Upgrade BasicAliasAnalysis::getModRefBehavior to not call Value::getName,
which dynamically allocates the string result. This speeds up dse on the
testcase from PR1432 from 0.3781s to 0.1804s (2.1x).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@40838 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/BasicAliasAnalysis.cpp b/lib/Analysis/BasicAliasAnalysis.cpp
index eba2131..a1bf69e 100644
--- a/lib/Analysis/BasicAliasAnalysis.cpp
+++ b/lib/Analysis/BasicAliasAnalysis.cpp
@@ -24,6 +24,7 @@
#include "llvm/Pass.h"
#include "llvm/Target/TargetData.h"
#include "llvm/ADT/SmallVector.h"
+#include "llvm/ADT/StringMap.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Support/GetElementPtrTypeIterator.h"
#include "llvm/Support/ManagedStatic.h"
@@ -900,17 +901,26 @@
StringCompare());
Initialized = true;
}
+
+ ValueName *Name = F->getValueName();
+ unsigned NameLen = Name->getKeyLength();
+ const char *NamePtr = Name->getKeyData();
+
+ // If there is an embedded nul character in the function name, we can never
+ // match it.
+ if (strlen(NamePtr) != NameLen)
+ return UnknownModRefBehavior;
std::vector<const char*>::iterator Ptr =
std::lower_bound(NoMemoryTable->begin(), NoMemoryTable->end(),
- F->getName().c_str(), StringCompare());
- if (Ptr != NoMemoryTable->end() && *Ptr == F->getName())
+ NamePtr, StringCompare());
+ if (Ptr != NoMemoryTable->end() && strcmp(*Ptr, NamePtr) == 0)
return DoesNotAccessMemory;
Ptr = std::lower_bound(OnlyReadsMemoryTable->begin(),
OnlyReadsMemoryTable->end(),
- F->getName().c_str(), StringCompare());
- if (Ptr != OnlyReadsMemoryTable->end() && *Ptr == F->getName())
+ NamePtr, StringCompare());
+ if (Ptr != OnlyReadsMemoryTable->end() && strcmp(*Ptr, NamePtr) == 0)
return OnlyReadsMemory;
return UnknownModRefBehavior;