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Diffstat (limited to 'runtime/powerpc/i64_utof.s')
| -rw-r--r-- | runtime/powerpc/i64_utof.s | 64 |
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diff --git a/runtime/powerpc/i64_utof.s b/runtime/powerpc/i64_utof.s new file mode 100644 index 0000000..b31e520 --- /dev/null +++ b/runtime/powerpc/i64_utof.s @@ -0,0 +1,64 @@ +# ***************************************************************** +# +# 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 + srlwi. r0, r3, 21 # test if X >> 53 == 0 + 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 + |