[llvm] a6b06b7 - [VPlan] Print VPValue operands for VPWidenPHI if possible.

[Florian Hahn via llvm-commits]

Author: Florian Hahn
Date: 2021-04-06T12:11:21+01:00
New Revision: a6b06b785cda1bb94dd05f29d66892ccb44cf0cd

URL: https://github.com/llvm/llvm-project/commit/a6b06b785cda1bb94dd05f29d66892ccb44cf0cd
DIFF: https://github.com/llvm/llvm-project/commit/a6b06b785cda1bb94dd05f29d66892ccb44cf0cd.diff

LOG: [VPlan] Print VPValue operands for VPWidenPHI if possible.

For VPWidenPHIRecipes that model all incoming values as VPValue
operands, print those operands instead of printing the original PHI.

D99294 updates recipes of reduction PHIs to use the VPValue for the
incoming value from the loop backedge, making use of this new printing.

Added: 
    

Modified: 
    llvm/lib/Transforms/Vectorize/VPlan.cpp
    llvm/unittests/Transforms/Vectorize/VPlanHCFGTest.cpp

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Transforms/Vectorize/VPlan.cpp b/llvm/lib/Transforms/Vectorize/VPlan.cpp
index ab793e95d2414..421ecb28029a7 100644
--- a/llvm/lib/Transforms/Vectorize/VPlan.cpp
+++ b/llvm/lib/Transforms/Vectorize/VPlan.cpp
@@ -1008,7 +1008,21 @@ void VPWidenGEPRecipe::print(raw_ostream &O, const Twine &Indent,
 
 void VPWidenPHIRecipe::print(raw_ostream &O, const Twine &Indent,
                              VPSlotTracker &SlotTracker) const {
-  O << Indent << "WIDEN-PHI " << VPlanIngredient(getUnderlyingValue());
+  O << Indent << "WIDEN-PHI ";
+
+  auto *OriginalPhi = cast<PHINode>(getUnderlyingValue());
+  // Unless all incoming values are modeled in VPlan  print the original PHI
+  // directly.
+  // TODO: Remove once all VPWidenPHIRecipe instances keep all relevant incoming
+  // values as VPValues.
+  if (getNumOperands() != OriginalPhi->getNumOperands()) {
+    O << VPlanIngredient(OriginalPhi);
+    return;
+  }
+
+  printAsOperand(O, SlotTracker);
+  O << " = phi ";
+  printOperands(O, SlotTracker);
 }
 
 void VPBlendRecipe::print(raw_ostream &O, const Twine &Indent,

diff  --git a/llvm/unittests/Transforms/Vectorize/VPlanHCFGTest.cpp b/llvm/unittests/Transforms/Vectorize/VPlanHCFGTest.cpp
index 853be5757731c..ea84034354a91 100644
--- a/llvm/unittests/Transforms/Vectorize/VPlanHCFGTest.cpp
+++ b/llvm/unittests/Transforms/Vectorize/VPlanHCFGTest.cpp
@@ -111,7 +111,7 @@ compound=true
     N1 -> N2 [ label=""]
     N2 [label =
       "for.body:\l" +
-      "  WIDEN-PHI %indvars.iv = phi 0, %indvars.iv.next\l" +
+      "  WIDEN-PHI ir\<%indvars.iv\> = phi ir\<0\>, ir\<%indvars.iv.next\>\l" +
       "  EMIT ir\<%arr.idx\> = getelementptr ir\<%A\> ir\<%indvars.iv\>\l" +
       "  EMIT ir\<%l1\> = load ir\<%arr.idx\>\l" +
       "  EMIT ir\<%res\> = add ir\<%l1\> ir\<10\>\l" +