[llvm] d1f849a - [LV] Hoist code to mark conditional assumes as dead to caller (NFC).

[Florian Hahn via llvm-commits]

Author: Florian Hahn
Date: 2020-01-28T08:50:44-08:00
New Revision: d1f849a284d9d180c23b9455aa3c68a3b462b1f0

URL: https://github.com/llvm/llvm-project/commit/d1f849a284d9d180c23b9455aa3c68a3b462b1f0
DIFF: https://github.com/llvm/llvm-project/commit/d1f849a284d9d180c23b9455aa3c68a3b462b1f0.diff

LOG: [LV] Hoist code to mark conditional assumes as dead to caller (NFC).

This is a follow-up suggested in D73423. It is sufficient to just add
the conditional assumes to DeadInstructions once.

Added: 
    

Modified: 
    llvm/lib/Transforms/Vectorize/LoopVectorize.cpp

Removed: 
    


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diff  --git a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
index 707979f6b4a2..e1446ce4adb9 100644
--- a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
+++ b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
@@ -7130,6 +7130,13 @@ void LoopVectorizationPlanner::buildVPlansWithVPRecipes(unsigned MinVF,
   SmallPtrSet<Instruction *, 4> DeadInstructions;
   collectTriviallyDeadInstructions(DeadInstructions);
 
+  // Add assume instructions we need to drop to DeadInstructions, to prevent
+  // them from being added to the VPlan.
+  // TODO: We only need to drop assumes in blocks that get flattend. If the
+  // control flow is preserved, we should keep them.
+  auto &ConditionalAssumes = Legal->getConditionalAssumes();
+  DeadInstructions.insert(ConditionalAssumes.begin(), ConditionalAssumes.end());
+
   DenseMap<Instruction *, Instruction *> &SinkAfter = Legal->getSinkAfter();
   // Dead instructions do not need sinking. Remove them from SinkAfter.
   for (Instruction *I : DeadInstructions)
@@ -7192,13 +7199,6 @@ VPlanPtr LoopVectorizationPlanner::buildVPlanWithVPRecipes(
   // visit each basic block after having visited its predecessor basic blocks.
   // ---------------------------------------------------------------------------
 
-  // Add assume instructions we need to drop to DeadInstructions, to prevent
-  // them from being added to the VPlan.
-  // TODO: We only need to drop assumes in blocks that get flattend. If the
-  // control flow is preserved, we should keep them.
-  auto &ConditionalAssumes = Legal->getConditionalAssumes();
-  DeadInstructions.insert(ConditionalAssumes.begin(), ConditionalAssumes.end());
-
   // Create a dummy pre-entry VPBasicBlock to start building the VPlan.
   VPBasicBlock *VPBB = new VPBasicBlock("Pre-Entry");
   auto Plan = std::make_unique<VPlan>(VPBB);