diff options
| -rw-r--r-- | lib/Target/Mips/MipsAsmPrinter.cpp | 27 |
1 files changed, 26 insertions, 1 deletions
diff --git a/lib/Target/Mips/MipsAsmPrinter.cpp b/lib/Target/Mips/MipsAsmPrinter.cpp index 24f2e89aa5..8dd6a37e75 100644 --- a/lib/Target/Mips/MipsAsmPrinter.cpp +++ b/lib/Target/Mips/MipsAsmPrinter.cpp @@ -247,7 +247,32 @@ bool MipsAsmPrinter::isBlockOnlyReachableByFallthrough(const MachineBasicBlock * if (isa<SwitchInst>(bb->getTerminator())) return false; - return AsmPrinter::isBlockOnlyReachableByFallthrough(MBB); + // If this is a landing pad, it isn't a fall through. If it has no preds, + // then nothing falls through to it. + if (MBB->isLandingPad() || MBB->pred_empty()) + return false; + + // If there isn't exactly one predecessor, it can't be a fall through. + MachineBasicBlock::const_pred_iterator PI = MBB->pred_begin(), PI2 = PI; + ++PI2; + + if (PI2 != MBB->pred_end()) + return false; + + // The predecessor has to be immediately before this block. + if (!Pred->isLayoutSuccessor(MBB)) + return false; + + // If the block is completely empty, then it definitely does fall through. + if (Pred->empty()) + return true; + + // Otherwise, check the last instruction. + // Check if the last terminator is an unconditional branch. + MachineBasicBlock::const_iterator I = Pred->end(); + while (I != Pred->begin() && !(--I)->getDesc().isTerminator()); + + return !I->getDesc().isBarrier(); } // Print out an operand for an inline asm expression. |