[SimplifyLibcalls] Atoi, strtol replacements
Reviewers: spatel, lebedev.ri, xbolva00, efriedma
Reviewed By: xbolva00, efriedma
Subscribers: efriedma, llvm-commits
Differential Revision: https://reviews.llvm.org/D45418
llvm-svn: 330860
diff --git a/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp b/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp
index e65ecc5..ce804ae 100644
--- a/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp
+++ b/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp
@@ -102,6 +102,31 @@
});
}
+static Value *convertStrToNumber(CallInst *CI, StringRef &Str, int64_t Base) {
+ if (Base < 2 || Base > 36)
+ // handle special zero base
+ if (Base != 0)
+ return nullptr;
+
+ char *End;
+ std::string nptr = Str.str();
+ errno = 0;
+ long long int Result = strtoll(nptr.c_str(), &End, Base);
+ if (errno)
+ return nullptr;
+
+ // if we assume all possible target locales are ASCII supersets,
+ // then if strtoll successfully parses a number on the host,
+ // it will also successfully parse the same way on the target
+ if (*End != '\0')
+ return nullptr;
+
+ if (!isIntN(CI->getType()->getPrimitiveSizeInBits(), Result))
+ return nullptr;
+
+ return ConstantInt::get(CI->getType(), Result);
+}
+
//===----------------------------------------------------------------------===//
// String and Memory Library Call Optimizations
//===----------------------------------------------------------------------===//
@@ -1663,6 +1688,29 @@
ConstantInt::get(CI->getType(), 0x7F));
}
+Value *LibCallSimplifier::optimizeAtoi(CallInst *CI, IRBuilder<> &B) {
+ StringRef Str;
+ if (!getConstantStringInfo(CI->getArgOperand(0), Str))
+ return nullptr;
+
+ return convertStrToNumber(CI, Str, 10);
+}
+
+Value *LibCallSimplifier::optimizeStrtol(CallInst *CI, IRBuilder<> &B) {
+ StringRef Str;
+ if (!getConstantStringInfo(CI->getArgOperand(0), Str))
+ return nullptr;
+
+ if (!isa<ConstantPointerNull>(CI->getArgOperand(1)))
+ return nullptr;
+
+ if (ConstantInt *CInt = dyn_cast<ConstantInt>(CI->getArgOperand(2))) {
+ return convertStrToNumber(CI, Str, CInt->getSExtValue());
+ }
+
+ return nullptr;
+}
+
//===----------------------------------------------------------------------===//
// Formatting and IO Library Call Optimizations
//===----------------------------------------------------------------------===//
@@ -2259,6 +2307,13 @@
return optimizeIsAscii(CI, Builder);
case LibFunc_toascii:
return optimizeToAscii(CI, Builder);
+ case LibFunc_atoi:
+ case LibFunc_atol:
+ case LibFunc_atoll:
+ return optimizeAtoi(CI, Builder);
+ case LibFunc_strtol:
+ case LibFunc_strtoll:
+ return optimizeStrtol(CI, Builder);
case LibFunc_printf:
return optimizePrintF(CI, Builder);
case LibFunc_sprintf: