[Bug middle-end/103950] [9/10/11/12 Regression] printf("\xff") incorrectly optimized to putchar(-1)

[pinskia at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103950

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |9.5
            Summary|printf("\xff") incorrectly  |[9/10/11/12 Regression]
                   |optimized to putchar(-1)    |printf("\xff") incorrectly
                   |                            |optimized to putchar(-1)
      Known to work|                            |4.0.0

--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
The optimization was introduced in r0-69361 and so it is a regression from GCC
4.0.0 and before.
I think the following will fix the issue:
apinski@xeond:~/src/upstream-gcc/gcc/gcc$ git diff gimple-fold.c
diff --git a/gcc/gimple-fold.c b/gcc/gimple-fold.c
index 77c551af942..6f158d301c5 100644
--- a/gcc/gimple-fold.c
+++ b/gcc/gimple-fold.c
@@ -3907,7 +3907,7 @@ gimple_fold_builtin_printf (gimple_stmt_iterator *gsi,
tree fmt,
          /* Given printf("c"), (where c is any one character,)
             convert "c"[0] to an int and pass that to the replacement
             function.  */
-         newarg = build_int_cst (integer_type_node, str[0]);
+         newarg = build_int_cst (integer_type_node, (unsigned char)str[0]);
          if (fn_putchar)
            {
              gcall *repl = gimple_build_call (fn_putchar, 1, newarg);