[flang-commits] [flang] [flang][tco] Add -emit-final-mlir flag (PR #146533)

[Kajetan Puchalski via flang-commits]

https://github.com/mrkajetanp created https://github.com/llvm/llvm-project/pull/146533

Add a flag to tco for emitting the final MLIR, prior to lowering to LLVM IR. This is intended to produce output that can be passed directly to mlir-translate.

>From 072a3cfd4fdfcb43f7cb292879b6daf5f8540de5 Mon Sep 17 00:00:00 2001
From: Kajetan Puchalski <kajetan.puchalski at arm.com>
Date: Tue, 1 Jul 2025 13:56:43 +0000
Subject: [PATCH] [flang][tco] Add -emit-final-mlir flag

Add a flag to tco for emitting the final MLIR, prior to lowering to LLVM
IR. This is intended to produce output that can be passed directly to
mlir-translate.

Signed-off-by: Kajetan Puchalski <kajetan.puchalski at arm.com>
---
 flang/tools/tco/tco.cpp | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/flang/tools/tco/tco.cpp b/flang/tools/tco/tco.cpp
index eaf4bae088454..806cd3148d09f 100644
--- a/flang/tools/tco/tco.cpp
+++ b/flang/tools/tco/tco.cpp
@@ -70,6 +70,11 @@ static cl::opt<bool> codeGenLLVM(
     cl::desc("Run only CodeGen passes and translate FIR to LLVM IR"),
     cl::init(false));
 
+static cl::opt<bool> emitFinalMLIR(
+    "emit-final-mlir",
+    cl::desc("Only translate FIR to MLIR, do not lower to LLVM IR"),
+    cl::init(false));
+
 #include "flang/Optimizer/Passes/CommandLineOpts.h"
 #include "flang/Optimizer/Passes/Pipelines.h"
 
@@ -149,13 +154,15 @@ compileFIR(const mlir::PassPipelineCLParser &passPipeline) {
       fir::registerDefaultInlinerPass(config);
       fir::createMLIRToLLVMPassPipeline(pm, config);
     }
-    fir::addLLVMDialectToLLVMPass(pm, out.os());
+    if (!emitFinalMLIR)
+      fir::addLLVMDialectToLLVMPass(pm, out.os());
   }
 
   // run the pass manager
   if (mlir::succeeded(pm.run(*owningRef))) {
     // passes ran successfully, so keep the output
-    if ((emitFir || passPipeline.hasAnyOccurrences()) && !codeGenLLVM)
+    if ((emitFir || passPipeline.hasAnyOccurrences() || emitFinalMLIR) &&
+        !codeGenLLVM)
       printModule(*owningRef, out.os());
     out.keep();
     return mlir::success();