[flang] Run algebraic simplification optimization pass.

Flang algebraic simplification pass will run algebraic simplification
rewrite patterns for Math/Complex/etc. dialects. It is enabled
under opt-for-speed optimization levels (i.e. for O1/O2/O3; Os/Oz will not
enable it).

With this change the FIR/MLIR optimization pipeline becomes affected
by the -O* optimization level switches. Until now these switches
only affected the middle-end and back-end.

Differential Revision: https://reviews.llvm.org/D130035

2 files changed, 6 insertions, 3 deletions

diff --git a/flang/tools/bbc/bbc.cpp b/flang/tools/bbc/bbc.cpp
index cb8c78427a79..56ca8f79afee 100644
--- a/flang/tools/bbc/bbc.cpp
+++ b/flang/tools/bbc/bbc.cpp
@@ -47,6 +47,7 @@
 #include "mlir/Pass/PassRegistry.h"
 #include "mlir/Transforms/GreedyPatternRewriteDriver.h"
 #include "mlir/Transforms/Passes.h"
+#include "llvm/Passes/OptimizationLevel.h"
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/ErrorOr.h"
 #include "llvm/Support/FileSystem.h"
@@ -255,8 +256,8 @@ static mlir::LogicalResult convertFortranSourceToMLIR(
     // run the default canned pipeline
     pm.addPass(std::make_unique<Fortran::lower::VerifierPass>());
 
-    // Add default optimizer pass pipeline.
-    fir::createDefaultFIROptimizerPassPipeline(pm);
+    // Add O2 optimizer pass pipeline.
+    fir::createDefaultFIROptimizerPassPipeline(pm, llvm::OptimizationLevel::O2);
   }
 
   if (mlir::succeeded(pm.run(mlirModule))) {
diff --git a/flang/tools/tco/tco.cpp b/flang/tools/tco/tco.cpp
index 0c9e2f528a3f..5fe0d8114742 100644
--- a/flang/tools/tco/tco.cpp
+++ b/flang/tools/tco/tco.cpp
@@ -24,6 +24,7 @@
 #include "mlir/Pass/Pass.h"
 #include "mlir/Pass/PassManager.h"
 #include "mlir/Transforms/Passes.h"
+#include "llvm/Passes/OptimizationLevel.h"
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/ErrorOr.h"
 #include "llvm/Support/FileSystem.h"
@@ -111,7 +112,8 @@ compileFIR(const mlir::PassPipelineCLParser &passPipeline) {
     if (mlir::failed(passPipeline.addToPipeline(pm, errorHandler)))
       return mlir::failure();
   } else {
-    fir::createMLIRToLLVMPassPipeline(pm);
+    // Run tco with O2 by default.
+    fir::createMLIRToLLVMPassPipeline(pm, llvm::OptimizationLevel::O2);
     fir::addLLVMDialectToLLVMPass(pm, out.os());
   }