Revert r146184. I am seeing performance regression cause by this patch in one test case.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@146205 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/MachineSink.cpp b/lib/CodeGen/MachineSink.cpp
index 7740a75..dff8109 100644
--- a/lib/CodeGen/MachineSink.cpp
+++ b/lib/CodeGen/MachineSink.cpp
@@ -485,16 +485,6 @@
for (MachineBasicBlock::succ_iterator SI = ParentBlock->succ_begin(),
E = ParentBlock->succ_end(); SI != E; ++SI) {
MachineBasicBlock *SuccBlock = *SI;
- // It is not possible to sink an instruction into its own block. This can
- // happen with loops.
- if (ParentBlock == SuccBlock)
- continue;
-
- // It's not safe to sink instructions to EH landing pad. Control flow into
- // landing pad is implicitly defined.
- if (SuccBlock->isLandingPad())
- continue;
-
bool LocalUse = false;
if (AllUsesDominatedByBlock(Reg, SuccBlock, ParentBlock,
BreakPHIEdge, LocalUse)) {
@@ -511,6 +501,17 @@
return NULL;
}
}
+
+ // It is not possible to sink an instruction into its own block. This can
+ // happen with loops.
+ if (ParentBlock == SuccToSinkTo)
+ return NULL;
+
+ // It's not safe to sink instructions to EH landing pad. Control flow into
+ // landing pad is implicitly defined.
+ if (SuccToSinkTo && SuccToSinkTo->isLandingPad())
+ return NULL;
+
return SuccToSinkTo;
}