sdcc-3.9.0 fork implementing GNU assembler syntax

This fork aims to provide better support for stm8-binutils

1 files changed, 137 insertions, 0 deletions

diff --git a/device/lib/z80/divsigned.s b/device/lib/z80/divsigned.s
new file mode 100644
index 0000000..1ebc729
--- /dev/null
+++ b/device/lib/z80/divsigned.s
@@ -0,0 +1,137 @@
+;--------------------------------------------------------------------------
+;  divsigned.s
+;
+;  Copyright (C) 2000-2010, Michael Hope, Philipp Klaus Krause
+;
+;  This library 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.
+;
+;  This library 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 library; see the file COPYING. If not, write to the
+;  Free Software Foundation, 51 Franklin Street, Fifth Floor, Boston,
+;   MA 02110-1301, USA.
+;
+;  As a special exception, if you link this library with other files,
+;  some of which are compiled with SDCC, to produce an executable,
+;  this library does not by itself cause the resulting executable to
+;  be covered by the GNU General Public License. This exception does
+;  not however invalidate any other reasons why the executable file
+;   might be covered by the GNU General Public License.
+;--------------------------------------------------------------------------
+
+.area	_CODE
+
+.globl	__divsint
+.globl	__divschar
+
+__divsint:
+        pop     af
+        pop     hl
+        pop     de
+        push    de
+        push    hl
+        push    af
+
+        jp      __div16
+
+__divschar:
+        ld      hl, #2+1
+        add     hl, sp
+
+        ld      e, (hl)
+        dec     hl
+        ld      l, (hl)
+
+__div8::
+        ld      a, l            ; Sign extend
+        rlca
+        sbc     a,a
+        ld      h, a
+__div_signexte::
+        ld      a, e            ; Sign extend
+        rlca
+        sbc     a,a
+        ld      d, a
+        ; Fall through to __div16
+
+        ;; signed 16-bit division
+        ;;
+        ;; Entry conditions
+        ;;   HL = dividend
+        ;;   DE = divisor
+        ;;
+        ;; Exit conditions
+        ;;   HL = quotient
+        ;;   DE = remainder
+        ;;
+        ;; Register used: AF,B,DE,HL
+__div16::
+        ;; Determine sign of quotient by xor-ing high bytes of dividend
+        ;;  and divisor. Quotient is positive if signs are the same, negative
+        ;;  if signs are different
+        ;; Remainder has same sign as dividend
+        ld      a, h            ; Get high byte of dividend
+        xor     a, d            ; Xor with high byte of divisor
+        rla                     ; Sign of quotient goes into the carry
+        ld      a, h            ; Get high byte of dividend
+        push    af              ; Save sign of both quotient and reminder
+
+        ; Take absolute value of dividend
+        rla
+        jr      NC, .chkde      ; Jump if dividend is positive
+        sub     a, a            ; Substract dividend from 0
+        sub     a, l
+        ld      l, a
+        sbc     a, a            ; Propagate borrow (A=0xFF if borrow)
+        sub     a, h
+        ld      h, a
+
+        ; Take absolute value of divisor
+.chkde:
+        bit     7, d
+        jr      Z, .dodiv       ; Jump if divisor is positive
+        sub     a, a            ; Subtract divisor from 0
+        sub     a, e
+        ld      e, a
+        sbc     a, a            ; Propagate borrow (A=0xFF if borrow)
+        sub     a, d
+        ld      d, a
+
+        ; Divide absolute values
+.dodiv:
+        call    __divu16
+
+.fix_quotient:
+        ; Negate quotient if it is negative
+        pop     af              ; recover sign of quotient
+        ret	NC		; Jump if quotient is positive
+        ld      b, a
+        sub     a, a            ; Subtract quotient from 0
+        sub     a, l
+        ld      l, a
+        sbc     a, a            ; Propagate borrow (A=0xFF if borrow)
+        sub     a, h
+        ld      h, a
+        ld      a, b
+	ret
+
+__get_remainder::
+        ; Negate remainder if it is negative and move it into hl
+        rla
+	ex	de, hl
+        ret     NC              ; Return if remainder is positive
+        sub     a, a            ; Subtract remainder from 0
+        sub     a, l
+        ld      l, a
+        sbc     a, a             ; Propagate remainder (A=0xFF if borrow)
+        sub     a, h
+        ld      h, a
+        ret
+