dnl  x86 fat binary entrypoints.

dnl  Contributed to the GNU project by Kevin Ryde (original x86_32 code) and

dnl  Torbjorn Granlund (port to x86_64)

dnl  Copyright 2003, 2009, 2011-2014, 2016 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')

dnl  Forcibly disable profiling.

dnl

dnl  The entrypoints and inits are small enough not to worry about, the real

dnl  routines arrived at will have any profiling.  Also, the way the code

dnl  here ends with a jump means we won't work properly with the

dnl  "instrument" profiling scheme anyway.

define(`WANT_PROFILING',no)

dnl  We define PRETEND_PIC as a helper symbol, the use it for suppressing

dnl  normal, fast call code, since that triggers problems on Darwin, OpenBSD

dnl  and some versions of GNU/Linux.  This will go away when symbol hiding is

dnl  finished.

ifdef(`DARWIN',

`define(`PRETEND_PIC')')

ifdef(`OPENBSD',

`define(`PRETEND_PIC')')

ifdef(`LINUX',

`define(`PRETEND_PIC')')

ifdef(`PIC',

`define(`PRETEND_PIC')')

ABI_SUPPORT(DOS64)

ABI_SUPPORT(STD64)

	TEXT

dnl  Usage: FAT_ENTRY(name, offset)

dnl

dnl  Emit a fat binary entrypoint function of the given name.  This is the

dnl  normal entry for applications, eg. __gmpn_add_n.

dnl

dnl  The code simply jumps through the function pointer in __gmpn_cpuvec at

dnl  the given "offset" (in bytes).

dnl

dnl  For non-PIC, the jumps are 5 bytes each, aligning them to 8 should be

dnl  fine for all x86s.

dnl

dnl  For ELF/DARWIN PIC, the jumps are 20 bytes each, and are best aligned to

dnl  16 to ensure at least the first two instructions don't cross a cache line

dnl  boundary.

dnl

dnl  For DOS64, the jumps are 6 bytes.  The same form works also for GNU/Linux

dnl  (at least with certain assembler/linkers) but FreeBSD 8.2 crashes.  Not

dnl  tested on Darwin, Slowaris, NetBSD, etc.

dnl

dnl  Note the extra `' ahead of PROLOGUE obscures it from the HAVE_NATIVE

dnl  grepping in configure, stopping that code trying to eval something with

dnl  $1 in it.

define(FAT_ENTRY,

m4_assert_numargs(2)

`ifdef(`HOST_DOS64',

`	ALIGN(8)

`'PROLOGUE($1)

	jmp	*$2+GSYM_PREFIX`'__gmpn_cpuvec(%rip)

EPILOGUE()

',

`	ALIGN(ifdef(`PIC',16,8))

`'PROLOGUE($1)

ifdef(`PRETEND_PIC',

`	LEA(	GSYM_PREFIX`'__gmpn_cpuvec, %rax)

	jmp	*$2(%rax)

',`dnl non-PIC

	jmp	*GSYM_PREFIX`'__gmpn_cpuvec+$2

')

EPILOGUE()

')')

dnl  FAT_ENTRY for each CPUVEC_FUNCS_LIST

dnl

define(`CPUVEC_offset',0)

foreach(i,

`FAT_ENTRY(MPN(i),CPUVEC_offset)

define(`CPUVEC_offset',eval(CPUVEC_offset + 8))',

CPUVEC_FUNCS_LIST)

dnl  Usage: FAT_INIT(name, offset)

dnl

dnl  Emit a fat binary initializer function of the given name.  These

dnl  functions are the initial values for the pointers in __gmpn_cpuvec.

dnl

dnl  The code simply calls __gmpn_cpuvec_init, and then jumps back through

dnl  the __gmpn_cpuvec pointer, at the given "offset" (in bytes).

dnl  __gmpn_cpuvec_init will have stored the address of the selected

dnl  implementation there.

dnl

dnl  Only one of these routines will be executed, and only once, since after

dnl  that all the __gmpn_cpuvec pointers go to real routines.  So there's no

dnl  need for anything special here, just something small and simple.  To

dnl  keep code size down, "fat_init" is a shared bit of code, arrived at

dnl  with the offset in %al.  %al is used since the movb instruction is 2

dnl  bytes where %eax would be 4.

dnl

dnl  Note having `PROLOGUE in FAT_INIT obscures that PROLOGUE from the

dnl  HAVE_NATIVE grepping in configure, preventing that code trying to eval

dnl  something with $1 in it.

dnl

dnl  We need to preserve parameter registers over the __gmpn_cpuvec_init call

define(FAT_INIT,

m4_assert_numargs(2)

`PROLOGUE($1)

	mov	$`'$2, %al

	jmp	L(fat_init)

EPILOGUE()

')

dnl  FAT_INIT for each CPUVEC_FUNCS_LIST

dnl

define(`CPUVEC_offset',0)

foreach(i,

`FAT_INIT(MPN(i`'_init),CPUVEC_offset)

define(`CPUVEC_offset',eval(CPUVEC_offset + 1))',

CPUVEC_FUNCS_LIST)

L(fat_init):

	C al	__gmpn_cpuvec byte offset

	movzbl	%al, %eax

IFSTD(`	push	%rdi	')

IFSTD(`	push	%rsi	')

	push	%rdx

	push	%rcx

	push	%r8

	push	%r9

	push	%rax

	CALL(	__gmpn_cpuvec_init)

	pop	%rax

	pop	%r9

	pop	%r8

	pop	%rcx

	pop	%rdx

IFSTD(`	pop	%rsi	')

IFSTD(`	pop	%rdi	')

ifdef(`PRETEND_PIC',`

	LEA(	GSYM_PREFIX`'__gmpn_cpuvec, %r10)

	jmp	*(%r10,%rax,8)

',`dnl non-PIC

	jmp	*GSYM_PREFIX`'__gmpn_cpuvec(,%rax,8)

')

C long __gmpn_cpuid (char dst[12], int id);

C

C This is called only 3 times, so just something simple and compact is fine.

C

C The rcx/ecx zeroing here is needed for the BMI2 check.

define(`rp',  `%rdi')

define(`idx', `%rsi')

PROLOGUE(__gmpn_cpuid)

	FUNC_ENTRY(2)

	mov	%rbx, %r8

	mov	R32(idx), R32(%rax)

	xor	%ecx, %ecx

	cpuid

	mov	%ebx, (rp)

	mov	%edx, 4(rp)

	mov	%ecx, 8(rp)

	mov	%r8, %rbx

	FUNC_EXIT()

	ret

EPILOGUE()

CF_PROT