H.J. Lu c5cc45148c i586: Use conditional branches in strcpy.S [BZ #22353] ... i586 strcpy.S used a clever trick with LEA to implement jump table: /* ECX has the last 2 bits of the address of source - 1. */ andl $3, %ecx call 2f 2: popl %edx /* 0xb is the distance between 2: and 1:. */ leal 0xb(%edx,%ecx,8), %ecx jmp *%ecx .align 8 1: /* ECX == 0 */ orb (%esi), %al jz L(end) stosb xorl %eax, %eax incl %esi /* ECX == 1 */ orb (%esi), %al jz L(end) stosb xorl %eax, %eax incl %esi /* ECX == 2 */ orb (%esi), %al jz L(end) stosb xorl %eax, %eax incl %esi /* ECX == 3 */ L(1): movl (%esi), %ecx leal 4(%esi),%esi This fails if there are instruction length changes before L(1):. This patch replaces it with conditional branches: cmpb $2, %cl je L(Src2) ja L(Src3) cmpb $1, %cl je L(Src1) L(Src0): which have similar performance and work with any instruction lengths. Tested on i586 and i686 with and without --disable-multi-arch. [BZ #22353] * sysdeps/i386/i586/strcpy.S (STRCPY): Use conditional branches. (1): Renamed to ... (L(Src0)): This. (L(Src1)): New. (L(Src2)): Likewise. (L(1)): Renamed to ... (L(Src3)): This.		2017-10-30 10:02:30 -07:00
..
add_n.S
addmul_1.S
bzero.S
init-arch.h
lshift.S
memcopy.h
memcpy.S
mempcpy.S
memset.S
memusage.h
mul_1.S
rshift.S
stpcpy.S
strchr.S
strcpy.S
strlen.S
sub_n.S
submul_1.S