From 4279f3c9845e1030877c81263aad35d2fa59e3f5 Mon Sep 17 00:00:00 2001 From: Chris Lattner Date: Sun, 29 Feb 2004 06:41:20 +0000 Subject: [PATCH] Fix PR255: [tailduplication] Single basic block loops are very rare Note that this is a band-aid put over a band-aid. This just undisables tail duplication in on very specific case that it seems to work in. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@11989 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Transforms/Scalar/TailDuplication.cpp | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/lib/Transforms/Scalar/TailDuplication.cpp b/lib/Transforms/Scalar/TailDuplication.cpp index 7d5aac4fe73..315b90697cf 100644 --- a/lib/Transforms/Scalar/TailDuplication.cpp +++ b/lib/Transforms/Scalar/TailDuplication.cpp @@ -125,6 +125,7 @@ bool TailDup::shouldEliminateUnconditionalBranch(TerminatorInst *TI) { bool TailDup::canEliminateUnconditionalBranch(TerminatorInst *TI) { // Basically, we refuse to make the transformation if any of the values // computed in the 'tail' are used in any other basic blocks. + BasicBlock *BB = TI->getParent(); BasicBlock *Tail = TI->getSuccessor(0); assert(isa(TI) && cast(TI)->isUnconditional()); @@ -132,7 +133,7 @@ bool TailDup::canEliminateUnconditionalBranch(TerminatorInst *TI) { for (Value::use_iterator UI = I->use_begin(), E = I->use_end(); UI != E; ++UI) { Instruction *User = cast(*UI); - if (User->getParent() != Tail || isa(User)) + if (User->getParent() != Tail && User->getParent() != BB) return false; } return true;