Retro68/gcc/libgcc/config/mips/vr4120-div.S

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2012-03-27 23:13:14 +00:00
/* Support file for -mfix-vr4120.
Copyright (C) 2002, 2004, 2007 Free Software Foundation, Inc.
This file is part of GCC.
GCC 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 3, or (at your option)
any later version.
GCC 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 GCC; see the file COPYING3. If not see
<http://www.gnu.org/licenses/>. */
/* This file contains functions which implement divsi3 and modsi3 for
-mfix-vr4120. div and ddiv do not give the correct result when one
of the operands is negative. */
.set nomips16
#define DIV \
xor $3,$4,$5 /* t = x ^ y */ ; \
li $2,0x80000000; \
.set noreorder; \
bgez $4,1f /* x >= 0 */; \
and $3,$3,$2 /* t = (x ^ y) & 0x80000000 in delay slot */ ;\
.set reorder; \
subu $4,$0,$4 /* x = -x */ ; \
1:; \
.set noreorder; \
bgez $5,2f /* y >= 0 */ ; \
nop; \
subu $5,$0,$5 /* y = -y */ ; \
.set reorder; \
2:; \
divu $0,$4,$5; /* we use divu because of INT_MIN */ \
.set noreorder; \
bne $5,$0,3f; \
nop; \
break 7 /* division on zero y */ ; \
3:; \
.set reorder; \
mflo $2 /* r = x / y */ ; \
.set noreorder; \
beq $3,$0,4f /* t == 0 */ ; \
nop; \
subu $2,$0,$2 /* r = -r */ ; \
.set reorder; \
4:
.globl __vr4120_divsi3
.ent __vr4120_divsi3
__vr4120_divsi3:
DIV
j $31
.end __vr4120_divsi3
.globl __vr4120_modsi3
.ent __vr4120_modsi3
__vr4120_modsi3:
move $6,$4 # x1 = x
move $7,$5 # y1 = y
DIV
mult $2,$7 # r = r * y1
mflo $2
.set noreorder
j $31
subu $2,$6,$2 # r = x1 - r in delay slot
.end __vr4120_modsi3