[flang-commits] [flang] [flang] Fix flang build after #83132 (PR #83253)

[Matthias Springer via flang-commits]

https://github.com/matthias-springer created https://github.com/llvm/llvm-project/pull/83253

This fix is a temporary workaround. `LowerHLFIRIntrinsics.cpp` should be using the greedy pattern rewriter or a manual IR traversal. All patterns in this file are rewrite patterns. The test failure was caused by `replaceAllUsesWith`, which is not supported by the dialect conversion; additional asserts were added recently to prevent incorrect API usage. These trigger now.

Alternatively, turning the patterns into conversion patterns and specifying a type converter may work.

Failing test case: `Fortran/gfortran/regression/gfortran-regression-compile-regression__inline_matmul_14_f90.test`

>From 2ac201d1b9b260d9fe760df80f8fac0c2a768460 Mon Sep 17 00:00:00 2001
From: Matthias Springer <springerm at google.com>
Date: Wed, 28 Feb 2024 11:41:27 +0000
Subject: [PATCH] [flang] Fix flang build after #83132

This fix is a temporary workaround. `LowerHLFIRIntrinsics.cpp` should be
using the greedy pattern rewriter or a manual IR traversal. All patterns
in this file are rewrite patterns. The test failure was caused by
`replaceAllUsesWith`, which is not supported by the dialect conversion;
additional asserts were added recently to prevent incorrect API usage.
These trigger now.

Alternatively, turning the patterns into conversion patterns and
specifying a type converter may work.

Failing test case: `Fortran/gfortran/regression/gfortran-regression-compile-regression__inline_matmul_14_f90.test`
---
 .../Optimizer/HLFIR/Transforms/LowerHLFIRIntrinsics.cpp  | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/flang/lib/Optimizer/HLFIR/Transforms/LowerHLFIRIntrinsics.cpp b/flang/lib/Optimizer/HLFIR/Transforms/LowerHLFIRIntrinsics.cpp
index 314e4264c17e83..377cc44392028f 100644
--- a/flang/lib/Optimizer/HLFIR/Transforms/LowerHLFIRIntrinsics.cpp
+++ b/flang/lib/Optimizer/HLFIR/Transforms/LowerHLFIRIntrinsics.cpp
@@ -176,7 +176,14 @@ class HlfirIntrinsicConversion : public mlir::OpRewritePattern<OP> {
           rewriter.eraseOp(use);
       }
     }
-    rewriter.replaceAllUsesWith(op->getResults(), {base});
+    // TODO: This entire pass should be a greedy pattern rewrite or a manual
+    // IR traversal. A dialect conversion cannot be used here because
+    // `replaceAllUsesWith` is not supported. Similarly, `replaceOp` is not
+    // suitable because "op->getResult(0)" and "base" can have different types.
+    // In such a case, the dialect conversion will attempt to convert the type,
+    // but no type converter is specified in this pass. Also note that all
+    // patterns in this pass are actually rewrite patterns.
+    op->getResult(0).replaceAllUsesWith(base);
     rewriter.replaceOp(op, base);
   }
 };