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

[Matt Arsenault via llvm-commits]

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@@ -32,12 +33,18 @@ using MBBVector = SmallVector<MachineBasicBlock *, 4>;
 
 namespace {
 
+static cl::opt<unsigned> MaxNumVGPRsForWwmAllocation(
+    "amdgpu-num-vgprs-for-wwm-alloc",
+    cl::desc("Max num VGPRs for whole-wave register allocation."),
+    cl::ReallyHidden, cl::init(5));
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arsenm wrote:

This seems really small and odd for a maximum? 

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