[llvm] [AMDGPU][LSV] Restrict large vectors in graphics (PR #92540)

[Piotr Sobczak via llvm-commits]

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@@ -364,14 +364,15 @@ unsigned GCNTTIImpl::getStoreVectorFactor(unsigned VF, unsigned StoreSize,
 }
 
 unsigned GCNTTIImpl::getLoadStoreVecRegBitWidth(unsigned AddrSpace) const {
-  if (AddrSpace == AMDGPUAS::GLOBAL_ADDRESS ||
-      AddrSpace == AMDGPUAS::CONSTANT_ADDRESS ||
+  if (AddrSpace == AMDGPUAS::GLOBAL_ADDRESS)
+    return 512;
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piotrAMD wrote:

I also note the values returned for R600 (R600TTIImpl::getLoadStoreVecRegBitWidth) are all not larger than 128.

https://github.com/llvm/llvm-project/pull/92540