[Bug middle-end/67220] GCC fails to properly handle libcall symbol visibility of built functions

["hjl.tools at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67220

H.J. Lu <hjl.tools at gmail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2015-08-14
     Ever confirmed|0                           |1

--- Comment #1 from H.J. Lu <hjl.tools at gmail dot com> ---
Inside the same function, one memset is called via PLT and the other
isn't:

[hjl@gnu-6 pr67220]$ cat y.c
typedef __SIZE_TYPE__ size_t;
extern void *memset(void *s, int c, size_t n)
  __attribute__ ((visibility ("hidden")));

extern void bar (void *s);

int
foo2 (void *s, int c, size_t n)
{
  memset (s, '\0', n);
  bar (s);
  memset (s, c, n);
  return 0;
}
[hjl@gnu-6 pr67220]$ make y.s
/export/build/gnu/gcc/build-x86_64-linux/gcc/xgcc
-B/export/build/gnu/gcc/build-x86_64-linux/gcc/ -O2 -fPIC  -S -o y.s y.c
[hjl@gnu-6 pr67220]$ cat y.s
        .file   "y.c"
        .section        .text.unlikely,"ax",@progbits
.LCOLDB0:
        .text
.LHOTB0:
        .p2align 4,,15
        .globl  foo2
        .type   foo2, @function
foo2:
.LFB0:
        .cfi_startproc
        pushq   %r12
        .cfi_def_cfa_offset 16
        .cfi_offset 12, -16
        pushq   %rbp
        .cfi_def_cfa_offset 24
        .cfi_offset 6, -24
        movl    %esi, %r12d
        pushq   %rbx
        .cfi_def_cfa_offset 32
        .cfi_offset 3, -32
        xorl    %esi, %esi
        movq    %rdi, %rbx
        movq    %rdx, %rbp
        call    memset@PLT  <<<< via PLT
        movq    %rbx, %rdi
        call    bar@PLT
        movq    %rbp, %rdx
        movl    %r12d, %esi
        movq    %rbx, %rdi
        call    memset     <<<< No PLT
        popq    %rbx
        .cfi_def_cfa_offset 24
        xorl    %eax, %eax
        popq    %rbp
        .cfi_def_cfa_offset 16
        popq    %r12
        .cfi_def_cfa_offset 8
        ret
        .cfi_endproc
.LFE0:
        .size   foo2, .-foo2
        .section        .text.unlikely
.LCOLDE0:
        .text
.LHOTE0:
        .hidden memset
        .ident  "GCC: (GNU) 6.0.0 20150812 (experimental)"
        .section        .note.GNU-stack,"",@progbits
[hjl@gnu-6 pr67220]$