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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 64 version.
.text
### Conversion from signed long to single float
.balign 16
.globl __compcert_i64_stof
__compcert_i64_stof:
rldimi r4, r3, 32, 0 # reassemble (r3,r4) as a 64-bit integer in r4
# Check whether -2^53 <= X < 2^53
sradi r5, r4, 53
addi r5, r5, 1
cmpldi r5, 2
blt 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)
rldicl r5, r4, 0, 53 # extract bits 0 to 11 of X
addi r5, r5, 0x7FF # r5 = (X & 0x7FF) + 0x7FF
# bit 12 of r5 is 0 if all low 12 bits of X are 0, 1 otherwise
# bits 13-63 of r5 are 0
or r4, r4, r5 # correct bit number 12 of X
rldicr r4, r4, 0, 52 # set to 0 bits 0 to 11 of X
# Convert to double, then round to single
1: stdu r4, -16(r1)
lfd f1, 0(r1)
fcfid f1, f1
frsp f1, f1
addi r1, r1, 16
blr
.type __compcert_i64_stof, @function
.size __compcert_i64_stof, .-__compcert_i64_stof
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