[llvm] [AMDGPU] Support function attribute to override postRA scheduling direction (PR #147708)

[Shilei Tian via llvm-commits]

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@@ -52,6 +52,11 @@ static cl::opt<unsigned>
                  cl::desc("Number of addresses from which to enable MIMG NSA."),
                  cl::init(2), cl::Hidden);
 
+static cl::opt<std::string>
+    AMDGPUPostRADirection("amdgpu-post-ra-direction",
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shiltian wrote:

leftover?

https://github.com/llvm/llvm-project/pull/147708