Simple optimizations

Why open-coding isdigit is a good idea?

Before: call   __ctype_b_loc
        movzbl (%ebx),%edx
        mov    (%eax),%eax
        testb  $0x8,0x1(%eax,%edx,2)
        je     lbl

After:  movzbl (%eax),%edx
        sub    $0x30,%edx
        cmp    $0x9,%dl
        ja     lbl

   text	   data	    bss	    dec	    hex	filename
 236869	    704	  18944	 256517	  3ea05	strace.before
 236719	    700	  18944	 256363	  3e96b	strace

* defs.h: Alias sigemptyset to __sigemptyset on glibc.
* syscall.c (qual_syscall): Open-code isdigit.
(qual_desc): Likewise.
(qual_signal): Open-code isdigit. Remove string copying
which was done for no apparent reason.

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2 files changed