[clang] [llvm] [NVPTX] Change the alloca address space in NVPTXLowerAlloca (PR #154814)

[Artem Belevich via cfe-commits]

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@@ -368,8 +354,17 @@ void NVPTXPassConfig::addIRPasses() {
   // NVPTXLowerArgs is required for correctness and should be run right
   // before the address space inference passes.
   addPass(createNVPTXLowerArgsPass());
+
+  if (getOptLevel() != CodeGenOptLevel::None)
+    // NVPTXLowerArgs emits alloca for byval parameters which can often
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Artem-B wrote:

Nit: "may emit". We do make an effort not to make copies of byval argument, if we can prove that it's safe.

https://github.com/llvm/llvm-project/pull/154814