110 lines
3.0 KiB
ArmAsm
110 lines
3.0 KiB
ArmAsm
/* Copyright (C) 1996, 1997 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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Contributed by Richard Henderson <rth@tamu.edu>.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, write to the Free
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Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
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02111-1307 USA. */
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#include <sysdep.h>
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#ifdef __linux__
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# include <asm/gentrap.h>
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# include <asm/pal.h>
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#else
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# include <machine/pal.h>
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#endif
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.set noat
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.align 4
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.globl div
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.ent div
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div:
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.frame sp, 0, ra
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#ifdef PROF
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ldgp gp, 0(pv)
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lda AT, _mcount
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jsr AT, (AT), _mcount
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.prologue 1
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#else
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.prologue 0
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#endif
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#define divisor t1
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#define mask t2
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#define quotient t3
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#define modulus t4
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#define tmp1 t5
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#define tmp2 t6
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#define compare t7
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/* find correct sign for input to unsigned divide loop. */
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negl a1, modulus # e0 :
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negl a2, divisor # .. e1 :
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sextl a1, a1 # e0 :
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sextl a2, a2 # .. e1 :
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mov zero, quotient # e0 :
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mov 1, mask # .. e1 :
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cmovge a1, a1, modulus # e0 :
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cmovge a2, a2, divisor # .. e1 :
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beq a2, $divbyzero # e1 :
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unop # :
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/* shift divisor left, using 3-bit shifts for 32-bit divides as we
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can't overflow. Three-bit shifts will result in looping three
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times less here, but can result in two loops more later. Thus
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using a large shift isn't worth it (and s8addq pairs better than
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a shift). */
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1: cmpult divisor, modulus, compare # e0 :
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s8addq divisor, zero, divisor # .. e1 :
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s8addq mask, zero, mask # e0 :
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bne compare, 1b # .. e1 :
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/* start to go right again. */
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2: addq quotient, mask, tmp2 # e1 :
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srl mask, 1, mask # .. e0 :
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cmpule divisor, modulus, compare # e0 :
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subq modulus, divisor, tmp1 # .. e1 :
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cmovne compare, tmp2, quotient # e1 :
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srl divisor, 1, divisor # .. e0 :
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cmovne compare, tmp1, modulus # e0 :
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bne mask, 2b # .. e1 :
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/* find correct sign for result. */
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xor a1, a2, compare # e0 :
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negl quotient, tmp1 # .. e1 :
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negl modulus, tmp2 # e0 :
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cmovlt compare, tmp1, quotient # .. e1 :
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cmovlt a1, tmp2, modulus # e1 :
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/* and store it away in the structure. */
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stl quotient, 0(a0) # .. e0 :
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mov a0, v0 # e1 :
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stl modulus, 4(a0) # .. e0 :
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ret # e1 :
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$divbyzero:
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mov a0, v0
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ldiq a0, GEN_INTDIV
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call_pal PAL_gentrap
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/* if trap returns, return zero. */
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stl zero, 0(v0)
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stl zero, 4(v0)
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ret
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.end div
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