diff options
Diffstat (limited to 'lib/Transforms')
| -rw-r--r-- | lib/Transforms/Scalar/InstructionCombining.cpp | 28 |
1 files changed, 18 insertions, 10 deletions
diff --git a/lib/Transforms/Scalar/InstructionCombining.cpp b/lib/Transforms/Scalar/InstructionCombining.cpp index 1ecefeb82b..9d0990f51b 100644 --- a/lib/Transforms/Scalar/InstructionCombining.cpp +++ b/lib/Transforms/Scalar/InstructionCombining.cpp @@ -8199,22 +8199,30 @@ Instruction *InstCombiner::visitCallInst(CallInst &CI) { } } - // If the stack restore is in a return/unwind block and if there are no - // allocas or calls between the restore and the return, nuke the restore. + // Scan down this block to see if there is another stack restore in the + // same block without an intervening call/alloca. + BasicBlock::iterator BI = II; TerminatorInst *TI = II->getParent()->getTerminator(); - if (isa<ReturnInst>(TI) || isa<UnwindInst>(TI)) { - BasicBlock::iterator BI = II; - bool CannotRemove = false; - for (++BI; &*BI != TI; ++BI) { - if (isa<AllocaInst>(BI) || - (isa<CallInst>(BI) && !isa<IntrinsicInst>(BI))) { + bool CannotRemove = false; + for (++BI; &*BI != TI; ++BI) { + if (isa<AllocaInst>(BI)) { + CannotRemove = true; + break; + } + if (isa<CallInst>(BI)) { + if (!isa<IntrinsicInst>(BI)) { CannotRemove = true; break; } - } - if (!CannotRemove) + // If there is a stackrestore below this one, remove this one. return EraseInstFromFunction(CI); + } } + + // If the stack restore is in a return/unwind block and if there are no + // allocas or calls between the restore and the return, nuke the restore. + if (!CannotRemove && (isa<ReturnInst>(TI) || isa<UnwindInst>(TI))) + return EraseInstFromFunction(CI); break; } } |