linux/arch/parisc/lib/string.S
Helge Deller 83af58f806 parisc: Add assembly implementations for memset, strlen, strcpy, strncpy and strcat
Add performance-optimized versions of some string functions.

Signed-off-by: Helge Deller <deller@gmx.de>
Tested-by: Sven Schnelle <svens@stackframe.org>
2019-08-03 08:56:57 +02:00

137 lines
2.4 KiB
ArmAsm

// SPDX-License-Identifier: GPL-2.0
/*
* PA-RISC assembly string functions
*
* Copyright (C) 2019 Helge Deller <deller@gmx.de>
*/
#include <asm/assembly.h>
#include <linux/linkage.h>
.section .text.hot
.level PA_ASM_LEVEL
t0 = r20
t1 = r21
t2 = r22
ENTRY_CFI(strlen, frame=0,no_calls)
or,COND(<>) arg0,r0,ret0
b,l,n .Lstrlen_null_ptr,r0
depwi 0,31,2,ret0
cmpb,COND(<>) arg0,ret0,.Lstrlen_not_aligned
ldw,ma 4(ret0),t0
cmpib,tr 0,r0,.Lstrlen_loop
uxor,nbz r0,t0,r0
.Lstrlen_not_aligned:
uaddcm arg0,ret0,t1
shladd t1,3,r0,t1
mtsar t1
depwi -1,%sar,32,t0
uxor,nbz r0,t0,r0
.Lstrlen_loop:
b,l,n .Lstrlen_end_loop,r0
ldw,ma 4(ret0),t0
cmpib,tr 0,r0,.Lstrlen_loop
uxor,nbz r0,t0,r0
.Lstrlen_end_loop:
extrw,u,<> t0,7,8,r0
addib,tr,n -3,ret0,.Lstrlen_out
extrw,u,<> t0,15,8,r0
addib,tr,n -2,ret0,.Lstrlen_out
extrw,u,<> t0,23,8,r0
addi -1,ret0,ret0
.Lstrlen_out:
bv r0(rp)
uaddcm ret0,arg0,ret0
.Lstrlen_null_ptr:
bv,n r0(rp)
ENDPROC_CFI(strlen)
ENTRY_CFI(strcpy, frame=0,no_calls)
ldb 0(arg1),t0
stb t0,0(arg0)
ldo 0(arg0),ret0
ldo 1(arg1),t1
cmpb,= r0,t0,2f
ldo 1(arg0),t2
1: ldb 0(t1),arg1
stb arg1,0(t2)
ldo 1(t1),t1
cmpb,<> r0,arg1,1b
ldo 1(t2),t2
2: bv,n r0(rp)
ENDPROC_CFI(strcpy)
ENTRY_CFI(strncpy, frame=0,no_calls)
ldb 0(arg1),t0
stb t0,0(arg0)
ldo 1(arg1),t1
ldo 0(arg0),ret0
cmpb,= r0,t0,2f
ldo 1(arg0),arg1
1: ldo -1(arg2),arg2
cmpb,COND(=),n r0,arg2,2f
ldb 0(t1),arg0
stb arg0,0(arg1)
ldo 1(t1),t1
cmpb,<> r0,arg0,1b
ldo 1(arg1),arg1
2: bv,n r0(rp)
ENDPROC_CFI(strncpy)
ENTRY_CFI(strcat, frame=0,no_calls)
ldb 0(arg0),t0
cmpb,= t0,r0,2f
ldo 0(arg0),ret0
ldo 1(arg0),arg0
1: ldb 0(arg0),t1
cmpb,<>,n r0,t1,1b
ldo 1(arg0),arg0
2: ldb 0(arg1),t2
stb t2,0(arg0)
ldo 1(arg0),arg0
ldb 0(arg1),t0
cmpb,<> r0,t0,2b
ldo 1(arg1),arg1
bv,n r0(rp)
ENDPROC_CFI(strcat)
ENTRY_CFI(memset, frame=0,no_calls)
copy arg0,ret0
cmpb,COND(=) r0,arg0,4f
copy arg0,t2
cmpb,COND(=) r0,arg2,4f
ldo -1(arg2),arg3
subi -1,arg3,t0
subi 0,t0,t1
cmpiclr,COND(>=) 0,t1,arg2
ldo -1(t1),arg2
extru arg2,31,2,arg0
2: stb arg1,0(t2)
ldo 1(t2),t2
addib,>= -1,arg0,2b
ldo -1(arg3),arg3
cmpiclr,COND(<=) 4,arg2,r0
b,l,n 4f,r0
#ifdef CONFIG_64BIT
depd,* r0,63,2,arg2
#else
depw r0,31,2,arg2
#endif
ldo 1(t2),t2
3: stb arg1,-1(t2)
stb arg1,0(t2)
stb arg1,1(t2)
stb arg1,2(t2)
addib,COND(>) -4,arg2,3b
ldo 4(t2),t2
4: bv,n r0(rp)
ENDPROC_CFI(memset)
.end