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Diffstat (limited to 'runtime/ia32/i64_udivmod.s')
| -rw-r--r-- | runtime/ia32/i64_udivmod.s | 106 |
1 files changed, 0 insertions, 106 deletions
diff --git a/runtime/ia32/i64_udivmod.s b/runtime/ia32/i64_udivmod.s deleted file mode 100644 index 8f1e97d..0000000 --- a/runtime/ia32/i64_udivmod.s +++ /dev/null @@ -1,106 +0,0 @@ -# ***************************************************************** -# -# 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. - -# Division and remainder - -# Auxiliary function, never called directly from C code -# Input: 20(esp), 24(esp) is dividend N -# 28(esp), 32(esp) is divisor D -# Output: esi:edi is quotient Q -# eax:edx is remainder R -# ebp is preserved - - .text - .globl __i64_udivmod - .balign 16 -__i64_udivmod: - cmpl $0, 32(%esp) # single-word divisor? (DH = 0) - jne 1f - # Special case 64 bits divided by 32 bits - movl 28(%esp), %ecx # divide NH by DL - movl 24(%esp), %eax # (will trap if D = 0) - xorl %edx, %edx - divl %ecx # eax = quotient, edx = remainder - movl %eax, %edi # high word of quotient in edi - movl 20(%esp), %eax # divide rem : NL by DL - divl %ecx # eax = quotient, edx = remainder - movl %eax, %esi # low word of quotient in esi */ - movl %edx, %eax # low word of remainder in eax - xorl %edx, %edx # high word of remainder is 0, in edx - ret - # The general case -1: movl 28(%esp), %ecx # esi:ecx = D - movl 32(%esp), %esi - movl 20(%esp), %eax # edx:eax = N - movl 24(%esp), %edx - # Scale D and N down, giving D' and N', until D' fits in 32 bits -2: shrl $1, %esi # shift D' right by one - rcrl $1, %ecx - shrl $1, %edx # shift N' right by one - rcrl $1, %eax - testl %esi, %esi # repeat until D'H = 0 - jnz 2b - # Divide N' by D' to get an approximate quotient - divl %ecx # eax = quotient, edx = remainder - movl %eax, %esi # save tentative quotient Q in esi - # Check for off by one quotient - # Compute Q * D -3: movl 32(%esp), %ecx - imull %esi, %ecx # ecx = Q * DH - movl 28(%esp), %eax - mull %esi # edx:eax = Q * DL - add %ecx, %edx # edx:eax = Q * D - jc 5f # overflow in addition means Q is too high - # Compare Q * D with N, computing the remainder in the process - movl %eax, %ecx - movl 20(%esp), %eax - subl %ecx, %eax - movl %edx, %ecx - movl 24(%esp), %edx - sbbl %ecx, %edx # edx:eax = N - Q * D - jnc 4f # no carry: N >= Q * D, we are fine - decl %esi # carry: N < Q * D, adjust Q down by 1 - addl 28(%esp), %eax # and remainder up by D - adcl 32(%esp), %edx - # Finished -4: xorl %edi, %edi # high half of quotient is 0 - ret - # Special case when Q * D overflows -5: decl %esi # adjust Q down by 1 - jmp 3b # and redo check & computation of remainder - - .type __i64_udivmod, @function - .size __i64_udivmod, . - __i64_udivmod |