gcc/libgcc/config/arm/bpabi.S
Charles Baylis 6857b807c2 bpabi.S (__aeabi_uldivmod, [...]): Add comment describing register usage on function entry and exit.
2014-06-18  Charles Baylis  <charles.baylis@linaro.org>

	* config/arm/bpabi.S (__aeabi_uldivmod, __aeabi_ldivmod): Add comment
	describing register usage on function entry and exit.

From-SVN: r211790
2014-06-18 15:39:56 +00:00

185 lines
3.9 KiB
ArmAsm

/* Miscellaneous BPABI functions.
Copyright (C) 2003-2014 Free Software Foundation, Inc.
Contributed by CodeSourcery, LLC.
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 3, or (at your option) any
later version.
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.
Under Section 7 of GPL version 3, you are granted additional
permissions described in the GCC Runtime Library Exception, version
3.1, as published by the Free Software Foundation.
You should have received a copy of the GNU General Public License and
a copy of the GCC Runtime Library Exception along with this program;
see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
<http://www.gnu.org/licenses/>. */
#ifdef __ARM_EABI__
/* Some attributes that are common to all routines in this file. */
/* Tag_ABI_align_needed: This code does not require 8-byte
alignment from the caller. */
/* .eabi_attribute 24, 0 -- default setting. */
/* Tag_ABI_align_preserved: This code preserves 8-byte
alignment in any callee. */
.eabi_attribute 25, 1
#endif /* __ARM_EABI__ */
#ifdef L_aeabi_lcmp
ARM_FUNC_START aeabi_lcmp
cmp xxh, yyh
do_it lt
movlt r0, #-1
do_it gt
movgt r0, #1
do_it ne
RETc(ne)
subs r0, xxl, yyl
do_it lo
movlo r0, #-1
do_it hi
movhi r0, #1
RET
FUNC_END aeabi_lcmp
#endif /* L_aeabi_lcmp */
#ifdef L_aeabi_ulcmp
ARM_FUNC_START aeabi_ulcmp
cmp xxh, yyh
do_it lo
movlo r0, #-1
do_it hi
movhi r0, #1
do_it ne
RETc(ne)
cmp xxl, yyl
do_it lo
movlo r0, #-1
do_it hi
movhi r0, #1
do_it eq
moveq r0, #0
RET
FUNC_END aeabi_ulcmp
#endif /* L_aeabi_ulcmp */
.macro test_div_by_zero signed
/* Tail-call to divide-by-zero handlers which may be overridden by the user,
so unwinding works properly. */
#if defined(__thumb2__)
cbnz yyh, 1f
cbnz yyl, 1f
cmp xxh, #0
do_it eq
cmpeq xxl, #0
.ifc \signed, unsigned
beq 2f
mov xxh, #0xffffffff
mov xxl, xxh
2:
.else
do_it lt, t
movlt xxl, #0
movlt xxh, #0x80000000
do_it gt, t
movgt xxh, #0x7fffffff
movgt xxl, #0xffffffff
.endif
b SYM (__aeabi_ldiv0) __PLT__
1:
#else
/* Note: Thumb-1 code calls via an ARM shim on processors which
support ARM mode. */
cmp yyh, #0
cmpeq yyl, #0
bne 2f
cmp xxh, #0
cmpeq xxl, #0
.ifc \signed, unsigned
movne xxh, #0xffffffff
movne xxl, #0xffffffff
.else
movlt xxh, #0x80000000
movlt xxl, #0
movgt xxh, #0x7fffffff
movgt xxl, #0xffffffff
.endif
b SYM (__aeabi_ldiv0) __PLT__
2:
#endif
.endm
#ifdef L_aeabi_ldivmod
/* Perform 64 bit signed division.
Inputs:
r0:r1 numerator
r2:r3 denominator
Outputs:
r0:r1 quotient
r2:r3 remainder
*/
ARM_FUNC_START aeabi_ldivmod
cfi_start __aeabi_ldivmod, LSYM(Lend_aeabi_ldivmod)
test_div_by_zero signed
sub sp, sp, #8
#if defined(__thumb2__)
mov ip, sp
push {ip, lr}
#else
do_push {sp, lr}
#endif
98: cfi_push 98b - __aeabi_ldivmod, 0xe, -0xc, 0x10
bl SYM(__gnu_ldivmod_helper) __PLT__
ldr lr, [sp, #4]
add sp, sp, #8
do_pop {r2, r3}
RET
cfi_end LSYM(Lend_aeabi_ldivmod)
#endif /* L_aeabi_ldivmod */
#ifdef L_aeabi_uldivmod
/* Perform 64 bit signed division.
Inputs:
r0:r1 numerator
r2:r3 denominator
Outputs:
r0:r1 quotient
r2:r3 remainder
*/
ARM_FUNC_START aeabi_uldivmod
cfi_start __aeabi_uldivmod, LSYM(Lend_aeabi_uldivmod)
test_div_by_zero unsigned
sub sp, sp, #8
#if defined(__thumb2__)
mov ip, sp
push {ip, lr}
#else
do_push {sp, lr}
#endif
98: cfi_push 98b - __aeabi_uldivmod, 0xe, -0xc, 0x10
bl SYM(__gnu_uldivmod_helper) __PLT__
ldr lr, [sp, #4]
add sp, sp, #8
do_pop {r2, r3}
RET
cfi_end LSYM(Lend_aeabi_uldivmod)
#endif /* L_aeabi_divmod */