glibc/sysdeps/s390/s390-32/multiarch/memcpy-s390.S
Stefan Liebler 4c01126896 S390: Implement mempcpy with help of memcpy. [BZ #19765]
There exist optimized memcpy functions on s390, but no optimized mempcpy.
This patch adds mempcpy entry points in memcpy.S files, which
use the memcpy implementation. Now mempcpy itself is also an IFUNC function
as memcpy is and the variants are listed in ifunc-impl-list.c.

The s390 string.h does not define _HAVE_STRING_ARCH_mempcpy.
Instead mempcpy string/string.h inlines memcpy() + n.
If n is constant and small enough, GCC emits instructions like mvi or mvc
and avoids the function call to memcpy.
If n is not constant, then memcpy is called and n is added afterwards.
If _HAVE_STRING_ARCH_mempcpy would be defined, mempcpy would be called in
every case.

According to PR70140 "Inefficient expansion of __builtin_mempcpy"
(https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70140) GCC should handle a
call to mempcpy in the same way as memcpy. Then either the mempcpy macro
in string/string.h has to be removed or _HAVE_STRING_ARCH_mempcpy has to
be defined for S390.

ChangeLog:

	[BZ #19765]
	* sysdeps/s390/mempcpy.S: New File.
	* sysdeps/s390/multiarch/mempcpy.c: Likewise.
	* sysdeps/s390/multiarch/Makefile (sysdep_routines): Add mempcpy.
	* sysdeps/s390/multiarch/ifunc-impl-list.c (__libc_ifunc_impl_list):
	Add mempcpy variants.
	* sysdeps/s390/s390-32/memcpy.S: Add mempcpy entry point.
	(memcpy): Adjust to be usable from mempcpy entry point.
	(__memcpy_mvcle): Likewise.
	* sysdeps/s390/s390-64/memcpy.S: Likewise.
	* sysdeps/s390/s390-32/multiarch/memcpy-s390.S: Add entry points
	____mempcpy_z196, ____mempcpy_z10 and add __GI_ symbols for mempcpy.
	(__memcpy_z196): Adjust to be usable from mempcpy entry point.
	(__memcpy_z10): Likewise.
	* sysdeps/s390/s390-64/multiarch/memcpy-s390x.S: Likewise.
2016-05-24 10:39:13 +02:00

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ArmAsm

/* CPU specific memcpy implementations. 32 bit S/390 version.
Copyright (C) 2012-2016 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include "sysdep.h"
#include "asm-syntax.h"
/* INPUT PARAMETERS
%r2 = target operands address
%r3 = source operands address
%r4 = number of bytes to copy. */
.text
#if defined SHARED && IS_IN (libc)
ENTRY(____mempcpy_z196)
.machine "z196"
.machinemode "zarch_nohighgprs"
lr %r1,%r2 # Use as dest
la %r2,0(%r4,%r2) # Return dest + n
j .L_Z196_start
END(____mempcpy_z196)
ENTRY(__memcpy_z196)
.machine "z196"
.machinemode "zarch_nohighgprs"
lr %r1,%r2 # r1: Use as dest ; r2: Return dest
.L_Z196_start:
llgfr %r4,%r4
ltgr %r4,%r4
je .L_Z196_4
aghi %r4,-1
srlg %r5,%r4,8
ltgr %r5,%r5
jne .L_Z196_5
.L_Z196_3:
exrl %r4,.L_Z196_14
.L_Z196_4:
br %r14
.L_Z196_5:
cgfi %r5,262144 # Switch to mvcle for copies >64MB
jh __memcpy_mvcle
.L_Z196_2:
pfd 1,768(%r3)
pfd 2,768(%r1)
mvc 0(256,%r1),0(%r3)
aghi %r5,-1
la %r1,256(%r1)
la %r3,256(%r3)
jne .L_Z196_2
j .L_Z196_3
.L_Z196_14:
mvc 0(1,%r1),0(%r3)
END(__memcpy_z196)
ENTRY(____mempcpy_z10)
.machine "z10"
.machinemode "zarch_nohighgprs"
lr %r1,%r2 # Use as dest
la %r2,0(%r4,%r2) # Return dest + n
j .L_Z10_start
END(____mempcpy_z10)
ENTRY(__memcpy_z10)
.machine "z10"
.machinemode "zarch_nohighgprs"
lr %r1,%r2 # r1: Use as dest ; r2: Return dest
.L_Z10_start:
llgfr %r4,%r4
cgije %r4,0,.L_Z10_4
aghi %r4,-1
srlg %r5,%r4,8
cgijlh %r5,0,.L_Z10_13
.L_Z10_3:
exrl %r4,.L_Z10_15
.L_Z10_4:
br %r14
.L_Z10_13:
cgfi %r5,65535 # Switch to mvcle for copies >16MB
jh __memcpy_mvcle
.L_Z10_12:
pfd 1,768(%r3)
pfd 2,768(%r1)
mvc 0(256,%r1),0(%r3)
la %r1,256(%r1)
la %r3,256(%r3)
brctg %r5,.L_Z10_12
j .L_Z10_3
.L_Z10_15:
mvc 0(1,%r1),0(%r3)
END(__memcpy_z10)
# define __mempcpy ____mempcpy_default
#endif /* SHARED && IS_IN (libc) */
#define memcpy __memcpy_default
#include "../memcpy.S"
#undef memcpy
#if defined SHARED && IS_IN (libc)
.globl __GI_memcpy
.set __GI_memcpy,__memcpy_default
.globl __GI_mempcpy
.set __GI_mempcpy,____mempcpy_default
.globl __GI___mempcpy
.set __GI___mempcpy,____mempcpy_default
#else
.globl memcpy
.set memcpy,__memcpy_default
.weak mempcpy
.set mempcpy,__mempcpy
#endif