[flang-commits] [flang] [flang] Insert stacksave/stackrestore when alloca are present in loops (PR #95173)

[via flang-commits]

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@@ -72,6 +75,22 @@ class CfgLoopConv : public mlir::OpRewritePattern<fir::DoLoopOp> {
         rewriter.splitBlock(conditionalBlock, conditionalBlock->begin());
     auto *lastBlock = &loop.getRegion().back();
 
+    // Insert stacksave/stackrestore if there is fir.alloca operation in the
+    // loop.
+    if (hasAllocas) {
+      auto mod = loop.getOperation()->getParentOfType<mlir::ModuleOp>();
+      fir::FirOpBuilder builder(rewriter, mod);
+      builder.setInsertionPointToStart(firstBlock);
+      mlir::func::FuncOp stackSave = fir::factory::getLlvmStackSave(builder);
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jeanPerier wrote:

>  they do not have any side effects that prevent moving them around fir.alloca

Are you sure? It seems the ops do not define any side effect interface, which means they can have any side effects and cannot be moved without by a generic pass.

https://github.com/llvm/llvm-project/pull/95173