[llvm] Improve selection of conditional branch on amdgcn.ballot!=0 condition in SelectionDAG. (PR #68714)

[Valery Pykhtin via llvm-commits]

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@@ -2259,6 +2259,30 @@ bool AMDGPUDAGToDAGISel::isCBranchSCC(const SDNode *N) const {
   return false;
 }
 
+bool isBoolSGPR(SDValue V);
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vpykhtin wrote:

The definition is in another source (SIISelLowering.cpp), I haven't found common header to place this declaration yet.

https://github.com/llvm/llvm-project/pull/68714