[llvm] Split vgpr regalloc pipeline (PR #93526)

[Christudasan Devadasan via llvm-commits]

================
@@ -0,0 +1,17 @@
+; RUN: not llc -mtriple=amdgcn-amd-amdhsa -mcpu=gfx900 -mattr=-flat-for-global -stress-regalloc=3 -filetype=null %s 2>&1 | FileCheck %s
----------------
cdevadas wrote:

The attr flat-for-global was used to force SGPR usage and eventually their spills. Otherwise, it uses GLOBAL_STORE_DWORD that only need VGPRs.

https://github.com/llvm/llvm-project/pull/93526