[clang] [CIR] Lower __builtin_assume_dereferenceable (PR #197262)

[via cfe-commits]

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@@ -820,8 +820,13 @@ mlir::LogicalResult CIRToLLVMSignBitOpLowering::matchAndRewrite(
 mlir::LogicalResult CIRToLLVMAssumeOpLowering::matchAndRewrite(
     cir::AssumeOp op, OpAdaptor adaptor,
     mlir::ConversionPatternRewriter &rewriter) const {
-  auto cond = adaptor.getPredicate();
-  rewriter.replaceOpWithNewOp<mlir::LLVM::AssumeOp>(op, cond);
+  mlir::Value cond = adaptor.getPredicate();
+  if (std::optional<llvm::StringRef> tag = op.getBundleTag()) {
+    rewriter.replaceOpWithNewOp<mlir::LLVM::AssumeOp>(op, cond, *tag,
+                                                      adaptor.getBundleArgs());
+  } else {
+    rewriter.replaceOpWithNewOp<mlir::LLVM::AssumeOp>(op, cond);
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adams381 wrote:

Done -- under the new parallel-array bundle shape the lowering is a single `replaceOpWithNewOp` forward of `(predicate, materialized SmallVector<ValueRange>, op_bundle_tags ArrayAttr)`.  Couldn't literally use `value_or("")` because `llvm.assume`'s `(cond, StringRef tag, ValueRange args)` builder always wraps into a one-bundle form (LLVMDialect.cpp:4321-4324), so an empty tag would mean "one bundle with an empty tag," not "no bundle."  Forwarding the three parallel fields sidesteps that.


https://github.com/llvm/llvm-project/pull/197262