[LV][NFC] Print VPlan's transformation pipline #72665

nikolaypanchenko · 2023-11-17T15:38:19Z

Print VPlan before each pass in VPlanTransforms::optimize with a debug type vplan-xforms.

llvmbot · 2023-11-17T15:38:46Z

@llvm/pr-subscribers-llvm-transforms

Author: Kolya Panchenko (nikolaypanchenko)

Changes

Print VPlan before each pass in VPlanTransforms::optimize with a debug type vplan-xforms.

Full diff: https://github.com/llvm/llvm-project/pull/72665.diff

1 Files Affected:

(modified) llvm/lib/Transforms/Vectorize/VPlanTransforms.cpp (+25)

diff --git a/llvm/lib/Transforms/Vectorize/VPlanTransforms.cpp b/llvm/lib/Transforms/Vectorize/VPlanTransforms.cpp
index 0eaaa037ad5782f..142cda07adbd763 100644
--- a/llvm/lib/Transforms/Vectorize/VPlanTransforms.cpp
+++ b/llvm/lib/Transforms/Vectorize/VPlanTransforms.cpp
@@ -24,6 +24,8 @@
 #include "llvm/IR/Intrinsics.h"
 #include "llvm/IR/PatternMatch.h"
 
+#define DEBUG_TYPE "vplan-xforms"
+
 using namespace llvm;
 
 using namespace llvm::PatternMatch;
@@ -871,16 +873,39 @@ static void simplifyRecipes(VPlan &Plan, LLVMContext &Ctx) {
 }
 
 void VPlanTransforms::optimize(VPlan &Plan, ScalarEvolution &SE) {
+  LLVM_DEBUG(dbgs() << "LV: --- VPlan before removeRedundantCanonicalIVs ---\n";
+             Plan.dump(); dbgs() << "\n\n");
   removeRedundantCanonicalIVs(Plan);
+
+  LLVM_DEBUG(
+      dbgs() << "LV: --- VPlan before removeRedundantInductionCasts ---\n";
+      Plan.dump(); dbgs() << "\n\n");
   removeRedundantInductionCasts(Plan);
 
+  LLVM_DEBUG(dbgs() << "LV: --- VPlan before optimizeInductions ---\n";
+             Plan.dump(); dbgs() << "\n\n");
   optimizeInductions(Plan, SE);
+
+  LLVM_DEBUG(dbgs() << "LV: --- VPlan before simplifyRecipes ---\n";
+             Plan.dump(); dbgs() << "\n\n");
   simplifyRecipes(Plan, SE.getContext());
+
+  LLVM_DEBUG(dbgs() << "LV: --- VPlan before removeDeadRecipes ---\n";
+             Plan.dump(); dbgs() << "\n\n");
   removeDeadRecipes(Plan);
 
+  LLVM_DEBUG(
+      dbgs() << "LV: --- VPlan before createAndOptimizeReplicateRegions ---\n";
+      Plan.dump(); dbgs() << "\n\n");
   createAndOptimizeReplicateRegions(Plan);
 
+  LLVM_DEBUG(
+      dbgs() << "LV: --- VPlan before removeRedundantExpandSCEVRecipes ---\n";
+      Plan.dump(); dbgs() << "\n\n");
   removeRedundantExpandSCEVRecipes(Plan);
+
+  LLVM_DEBUG(dbgs() << "LV: --- VPlan before mergeBlocksIntoPredecessors ---\n";
+             Plan.dump(); dbgs() << "\n\n");
   mergeBlocksIntoPredecessors(Plan);
 }

fhahn · 2023-11-20T15:33:58Z

Thanks for working on this functionality, should be very helpful in the future.

I think it would be good to have a generic way to register a pass to run, so we have a single place to add the print statements. Eg have a RUN_PASS macro or helper function that takes the function to run plus a name perhaps (or just uses the function name).

Not sure about tying this to debug output, as this potentially adds a lot of output. It might be better to have this controlled by a separate -vplan-print-before-all? Or even better to update all transforms to indicate whether they made changes and have a more compact -vplan-print-before-changed

nikolaypanchenko · 2023-11-21T00:47:29Z

Thanks for working on this functionality, should be very helpful in the future.

I think it would be good to have a generic way to register a pass to run, so we have a single place to add the print statements. Eg have a RUN_PASS macro or helper function that takes the function to run plus a name perhaps (or just uses the function name).

Not sure about tying this to debug output, as this potentially adds a lot of output. It might be better to have this controlled by a separate -vplan-print-before-all? Or even better to update all transforms to indicate whether they made changes and have a more compact -vplan-print-before-changed

Thanks for working on this functionality, should be very helpful in the future.

I think it would be good to have a generic way to register a pass to run, so we have a single place to add the print statements. Eg have a RUN_PASS macro or helper function that takes the function to run plus a name perhaps (or just uses the function name).

Sure, I can build VPlanPass and VPlanPassManager. At this point they don't need to be as advanced as LLVM's or MLIR's pass/passmanager, but they can evolve later

Not sure about tying this to debug output, as this potentially adds a lot of output. It might be better to have this controlled by a separate -vplan-print-before-all? Or even better to update all transforms to indicate whether they made changes and have a more compact -vplan-print-before-changed

I was thinking about that too and tried to minimize changes and impact on a loop-vectorize debug output, so with the changeset extra output will only appear with vplan-xforms debug type.

fhahn · 2023-11-21T09:38:17Z

Sure, I can build VPlanPass and VPlanPassManager. At this point they don't need to be as advanced as LLVM's or MLIR's pass/passmanager, but they can evolve later

I don't think we need to add all the extra structure & complexity yet; runner macro or function taking a function_ref would suffice?

I was thinking about that too and tried to minimize changes and impact on a loop-vectorize debug output, so with the changeset extra output will only appear with vplan-xforms debug type.

I was thinking about cases where people just use -debug (in tests and while debugging issues), which will get the full output

github-actions · 2023-11-27T23:35:02Z

⚠️ C/C++ code formatter, clang-format found issues in your code. ⚠️

You can test this locally with the following command:

git-clang-format --diff 8cd7184dc0f1e5e28e39b03c90bc9aeee96d104f eb7125b99b921fc19ad736fa42150266b4ba2e01 -- llvm/lib/Transforms/Vectorize/VPlanTransforms.cpp llvm/lib/Transforms/Vectorize/VPlanTransforms.h

View the diff from clang-format here.

diff --git a/llvm/lib/Transforms/Vectorize/VPlanTransforms.cpp b/llvm/lib/Transforms/Vectorize/VPlanTransforms.cpp
index 4d55669648..4bb0e88e57 100644
--- a/llvm/lib/Transforms/Vectorize/VPlanTransforms.cpp
+++ b/llvm/lib/Transforms/Vectorize/VPlanTransforms.cpp
@@ -24,7 +24,6 @@
 #include "llvm/IR/Intrinsics.h"
 #include "llvm/IR/PatternMatch.h"
 
-
 using namespace llvm;
 
 static cl::list<std::string>
@@ -37,12 +36,14 @@ static cl::list<std::string>
                llvm::cl::desc("Print VPlan after specified VPlan passes"),
                cl::CommaSeparated, cl::Hidden);
 
-static cl::opt<bool> PrintBeforeAll("vplan-print-before-all",
-                                    llvm::cl::desc("Print VPlan before each VPlan pass"),
-                                    cl::init(false), cl::Hidden);
-static cl::opt<bool> PrintAfterAll("vplan-print-after-all",
-                                   llvm::cl::desc("Print VPlan after each VPlanpass"),
-                                   cl::init(false), cl::Hidden);
+static cl::opt<bool>
+    PrintBeforeAll("vplan-print-before-all",
+                   llvm::cl::desc("Print VPlan before each VPlan pass"),
+                   cl::init(false), cl::Hidden);
+static cl::opt<bool>
+    PrintAfterAll("vplan-print-after-all",
+                  llvm::cl::desc("Print VPlan after each VPlanpass"),
+                  cl::init(false), cl::Hidden);
 
 using namespace llvm::PatternMatch;
 
@@ -560,10 +561,10 @@ struct RemoveDeadRecipes : public VPlanPass<RemoveDeadRecipes> {
   }
 };
 
-static VPValue *
-createScalarIVSteps(VPlan &Plan, const InductionDescriptor &ID,
-                    ScalarEvolution &SE, Instruction *TruncI, Type *IVTy,
-                    VPValue *StartV, VPValue *Step) {
+static VPValue *createScalarIVSteps(VPlan &Plan, const InductionDescriptor &ID,
+                                    ScalarEvolution &SE, Instruction *TruncI,
+                                    Type *IVTy, VPValue *StartV,
+                                    VPValue *Step) {
   VPBasicBlock *HeaderVPBB = Plan.getVectorLoopRegion()->getEntryBasicBlock();
   auto IP = HeaderVPBB->getFirstNonPhi();
   VPCanonicalIVPHIRecipe *CanonicalIV = Plan.getCanonicalIV();
@@ -591,7 +592,9 @@ private:
 public:
   explicit OptimizeInductionsPass(ScalarEvolution &SE) : SE(SE) {}
 
-  virtual StringRef getPassArgument() const override { return "optimize-inductions"; }
+  virtual StringRef getPassArgument() const override {
+    return "optimize-inductions";
+  }
 
   virtual void run(VPlan &Plan) override {
     SmallVector<VPRecipeBase *> ToRemove;

Introduced `VPlanPass` as a base-class for transformations on a VPlan. The class itself is extremely simple and has only 3 methods: - `run(VPlan)`: executes the pass on a given `VPlan` - `getName`: returns a name of the pass. Used to print `VPlan` - `getPassArgument`: returns a name of the command line option to use in `vplan-print-[before|after]=<name>` Wrapped all existing transformations of `VPlanTransforms` with that new class and added convenient function to run the pass and print `VPlan` before/after it, i.e. that functionality is similar to LLVM's `print-before*` and `print-after*` options.

nikolaypanchenko · 2023-11-27T23:40:49Z

I don't think we need to add all the extra structure & complexity yet; runner macro or function taking a function_ref would suffice?

I do agree that that is good simple approach. On the other hand to do some baby step towards to pass/passmanager for vectorizer might be useful. The last commit introduces simple base class for pass, wraps all existing xforms and copies existing logic of print-before/after* options. If that looks to much, I'm fine to go with much simpler option

nikolaypanchenko · 2024-01-04T23:46:21Z

@fhahn ping

fhahn · 2024-01-08T14:12:18Z

I do agree that that is good simple approach. On the other hand to do some baby step towards to pass/passmanager for vectorizer might be useful. The last commit introduces simple base class for pass, wraps all existing xforms and copies existing logic of print-before/after* options. If that looks to much, I'm fine to go with much simpler option

Thanks for the update! I think to start with a simpler option would be preferred.

fhahn · 2024-02-29T09:23:03Z

reverse ping :)

llvmbot added vectorization llvm:transforms labels Nov 17, 2023

npanchen requested a review from fhahn November 17, 2023 15:39

fhahn assigned ayalz and aniragil and unassigned ayalz and aniragil Nov 20, 2023

fhahn requested review from ayalz and aniragil November 20, 2023 15:25

nikolaypanchenko force-pushed the pr/npanchen/vplan_xforms_dump branch from 0922a18 to 9416e84 Compare November 27, 2023 23:32

nikolaypanchenko force-pushed the pr/npanchen/vplan_xforms_dump branch from 9416e84 to eb7125b Compare November 27, 2023 23:37

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

[LV][NFC] Print VPlan's transformation pipline #72665

[LV][NFC] Print VPlan's transformation pipline #72665

nikolaypanchenko commented Nov 17, 2023

llvmbot commented Nov 17, 2023

fhahn commented Nov 20, 2023

nikolaypanchenko commented Nov 21, 2023

fhahn commented Nov 21, 2023

github-actions bot commented Nov 27, 2023 •

edited

nikolaypanchenko commented Nov 27, 2023

nikolaypanchenko commented Jan 4, 2024

fhahn commented Jan 8, 2024

fhahn commented Feb 29, 2024

[LV][NFC] Print VPlan's transformation pipline #72665

Are you sure you want to change the base?

[LV][NFC] Print VPlan's transformation pipline #72665

Conversation

nikolaypanchenko commented Nov 17, 2023

llvmbot commented Nov 17, 2023

fhahn commented Nov 20, 2023

nikolaypanchenko commented Nov 21, 2023

fhahn commented Nov 21, 2023

github-actions bot commented Nov 27, 2023 • edited

nikolaypanchenko commented Nov 27, 2023

nikolaypanchenko commented Jan 4, 2024

fhahn commented Jan 8, 2024

fhahn commented Feb 29, 2024

github-actions bot commented Nov 27, 2023 •

edited