linux/arch/sh/lib/udivsi3_i4i-Os.S
Takashi YOSHII 3b041227f7 sh: Add plain udivsi3 (not _i4*) for gcc-4.1 and lower.
We chan't share code for udivsi3 and udivsi3_i4, because they
have a different clobber list. Copy udivsi3 from gcc-4.1.2.

As shown in arch/sh/lib/udivsi3.S (and -Os.S),

  .global __udivsi3_i4i
  .global __udivsi3_i4
  .global __udivsi3
__udivsi3_i4i:
  ...

Three symbols are sharing one code, which is actually udivsi3_i4i.
But, this results unwanted code with gcc 4.1.

In gcc, these three are treated as pseudo instructions that have
their own clobber list apart from the usual calling convention.

According to sh's machine description. The clobber list is as
follows:

 - udivsi3_i4i : t,r1,pr,mach,macl
 - udivsi3_i4  : t,r0,r1,r4,r5,pr,dr0,dr2,dr4
 - udivsi3     : t,r4,pr

The caller of udivsi3 will be left with a broken r1 and mac*.

gcc-4.1.x and older(at least to 3.4) generate udivsi3.
ST's gcc-4.1.1 seems to be OK because it has _i4i.

Signed-off-by: Takashi YOSHII <yoshii.takashi@renesas.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2008-12-22 18:43:53 +09:00

149 lines
3.3 KiB
ArmAsm

/* Copyright (C) 2006 Free Software Foundation, Inc.
This file is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by the
Free Software Foundation; either version 2, or (at your option) any
later version.
In addition to the permissions in the GNU General Public License, the
Free Software Foundation gives you unlimited permission to link the
compiled version of this file into combinations with other programs,
and to distribute those combinations without any restriction coming
from the use of this file. (The General Public License restrictions
do apply in other respects; for example, they cover modification of
the file, and distribution when not linked into a combine
executable.)
This file is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; see the file COPYING. If not, write to
the Free Software Foundation, 51 Franklin Street, Fifth Floor,
Boston, MA 02110-1301, USA. */
/* Moderately Space-optimized libgcc routines for the Renesas SH /
STMicroelectronics ST40 CPUs.
Contributed by J"orn Rennecke joern.rennecke@st.com. */
/* Size: 186 bytes jointly for udivsi3_i4i and sdivsi3_i4i
sh4-200 run times:
udiv small divisor: 55 cycles
udiv large divisor: 52 cycles
sdiv small divisor, positive result: 59 cycles
sdiv large divisor, positive result: 56 cycles
sdiv small divisor, negative result: 65 cycles (*)
sdiv large divisor, negative result: 62 cycles (*)
(*): r2 is restored in the rts delay slot and has a lingering latency
of two more cycles. */
.balign 4
.global __udivsi3_i4i
.global __udivsi3_i4
.set __udivsi3_i4, __udivsi3_i4i
.type __udivsi3_i4i, @function
.type __sdivsi3_i4i, @function
__udivsi3_i4i:
sts pr,r1
mov.l r4,@-r15
extu.w r5,r0
cmp/eq r5,r0
swap.w r4,r0
shlr16 r4
bf/s large_divisor
div0u
mov.l r5,@-r15
shll16 r5
sdiv_small_divisor:
div1 r5,r4
bsr div6
div1 r5,r4
div1 r5,r4
bsr div6
div1 r5,r4
xtrct r4,r0
xtrct r0,r4
bsr div7
swap.w r4,r4
div1 r5,r4
bsr div7
div1 r5,r4
xtrct r4,r0
mov.l @r15+,r5
swap.w r0,r0
mov.l @r15+,r4
jmp @r1
rotcl r0
div7:
div1 r5,r4
div6:
div1 r5,r4; div1 r5,r4; div1 r5,r4
div1 r5,r4; div1 r5,r4; rts; div1 r5,r4
divx3:
rotcl r0
div1 r5,r4
rotcl r0
div1 r5,r4
rotcl r0
rts
div1 r5,r4
large_divisor:
mov.l r5,@-r15
sdiv_large_divisor:
xor r4,r0
.rept 4
rotcl r0
bsr divx3
div1 r5,r4
.endr
mov.l @r15+,r5
mov.l @r15+,r4
jmp @r1
rotcl r0
.global __sdivsi3_i4i
.global __sdivsi3_i4
.global __sdivsi3
.set __sdivsi3_i4, __sdivsi3_i4i
.set __sdivsi3, __sdivsi3_i4i
__sdivsi3_i4i:
mov.l r4,@-r15
cmp/pz r5
mov.l r5,@-r15
bt/s pos_divisor
cmp/pz r4
neg r5,r5
extu.w r5,r0
bt/s neg_result
cmp/eq r5,r0
neg r4,r4
pos_result:
swap.w r4,r0
bra sdiv_check_divisor
sts pr,r1
pos_divisor:
extu.w r5,r0
bt/s pos_result
cmp/eq r5,r0
neg r4,r4
neg_result:
mova negate_result,r0
;
mov r0,r1
swap.w r4,r0
lds r2,macl
sts pr,r2
sdiv_check_divisor:
shlr16 r4
bf/s sdiv_large_divisor
div0u
bra sdiv_small_divisor
shll16 r5
.balign 4
negate_result:
neg r0,r0
jmp @r2
sts macl,r2