[llvm] [NVPTX][InferAS] assume alloca instructions are in local AS (PR #121710)

[Alex MacLean via llvm-commits]

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@@ -6,13 +6,13 @@
 ; Ensure we access the local stack properly
 
 ; PTX32:        mov.u32          %SPL, __local_depot{{[0-9]+}};
-; PTX32:        cvta.local.u32   %SP, %SPL;
 ; PTX32:        ld.param.u32     %r{{[0-9]+}}, [foo_param_0];
-; PTX32:        st.volatile.u32  [%SP], %r{{[0-9]+}};
+; PTX32:        add.u32          %r[[SP_REG:[0-9]+]], %SPL, 0;
+; PTX32:        st.local.u32  [%r[[SP_REG]]], %r{{[0-9]+}};
 ; PTX64:        mov.u64          %SPL, __local_depot{{[0-9]+}};
-; PTX64:        cvta.local.u64   %SP, %SPL;
 ; PTX64:        ld.param.u32     %r{{[0-9]+}}, [foo_param_0];
-; PTX64:        st.volatile.u32  [%SP], %r{{[0-9]+}};
+; PTX64:        add.u64          %rd[[SP_REG:[0-9]+]], %SPL, 0;
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AlexMaclean wrote:

I agree this is an unsightly quirk. However, these stack pointer adds have been a part of how we handle frame indices in NVPTX for a long time and likely won't impact SASS at all. I think they're out of scope to fix in this MR (perhaps a good first issue @justinfargnoli)

https://github.com/llvm/llvm-project/pull/121710