enhance memcpyopt to obey -fno-builtin and friends. This addresses a
problem reported on cfe-dev.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@130661 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/MemCpyOptimizer.cpp b/lib/Transforms/Scalar/MemCpyOptimizer.cpp
index 1db2e6e..a3035cb 100644
--- a/lib/Transforms/Scalar/MemCpyOptimizer.cpp
+++ b/lib/Transforms/Scalar/MemCpyOptimizer.cpp
@@ -28,6 +28,7 @@
#include "llvm/Support/IRBuilder.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Target/TargetData.h"
+#include "llvm/Target/TargetLibraryInfo.h"
#include <list>
using namespace llvm;
@@ -299,12 +300,15 @@
namespace {
class MemCpyOpt : public FunctionPass {
MemoryDependenceAnalysis *MD;
+ TargetLibraryInfo *TLI;
const TargetData *TD;
public:
static char ID; // Pass identification, replacement for typeid
MemCpyOpt() : FunctionPass(ID) {
initializeMemCpyOptPass(*PassRegistry::getPassRegistry());
MD = 0;
+ TLI = 0;
+ TD = 0;
}
bool runOnFunction(Function &F);
@@ -316,6 +320,7 @@
AU.addRequired<DominatorTree>();
AU.addRequired<MemoryDependenceAnalysis>();
AU.addRequired<AliasAnalysis>();
+ AU.addRequired<TargetLibraryInfo>();
AU.addPreserved<AliasAnalysis>();
AU.addPreserved<MemoryDependenceAnalysis>();
}
@@ -346,6 +351,7 @@
false, false)
INITIALIZE_PASS_DEPENDENCY(DominatorTree)
INITIALIZE_PASS_DEPENDENCY(MemoryDependenceAnalysis)
+INITIALIZE_PASS_DEPENDENCY(TargetLibraryInfo)
INITIALIZE_AG_DEPENDENCY(AliasAnalysis)
INITIALIZE_PASS_END(MemCpyOpt, "memcpyopt", "MemCpy Optimization",
false, false)
@@ -804,6 +810,9 @@
bool MemCpyOpt::processMemMove(MemMoveInst *M) {
AliasAnalysis &AA = getAnalysis<AliasAnalysis>();
+ if (!TLI->has(LibFunc::memmove))
+ return false;
+
// See if the pointers alias.
if (!AA.isNoAlias(AA.getLocationForDest(M), AA.getLocationForSource(M)))
return false;
@@ -935,6 +944,14 @@
bool MadeChange = false;
MD = &getAnalysis<MemoryDependenceAnalysis>();
TD = getAnalysisIfAvailable<TargetData>();
+ TLI = &getAnalysis<TargetLibraryInfo>();
+
+ // If we don't have at least memset and memcpy, there is little point of doing
+ // anything here. These are required by a freestanding implementation, so if
+ // even they are disabled, there is no point in trying hard.
+ if (!TLI->has(LibFunc::memset) || !TLI->has(LibFunc::memcpy))
+ return false;
+
while (1) {
if (!iterateOnFunction(F))
break;