diff options
Diffstat (limited to 'runtime/powerpc64/i64_utod.s')
| -rw-r--r-- | runtime/powerpc64/i64_utod.s | 79 |
1 files changed, 79 insertions, 0 deletions
diff --git a/runtime/powerpc64/i64_utod.s b/runtime/powerpc64/i64_utod.s new file mode 100644 index 00000000..491ee26b --- /dev/null +++ b/runtime/powerpc64/i64_utod.s @@ -0,0 +1,79 @@ +# ***************************************************************** +# +# 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 unsigned long to double float + + .balign 16 + .globl __compcert_i64_utod +__compcert_i64_utod: + rldicl r3, r3, 0, 32 # clear top 32 bits + rldicl r4, r4, 0, 32 # clear top 32 bits + lis r5, 0x4f80 # 0x4f80_0000 = 2^32 in binary32 format + stdu r3, -32(r1) + std r4, 8(r1) + stw r5, 16(r1) + lfd f1, 0(r1) # high 32 bits of argument + lfd f2, 8(r1) # low 32 bits of argument + lfs f3, 16(r1) # 2^32 + fcfid f1, f1 # convert both 32-bit halves to FP (exactly) + fcfid f2, f2 + fmadd f1, f1, f3, f2 # compute hi * 2^32 + lo + addi r1, r1, 32 + blr + .type __compcert_i64_utod, @function + .size __compcert_i64_utod, .-__compcert_i64_utod + +# Alternate implementation using round-to-odd: +# rldimi r4, r3, 32, 0 # reassemble (r3,r4) as a 64-bit integer in r4 +# cmpdi r4, 0 # is r4 >= 2^63 ? +# blt 1f +# stdu r4, -16(r1) # r4 < 2^63: convert as signed +# lfd f1, 0(r1) +# fcfid f1, f1 +# addi r1, r1, 16 +# blr +#1: rldicl r0, r4, 0, 63 # extract low bit of r4 +# srdi r4, r4, 1 +# or r4, r4, r0 # round r4 to 63 bits, using round-to-odd +# stdu r4, -16(r1) # convert to binary64 +# lfd f1, 0(r1) +# fcfid f1, f1 +# fadd f1, f1, f1 # multiply result by 2 +# addi r1, r1, 16 +# blr +
\ No newline at end of file |