Simplify code. No intended functionality/performance change.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92938 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/PreAllocSplitting.cpp b/lib/CodeGen/PreAllocSplitting.cpp
index 5dc14e1..8cbc8c2 100644
--- a/lib/CodeGen/PreAllocSplitting.cpp
+++ b/lib/CodeGen/PreAllocSplitting.cpp
@@ -481,31 +481,20 @@
// Search for the use in this block that precedes the instruction we care
// about, going to the fallback case if we don't find it.
- if (UseI == MBB->begin())
- return PerformPHIConstructionFallBack(UseI, MBB, LI, Visited, Defs,
- Uses, NewVNs, LiveOut, Phis,
- IsTopLevel, IsIntraBlock);
-
MachineBasicBlock::iterator Walker = UseI;
- --Walker;
bool found = false;
while (Walker != MBB->begin()) {
+ --Walker;
if (BlockUses.count(Walker)) {
found = true;
break;
}
- --Walker;
}
-
- // Must check begin() too.
- if (!found) {
- if (BlockUses.count(Walker))
- found = true;
- else
- return PerformPHIConstructionFallBack(UseI, MBB, LI, Visited, Defs,
- Uses, NewVNs, LiveOut, Phis,
- IsTopLevel, IsIntraBlock);
- }
+
+ if (!found)
+ return PerformPHIConstructionFallBack(UseI, MBB, LI, Visited, Defs,
+ Uses, NewVNs, LiveOut, Phis,
+ IsTopLevel, IsIntraBlock);
SlotIndex UseIndex = LIs->getInstructionIndex(Walker);
UseIndex = UseIndex.getUseIndex();
@@ -533,17 +522,11 @@
// This case is basically a merging of the two preceding case, with the
// special note that checking for defs must take precedence over checking
// for uses, because of two-address instructions.
-
- if (UseI == MBB->begin())
- return PerformPHIConstructionFallBack(UseI, MBB, LI, Visited, Defs, Uses,
- NewVNs, LiveOut, Phis,
- IsTopLevel, IsIntraBlock);
-
MachineBasicBlock::iterator Walker = UseI;
- --Walker;
bool foundDef = false;
bool foundUse = false;
while (Walker != MBB->begin()) {
+ --Walker;
if (BlockDefs.count(Walker)) {
foundDef = true;
break;
@@ -551,20 +534,12 @@
foundUse = true;
break;
}
- --Walker;
}
-
- // Must check begin() too.
- if (!foundDef && !foundUse) {
- if (BlockDefs.count(Walker))
- foundDef = true;
- else if (BlockUses.count(Walker))
- foundUse = true;
- else
- return PerformPHIConstructionFallBack(UseI, MBB, LI, Visited, Defs,
- Uses, NewVNs, LiveOut, Phis,
- IsTopLevel, IsIntraBlock);
- }
+
+ if (!foundDef && !foundUse)
+ return PerformPHIConstructionFallBack(UseI, MBB, LI, Visited, Defs,
+ Uses, NewVNs, LiveOut, Phis,
+ IsTopLevel, IsIntraBlock);
SlotIndex StartIndex = LIs->getInstructionIndex(Walker);
StartIndex = foundDef ? StartIndex.getDefIndex() : StartIndex.getUseIndex();