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;   Copyright (C) 2011 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/>.


; clobberable
r8      =       0xffef0

        .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.

        .global ___cmpsi2
        .type   ___cmpsi2, @function
___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

        .size   ___cmpsi2, . - ___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.

        .global ___ucmpsi2
        .type   ___ucmpsi2, @function
___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

        .size   ___ucmpsi2, . - ___ucmpsi2