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-rw-r--r--llvm/lib/Transforms/Scalar/DFAJumpThreading.cpp46
-rw-r--r--llvm/test/Transforms/DFAJumpThreading/dfa-jump-threading-transform.ll123
2 files changed, 152 insertions, 17 deletions
diff --git a/llvm/lib/Transforms/Scalar/DFAJumpThreading.cpp b/llvm/lib/Transforms/Scalar/DFAJumpThreading.cpp
index ef9c264..0e2b5c9 100644
--- a/llvm/lib/Transforms/Scalar/DFAJumpThreading.cpp
+++ b/llvm/lib/Transforms/Scalar/DFAJumpThreading.cpp
@@ -194,7 +194,6 @@ void unfold(DomTreeUpdater *DTU, LoopInfo *LI, SelectInstToUnfold SIToUnfold,
SelectInst *SI = SIToUnfold.getInst();
PHINode *SIUse = SIToUnfold.getUse();
BasicBlock *StartBlock = SI->getParent();
- BasicBlock *EndBlock = SIUse->getParent();
BranchInst *StartBlockTerm =
dyn_cast<BranchInst>(StartBlock->getTerminator());
@@ -202,6 +201,7 @@ void unfold(DomTreeUpdater *DTU, LoopInfo *LI, SelectInstToUnfold SIToUnfold,
assert(SI->hasOneUse());
if (StartBlockTerm->isUnconditional()) {
+ BasicBlock *EndBlock = StartBlock->getUniqueSuccessor();
// Arbitrarily choose the 'false' side for a new input value to the PHI.
BasicBlock *NewBlock = BasicBlock::Create(
SI->getContext(), Twine(SI->getName(), ".si.unfold.false"),
@@ -223,32 +223,44 @@ void unfold(DomTreeUpdater *DTU, LoopInfo *LI, SelectInstToUnfold SIToUnfold,
NewBlock->getFirstInsertionPt());
NewPhi->addIncoming(SIOp2, StartBlock);
- if (auto *OpSi = dyn_cast<SelectInst>(SIOp1))
- NewSIsToUnfold->push_back(SelectInstToUnfold(OpSi, SIUse));
- if (auto *OpSi = dyn_cast<SelectInst>(SIOp2))
- NewSIsToUnfold->push_back(SelectInstToUnfold(OpSi, NewPhi));
-
- // Update the phi node of SI.
- for (unsigned Idx = 0; Idx < SIUse->getNumIncomingValues(); ++Idx) {
- if (SIUse->getIncomingBlock(Idx) == StartBlock)
- SIUse->setIncomingValue(Idx, SIOp1);
+ // Update any other PHI nodes in EndBlock.
+ for (PHINode &Phi : EndBlock->phis()) {
+ if (SIUse == &Phi)
+ continue;
+ Phi.addIncoming(Phi.getIncomingValueForBlock(StartBlock), NewBlock);
}
- SIUse->addIncoming(NewPhi, NewBlock);
- // Update any other PHI nodes in EndBlock.
- for (auto II = EndBlock->begin(); PHINode *Phi = dyn_cast<PHINode>(II);
- ++II) {
- if (Phi != SIUse)
- Phi->addIncoming(Phi->getIncomingValueForBlock(StartBlock), NewBlock);
+ // Update the phi node of SI, which is its only use.
+ if (EndBlock == SIUse->getParent()) {
+ SIUse->addIncoming(NewPhi, NewBlock);
+ SIUse->replaceUsesOfWith(SI, SIOp1);
+ } else {
+ PHINode *EndPhi = PHINode::Create(SIUse->getType(), pred_size(EndBlock),
+ Twine(SI->getName(), ".si.unfold.phi"),
+ EndBlock->getFirstInsertionPt());
+ for (BasicBlock *Pred : predecessors(EndBlock)) {
+ if (Pred != StartBlock && Pred != NewBlock)
+ EndPhi->addIncoming(EndPhi, Pred);
+ }
+
+ EndPhi->addIncoming(SIOp1, StartBlock);
+ EndPhi->addIncoming(NewPhi, NewBlock);
+ SIUse->replaceUsesOfWith(SI, EndPhi);
+ SIUse = EndPhi;
}
- StartBlockTerm->eraseFromParent();
+ if (auto *OpSi = dyn_cast<SelectInst>(SIOp1))
+ NewSIsToUnfold->push_back(SelectInstToUnfold(OpSi, SIUse));
+ if (auto *OpSi = dyn_cast<SelectInst>(SIOp2))
+ NewSIsToUnfold->push_back(SelectInstToUnfold(OpSi, NewPhi));
// Insert the real conditional branch based on the original condition.
+ StartBlockTerm->eraseFromParent();
BranchInst::Create(EndBlock, NewBlock, SI->getCondition(), StartBlock);
DTU->applyUpdates({{DominatorTree::Insert, StartBlock, EndBlock},
{DominatorTree::Insert, StartBlock, NewBlock}});
} else {
+ BasicBlock *EndBlock = SIUse->getParent();
BasicBlock *NewBlockT = BasicBlock::Create(
SI->getContext(), Twine(SI->getName(), ".si.unfold.true"),
EndBlock->getParent(), EndBlock);
diff --git a/llvm/test/Transforms/DFAJumpThreading/dfa-jump-threading-transform.ll b/llvm/test/Transforms/DFAJumpThreading/dfa-jump-threading-transform.ll
index c38f81d..cba1ba8 100644
--- a/llvm/test/Transforms/DFAJumpThreading/dfa-jump-threading-transform.ll
+++ b/llvm/test/Transforms/DFAJumpThreading/dfa-jump-threading-transform.ll
@@ -300,3 +300,126 @@ define void @self-reference() {
end:
ret void
}
+
+define void @pr106083_invalidBBarg_fold(i1 %cmp1, i1 %cmp2, i1 %not, ptr %d) {
+; CHECK-LABEL: @pr106083_invalidBBarg_fold(
+; CHECK-NEXT: bb:
+; CHECK-NEXT: br i1 [[CMP1:%.*]], label [[BB1:%.*]], label [[SEL_SI_UNFOLD_FALSE:%.*]]
+; CHECK: sel.si.unfold.false:
+; CHECK-NEXT: [[DOTSI_UNFOLD_PHI1:%.*]] = phi i32 [ 1, [[BB:%.*]] ]
+; CHECK-NEXT: br label [[BB1]]
+; CHECK: BB1:
+; CHECK-NEXT: [[I:%.*]] = phi i16 [ 0, [[BB1_BACKEDGE:%.*]] ], [ 0, [[BB]] ], [ 1, [[BB7:%.*]] ], [ 0, [[SEL_SI_UNFOLD_FALSE]] ], [ 1, [[BB7_JT0:%.*]] ]
+; CHECK-NEXT: [[SEL_SI_UNFOLD_PHI:%.*]] = phi i32 [ [[SEL_SI_UNFOLD_PHI]], [[BB1_BACKEDGE]] ], [ [[SEL_SI_UNFOLD_PHI]], [[BB7]] ], [ 0, [[BB]] ], [ [[DOTSI_UNFOLD_PHI1]], [[SEL_SI_UNFOLD_FALSE]] ], [ [[SEL_SI_UNFOLD_PHI]], [[BB7_JT0]] ]
+; CHECK-NEXT: br i1 [[NOT:%.*]], label [[BB7_JT0]], label [[BB2:%.*]]
+; CHECK: BB2:
+; CHECK-NEXT: store i16 0, ptr [[D:%.*]], align 2
+; CHECK-NEXT: br i1 [[CMP2:%.*]], label [[BB7]], label [[SPEC_SELECT_SI_UNFOLD_FALSE_JT0:%.*]]
+; CHECK: spec.select.si.unfold.false:
+; CHECK-NEXT: br label [[BB7]]
+; CHECK: spec.select.si.unfold.false.jt0:
+; CHECK-NEXT: [[DOTSI_UNFOLD_PHI_JT0:%.*]] = phi i32 [ 0, [[BB2]] ]
+; CHECK-NEXT: br label [[BB7_JT0]]
+; CHECK: BB7:
+; CHECK-NEXT: [[D_PROMOTED4:%.*]] = phi i16 [ 1, [[BB2]] ], [ 1, [[SPEC_SELECT_SI_UNFOLD_FALSE:%.*]] ]
+; CHECK-NEXT: [[_3:%.*]] = phi i32 [ [[SEL_SI_UNFOLD_PHI]], [[BB2]] ], [ poison, [[SPEC_SELECT_SI_UNFOLD_FALSE]] ]
+; CHECK-NEXT: switch i32 [[_3]], label [[BB1_BACKEDGE]] [
+; CHECK-NEXT: i32 0, label [[BB1]]
+; CHECK-NEXT: i32 1, label [[BB8:%.*]]
+; CHECK-NEXT: ]
+; CHECK: BB7.jt0:
+; CHECK-NEXT: [[D_PROMOTED4_JT0:%.*]] = phi i16 [ 0, [[BB1]] ], [ 1, [[SPEC_SELECT_SI_UNFOLD_FALSE_JT0]] ]
+; CHECK-NEXT: [[_3_JT0:%.*]] = phi i32 [ 0, [[BB1]] ], [ [[DOTSI_UNFOLD_PHI_JT0]], [[SPEC_SELECT_SI_UNFOLD_FALSE_JT0]] ]
+; CHECK-NEXT: br label [[BB1]]
+; CHECK: BB1.backedge:
+; CHECK-NEXT: br label [[BB1]]
+; CHECK: BB8:
+; CHECK-NEXT: ret void
+;
+bb:
+ %sel = select i1 %cmp1, i32 0, i32 1
+ br label %BB1
+
+BB1: ; preds = %BB1.backedge, %BB7, %bb
+ %i = phi i16 [ 0, %BB1.backedge ], [ 0, %bb ], [ 1, %BB7 ]
+ br i1 %not, label %BB7, label %BB2
+
+BB2: ; preds = %BB1
+ store i16 0, ptr %d, align 2
+ %spec.select = select i1 %cmp2, i32 %sel, i32 0
+ br label %BB7
+
+BB7: ; preds = %BB2, %BB1
+ %d.promoted4 = phi i16 [ 0, %BB1 ], [ 1, %BB2 ]
+ %_3 = phi i32 [ 0, %BB1 ], [ %spec.select, %BB2 ]
+ switch i32 %_3, label %BB1.backedge [
+ i32 0, label %BB1
+ i32 1, label %BB8
+ ]
+
+BB1.backedge: ; preds = %BB7
+ br label %BB1
+
+BB8: ; preds = %BB7
+ ret void
+}
+
+define void @pr106083_select_dead_uses(i1 %cmp1, i1 %not, ptr %p) {
+; CHECK-LABEL: @pr106083_select_dead_uses(
+; CHECK-NEXT: bb:
+; CHECK-NEXT: br i1 [[CMP1:%.*]], label [[DOTLOOPEXIT6:%.*]], label [[SPEC_SELECT_SI_UNFOLD_FALSE:%.*]]
+; CHECK: spec.select.si.unfold.false:
+; CHECK-NEXT: [[DOTSI_UNFOLD_PHI1:%.*]] = phi i32 [ 1, [[BB:%.*]] ]
+; CHECK-NEXT: br label [[DOTLOOPEXIT6]]
+; CHECK: .loopexit6:
+; CHECK-NEXT: [[SPEC_SELECT_SI_UNFOLD_PHI:%.*]] = phi i32 [ [[SPEC_SELECT_SI_UNFOLD_PHI]], [[SELECT_UNFOLD:%.*]] ], [ 0, [[BB]] ], [ [[DOTSI_UNFOLD_PHI1]], [[SPEC_SELECT_SI_UNFOLD_FALSE]] ]
+; CHECK-NEXT: br i1 [[NOT:%.*]], label [[SELECT_UNFOLD_JT0:%.*]], label [[BB1:%.*]]
+; CHECK: bb1:
+; CHECK-NEXT: [[I:%.*]] = load i32, ptr [[P:%.*]], align 4
+; CHECK-NEXT: [[NOT2:%.*]] = icmp eq i32 0, 0
+; CHECK-NEXT: br i1 [[NOT2]], label [[SELECT_UNFOLD]], label [[SPEC_SELECT7_SI_UNFOLD_FALSE_JT0:%.*]]
+; CHECK: spec.select7.si.unfold.false:
+; CHECK-NEXT: br label [[SELECT_UNFOLD]]
+; CHECK: spec.select7.si.unfold.false.jt0:
+; CHECK-NEXT: [[DOTSI_UNFOLD_PHI_JT0:%.*]] = phi i32 [ 0, [[BB1]] ]
+; CHECK-NEXT: br label [[SELECT_UNFOLD_JT0]]
+; CHECK: select.unfold:
+; CHECK-NEXT: [[_2:%.*]] = phi i32 [ [[SPEC_SELECT_SI_UNFOLD_PHI]], [[BB1]] ], [ poison, [[SPEC_SELECT7_SI_UNFOLD_FALSE:%.*]] ]
+; CHECK-NEXT: switch i32 [[_2]], label [[BB2:%.*]] [
+; CHECK-NEXT: i32 0, label [[DOTPREHEADER_PREHEADER:%.*]]
+; CHECK-NEXT: i32 1, label [[DOTLOOPEXIT6]]
+; CHECK-NEXT: ]
+; CHECK: select.unfold.jt0:
+; CHECK-NEXT: [[_2_JT0:%.*]] = phi i32 [ 0, [[DOTLOOPEXIT6]] ], [ [[DOTSI_UNFOLD_PHI_JT0]], [[SPEC_SELECT7_SI_UNFOLD_FALSE_JT0]] ]
+; CHECK-NEXT: br label [[DOTPREHEADER_PREHEADER]]
+; CHECK: .preheader.preheader:
+; CHECK-NEXT: ret void
+; CHECK: bb2:
+; CHECK-NEXT: unreachable
+;
+bb:
+ %spec.select = select i1 %cmp1, i32 0, i32 1
+ br label %.loopexit6
+
+.loopexit6: ; preds = %select.unfold, %bb
+ br i1 %not, label %select.unfold, label %bb1
+
+bb1: ; preds = %.loopexit6
+ %i = load i32, ptr %p, align 4
+ %not2 = icmp eq i32 0, 0
+ %spec.select7 = select i1 %not2, i32 %spec.select, i32 0
+ br label %select.unfold
+
+select.unfold: ; preds = %bb1, %.loopexit6
+ %_2 = phi i32 [ 0, %.loopexit6 ], [ %spec.select7, %bb1 ]
+ switch i32 %_2, label %bb2 [
+ i32 0, label %.preheader.preheader
+ i32 1, label %.loopexit6
+ ]
+
+.preheader.preheader: ; preds = %select.unfold
+ ret void
+
+bb2: ; preds = %select.unfold
+ unreachable
+}
generated by cgit v1.1 at 2025-10-21 09:52:19 +0000