dnl AMD64 MULX/ADX simulation support.
dnl Contributed to the GNU project by Torbjörn Granlund.
dnl Copyright 2013 Free Software Foundation,
Inc.
dnl
This file is part of the GNU MP Library.
dnl
dnl The GNU MP Library is free software
; you can redistribute it and/or modify
dnl it under the terms of either:
dnl
dnl * the GNU Lesser General
Public License as published by the Free
dnl Software Foundation
; either version 3 of the License, or (at your
dnl
option) any later
version.
dnl
dnl
or
dnl
dnl * the GNU General
Public License as published by the Free Software
dnl Foundation
; either version 2 of the License, or (at your option) any
dnl later
version.
dnl
dnl
or both in parallel, as here.
dnl
dnl The GNU MP Library is distributed in the hope that it will be useful, but
dnl WITHOUT ANY WARRANTY
; without even the implied warranty of MERCHANTABILITY
dnl
or FITNESS
FOR A PARTICULAR PURPOSE. See the GNU General
Public License
dnl
for more details.
dnl
dnl You should have received copies of the GNU General
Public License
and the
dnl GNU Lesser General
Public License along with the GNU MP Library.
If not,
dnl see
https://www.gnu.org/licenses/.
include(`../config.m4
')
ASM_START()
C Fake the MULX instruction
C
C Accept the single explicit parameter on the
stack, return the two result
C words on the
stack.
This calling convention means that we need to move the
C return address up.
C
PROLOGUE(__gmp_mulx)
lea -8(%rsp), %rsp
push %rax
push %rdx
pushfq C preserve all flags
mov 32(%rsp), %rax C move retaddr...
mov %rax, 24(%rsp) C ...up the
stack
mov 40(%rsp), %rax C input parameter
mul %rdx
mov %rax, 32(%rsp)
mov %rdx, 40(%rsp)
popfq C restore
eflags
pop %rdx
pop %rax
ret
EPILOGUE()
PROTECT(__gmp_mulx)
C Fake the ADOX instruction
C
C Accept the two parameters on the
stack, return the result
word on the
stack.
C
This calling convention means that we need to move the return address down.
C
PROLOGUE(__gmp_adox)
push %rcx
push %rbx
push %rax
mov 32(%rsp), %rcx C src2
mov 24(%rsp), %rax C move retaddr...
mov %rax, 32(%rsp) C ...down the
stack
pushfq
C copy 0(%rsp):11 to 0(%rsp):0
mov (%rsp), %rbx
shr %rbx
bt $10, %rbx
adc %rbx, %rbx
push %rbx
C put manipulated flags into
eflags, execute a plain
adc
popfq
adc %rcx, 48(%rsp)
C copy CF to 0(%rsp):11
pop %rbx
sbb R32(%rax), R32(%rax)
and $0x800, R32(%rax)
and $0xfffffffffffff7ff, %rbx
or %rax, %rbx
push %rbx
C put manipulated flags into
eflags
popfq
pop %rax
pop %rbx
pop %rcx
lea 8(%rsp), %rsp
ret
EPILOGUE()
PROTECT(__gmp_adox)
C Fake the ADCX instruction
C
C Accept the two parameters on the
stack, return the result
word on the
stack.
C
This calling convention means that we need to move the return address down.
C
PROLOGUE(__gmp_adcx)
push %rcx
push %rbx
push %rax
mov 32(%rsp), %rcx C src2
mov 24(%rsp), %rax C move retaddr...
mov %rax, 32(%rsp) C ...down the
stack
pushfq
adc %rcx, 48(%rsp)
pop %rbx
sbb R32(%rax), R32(%rax)
and $`
'0xfffffffffffffffe, %rbx
sub %rax, %rbx
push %rbx
popfq
pop %rax
pop %rbx
pop %rcx
lea 8(%rsp), %rsp
ret
EPILOGUE()
PROTECT(__gmp_adcx)
