(patterns),
-                                     config);
+  (void)applyPatternsGreedily(getOperation(), std::move(patterns), config);
 }
 
 std::unique_ptr<mlir::Pass> fir::createAlgebraicSimplificationPass() {

flang/lib/Optimizer/Transforms/AssumedRankOpConversion.cpp

@@ -154,7 +154,7 @@ class AssumedRankOpConversion
     mlir::GreedyRewriteConfig config;
     config.enableRegionSimplification =
         mlir::GreedySimplifyRegionLevel::Disabled;
-    (void)applyPatternsAndFoldGreedily(mod, std::move(patterns), config);
+    (void)applyPatternsGreedily(mod, std::move(patterns), config);
   }
 };
 } // namespace

flang/lib/Optimizer/Transforms/ConstantArgumentGlobalisation.cpp

@@ -173,8 +173,8 @@ class ConstantArgumentGlobalisationOpt
     config.strictMode = mlir::GreedyRewriteStrictness::ExistingOps;
 
     patterns.insert<CallOpRewriter>(context, *di);
-    if (mlir::failed(mlir::applyPatternsAndFoldGreedily(
-            mod, std::move(patterns), config))) {
+    if (mlir::failed(
+            mlir::applyPatternsGreedily(mod, std::move(patterns), config))) {
       mlir::emitError(mod.getLoc(),
                       "error in constant globalisation optimization\n");
       signalPassFailure();

flang/lib/Optimizer/Transforms/StackArrays.cpp

@@ -793,8 +793,8 @@ void StackArraysPass::runOnOperation() {
   config.enableRegionSimplification = mlir::GreedySimplifyRegionLevel::Disabled;
 
   patterns.insert<AllocMemConversion>(&context, *candidateOps);
-  if (mlir::failed(mlir::applyOpPatternsAndFold(opsToConvert,
-                                                std::move(patterns), config))) {
+  if (mlir::failed(mlir::applyOpPatternsGreedily(
+          opsToConvert, std::move(patterns), config))) {
     mlir::emitError(func->getLoc(), "error in stack arrays optimization\n");
     signalPassFailure();
   }

mlir/docs/PatternRewriter.md

@@ -358,7 +358,7 @@ which point the driver finishes.
 
 This driver comes in two fashions:
 
-*   `applyPatternsAndFoldGreedily` ("region-based driver") applies patterns to
+*   `applyPatternsGreedily` ("region-based driver") applies patterns to
     all ops in a given region or a given container op (but not the container op
     itself). I.e., the worklist is initialized with all containing ops.
 *   `applyOpPatternsAndFold` ("op-based driver") applies patterns to the

mlir/examples/standalone/lib/Standalone/StandalonePasses.cpp

@@ -39,7 +39,7 @@ class StandaloneSwitchBarFoo
     RewritePatternSet patterns(&getContext());
     patterns.add<StandaloneSwitchBarFooRewriter>(&getContext());
     FrozenRewritePatternSet patternSet(std::move(patterns));
-    if (failed(applyPatternsAndFoldGreedily(getOperation(), patternSet)))
+    if (failed(applyPatternsGreedily(getOperation(), patternSet)))
       signalPassFailure();
   }
 };