------- Comment #21 from ubizjak at gmail dot com 2008-02-06 19:10 -------
(In reply to comment #20)
> Since -fo-f-p adds another free reg, it looks that since inlining increases
> register pressure some unlucky heavy-used variable gets allocated to the stack
> slot.
It is "best_len" (and probably some others, too):
[EMAIL PROTECTED] gzip-1.2.4]$ grep best_len fp.s
movl %edx, -68(%ebp) #, best_len
movl -68(%ebp), %edx # best_len, best_len.494
movl %edx, -68(%ebp) # best_len.494, best_len
movl -68(%ebp), %edx # best_len,
movl -68(%ebp), %edx # best_len,
movl -68(%ebp), %edx # best_len, best_len.494
cmpl %esi, %edx # lookahead, best_len.494
movl %edx, -108(%ebp) # best_len.494, match_length
movl -68(%ebp), %edx # best_len, best_len.494
movl %edx, -88(%ebp) # prev_length.28, best_len
movl -88(%ebp), %edx # best_len, best_len.457
movl %edx, -88(%ebp) # best_len.457, best_len
movl -88(%ebp), %eax # best_len,
movl -88(%ebp), %edx # best_len,
movl -88(%ebp), %edx # best_len, best_len.457
cmpl %esi, %edx # lookahead, best_len.457
movl %edx, -40(%ebp) # best_len.457, match_length.404
movl -88(%ebp), %edx # best_len, best_len.457
leal (%ecx,%eax), %edx #, best_len.457
cmpl %edx, -88(%ebp) # best_len.457, best_len
cmpl -96(%ebp), %edx # nice_match.34, best_len.457
leal (%ecx,%eax), %edx #, best_len.494
cmpl %edx, -68(%ebp) # best_len.494, best_len
cmpl -76(%ebp), %edx # nice_match.34, best_len.494
[EMAIL PROTECTED] gzip-1.2.4]$ grep best_len no-fp.s
movl %edx, 76(%esp) #, best_len
movl 76(%esp), %edx # best_len,
movl 76(%esp), %edx # best_len, best_len.494
movl %edx, 76(%esp) # best_len.494, best_len
movl 76(%esp), %eax # best_len,
movl 76(%esp), %edx # best_len, best_len.494
movl %edx, %ebp # best_len.494, match_length
movl 76(%esp), %edx # best_len, best_len.494
movl %edx, %ebp # prev_length.28, best_len
movl %ebp, %edx # best_len, best_len.457
movl %edx, %ebp # best_len.457, best_len
movl %ebp, %edx # best_len, best_len.457
cmpl %esi, %edx # lookahead, best_len.457
movl %ebp, %edx # best_len, best_len.457
leal (%ecx,%eax), %edx #, best_len.494
cmpl %edx, 76(%esp) # best_len.494, best_len
cmpl 68(%esp), %edx # nice_match.34, best_len.494
leal (%ecx,%eax), %edx #, best_len.457
cmpl %edx, %ebp # best_len.457, best_len
cmpl 52(%esp), %edx # nice_match.34, best_len.457
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33761
