[PATCH] D106277: [SVE] Remove the interface for getMaxVScale in favour of the IR attributes

[Bradley Smith via Phabricator via cfe-commits]

bsmith added a reviewer: paulwalker-arm.
bsmith added inline comments.


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Comment at: clang/lib/CodeGen/CodeGenFunction.cpp:505-506
+  } else if (getContext().getTargetInfo().hasFeature("sve")) {
+    CurFn->addFnAttr(
+        llvm::Attribute::getWithVScaleRangeArgs(getLLVMContext(), 0, 16));
   }
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Is this really what we want? Won't this enable fixed length codegen all of the time?


================
Comment at: llvm/lib/Target/RISCV/RISCVTargetTransformInfo.cpp:119-131
-Optional<unsigned> RISCVTTIImpl::getMaxVScale() const {
-  // There is no assumption of the maximum vector length in V specification.
-  // We use the value specified by users as the maximum vector length.
-  // This function will use the assumed maximum vector length to get the
-  // maximum vscale for LoopVectorizer.
-  // If users do not specify the maximum vector length, we have no way to
-  // know whether the LoopVectorizer is safe to do or not.
----------------
I'm not sure that RISCV have made a commitment to use the vscale_range attribute yet have they? In either case I think they should be involved in a change like this.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D106277/new/

https://reviews.llvm.org/D106277