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authorrdivacky <rdivacky@FreeBSD.org>2010-03-03 17:27:15 +0000
committerrdivacky <rdivacky@FreeBSD.org>2010-03-03 17:27:15 +0000
commit8230c40430a1325b5cc5bc0221931487b4bd573c (patch)
tree836a05cff50ca46176117b86029f061fa4db54f0 /lib/CodeGen/CodePlacementOpt.cpp
parentf25ddd991a5601d0101602c4c263a58c7af4b8a2 (diff)
downloadFreeBSD-src-8230c40430a1325b5cc5bc0221931487b4bd573c.zip
FreeBSD-src-8230c40430a1325b5cc5bc0221931487b4bd573c.tar.gz
Update LLVM to 97654.
Diffstat (limited to 'lib/CodeGen/CodePlacementOpt.cpp')
-rw-r--r--lib/CodeGen/CodePlacementOpt.cpp15
1 files changed, 8 insertions, 7 deletions
diff --git a/lib/CodeGen/CodePlacementOpt.cpp b/lib/CodeGen/CodePlacementOpt.cpp
index a13a310..3ff2a04 100644
--- a/lib/CodeGen/CodePlacementOpt.cpp
+++ b/lib/CodeGen/CodePlacementOpt.cpp
@@ -102,13 +102,6 @@ bool CodePlacementOpt::HasAnalyzableTerminator(MachineBasicBlock *MBB) {
// Conservatively ignore EH landing pads.
if (MBB->isLandingPad()) return false;
- // Ignore blocks which look like they might have EH-related control flow.
- // At the time of this writing, there are blocks which AnalyzeBranch
- // thinks end in single uncoditional branches, yet which have two CFG
- // successors. Code in this file is not prepared to reason about such things.
- if (!MBB->empty() && MBB->back().isEHLabel())
- return false;
-
// Aggressively handle return blocks and similar constructs.
if (MBB->succ_empty()) return true;
@@ -118,6 +111,14 @@ bool CodePlacementOpt::HasAnalyzableTerminator(MachineBasicBlock *MBB) {
// Make sure the terminator is understood.
if (TII->AnalyzeBranch(*MBB, TBB, FBB, Cond))
return false;
+ // Ignore blocks which look like they might have EH-related control flow.
+ // AnalyzeBranch thinks it knows how to analyze such things, but it doesn't
+ // recognize the possibility of a control transfer through an unwind.
+ // Such blocks contain EH_LABEL instructions, however they may be in the
+ // middle of the block. Instead of searching for them, just check to see
+ // if the CFG disagrees with AnalyzeBranch.
+ if (1u + !Cond.empty() != MBB->succ_size())
+ return false;
// Make sure we have the option of reversing the condition.
if (!Cond.empty() && TII->ReverseBranchCondition(Cond))
return false;
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