[thirdparty/glibc.git] / sysdeps / s390 / multiarch / wcsncpy-vx.S

/* Vector optimized 32/64 bit S/390 version of wcsncpy.
   Copyright (C) 2015-2016 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/>.  */

#if defined HAVE_S390_VX_ASM_SUPPORT && IS_IN (libc)

# include "sysdep.h"
# include "asm-syntax.h"

	.text

/* wchar_t *wcsncpy (const wchar_t *dest, const wchar_t *src, size_t n)
   Copy at most n characters of string  src to dest.

   Register usage:
   -r0=dest pointer for return
   -r1=tmp, zero byte index
   -r2=dest
   -r3=src
   -r4=n
   -r5=current_len
   -r6=tmp, loaded bytes
   -r7=tmp, border
   -v16=part of src
   -v17=index of zero
   -v18=part of src
   -v31=register save area for r6, r7
*/
ENTRY(__wcsncpy_vx)
	.machine "z13"
	.machinemode "zarch_nohighgprs"

# if !defined __s390x__
	llgfr	%r4,%r4
# endif /* !defined __s390x__ */

	clgfi	%r4,0
	ber	%r14		/* Nothing to do, if n == 0.  */

	vlbb	%v16,0(%r3),6	/* Load s until next 4k-byte boundary.  */

	tmll	%r3,3		/* Test if s is 4-byte aligned?  */
	jne	.Lfallback	/* And use common-code variant if not.  */

	vlvgp	%v31,%r6,%r7	/* Save registers.  */
	lgr	%r0,%r2		/* Save destination pointer for return.  */

	lcbb	%r6,0(%r3),6	/* Get bytes to 4k-byte boundary or 16.  */
	llgfr	%r6,%r6		/* Convert 32bit to 64bit.  */

	lghi	%r5,0		/* current_len = 0.  */

	/* Check range of maxlen and convert to byte-count.  */
# ifdef __s390x__
	tmhh	%r4,49152	/* Test bit 0 or 1 of n.  */
	lghi	%r1,-4		/* Max byte-count is 18446744073709551612.  */
# else
	tmlh	%r4,49152	/* Test bit 0 or 1 of n.  */
	llilf	%r1,4294967292	/* Max byte-count is 4294967292.  */
# endif /* !__s390x__ */
	sllg	%r4,%r4,2	/* Convert character-count to byte-count.  */
	locgrne	%r4,%r1		/* Use max byte-count, if bit 0/1 was one.  */

	clgrjle	%r4,%r6,.Lremaining_v16 /* If n <= loaded-bytes
					   -> process remaining.  */

	/* n > loaded-byte-count.  */
	vfenezf	%v17,%v16,%v16	/* Find element not equal with zero search.  */
	vlgvb	%r1,%v17,7	/* Load zero index or 16 if not found.  */
	aghi	%r1,3		/* Also copy remaining bytes of zero.  */
	clrjl	%r1,%r6,.Lfound_v16_store /* Found zero within loaded bytes,
					     copy and return.  */

	/* Align s to 16 byte.  */
	risbgn	%r7,%r3,60,128+63,0 /* %r3 = bits 60-63 of %r2 'and' 15.  */
	lghi	%r5,15		/* current_len = 15.  */
	slr	%r5,%r7		/* Compute highest index to 16byte boundary.  */

	/* Zero not found and n > loaded-byte-count.  */
	vstl	%v16,%r5,0(%r2)	/* Copy loaded characters - no zero.  */
	ahi	%r5,1		/* Start loop at next character.  */

	/* Now we are 16byte aligned, so we can load
	   a full vreg without page fault.  */
	lgr	%r1,%r5		/* If %r5 + 64 < maxlen? -> loop64.  */
	aghi	%r1,64
	clgrjl	%r1,%r4,.Lloop64

	vl	%v16,0(%r5,%r3)	/* Load s.  */
	clgijl	%r4,17,.Lremaining_v16	/* If n <=16, process remaining
					   bytes.  */
.Llt64:
	lgr	%r7,%r4
	slgfi	%r7,16		/* border_len = maxlen - 16.  */

	clgrjhe	%r5,%r7,.Lremaining_v16 /* If current_len >= border
					       then process remaining bytes.  */
	vfenezfs %v17,%v16,%v16	/* Find element not equal with zero search.  */
	je	.Lfound_v16	/* Jump away if zero was found.  */
	vl	%v18,16(%r5,%r3) /* Load next part of s.  */
	vst	%v16,0(%r5,%r2)	/* Store previous part without zero to dst.  */
	aghi	%r5,16

	clgrjhe	%r5,%r7,.Lremaining_v18
	vfenezfs %v17,%v18,%v18
	je	.Lfound_v18
	vl	%v16,16(%r5,%r3)
	vst	%v18,0(%r5,%r2)
	aghi	%r5,16

	clgrjhe	%r5,%r7,.Lremaining_v16
	vfenezfs %v17,%v16,%v16
	je	.Lfound_v16
	vl	%v18,16(%r5,%r3)
	vst	%v16,0(%r5,%r2)
	aghi	%r5,16

.Lremaining_v18:
	vlr	%v16,%v18
.Lremaining_v16:
	/* v16 contains the remaining bytes [1...16].
	   Store remaining bytes and append string-termination.  */
	vfenezf	%v17,%v16,%v16	/* Find element not equal with zero search.  */
	slgrk	%r7,%r4,%r5	/* Remaining bytes = maxlen - current_len.  */
	aghi	%r7,-1		/* vstl needs highest index.  */
	la	%r2,0(%r5,%r2)	/* vstl has no index register.  */
	vlgvb	%r1,%v17,7	/* Load zero index or 16 if not found.  */
	aghi	%r1,3		/* Also copy remaining bytes of zero.  */
	/* Zero in remaining bytes? -> jump away (zero-index < max-index)
	   Do not jump away if zero-index == max-index,
	   but simply copy zero with vstl below.  */
	clrjl	%r1,%r7,.Lfound_v16_store
	vstl	%v16,%r7,0(%r2)	/* Store remaining bytes without null
				   termination!.  */
.Lend:
	/* Restore saved registers.  */
	vlgvg	%r6,%v31,0
	vlgvg	%r7,%v31,1
	lgr	%r2,%r0		/* Load saved dest-ptr.  */
	br	%r14

.Lfound_v16_32:
	aghi	%r5,32
	j	.Lfound_v16
.Lfound_v18_48:
	aghi	%r5,32
.Lfound_v18_16:
	aghi	%r5,16
.Lfound_v18:
	vlr	%v16,%v18
.Lfound_v16:
	/* v16 contains a zero. Store remaining bytes to zero. current_len
	   has not reached border, thus checking for n is not needed! */
	vlgvb	%r1,%v17,7	/* Load byte index of zero.  */
	la	%r2,0(%r5,%r2)	/* vstl has no support for index-register.  */
	aghi	%r1,3		/* Also copy remaining bytes of zero.  */
.Lfound_v16_store:
	vstl	%v16,%r1,0(%r2)	/* Copy characters including zero.  */
	/* Fill remaining bytes with zero - remaining count always > 0.  */
	algr	%r5,%r1		/* Remaining bytes (=%r4) = ...  */
	slgr	%r4,%r5		/* = maxlen - (currlen + zero_index + 1).  */
	la	%r2,0(%r1,%r2)	/* Pointer to zero. start filling beyond.  */
	aghi	%r4,-2		/* mvc with exrl needs count - 1.
				   (additional -1, see remaining bytes above) */
	srlg	%r6,%r4,8	/* Split into 256 byte blocks.  */
	ltgr	%r6,%r6
	je	.Lzero_lt256
.Lzero_loop256:
	mvc	1(256,%r2),0(%r2) /* Fill 256 zeros at once.  */
	la	%r2,256(%r2)
	brctg	%r6,.Lzero_loop256 /* Loop until all blocks are processed.  */
.Lzero_lt256:
	exrl	%r4,.Lmvc_lt256
	j	.Lend
.Lmvc_lt256:
	mvc	1(1,%r2),0(%r2)

	/* Find zero in 16byte aligned loop.  */
.Lloop64:
	vl	%v16,0(%r5,%r3) /* Load s.  */
	vfenezfs %v17,%v16,%v16	/* Find element not equal with zero search.  */
	je	.Lfound_v16	/* Jump away if zero was found.  */
	vl	%v18,16(%r5,%r3) /* Load next part of s.  */
	vst	%v16,0(%r5,%r2)	/* Store previous part without zero to dst.  */
	vfenezfs %v17,%v18,%v18
	je	.Lfound_v18_16
	vl	%v16,32(%r5,%r3)
	vst	%v18,16(%r5,%r2)
	vfenezfs %v17,%v16,%v16
	je	.Lfound_v16_32
	vl	%v18,48(%r5,%r3)
	vst	%v16,32(%r5,%r2)
	vfenezfs %v17,%v18,%v18
	je	.Lfound_v18_48
	vst	%v18,48(%r5,%r2)

	aghi	%r5,64
	lgr	%r1,%r5		/* If %r5 + 64 < maxlen? -> loop64.  */
	aghi	%r1,64
	clgrjl	%r1,%r4,.Lloop64

	vl	%v16,0(%r5,%r3)	/* Load s.  */
	j	.Llt64

.Lfallback:
	jg	__wcsncpy_c
END(__wcsncpy_vx)

#endif /* HAVE_S390_VX_ASM_SUPPORT && IS_IN (libc) */
Commit	Line	Data
d183b96e	1	/* Vector optimized 32/64 bit S/390 version of wcsncpy.
f7a9f785	2	Copyright (C) 2015-2016 Free Software Foundation, Inc.
d183b96e SL	3	This file is part of the GNU C Library.
	4
	5	The GNU C Library is free software; you can redistribute it and/or
	6	modify it under the terms of the GNU Lesser General Public
	7	License as published by the Free Software Foundation; either
	8	version 2.1 of the License, or (at your option) any later version.
	9
	10	The GNU C Library is distributed in the hope that it will be useful,
	11	but WITHOUT ANY WARRANTY; without even the implied warranty of
	12	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	13	Lesser General Public License for more details.
	14
	15	You should have received a copy of the GNU Lesser General Public
	16	License along with the GNU C Library; if not, see
	17	<http://www.gnu.org/licenses/>. */
	18
	19	#if defined HAVE_S390_VX_ASM_SUPPORT && IS_IN (libc)
	20
	21	# include "sysdep.h"
	22	# include "asm-syntax.h"
	23
	24	.text
	25
	26	/* wchar_t wcsncpy (const wchar_t dest, const wchar_t *src, size_t n)
	27	Copy at most n characters of string src to dest.
	28
	29	Register usage:
	30	-r0=dest pointer for return
	31	-r1=tmp, zero byte index
	32	-r2=dest
	33	-r3=src
	34	-r4=n
	35	-r5=current_len
	36	-r6=tmp, loaded bytes
	37	-r7=tmp, border
	38	-v16=part of src
	39	-v17=index of zero
	40	-v18=part of src
	41	-v31=register save area for r6, r7
	42	*/
	43	ENTRY(__wcsncpy_vx)
	44	.machine "z13"
	45	.machinemode "zarch_nohighgprs"
	46
	47	# if !defined __s390x__
	48	llgfr %r4,%r4
	49	# endif /* !defined __s390x__ */
	50
	51	clgfi %r4,0
	52	ber %r14 /* Nothing to do, if n == 0. */
	53
	54	vlbb %v16,0(%r3),6 /* Load s until next 4k-byte boundary. */
	55
	56	tmll %r3,3 /* Test if s is 4-byte aligned? */
	57	jne .Lfallback /* And use common-code variant if not. */
	58
	59	vlvgp %v31,%r6,%r7 /* Save registers. */
	60	lgr %r0,%r2 /* Save destination pointer for return. */
	61
	62	lcbb %r6,0(%r3),6 /* Get bytes to 4k-byte boundary or 16. */
	63	llgfr %r6,%r6 /* Convert 32bit to 64bit. */
	64
	65	lghi %r5,0 /* current_len = 0. */
	66
67	/* Check range of maxlen and convert to byte-count. */
68	# ifdef __s390x__
69	tmhh %r4,49152 /* Test bit 0 or 1 of n. */
70	lghi %r1,-4 /* Max byte-count is 18446744073709551612. */
71	# else
72	tmlh %r4,49152 /* Test bit 0 or 1 of n. */
73	llilf %r1,4294967292 /* Max byte-count is 4294967292. */
74	# endif /* !__s390x__ */
75	sllg %r4,%r4,2 /* Convert character-count to byte-count. */
76	locgrne %r4,%r1 /* Use max byte-count, if bit 0/1 was one. */
77
78	clgrjle %r4,%r6,.Lremaining_v16 /* If n <= loaded-bytes
79	-> process remaining. */
80
81	/* n > loaded-byte-count. */
82	vfenezf %v17,%v16,%v16 /* Find element not equal with zero search. */
83	vlgvb %r1,%v17,7 /* Load zero index or 16 if not found. */
84	aghi %r1,3 /* Also copy remaining bytes of zero. */
85	clrjl %r1,%r6,.Lfound_v16_store /* Found zero within loaded bytes,
86	copy and return. */
87
88	/* Align s to 16 byte. */
89	risbgn %r7,%r3,60,128+63,0 /* %r3 = bits 60-63 of %r2 'and' 15. */
90	lghi %r5,15 /* current_len = 15. */
91	slr %r5,%r7 /* Compute highest index to 16byte boundary. */
92
93	/* Zero not found and n > loaded-byte-count. */
94	vstl %v16,%r5,0(%r2) /* Copy loaded characters - no zero. */
95	ahi %r5,1 /* Start loop at next character. */
96
97	/* Now we are 16byte aligned, so we can load
98	a full vreg without page fault. */
99	lgr %r1,%r5 /* If %r5 + 64 < maxlen? -> loop64. */
100	aghi %r1,64
101	clgrjl %r1,%r4,.Lloop64
102
103	vl %v16,0(%r5,%r3) /* Load s. */
104	clgijl %r4,17,.Lremaining_v16 /* If n <=16, process remaining
105	bytes. */
106	.Llt64:
107	lgr %r7,%r4
108	slgfi %r7,16 /* border_len = maxlen - 16. */
109
110	clgrjhe %r5,%r7,.Lremaining_v16 /* If current_len >= border
111	then process remaining bytes. */
112	vfenezfs %v17,%v16,%v16 /* Find element not equal with zero search. */
113	je .Lfound_v16 /* Jump away if zero was found. */
114	vl %v18,16(%r5,%r3) /* Load next part of s. */
115	vst %v16,0(%r5,%r2) /* Store previous part without zero to dst. */
116	aghi %r5,16
117
118	clgrjhe %r5,%r7,.Lremaining_v18
119	vfenezfs %v17,%v18,%v18
120	je .Lfound_v18
121	vl %v16,16(%r5,%r3)
122	vst %v18,0(%r5,%r2)
123	aghi %r5,16
124
125	clgrjhe %r5,%r7,.Lremaining_v16
126	vfenezfs %v17,%v16,%v16
127	je .Lfound_v16
128	vl %v18,16(%r5,%r3)
129	vst %v16,0(%r5,%r2)
130	aghi %r5,16
131
132	.Lremaining_v18:
133	vlr %v16,%v18
134	.Lremaining_v16:
135	/* v16 contains the remaining bytes [1...16].
136	Store remaining bytes and append string-termination. */
137	vfenezf %v17,%v16,%v16 /* Find element not equal with zero search. */
138	slgrk %r7,%r4,%r5 /* Remaining bytes = maxlen - current_len. */
139	aghi %r7,-1 /* vstl needs highest index. */
140	la %r2,0(%r5,%r2) /* vstl has no index register. */
141	vlgvb %r1,%v17,7 /* Load zero index or 16 if not found. */
142	aghi %r1,3 /* Also copy remaining bytes of zero. */
143	/* Zero in remaining bytes? -> jump away (zero-index < max-index)
144	Do not jump away if zero-index == max-index,
145	but simply copy zero with vstl below. */
146	clrjl %r1,%r7,.Lfound_v16_store
147	vstl %v16,%r7,0(%r2) /* Store remaining bytes without null
148	termination!. */
149	.Lend:
150	/* Restore saved registers. */
151	vlgvg %r6,%v31,0
152	vlgvg %r7,%v31,1
153	lgr %r2,%r0 /* Load saved dest-ptr. */
154	br %r14
155
156	.Lfound_v16_32:
157	aghi %r5,32
158	j .Lfound_v16
159	.Lfound_v18_48:
160	aghi %r5,32
161	.Lfound_v18_16:
162	aghi %r5,16
163	.Lfound_v18:
164	vlr %v16,%v18
165	.Lfound_v16:
166	/* v16 contains a zero. Store remaining bytes to zero. current_len
167	has not reached border, thus checking for n is not needed! */
168	vlgvb %r1,%v17,7 /* Load byte index of zero. */
169	la %r2,0(%r5,%r2) /* vstl has no support for index-register. */
170	aghi %r1,3 /* Also copy remaining bytes of zero. */
171	.Lfound_v16_store:
172	vstl %v16,%r1,0(%r2) /* Copy characters including zero. */
173	/* Fill remaining bytes with zero - remaining count always > 0. */
174	algr %r5,%r1 /* Remaining bytes (=%r4) = ... */
175	slgr %r4,%r5 /* = maxlen - (currlen + zero_index + 1). */
176	la %r2,0(%r1,%r2) /* Pointer to zero. start filling beyond. */
177	aghi %r4,-2 /* mvc with exrl needs count - 1.
178	(additional -1, see remaining bytes above) */
179	srlg %r6,%r4,8 /* Split into 256 byte blocks. */
180	ltgr %r6,%r6
181	je .Lzero_lt256
182	.Lzero_loop256:
183	mvc 1(256,%r2),0(%r2) /* Fill 256 zeros at once. */
184	la %r2,256(%r2)
185	brctg %r6,.Lzero_loop256 /* Loop until all blocks are processed. */
186	.Lzero_lt256:
187	exrl %r4,.Lmvc_lt256
188	j .Lend
189	.Lmvc_lt256:
190	mvc 1(1,%r2),0(%r2)
191
192	/* Find zero in 16byte aligned loop. */
193	.Lloop64:
194	vl %v16,0(%r5,%r3) /* Load s. */
195	vfenezfs %v17,%v16,%v16 /* Find element not equal with zero search. */
196	je .Lfound_v16 /* Jump away if zero was found. */
197	vl %v18,16(%r5,%r3) /* Load next part of s. */
198	vst %v16,0(%r5,%r2) /* Store previous part without zero to dst. */
199	vfenezfs %v17,%v18,%v18
200	je .Lfound_v18_16
201	vl %v16,32(%r5,%r3)
202	vst %v18,16(%r5,%r2)
203	vfenezfs %v17,%v16,%v16
204	je .Lfound_v16_32
205	vl %v18,48(%r5,%r3)
206	vst %v16,32(%r5,%r2)
207	vfenezfs %v17,%v18,%v18
208	je .Lfound_v18_48
209	vst %v18,48(%r5,%r2)
210
211	aghi %r5,64
212	lgr %r1,%r5 /* If %r5 + 64 < maxlen? -> loop64. */
213	aghi %r1,64
214	clgrjl %r1,%r4,.Lloop64
215
216	vl %v16,0(%r5,%r3) /* Load s. */
217	j .Llt64
218
219	.Lfallback:
220	jg __wcsncpy_c
221	END(__wcsncpy_vx)
222
223	#endif /* HAVE_S390_VX_ASM_SUPPORT && IS_IN (libc) */