[llvm] [AMDGPU] Make globally-addressable-scratch opt-in (PR #189555)

[Sameer Sahasrabuddhe via llvm-commits]

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@@ -827,6 +831,11 @@ unsigned GCNSubtarget::getNSAThreshold(const MachineFunction &MF) const {
   return NSAThreshold;
 }
 
+bool GCNSubtarget::isGloballyAddressableScratchEnabled() const {
+  return HasGloballyAddressableScratchSupport &&
+         EnableGloballyAddressableScratch;
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ssahasra wrote:

I was hoping we could get an explanation for this. I am actually not able to make out what is the "constructor" being referred to here.

https://github.com/llvm/llvm-project/pull/189555