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# *****************************************************************
#
# The Compcert verified compiler
#
# Xavier Leroy, INRIA Paris-Rocquencourt
#
# Copyright (c) 2013 Institut National de Recherche en Informatique et
# en Automatique.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
# * Redistributions of source code must retain the above copyright
# notice, this list of conditions and the following disclaimer.
# * Redistributions in binary form must reproduce the above copyright
# notice, this list of conditions and the following disclaimer in the
# documentation and/or other materials provided with the distribution.
# * Neither the name of the <organization> nor the
# names of its contributors may be used to endorse or promote products
# derived from this software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL <COPYRIGHT
# HOLDER> BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
# EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
# PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
# PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
# LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
# NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
# SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#
# *********************************************************************
# Helper functions for 64-bit integer arithmetic. PowerPC version.
.text
### Unsigned comparison
.balign 16
.globl __i64_ucmp
__i64_ucmp:
cmpw cr0, r3, r5 # compare high words (signed)
cmplw cr1, r4, r6 # compare low words (unsigned)
mfcr r0
# At this point, the bits of r0 are as follow:
# bit 31: XH < YH
# bit 30: XH > YH
# bit 27: XL > YL
# bit 26: XL < YL
rlwinm r3, r0, 0, 0, 1 # r3 = r0 & 0xC000_0000
srawi r3, r3, 24 # r4 = r4 >>s 28
# r3 = -0x80 if XH < YH
# = 0x40 if XH > YH
# = 0 if XH = YH
rlwinm r4, r0, 4, 0, 1 # r4 = (r0 << 4) & 0xC000_0000
srawi r4, r4, 28 # r4 = r4 >>s 28
# r4 = -8 if XL < YL
# = 4 if XL > YL
# = 0 if XL = YL
add r3, r3, r4
# r3 = -0x80 or -0x80 - 8 or -0x80 + 4 or -8 if X < Y
# (in all cases, r3 < 0 if X < Y)
# = 0x40 or 0x40 - 8 or 0x40 + 4 or 4 if X > Y
# (in all cases, r3 > 0 if X > Y)
# = 0 if X = Y
blr
.type __i64_scmp, @function
.size __i64_scmp, .-__i64_ucmp
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