SimplifyLibCalls: Add missing legalize check on various printf to puts and
putchar transforms, their return values are not compatible.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@125442 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/SimplifyLibCalls.cpp b/lib/Transforms/Scalar/SimplifyLibCalls.cpp
index c8c0098..ec45b71 100644
--- a/lib/Transforms/Scalar/SimplifyLibCalls.cpp
+++ b/lib/Transforms/Scalar/SimplifyLibCalls.cpp
@@ -1092,8 +1092,13 @@
return CI->use_empty() ? (Value*)CI :
ConstantInt::get(CI->getType(), 0);
- // printf("x") -> putchar('x'), even for '%'. Return the result of putchar
- // in case there is an error writing to stdout.
+ // Do not do any of the following transformations if the printf return value
+ // is used, in general the printf return value is not compatible with either
+ // putchar() or puts().
+ if (!CI->use_empty())
+ return 0;
+
+ // printf("x") -> putchar('x'), even for '%'.
if (FormatStr.size() == 1) {
Value *Res = EmitPutChar(B.getInt32(FormatStr[0]), B, TD);
if (CI->use_empty()) return CI;
@@ -1126,8 +1131,7 @@
// printf("%s\n", str) --> puts(str)
if (FormatStr == "%s\n" && CI->getNumArgOperands() > 1 &&
- CI->getArgOperand(1)->getType()->isPointerTy() &&
- CI->use_empty()) {
+ CI->getArgOperand(1)->getType()->isPointerTy()) {
EmitPutS(CI->getArgOperand(1), B, TD);
return CI;
}
@@ -1344,7 +1348,7 @@
if (!GetConstantStringInfo(CI->getArgOperand(0), Str))
return 0;
- if (Str.empty()) {
+ if (Str.empty() && CI->use_empty()) {
// puts("") -> putchar('\n')
Value *Res = EmitPutChar(B.getInt32('\n'), B, TD);
if (CI->use_empty()) return CI;