[VPlan] Implement printing VPIRMetadata. #165825

fhahn · 2025-10-31T04:45:11Z

Implement and use debug printing for VPIRMetadata.

github-actions · 2025-10-31T04:47:08Z

✅ With the latest revision this PR passed the C/C++ code formatter.

llvmbot · 2025-10-31T04:50:02Z

@llvm/pr-subscribers-vectorizers

@llvm/pr-subscribers-llvm-transforms

Author: Florian Hahn (fhahn)

Changes

Implement and use debug printing for VPIRMetadata.

Full diff: https://github.com/llvm/llvm-project/pull/165825.diff

2 Files Affected:

(modified) llvm/lib/Transforms/Vectorize/VPlan.h (+8)
(modified) llvm/lib/Transforms/Vectorize/VPlanRecipes.cpp (+27)

diff --git a/llvm/lib/Transforms/Vectorize/VPlan.h b/llvm/lib/Transforms/Vectorize/VPlan.h
index 1f10058ab4a9a..79583ce34c74d 100644
--- a/llvm/lib/Transforms/Vectorize/VPlan.h
+++ b/llvm/lib/Transforms/Vectorize/VPlan.h
@@ -968,6 +968,9 @@ class VPIRMetadata {
   /// Intersect this VPIRMetada object with \p MD, keeping only metadata
   /// nodes that are common to both.
   void intersect(const VPIRMetadata &MD);
+
+  /// Print metadata with node IDs.
+  void print(raw_ostream &O, const Module &M) const;
 };
 
 /// This is a concrete Recipe that models a single VPlan-level instruction.
@@ -4268,6 +4271,11 @@ class VPlan {
   /// Return the VPIRBasicBlock wrapping the header of the scalar loop.
   VPIRBasicBlock *getScalarHeader() const { return ScalarHeader; }
 
+  /// Return the Module from the scalar header.
+  const Module &getModule() const {
+    return *ScalarHeader->getIRBasicBlock()->getModule();
+  }
+
   /// Return an ArrayRef containing VPIRBasicBlocks wrapping the exit blocks of
   /// the original scalar loop.
   ArrayRef<VPIRBasicBlock *> getExitBlocks() const { return ExitBlocks; }
diff --git a/llvm/lib/Transforms/Vectorize/VPlanRecipes.cpp b/llvm/lib/Transforms/Vectorize/VPlanRecipes.cpp
index bde62dd6dd4bc..132bb50e92a7f 100644
--- a/llvm/lib/Transforms/Vectorize/VPlanRecipes.cpp
+++ b/llvm/lib/Transforms/Vectorize/VPlanRecipes.cpp
@@ -1443,6 +1443,7 @@ void VPInstruction::print(raw_ostream &O, const Twine &Indent,
 
   printFlags(O);
   printOperands(O, SlotTracker);
+  VPIRMetadata::print(O, getParent()->getPlan()->getModule());
 
   if (auto DL = getDebugLoc()) {
     O << ", !dbg ";
@@ -1669,6 +1670,26 @@ void VPIRMetadata::intersect(const VPIRMetadata &Other) {
   Metadata = std::move(MetadataIntersection);
 }
 
+void VPIRMetadata::print(raw_ostream &O, const Module &M) const {
+  if (Metadata.empty())
+    return;
+
+  SmallVector<StringRef, 8> MDNames;
+  M.getContext().getMDKindNames(MDNames);
+
+  O << " (";
+  interleaveComma(Metadata, O, [&](const auto &KindNodePair) {
+    auto [Kind, Node] = KindNodePair;
+    assert(Kind != 0 && "Debug metadata should not be managed by VPIRMetadata");
+    assert(Kind < MDNames.size() && !MDNames[Kind].empty() &&
+           "Unexpected unnamed metadata kind");
+    O << "!" << MDNames[Kind] << " ";
+    Node->printAsOperand(O, &M);
+  });
+  O << ")";
+}
+
+
 void VPWidenCallRecipe::execute(VPTransformState &State) {
   assert(State.VF.isVector() && "not widening");
   assert(Variant != nullptr && "Can't create vector function.");
@@ -1729,6 +1750,7 @@ void VPWidenCallRecipe::print(raw_ostream &O, const Twine &Indent,
     Op->printAsOperand(O, SlotTracker);
   });
   O << ")";
+  VPIRMetadata::print(O, getParent()->getPlan()->getModule());
 
   O << " (using library function";
   if (Variant->hasName())
@@ -1863,6 +1885,7 @@ void VPWidenIntrinsicRecipe::print(raw_ostream &O, const Twine &Indent,
     Op->printAsOperand(O, SlotTracker);
   });
   O << ")";
+  VPIRMetadata::print(O, getParent()->getPlan()->getModule());
 }
 #endif
 
@@ -2255,6 +2278,7 @@ void VPWidenRecipe::print(raw_ostream &O, const Twine &Indent,
   O << " = " << Instruction::getOpcodeName(Opcode);
   printFlags(O);
   printOperands(O, SlotTracker);
+  VPIRMetadata::print(O, getParent()->getPlan()->getModule());
 }
 #endif
 
@@ -2336,6 +2360,7 @@ void VPWidenCastRecipe::print(raw_ostream &O, const Twine &Indent,
   printFlags(O);
   printOperands(O, SlotTracker);
   O << " to " << *getResultType();
+  VPIRMetadata::print(O, getParent()->getPlan()->getModule());
 }
 #endif
 
@@ -3618,6 +3643,7 @@ void VPWidenLoadRecipe::print(raw_ostream &O, const Twine &Indent,
   printAsOperand(O, SlotTracker);
   O << " = load ";
   printOperands(O, SlotTracker);
+  VPIRMetadata::print(O, getParent()->getPlan()->getModule());
 }
 #endif
 
@@ -3739,6 +3765,7 @@ void VPWidenStoreRecipe::print(raw_ostream &O, const Twine &Indent,
                                VPSlotTracker &SlotTracker) const {
   O << Indent << "WIDEN store ";
   printOperands(O, SlotTracker);
+  VPIRMetadata::print(O, getParent()->getPlan()->getModule());
 }
 #endif

Implement and use debug printing for VPIRMetadata.

Mel-Chen

LG, but it seems some recipes were missed, such as the interleave recipe.

ayalz · 2025-11-03T13:24:45Z

LG, but it seems some recipes were missed, such as the interleave recipe.

Wonder if there's a way to catch/enforce all derived recipes to print their metadata; seems difficult by intercepting VPValue::printAsOperand() due to multiple inheritance(?)

ayalz · 2025-11-03T13:05:27Z

llvm/lib/Transforms/Vectorize/VPlan.h

  /// Intersect this VPIRMetada object with \p MD, keeping only metadata
  /// nodes that are common to both.
  void intersect(const VPIRMetadata &MD);
+


Under

Suggested change

#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)

?

Done thanks

ayalz · 2025-11-03T13:06:45Z

llvm/lib/Transforms/Vectorize/VPlan.h

+
+  /// Return true if there is any metadata to print.
+  bool empty() const { return Metadata.empty(); }


Redundant - print() checks anyhow if there is any metadata to print?

This was used to check before printing; removed now, thanks

ayalz · 2025-11-03T13:08:00Z

llvm/lib/Transforms/Vectorize/VPlan.h

+  /// Return the Module from the scalar header.
+  const Module &getModule() const {
+    return *ScalarHeader->getIRBasicBlock()->getModule();
+  }
+


Have VPlan return Module only for VPIRMetadata to print itself (under DEBUG)?
Could (the Module of) VPSlotTracker's MST be used instead?

I don't think so, as MST also may not be set. I update the code to return the module by reference, so the empty check can be removed before call print.

ayalz · 2025-11-03T13:08:49Z

llvm/lib/Transforms/Vectorize/VPlanRecipes.cpp

+  if (Metadata.empty())
+    return;


Empty checked anyhow.

Yes, used to check at callsite before dereferencing Module. Updated now, only checked here.

Add a new pinrRecipe which handles printing the recipe without common info like debug info or metadata. Prepares to print them once, in ::print(), after/in combination with llvm#165825.

Implement CastInfo from VPRecipeBase to VPIRMetadata to support isa/dyn_Cast. This is similar to CastInfoVPPhiAccessors, supporting dyn_cast by down-casting to the concrete recipe types inheriting from VPIRMetadata. Can be used for more generalized VPIRMetadata printing following llvm#165825.

fhahn

LG, but it seems some recipes were missed, such as the interleave recipe.

Wonder if there's a way to catch/enforce all derived recipes to print their metadata; seems difficult by intercepting VPValue::printAsOperand() due to multiple inheritance(?)

One option would be to change recipe's printing without common info like metadata to be called printRecipe, then have VPRecipeBase::print() call printRecipe and print common metadata (and others like debug info): #166244

We will also need to be able to check if a VPRecipeBase has VPIRMetadata, which can be done by implemeting CastInfo: #166245

LG, but it seems some recipes were missed, such as the interleave recipe.

Thanks, added some of the missing ones

fhahn · 2025-11-03T22:00:36Z

llvm/lib/Transforms/Vectorize/VPlan.h

+
+  /// Return true if there is any metadata to print.
+  bool empty() const { return Metadata.empty(); }


This was used to check before printing; removed now, thanks

fhahn · 2025-11-03T22:01:32Z

llvm/lib/Transforms/Vectorize/VPlan.h

+  /// Return the Module from the scalar header.
+  const Module &getModule() const {
+    return *ScalarHeader->getIRBasicBlock()->getModule();
+  }
+


I don't think so, as MST also may not be set. I update the code to return the module by reference, so the empty check can be removed before call print.

fhahn · 2025-11-03T22:02:05Z

llvm/lib/Transforms/Vectorize/VPlanRecipes.cpp

+  if (Metadata.empty())
+    return;


Yes, used to check at callsite before dereferencing Module. Updated now, only checked here.

fhahn requested review from Mel-Chen, aniragil, ayalz and rengolin October 31, 2025 04:45

llvmbot added vectorizers llvm:transforms labels Oct 31, 2025

fhahn force-pushed the vplan-print-metadata branch 2 times, most recently from bcd6751 to 368bacd Compare November 1, 2025 22:08

[VPlan] Implement printing VPIRMetadata.

6cf1ed5

Implement and use debug printing for VPIRMetadata.

fhahn force-pushed the vplan-print-metadata branch from 368bacd to 6cf1ed5 Compare November 2, 2025 15:18

Mel-Chen reviewed Nov 3, 2025

View reviewed changes

ayalz reviewed Nov 3, 2025

View reviewed changes

Merge remote-tracking branch 'origin/main' into vplan-print-metadata

1a1172e

This was referenced Nov 3, 2025

[VPlan] Add printRecipe, prepare printing metadata in ::print (NFC) #166244

Open

[VPlan] Support isa/dyn_cast from VPRecipeBase to VPIRMetadata (NFC). #166245

Open

fhahn force-pushed the vplan-print-metadata branch from f1e7f7d to 02a8a9a Compare November 3, 2025 22:03

!fixup address comments, thanks!

0dc9780

fhahn force-pushed the vplan-print-metadata branch from 02a8a9a to 0dc9780 Compare November 3, 2025 22:08

fhahn commented Nov 3, 2025

View reviewed changes


		/// Return true if there is any metadata to print.
		bool empty() const { return Metadata.empty(); }

[VPlan] Implement printing VPIRMetadata. #165825

Are you sure you want to change the base?

[VPlan] Implement printing VPIRMetadata. #165825

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