start moving SimplifyLibcalls over to getConstantStringInfo, which is
dramatically more efficient than GetConstantStringInfo.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@149352 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/SimplifyLibCalls.cpp b/lib/Transforms/Scalar/SimplifyLibCalls.cpp
index dcfcf1a..8935cc7 100644
--- a/lib/Transforms/Scalar/SimplifyLibCalls.cpp
+++ b/lib/Transforms/Scalar/SimplifyLibCalls.cpp
@@ -256,19 +256,18 @@
ConstantInt::get(TD->getIntPtrType(*Context), Len),
B, TD);
}
-
+
// Otherwise, the character is a constant, see if the first argument is
// a string literal. If so, we can constant fold.
- std::string Str;
- if (!GetConstantStringInfo(SrcStr, Str))
+ StringRef Str;
+ if (!getConstantStringInfo(SrcStr, Str))
return 0;
- // strchr can find the nul character.
- Str += '\0';
-
- // Compute the offset.
- size_t I = Str.find(CharC->getSExtValue());
- if (I == std::string::npos) // Didn't find the char. strchr returns null.
+ // Compute the offset, make sure to handle the case when we're searching for
+ // zero (a weird way to spell strlen).
+ size_t I = CharC->getSExtValue() == 0 ?
+ Str.size() : Str.find(CharC->getSExtValue());
+ if (I == StringRef::npos) // Didn't find the char. strchr returns null.
return Constant::getNullValue(CI->getType());
// strchr(s+n,c) -> gep(s+n+i,c)
@@ -296,20 +295,18 @@
if (!CharC)
return 0;
- std::string Str;
- if (!GetConstantStringInfo(SrcStr, Str)) {
+ StringRef Str;
+ if (!getConstantStringInfo(SrcStr, Str)) {
// strrchr(s, 0) -> strchr(s, 0)
if (TD && CharC->isZero())
return EmitStrChr(SrcStr, '\0', B, TD);
return 0;
}
- // strrchr can find the nul character.
- Str += '\0';
-
// Compute the offset.
- size_t I = Str.rfind(CharC->getSExtValue());
- if (I == std::string::npos) // Didn't find the char. Return null.
+ size_t I = CharC->getSExtValue() == 0 ?
+ Str.size() : Str.rfind(CharC->getSExtValue());
+ if (I == StringRef::npos) // Didn't find the char. Return null.
return Constant::getNullValue(CI->getType());
// strrchr(s+n,c) -> gep(s+n+i,c)
@@ -334,14 +331,13 @@
if (Str1P == Str2P) // strcmp(x,x) -> 0
return ConstantInt::get(CI->getType(), 0);
- std::string Str1, Str2;
- bool HasStr1 = GetConstantStringInfo(Str1P, Str1);
- bool HasStr2 = GetConstantStringInfo(Str2P, Str2);
+ StringRef Str1, Str2;
+ bool HasStr1 = getConstantStringInfo(Str1P, Str1);
+ bool HasStr2 = getConstantStringInfo(Str2P, Str2);
// strcmp(x, y) -> cnst (if both x and y are constant strings)
if (HasStr1 && HasStr2)
- return ConstantInt::get(CI->getType(),
- StringRef(Str1).compare(Str2));
+ return ConstantInt::get(CI->getType(), Str1.compare(Str2));
if (HasStr1 && Str1.empty()) // strcmp("", x) -> -*x
return B.CreateNeg(B.CreateZExt(B.CreateLoad(Str2P, "strcmpload"),
@@ -397,14 +393,14 @@
if (TD && Length == 1) // strncmp(x,y,1) -> memcmp(x,y,1)
return EmitMemCmp(Str1P, Str2P, CI->getArgOperand(2), B, TD);
- std::string Str1, Str2;
- bool HasStr1 = GetConstantStringInfo(Str1P, Str1);
- bool HasStr2 = GetConstantStringInfo(Str2P, Str2);
+ StringRef Str1, Str2;
+ bool HasStr1 = getConstantStringInfo(Str1P, Str1);
+ bool HasStr2 = getConstantStringInfo(Str2P, Str2);
// strncmp(x, y) -> cnst (if both x and y are constant strings)
if (HasStr1 && HasStr2) {
- StringRef SubStr1 = StringRef(Str1).substr(0, Length);
- StringRef SubStr2 = StringRef(Str2).substr(0, Length);
+ StringRef SubStr1 = Str1.substr(0, Length);
+ StringRef SubStr2 = Str2.substr(0, Length);
return ConstantInt::get(CI->getType(), SubStr1.compare(SubStr2));
}
@@ -609,9 +605,9 @@
!FT->getReturnType()->isIntegerTy())
return 0;
- std::string S1, S2;
- bool HasS1 = GetConstantStringInfo(CI->getArgOperand(0), S1);
- bool HasS2 = GetConstantStringInfo(CI->getArgOperand(1), S2);
+ StringRef S1, S2;
+ bool HasS1 = getConstantStringInfo(CI->getArgOperand(0), S1);
+ bool HasS2 = getConstantStringInfo(CI->getArgOperand(1), S2);
// strspn(s, "") -> 0
// strspn("", s) -> 0
@@ -619,8 +615,11 @@
return Constant::getNullValue(CI->getType());
// Constant folding.
- if (HasS1 && HasS2)
- return ConstantInt::get(CI->getType(), strspn(S1.c_str(), S2.c_str()));
+ if (HasS1 && HasS2) {
+ size_t Pos = S1.find_first_not_of(S2);
+ if (Pos == StringRef::npos) Pos = S1.size();
+ return ConstantInt::get(CI->getType(), Pos);
+ }
return 0;
}
@@ -638,17 +637,20 @@
!FT->getReturnType()->isIntegerTy())
return 0;
- std::string S1, S2;
- bool HasS1 = GetConstantStringInfo(CI->getArgOperand(0), S1);
- bool HasS2 = GetConstantStringInfo(CI->getArgOperand(1), S2);
+ StringRef S1, S2;
+ bool HasS1 = getConstantStringInfo(CI->getArgOperand(0), S1);
+ bool HasS2 = getConstantStringInfo(CI->getArgOperand(1), S2);
// strcspn("", s) -> 0
if (HasS1 && S1.empty())
return Constant::getNullValue(CI->getType());
// Constant folding.
- if (HasS1 && HasS2)
- return ConstantInt::get(CI->getType(), strcspn(S1.c_str(), S2.c_str()));
+ if (HasS1 && HasS2) {
+ size_t Pos = S1.find_first_of(S2);
+ if (Pos == StringRef::npos) Pos = S1.size();
+ return ConstantInt::get(CI->getType(), Pos);
+ }
// strcspn(s, "") -> strlen(s)
if (TD && HasS2 && S2.empty())
@@ -756,11 +758,11 @@
}
// Constant folding: memcmp(x, y, l) -> cnst (all arguments are constant)
- std::string LHSStr, RHSStr;
- if (GetConstantStringInfo(LHS, LHSStr) &&
- GetConstantStringInfo(RHS, RHSStr)) {
+ StringRef LHSStr, RHSStr;
+ if (getConstantStringInfo(LHS, LHSStr) &&
+ getConstantStringInfo(RHS, RHSStr)) {
// Make sure we're not reading out-of-bounds memory.
- if (Len > LHSStr.length() || Len > RHSStr.length())
+ if (Len > LHSStr.size() || Len > RHSStr.size())
return 0;
uint64_t Ret = memcmp(LHSStr.data(), RHSStr.data(), Len);
return ConstantInt::get(CI->getType(), Ret);
@@ -1116,8 +1118,8 @@
Value *OptimizeFixedFormatString(Function *Callee, CallInst *CI,
IRBuilder<> &B) {
// Check for a fixed format string.
- std::string FormatStr;
- if (!GetConstantStringInfo(CI->getArgOperand(0), FormatStr))
+ StringRef FormatStr;
+ if (!getConstantStringInfo(CI->getArgOperand(0), FormatStr))
return 0;
// Empty format string -> noop.
@@ -1143,7 +1145,7 @@
FormatStr.find('%') == std::string::npos) { // no format characters.
// Create a string literal with no \n on it. We expect the constant merge
// pass to be run after this pass, to merge duplicate strings.
- FormatStr.erase(FormatStr.end()-1);
+ FormatStr = FormatStr.drop_back();
Value *GV = B.CreateGlobalString(FormatStr, "str");
EmitPutS(GV, B, TD);
return CI->use_empty() ? (Value*)CI :
@@ -1203,8 +1205,8 @@
Value *OptimizeFixedFormatString(Function *Callee, CallInst *CI,
IRBuilder<> &B) {
// Check for a fixed format string.
- std::string FormatStr;
- if (!GetConstantStringInfo(CI->getArgOperand(1), FormatStr))
+ StringRef FormatStr;
+ if (!getConstantStringInfo(CI->getArgOperand(1), FormatStr))
return 0;
// If we just have a format string (nothing else crazy) transform it.
@@ -1358,8 +1360,8 @@
Value *OptimizeFixedFormatString(Function *Callee, CallInst *CI,
IRBuilder<> &B) {
// All the optimizations depend on the format string.
- std::string FormatStr;
- if (!GetConstantStringInfo(CI->getArgOperand(1), FormatStr))
+ StringRef FormatStr;
+ if (!getConstantStringInfo(CI->getArgOperand(1), FormatStr))
return 0;
// fprintf(F, "foo") --> fwrite("foo", 3, 1, F)
@@ -1442,8 +1444,8 @@
return 0;
// Check for a constant string.
- std::string Str;
- if (!GetConstantStringInfo(CI->getArgOperand(0), Str))
+ StringRef Str;
+ if (!getConstantStringInfo(CI->getArgOperand(0), Str))
return 0;
if (Str.empty() && CI->use_empty()) {
@@ -2413,6 +2415,8 @@
// * stpcpy(str, "literal") ->
// llvm.memcpy(str,"literal",strlen("literal")+1,1)
//
+// strchr:
+// * strchr(p, 0) -> strlen(p)
// tan, tanf, tanl:
// * tan(atan(x)) -> x
//