[clang] [llvm] [SPIRV] GPU intrinsics (PR #131190)

[Jon Chesterfield via llvm-commits]

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@@ -0,0 +1,501 @@
+//===- LowerGPUIntrinsic.cpp ----------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// Lower the llvm.gpu intrinsics to target specific code sequences.
+// Can be called from clang if building for a specific GPU or from the backend
+// as part of a SPIRV lowering pipeline. Initial pass can lower to amdgcn or
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JonChesterfield wrote:

This is all written in terms of the spirv64-unknown-unknown triple. The in tree backend writes that out as SPV which sort of punts the problem onward to someone else, or the spirv-translator converts the spirv--unknown-unknown LLVM IR into SPV. Then the spirv-translator or something else turns the SPV into something executable.

The spirv backend should stash these intrinsics in the SPV file like any other ones. It might need a patch to do so or we might get default handling for llvm prefixed intrinsics. That's the point really - we pass information about the SIMT computation through the SPV onward to whatever is dealing with that later.

https://github.com/llvm/llvm-project/pull/131190