improve the code that handles IR generation of byte-sized string literals to avoid
allocating an std::string.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@149924 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/CodeGenModule.cpp b/lib/CodeGen/CodeGenModule.cpp
index 5cc4f39..887513d 100644
--- a/lib/CodeGen/CodeGenModule.cpp
+++ b/lib/CodeGen/CodeGenModule.cpp
@@ -1913,8 +1913,7 @@
if (llvm::Constant *C = Entry.getValue())
return C;
- llvm::Constant *Zero =
- llvm::Constant::getNullValue(llvm::Type::getInt32Ty(VMContext));
+ llvm::Constant *Zero = llvm::Constant::getNullValue(Int32Ty);
llvm::Constant *Zeros[] = { Zero, Zero };
// If we don't already have it, get _NSConstantStringClassReference.
@@ -2054,34 +2053,20 @@
return ObjCFastEnumerationStateType;
}
-/// GetStringForStringLiteral - Return the appropriate bytes for a
-/// string literal, properly padded to match the literal type.
-static std::string GetStringForStringLiteral(const StringLiteral *E,
- const ASTContext &Context) {
- assert((E->isAscii() || E->isUTF8())
- && "Use GetConstantArrayFromStringLiteral for wide strings");
- const ConstantArrayType *CAT =
- Context.getAsConstantArrayType(E->getType());
- assert(CAT && "String isn't pointer or array!");
-
- // Resize the string to the right size.
- uint64_t RealLen = CAT->getSize().getZExtValue();
-
- std::string Str = E->getString().str();
- Str.resize(RealLen, '\0');
- return Str;
-}
-
llvm::Constant *
CodeGenModule::GetConstantArrayFromStringLiteral(const StringLiteral *E) {
assert(!E->getType()->isPointerType() && "Strings are always arrays");
// Don't emit it as the address of the string, emit the string data itself
// as an inline array.
- if (E->getCharByteWidth() == 1)
- return llvm::ConstantDataArray::getString(VMContext,
- GetStringForStringLiteral(E, getContext()),
- false);
+ if (E->getCharByteWidth() == 1) {
+ SmallString<64> Str(E->getString());
+
+ // Resize the string to the right size, which is indicated by its type.
+ const ConstantArrayType *CAT = Context.getAsConstantArrayType(E->getType());
+ Str.resize(CAT->getSize().getZExtValue());
+ return llvm::ConstantDataArray::getString(VMContext, Str, false);
+ }
llvm::ArrayType *AType =
cast<llvm::ArrayType>(getTypes().ConvertType(E->getType()));
@@ -2107,16 +2092,17 @@
/// constant array for the given string literal.
llvm::Constant *
CodeGenModule::GetAddrOfConstantStringFromLiteral(const StringLiteral *S) {
- // FIXME: This can be more efficient.
- // FIXME: We shouldn't need to bitcast the constant in the wide string case.
CharUnits Align = getContext().getTypeAlignInChars(S->getType());
if (S->isAscii() || S->isUTF8()) {
- return GetAddrOfConstantString(GetStringForStringLiteral(S, getContext()),
- /* GlobalName */ 0,
- Align.getQuantity());
+ SmallString<64> Str(S->getString());
+
+ // Resize the string to the right size, which is indicated by its type.
+ const ConstantArrayType *CAT = Context.getAsConstantArrayType(S->getType());
+ Str.resize(CAT->getSize().getZExtValue());
+ return GetAddrOfConstantString(Str, /*GlobalName*/ 0, Align.getQuantity());
}
- // FIXME: the following does not memoize wide strings
+ // FIXME: the following does not memoize wide strings.
llvm::Constant *C = GetConstantArrayFromStringLiteral(S);
llvm::GlobalVariable *GV =
new llvm::GlobalVariable(getModule(),C->getType(),
@@ -2126,7 +2112,6 @@
GV->setAlignment(Align.getQuantity());
GV->setUnnamedAddr(true);
-
return GV;
}
@@ -2172,14 +2157,12 @@
llvm::Constant *CodeGenModule::GetAddrOfConstantString(StringRef Str,
const char *GlobalName,
unsigned Alignment) {
- bool IsConstant = !Features.WritableStrings;
-
// Get the default prefix if a name wasn't specified.
if (!GlobalName)
GlobalName = ".str";
// Don't share any string literals if strings aren't constant.
- if (!IsConstant)
+ if (Features.WritableStrings)
return GenerateStringLiteral(Str, false, *this, GlobalName, Alignment);
llvm::StringMapEntry<llvm::GlobalVariable *> &Entry =
@@ -2193,7 +2176,8 @@
}
// Create a global variable for this.
- llvm::GlobalVariable *GV = GenerateStringLiteral(Str, true, *this, GlobalName, Alignment);
+ llvm::GlobalVariable *GV = GenerateStringLiteral(Str, true, *this, GlobalName,
+ Alignment);
Entry.setValue(GV);
return GV;
}
