[llvm] [Matrix] Propagate shape information through PHI insts (PR #141681)

[Florian Hahn via llvm-commits]

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@@ -561,6 +590,27 @@ class LowerMatrixIntrinsics {
       MatrixVal = M.embedInVector(Builder);
     }
 
+    // If it's a PHI, split it now. We'll take care of fixing up the operands
+    // later once we're in VisitPHI.
+    if (auto *PHI = dyn_cast<PHINode>(MatrixVal)) {
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fhahn wrote:

is there a reason we cannot handle phis like we handle other instructions and need to handle them here?

https://github.com/llvm/llvm-project/pull/141681