[PATCH] D94645: [AMDGPU] Fix llvm.amdgcn.init.exec and frame materialization

[Ruiling, Song via Phabricator via llvm-commits]

ruiling added inline comments.


================
Comment at: llvm/lib/Target/AMDGPU/SIInstrInfo.cpp:1887-1893
+    // Usually InputReg is a function live in, so there will not be one.
+    for (MachineBasicBlock::iterator I = MBB.begin(), E = MI.getIterator();
+         I != E && !FirstMI; ++I) {
+      isInputRead = isInputRead || I->readsRegister(InputReg);
+      if (I->definesRegister(InputReg))
+        FirstMI = &*(std::next(I));
+    }
----------------
critson wrote:
> arsenm wrote:
> > We shouldn't need to do ad-hoc use/def searches. Can you do this pre-RA, post-SSA like SILowerControlFlow?
> We definitely could do.
> Do you have an opinion about what pass it should go in?
> It looks to me that we would need to add one.
> We definitely could do.
> Do you have an opinion about what pass it should go in?
> It looks to me that we would need to add one.

Can we just implement this in SILowerControlFlow?


Repository:
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  https://reviews.llvm.org/D94645/new/

https://reviews.llvm.org/D94645