diff options
| -rw-r--r-- | llvm/lib/Transforms/Scalar/JumpThreading.cpp | 37 | ||||
| -rw-r--r-- | llvm/test/Transforms/JumpThreading/removed-use.ll | 28 |
2 files changed, 15 insertions, 50 deletions
diff --git a/llvm/lib/Transforms/Scalar/JumpThreading.cpp b/llvm/lib/Transforms/Scalar/JumpThreading.cpp index 85d2c323fa1..29c707799bd 100644 --- a/llvm/lib/Transforms/Scalar/JumpThreading.cpp +++ b/llvm/lib/Transforms/Scalar/JumpThreading.cpp @@ -66,7 +66,6 @@ #include "llvm/Transforms/Utils/BasicBlockUtils.h" #include "llvm/Transforms/Utils/Cloning.h" #include "llvm/Transforms/Utils/SSAUpdater.h" -#include "llvm/Transforms/Utils/SSAUpdaterBulk.h" #include "llvm/Transforms/Utils/ValueMapper.h" #include <algorithm> #include <cassert> @@ -1990,21 +1989,15 @@ bool JumpThreadingPass::ThreadEdge(BasicBlock *BB, // now have to update all uses of the value to use either the original value, // the cloned value, or some PHI derived value. This can require arbitrary // PHI insertion, of which we are prepared to do, clean these up now. - SSAUpdaterBulk SSAUpdate; + SSAUpdater SSAUpdate; SmallVector<Use*, 16> UsesToRename; - - unsigned VarNum = 0; for (Instruction &I : *BB) { - UsesToRename.clear(); - // Scan all uses of this instruction to see if it is used outside of its - // block, and if so, record them in UsesToRename. Also, skip phi operands - // from PredBB - we'll remove them anyway. + // block, and if so, record them in UsesToRename. for (Use &U : I.uses()) { Instruction *User = cast<Instruction>(U.getUser()); if (PHINode *UserPN = dyn_cast<PHINode>(User)) { - if (UserPN->getIncomingBlock(U) == BB || - UserPN->getIncomingBlock(U) == PredBB) + if (UserPN->getIncomingBlock(U) == BB) continue; } else if (User->getParent() == BB) continue; @@ -2015,15 +2008,19 @@ bool JumpThreadingPass::ThreadEdge(BasicBlock *BB, // If there are no uses outside the block, we're done with this instruction. if (UsesToRename.empty()) continue; - SSAUpdate.AddVariable(VarNum, I.getName(), I.getType()); - // We found a use of I outside of BB - we need to rename all uses of I that - // are outside its block to be uses of the appropriate PHI node etc. - SSAUpdate.AddAvailableValue(VarNum, BB, &I); - SSAUpdate.AddAvailableValue(VarNum, NewBB, ValueMapping[&I]); - for (auto U : UsesToRename) - SSAUpdate.AddUse(VarNum, U); - VarNum++; + DEBUG(dbgs() << "JT: Renaming non-local uses of: " << I << "\n"); + + // We found a use of I outside of BB. Rename all uses of I that are outside + // its block to be uses of the appropriate PHI node etc. See ValuesInBlocks + // with the two values we know. + SSAUpdate.Initialize(I.getType(), I.getName()); + SSAUpdate.AddAvailableValue(BB, &I); + SSAUpdate.AddAvailableValue(NewBB, ValueMapping[&I]); + + while (!UsesToRename.empty()) + SSAUpdate.RewriteUse(*UsesToRename.pop_back_val()); + DEBUG(dbgs() << "\n"); } // Ok, NewBB is good to go. Update the terminator of PredBB to jump to @@ -2040,10 +2037,6 @@ bool JumpThreadingPass::ThreadEdge(BasicBlock *BB, {DominatorTree::Insert, PredBB, NewBB}, {DominatorTree::Delete, PredBB, BB}}); - // Apply all updates we queued with DDT and get the updated Dominator Tree. - DominatorTree *DT = &DDT->flush(); - SSAUpdate.RewriteAllUses(DT); - // At this point, the IR is fully up to date and consistent. Do a quick scan // over the new instructions and zap any that are constants or dead. This // frequently happens because of phi translation. diff --git a/llvm/test/Transforms/JumpThreading/removed-use.ll b/llvm/test/Transforms/JumpThreading/removed-use.ll deleted file mode 100644 index d2c6836fc28..00000000000 --- a/llvm/test/Transforms/JumpThreading/removed-use.ll +++ /dev/null @@ -1,28 +0,0 @@ -; RUN: opt -S < %s -jump-threading | FileCheck %s -; CHECK-LABEL: @foo -; CHECK: bb6: -; CHECK-NEXT: ret void -; CHECK: bb3: -; CHECK: br label %bb3 -define void @foo() { -entry: - br i1 true, label %bb6, label %bb3 - -bb3: - %x0 = phi i32 [ undef, %entry ], [ %x1, %bb5 ] - %y = and i64 undef, 1 - %p = icmp ne i64 %y, 0 - br i1 %p, label %bb4, label %bb5 - -bb4: - br label %bb5 - -bb5: - %x1 = phi i32 [ %x0, %bb3 ], [ %x0, %bb4 ] - %z = phi i32 [ 0, %bb3 ], [ 1, %bb4 ] - %q = icmp eq i32 %z, 0 - br i1 %q, label %bb3, label %bb6 - -bb6: - ret void -} |
