[PATCH] D136169: [AMDGPU] Avoid SCC clobbering before S_CSELECT_B32

[Jay Foad via Phabricator via llvm-commits]

foad added inline comments.


================
Comment at: llvm/lib/Target/AMDGPU/SIRegisterInfo.cpp:2216-2224
+          while (I != MBB->end()) {
+            if (*I != MI && I->readsRegister(AMDGPU::SCC)) {
+              NeedSaveSCC = true;
+              break;
+            }
+            if (*I != MI && I->definesRegister(AMDGPU::SCC))
+              break;
----------------
What is this loop for? Isn't the scavenger already supposed to know whether SCC is live?


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136169/new/

https://reviews.llvm.org/D136169