diff options
| -rw-r--r-- | llvm/lib/CodeGen/IfConversion.cpp | 27 | ||||
| -rw-r--r-- | llvm/test/CodeGen/MIR/ARM/PR32721_ifcvt_triangle_unanalyzable.mir | 24 |
2 files changed, 6 insertions, 45 deletions
diff --git a/llvm/lib/CodeGen/IfConversion.cpp b/llvm/lib/CodeGen/IfConversion.cpp index 8f3b6f9269f..1c33f3b6800 100644 --- a/llvm/lib/CodeGen/IfConversion.cpp +++ b/llvm/lib/CodeGen/IfConversion.cpp @@ -1588,32 +1588,22 @@ bool IfConverter::IfConvertTriangle(BBInfo &BBI, IfcvtKind Kind) { BBCvt = MBPI->getEdgeProbability(BBI.BB, &CvtMBB); } - // To be able to insert code freely at the end of BBI we sometimes remove - // the branch from BBI to NextMBB temporarily. Remember if this happened. - bool RemovedBranchToNextMBB = false; if (CvtMBB.pred_size() > 1) { BBI.NonPredSize -= TII->removeBranch(*BBI.BB); // Copy instructions in the true block, predicate them, and add them to // the entry block. CopyAndPredicateBlock(BBI, *CvtBBI, Cond, true); - // Keep the CFG updated. + // RemoveExtraEdges won't work if the block has an unanalyzable branch, so + // explicitly remove CvtBBI as a successor. BBI.BB->removeSuccessor(&CvtMBB, true); } else { // Predicate the 'true' block after removing its branch. CvtBBI->NonPredSize -= TII->removeBranch(CvtMBB); PredicateBlock(*CvtBBI, CvtMBB.end(), Cond); - // Remove the branch from the entry of the triangle to NextBB to be able to - // do the merge below. Keep the CFG updated, but remember we removed the - // branch since we do want to execute NextMBB, either by introducing a - // branch to it again, or merging it into the entry block. - // How it's handled is decided further down. - BBI.NonPredSize -= TII->removeBranch(*BBI.BB); - BBI.BB->removeSuccessor(&NextMBB, true); - RemovedBranchToNextMBB = true; - // Now merge the entry of the triangle with the true block. + BBI.NonPredSize -= TII->removeBranch(*BBI.BB); MergeBlocks(BBI, *CvtBBI, false); } @@ -1651,19 +1641,12 @@ bool IfConverter::IfConvertTriangle(BBInfo &BBI, IfcvtKind Kind) { // block. By not merging them, we make it possible to iteratively // ifcvt the blocks. if (!HasEarlyExit && - // We might have removed BBI from NextMBB's predecessor list above but - // we want it to be there, so consider that too. - (NextMBB.pred_size() == (RemovedBranchToNextMBB ? 0 : 1)) && - !NextBBI->HasFallThrough && + NextMBB.pred_size() == 1 && !NextBBI->HasFallThrough && !NextMBB.hasAddressTaken()) { - // We will merge NextBBI into BBI, and thus remove the current - // fallthrough from BBI into CvtBBI. - BBI.BB->removeSuccessor(&CvtMBB, true); MergeBlocks(BBI, *NextBBI); FalseBBDead = true; } else { InsertUncondBranch(*BBI.BB, NextMBB, TII); - BBI.BB->addSuccessor(&NextMBB); BBI.HasFallThrough = false; } // Mixed predicated and unpredicated code. This cannot be iteratively @@ -1671,6 +1654,8 @@ bool IfConverter::IfConvertTriangle(BBInfo &BBI, IfcvtKind Kind) { IterIfcvt = false; } + RemoveExtraEdges(BBI); + // Update block info. BB can be iteratively if-converted. if (!IterIfcvt) BBI.IsDone = true; diff --git a/llvm/test/CodeGen/MIR/ARM/PR32721_ifcvt_triangle_unanalyzable.mir b/llvm/test/CodeGen/MIR/ARM/PR32721_ifcvt_triangle_unanalyzable.mir deleted file mode 100644 index 96801f5b0a3..00000000000 --- a/llvm/test/CodeGen/MIR/ARM/PR32721_ifcvt_triangle_unanalyzable.mir +++ /dev/null @@ -1,24 +0,0 @@ -# RUN: llc -mtriple=arm-apple-ios -run-pass=if-converter %s -o - | FileCheck %s ---- -name: foo -body: | - bb.0: - B %bb.2 - - bb.1: - BX_RET 14, 0 - - bb.2: - Bcc %bb.1, 1, %cpsr - - bb.3: - B %bb.1 - -... - -# We should get a single block containing the BX_RET, with no successors at all - -# CHECK: body: -# CHECK-NEXT: bb.0: -# CHECK-NEXT: BX_RET - |
