[llvm] [NVPTX] add support for 128-bit atomics (PR #154852)

[Alex MacLean via llvm-commits]

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@@ -4,24 +4,24 @@
 ; CHECK: error: unsupported cmpxchg
 ; CHECK: error: unsupported cmpxchg
 ; CHECK: error: unsupported cmpxchg
-define void @bitwise_i128(ptr %0, i128 %1) {
+define void @bitwise_i256(ptr %0, i256 %1) {
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AlexMaclean wrote:

There is already coverage of i128 failing when unsupported in `atomics-b128.ll`. I think there is any reason to add that here as well. 

https://github.com/llvm/llvm-project/pull/154852