[llvm] 5124b21 - [VPlan] Initial def-use verification.
Florian Hahn via llvm-commits
llvm-commits at lists.llvm.org
Wed Jul 20 03:06:45 PDT 2022
Author: Florian Hahn
Date: 2022-07-20T11:06:32+01:00
New Revision: 5124b21648c77a41ef61a10f5b150c8e7964e23e
URL: https://github.com/llvm/llvm-project/commit/5124b21648c77a41ef61a10f5b150c8e7964e23e
DIFF: https://github.com/llvm/llvm-project/commit/5124b21648c77a41ef61a10f5b150c8e7964e23e.diff
LOG: [VPlan] Initial def-use verification.
This patch introduces some initial def-use verification. This catches
cases like the one fixed by D129436.
Reviewed By: Ayal
Differential Revision: https://reviews.llvm.org/D129717
Added:
Modified:
llvm/lib/Transforms/Vectorize/VPlanVerifier.cpp
Removed:
################################################################################
diff --git a/llvm/lib/Transforms/Vectorize/VPlanVerifier.cpp b/llvm/lib/Transforms/Vectorize/VPlanVerifier.cpp
index 3501de6ab38e..43e0a40fedb9 100644
--- a/llvm/lib/Transforms/Vectorize/VPlanVerifier.cpp
+++ b/llvm/lib/Transforms/Vectorize/VPlanVerifier.cpp
@@ -133,7 +133,9 @@ void VPlanVerifier::verifyHierarchicalCFG(
verifyRegionRec(TopRegion);
}
-static bool verifyVPBasicBlock(const VPBasicBlock *VPBB) {
+static bool
+verifyVPBasicBlock(const VPBasicBlock *VPBB,
+ DenseMap<const VPBlockBase *, unsigned> &BlockNumbering) {
// Verify that phi-like recipes are at the beginning of the block, with no
// other recipes in between.
auto RecipeI = VPBB->begin();
@@ -165,15 +167,71 @@ static bool verifyVPBasicBlock(const VPBasicBlock *VPBB) {
RecipeI++;
}
+ // Verify that defs in VPBB dominate all their uses. The current
+ // implementation is still incomplete.
+ DenseMap<const VPRecipeBase *, unsigned> RecipeNumbering;
+ unsigned Cnt = 0;
+ for (const VPRecipeBase &R : *VPBB)
+ RecipeNumbering[&R] = Cnt++;
+
+ for (const VPRecipeBase &R : *VPBB) {
+ for (const VPValue *V : R.definedValues()) {
+ for (const VPUser *U : V->users()) {
+ auto *UI = dyn_cast<VPRecipeBase>(U);
+ if (!UI || isa<VPHeaderPHIRecipe>(UI))
+ continue;
+
+ // If the user is in the same block, check it comes after R in the
+ // block.
+ if (UI->getParent() == VPBB) {
+ if (RecipeNumbering[UI] < RecipeNumbering[&R]) {
+ errs() << "Use before def!\n";
+ return false;
+ }
+ continue;
+ }
+
+ // Skip blocks outside any region for now and blocks outside
+ // replicate-regions.
+ auto *ParentR = VPBB->getParent();
+ if (!ParentR || !ParentR->isReplicator())
+ continue;
+
+ // For replicators, verify that VPPRedInstPHIRecipe defs are only used
+ // in subsequent blocks.
+ if (isa<VPPredInstPHIRecipe>(&R)) {
+ auto I = BlockNumbering.find(UI->getParent());
+ unsigned BlockNumber = I == BlockNumbering.end() ? std::numeric_limits<unsigned>::max() : I->second;
+ if (BlockNumber < BlockNumbering[ParentR]) {
+ errs() << "Use before def!\n";
+ return false;
+ }
+ continue;
+ }
+
+ // All non-VPPredInstPHIRecipe recipes in the block must be used in
+ // the replicate region only.
+ if (UI->getParent()->getParent() != ParentR) {
+ errs() << "Use before def!\n";
+ return false;
+ }
+ }
+ }
+ }
return true;
}
bool VPlanVerifier::verifyPlanIsValid(const VPlan &Plan) {
+ DenseMap<const VPBlockBase *, unsigned> BlockNumbering;
+ unsigned Cnt = 0;
auto Iter = depth_first(
VPBlockRecursiveTraversalWrapper<const VPBlockBase *>(Plan.getEntry()));
- for (const VPBasicBlock *VPBB :
- VPBlockUtils::blocksOnly<const VPBasicBlock>(Iter)) {
- if (!verifyVPBasicBlock(VPBB))
+ for (const VPBlockBase *VPB : Iter) {
+ BlockNumbering[VPB] = Cnt++;
+ auto *VPBB = dyn_cast<VPBasicBlock>(VPB);
+ if (!VPBB)
+ continue;
+ if (!verifyVPBasicBlock(VPBB, BlockNumbering))
return false;
}
More information about the llvm-commits
mailing list