[SimplifyLibCalls] Garbage collect dead code.
We already skip optimizations if the return value
of printf() is used, so CI->use_empty() is always
true.
Differential Revision: http://reviews.llvm.org/D18656
llvm-svn: 265253
diff --git a/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp b/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp
index 3712575..35aa8ee 100644
--- a/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp
+++ b/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp
@@ -1832,12 +1832,8 @@
return nullptr;
// printf("x") -> putchar('x'), even for '%'.
- if (FormatStr.size() == 1) {
- Value *Res = emitPutChar(B.getInt32(FormatStr[0]), B, TLI);
- if (CI->use_empty() || !Res)
- return Res;
- return B.CreateIntCast(Res, CI->getType(), true);
- }
+ if (FormatStr.size() == 1)
+ return emitPutChar(B.getInt32(FormatStr[0]), B, TLI);
// printf("%s", "a") --> putchar('a')
if (FormatStr == "%s" && CI->getNumArgOperands() > 1) {
@@ -1846,15 +1842,7 @@
return nullptr;
if (ChrStr.size() != 1)
return nullptr;
- Value *Res = emitPutChar(B.getInt32(ChrStr[0]), B, TLI);
-
- // FIXME: Here we check that the return value is not used
- // but ealier we prevent transformations in case it is.
- // This should probably be an assert.
- if (CI->use_empty() || !Res)
- return Res;
-
- return B.CreateIntCast(Res, CI->getType(), true);
+ return emitPutChar(B.getInt32(ChrStr[0]), B, TLI);
}
// printf("foo\n") --> puts("foo")
@@ -1864,28 +1852,19 @@
// pass to be run after this pass, to merge duplicate strings.
FormatStr = FormatStr.drop_back();
Value *GV = B.CreateGlobalString(FormatStr, "str");
- Value *NewCI = emitPutS(GV, B, TLI);
- return (CI->use_empty() || !NewCI)
- ? NewCI
- : ConstantInt::get(CI->getType(), FormatStr.size() + 1);
+ return emitPutS(GV, B, TLI);
}
// Optimize specific format strings.
// printf("%c", chr) --> putchar(chr)
if (FormatStr == "%c" && CI->getNumArgOperands() > 1 &&
- CI->getArgOperand(1)->getType()->isIntegerTy()) {
- Value *Res = emitPutChar(CI->getArgOperand(1), B, TLI);
-
- if (CI->use_empty() || !Res)
- return Res;
- return B.CreateIntCast(Res, CI->getType(), true);
- }
+ CI->getArgOperand(1)->getType()->isIntegerTy())
+ return emitPutChar(CI->getArgOperand(1), B, TLI);
// printf("%s\n", str) --> puts(str)
if (FormatStr == "%s\n" && CI->getNumArgOperands() > 1 &&
- CI->getArgOperand(1)->getType()->isPointerTy()) {
+ CI->getArgOperand(1)->getType()->isPointerTy())
return emitPutS(CI->getArgOperand(1), B, TLI);
- }
return nullptr;
}