Add a puts optimization that converts puts() to putchar('\n').
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@120398 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/SimplifyLibCalls.cpp b/lib/Transforms/Scalar/SimplifyLibCalls.cpp
index 5b22b23..43c6f6d 100644
--- a/lib/Transforms/Scalar/SimplifyLibCalls.cpp
+++ b/lib/Transforms/Scalar/SimplifyLibCalls.cpp
@@ -1345,6 +1345,34 @@
}
};
+//===---------------------------------------===//
+// 'puts' Optimizations
+
+struct PutsOpt : public LibCallOptimization {
+ virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
+ // Require one fixed pointer argument and an integer/void result.
+ const FunctionType *FT = Callee->getFunctionType();
+ if (FT->getNumParams() < 1 || !FT->getParamType(0)->isPointerTy() ||
+ !(FT->getReturnType()->isIntegerTy() ||
+ FT->getReturnType()->isVoidTy()))
+ return 0;
+
+ // Check for a constant string.
+ std::string Str;
+ if (!GetConstantStringInfo(CI->getArgOperand(0), Str))
+ return 0;
+
+ if (Str.empty()) {
+ // puts("") -> putchar('\n')
+ Value *Res = EmitPutChar(B.getInt32('\n'), B, TD);
+ if (CI->use_empty()) return CI;
+ return B.CreateIntCast(Res, CI->getType(), true);
+ }
+
+ return 0;
+ }
+};
+
} // end anonymous namespace.
//===----------------------------------------------------------------------===//
@@ -1370,6 +1398,7 @@
// Formatting and IO Optimizations
SPrintFOpt SPrintF; PrintFOpt PrintF;
FWriteOpt FWrite; FPutsOpt FPuts; FPrintFOpt FPrintF;
+ PutsOpt Puts;
bool Modified; // This is only used by doInitialization.
public:
@@ -1484,6 +1513,7 @@
Optimizations["fwrite"] = &FWrite;
Optimizations["fputs"] = &FPuts;
Optimizations["fprintf"] = &FPrintF;
+ Optimizations["puts"] = &Puts;
}
@@ -2298,9 +2328,6 @@
// * pow(sqrt(x),y) -> pow(x,y*0.5)
// * pow(pow(x,y),z)-> pow(x,y*z)
//
-// puts:
-// * puts("") -> putchar('\n')
-//
// round, roundf, roundl:
// * round(cnst) -> cnst'
//