diff options
Diffstat (limited to 'runtime/ia32/i64_shr.s')
| -rw-r--r-- | runtime/ia32/i64_shr.s | 62 |
1 files changed, 62 insertions, 0 deletions
diff --git a/runtime/ia32/i64_shr.s b/runtime/ia32/i64_shr.s new file mode 100644 index 0000000..691c4d0 --- /dev/null +++ b/runtime/ia32/i64_shr.s @@ -0,0 +1,62 @@ +# ***************************************************************** +# +# 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 + +# Shift right unsigned + +# Note: IA32 shift instructions treat their amount (in %cl) modulo 32 + + .globl __i64_shr + .balign 16 +__i64_shr: + movl 12(%esp), %ecx # ecx = shift amount, treated mod 64 + testb $32, %cl + jne 1f + # shift amount < 32 + movl 4(%esp), %eax + movl 8(%esp), %edx + shrdl %cl, %edx, %eax # eax = low(XH:XL >> amount) + shrl %cl, %edx # edx = XH >> amount + ret + # shift amount >= 32 +1: movl 8(%esp), %eax + shrl %cl, %eax # eax = XH >> (amount - 32) + xorl %edx, %edx # edx = 0 + ret + .type __i64_shr, @function + .size __i64_shr, . - __i64_shr + |