[PATCH] D72714: [ARM][MVE] Tail-Predication: rematerialise iteration count in exit blocks

[Dave Green via Phabricator via llvm-commits]

dmgreen added inline comments.


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Comment at: llvm/lib/Target/ARM/MVETailPredication.cpp:141
+
+  if (!L->isRecursivelyLCSSAForm(*DT, *LI)) {
+    LLVM_DEBUG(dbgs() << "ARM TP: Loop is not in LCSSA form\n");
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Do you need to test this? Will formLCSSA either just work or not by calling it?

I just noticed an EXPENSIVE_CHECKS in formLCSSA that checks if the subloops are already in LCSSA form. Maybe use formLCSSARecursively instead?


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Comment at: llvm/lib/Target/ARM/MVETailPredication.cpp:144-145
+    if (!formLCSSA(*L, *DT, LI, SE)) {
+      LLVM_DEBUG(dbgs() << "ARM TP: couldn't bring loop in LCCS form,"
+                        << "can't rematerialise iteration count in exit "
+                        << "blocks\n");
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Space after the ","


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Comment at: llvm/lib/Target/ARM/MVETailPredication.cpp:147
+                        << "blocks\n");
+      return;
+    } else
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Does formLCSSA return false on failure, or nothing changed?


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D72714/new/

https://reviews.llvm.org/D72714