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Diffstat (limited to 'runtime/ia32/i64_dtou.s')
| -rw-r--r-- | runtime/ia32/i64_dtou.s | 77 |
1 files changed, 77 insertions, 0 deletions
diff --git a/runtime/ia32/i64_dtou.s b/runtime/ia32/i64_dtou.s new file mode 100644 index 0000000..d700d69 --- /dev/null +++ b/runtime/ia32/i64_dtou.s @@ -0,0 +1,77 @@ +# ***************************************************************** +# +# 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. IA32 version. + + .text + +# Conversion float -> unsigned long + + .globl __i64_dtou + .balign 16 +__i64_dtou: + subl $4, %esp + # Change rounding mode to "round towards zero" + fnstcw 0(%esp) + movw 0(%esp), %ax + movb $12, %ah + movw %ax, 2(%esp) + fldcw 2(%esp) + # Compare argument with 2^63 + fldl (4+4)(%esp) + flds LC1 + fucomp + fnstsw %ax + sahf + jbe 1f # branch if not (ARG < 2^63) + # Argument < 2^63: convert as is + fistpll 8(%esp) + movl 8(%esp), %eax + movl 12(%esp), %edx + jmp 2f + # Argument > 2^63: offset ARG by -2^63, then convert, then offset RES by 2^63 +1: fsubs LC1 + fistpll 8(%esp) + movl 8(%esp), %eax + movl 12(%esp), %edx + addl $0x80000000, %edx + # Restore rounding mode +2: fldcw 0(%esp) + addl $4, %esp + ret + .type __i64_dtou, @function + .size __i64_dtou, . - __i64_dtou + + .balign 4 +LC1: .long 0x5f000000 # 2^63 in single precision |