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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
### Conversion from unsigned long to single float
.balign 16
.globl __i64_utof
__i64_utof:
mflr r9
# Check whether X < 2^53
andis. r0, r3, 0xFFE0 # test bits 53...63 of X
beq 1f
# X is large enough that double rounding can occur.
# Avoid it by nudging X away from the points where double rounding
# occurs (the "round to odd" technique)
rlwinm r0, r4, 0, 21, 31 # extract bits 0 to 11 of X
addi r0, r0, 0x7FF # r0 = (X & 0x7FF) + 0x7FF
# bit 12 of r0 is 0 if all low 12 bits of X are 0, 1 otherwise
# bits 13-31 of r0 are 0
or r4, r4, r0 # correct bit number 12 of X
rlwinm r4, r4, 0, 0, 20 # set to 0 bits 0 to 11 of X
# Convert to double, then round to single
1: bl __i64_utod
mtlr r9
frsp f1, f1
blr
.type __i64_utof, @function
.size __i64_utof, .-__i64_utof
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