mirror of
https://github.com/autc04/Retro68.git
synced 2024-11-24 23:32:06 +00:00
173 lines
4.1 KiB
ArmAsm
173 lines
4.1 KiB
ArmAsm
; Copyright (C) 2011-2016 Free Software Foundation, Inc.
|
|
; Contributed by Red Hat.
|
|
;
|
|
; 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/>.
|
|
|
|
|
|
#include "vregs.h"
|
|
|
|
.text
|
|
|
|
;; int __cmpsi2 (signed long A, signed long B)
|
|
;;
|
|
;; Performs a signed comparison of A and B.
|
|
;; If A is less than B it returns 0. If A is greater
|
|
;; than B it returns 2. If they are equal it returns 1.
|
|
|
|
START_FUNC ___cmpsi2
|
|
|
|
;; A is at [sp+4]
|
|
;; B is at [sp+8]
|
|
;; Result put in R8
|
|
|
|
;; Initialise default return value.
|
|
onew bc
|
|
|
|
;; Compare the high words.
|
|
movw ax, [sp + 10]
|
|
movw de, ax
|
|
movw ax, [sp + 6]
|
|
cmpw ax, de
|
|
skz
|
|
br !!.Lconvert_to_signed
|
|
|
|
.Lcompare_bottom_words:
|
|
;; The top words are equal - compare the bottom words.
|
|
;; Note - code from __ucmpsi2 branches into here.
|
|
movw ax, [sp + 8]
|
|
movw de, ax
|
|
movw ax, [sp + 4]
|
|
cmpw ax, de
|
|
sknz
|
|
br !!.Lless_than_or_greater_than
|
|
;; The words are equal - return 1.
|
|
;; Note - we could branch to the return code at the end of the
|
|
;; function but a branch instruction takes 4 bytes, and the
|
|
;; return sequence itself is only 4 bytes long...
|
|
movw ax, bc
|
|
movw r8, ax
|
|
ret
|
|
|
|
.Lconvert_to_signed:
|
|
;; The top words are different. Unfortunately the comparison
|
|
;; is always unsigned, so to get a signed result we XOR the CY
|
|
;; flag with the top bits of AX and DE.
|
|
xor1 cy, a.7
|
|
mov a, d
|
|
xor1 cy, a.7
|
|
;; Fall through.
|
|
|
|
.Lless_than_or_greater_than:
|
|
;; We now have a signed less than/greater than result in CY.
|
|
;; Return 0 for less than, 2 for greater than.
|
|
;; Note - code from __ucmpsi2 branches into here.
|
|
incw bc
|
|
sknc
|
|
clrw bc
|
|
|
|
;; Get the result value, currently in BC, into r8
|
|
movw ax, bc
|
|
movw r8, ax
|
|
ret
|
|
|
|
END_FUNC ___cmpsi2
|
|
|
|
;; ------------------------------------------------------
|
|
|
|
;; int __ucmpsi2 (unsigned long A, unsigned long B)
|
|
;;
|
|
;; Performs an unsigned comparison of A and B.
|
|
;; If A is less than B it returns 0. If A is greater
|
|
;; than B it returns 2. If they are equal it returns 1.
|
|
|
|
START_FUNC ___ucmpsi2
|
|
|
|
;; A is at [sp+4]
|
|
;; B is at [sp+8]
|
|
;; Result put in R8..R9
|
|
|
|
;; Initialise default return value.
|
|
onew bc
|
|
|
|
;; Compare the high words.
|
|
movw ax, [sp + 10]
|
|
movw de, ax
|
|
movw ax, [sp + 6]
|
|
cmpw ax, de
|
|
skz
|
|
;; Note: These branches go into the __cmpsi2 code!
|
|
br !!.Lless_than_or_greater_than
|
|
br !!.Lcompare_bottom_words
|
|
|
|
END_FUNC ___ucmpsi2
|
|
|
|
;; ------------------------------------------------------
|
|
|
|
;; signed int __gcc_bcmp (const unsigned char *s1, const unsigned char *s2, size_t size)
|
|
;; Result is negative if S1 is less than S2,
|
|
;; positive if S1 is greater, 0 if S1 and S2 are equal.
|
|
|
|
START_FUNC __gcc_bcmp
|
|
|
|
;; S1 is at [sp+4]
|
|
;; S2 is at [sp+6]
|
|
;; SIZE is at [sp+8]
|
|
;; Result in r8/r9
|
|
|
|
movw r10, #0
|
|
1:
|
|
;; Compare R10 against the SIZE parameter
|
|
movw ax, [sp+8]
|
|
subw ax, r10
|
|
sknz
|
|
br !!1f
|
|
|
|
;; Load S2[r10] into R8
|
|
movw ax, [sp+6]
|
|
addw ax, r10
|
|
movw hl, ax
|
|
mov a, [hl]
|
|
mov r8, a
|
|
|
|
;; Load S1[r10] into A
|
|
movw ax, [sp+4]
|
|
addw ax, r10
|
|
movw hl, ax
|
|
mov a, [hl]
|
|
|
|
;; Increment offset
|
|
incw r10
|
|
|
|
;; Compare loaded bytes
|
|
cmp a, r8
|
|
sknz
|
|
br !!1b
|
|
|
|
;; They differ. Subtract *S2 from *S1 and return as the result.
|
|
mov x, a
|
|
mov a, #0
|
|
mov r9, #0
|
|
subw ax, r8
|
|
1:
|
|
movw r8, ax
|
|
ret
|
|
|
|
END_FUNC __gcc_bcmp
|