[Bug middle-end/122122] [16 Regression] FAIL: gcc.target/i386/memset-strategy-3.c scan-assembler-not rep stosb by r16-4165-g8498ef3d075801

[hjl.tools at gmail dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=122122

--- Comment #4 from H.J. Lu <hjl.tools at gmail dot com> ---
For gcc.target/i386/memset-strategy-3.c

825           if (a->count.initialized_p ())
$15 = {static n_bits = 60, static max_count = 1152921504606846974, 
  static uninitialized_count = 1152921504606846975, m_val = 78839492, 
  m_quality = GUESSED_LOCAL}
$16 = {static n_bits = 60, static max_count = 1152921504606846974, 
  static uninitialized_count = 1152921504606846975, m_val = 0, 
  m_quality = GUESSED_LOCAL}
(gdb) next
826             a->count = b->count;
(gdb) p a->count.quality ()
$17 = GUESSED_LOCAL
(gdb) p b->count.quality ()
$18 = GUESSED_LOCAL
(gdb) 

It doesn't make any senses to copy zero count.