/* Optimized strcasecmp implementation for PowerPC64.

   Copyright (C) 2016-2018 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 <locale-defines.h>

/* int [r3] strcasecmp (const char *s1 [r3], const char *s2 [r4] ) */

#ifndef USE_AS_STRNCASECMP

#  define __STRCASECMP __strcasecmp

#  define STRCASECMP   strcasecmp

#else

#  define __STRCASECMP __strncasecmp

#  define STRCASECMP   strncasecmp

#endif

/* Convert 16 bytes to lowercase and compare */

#define TOLOWER()     \

	vaddubm	v8, v4, v1; \

	vaddubm	v7, v4, v3; \

	vcmpgtub	v8, v8, v2; \

	vsel	v4, v7, v4, v8; \

	vaddubm	v8, v5, v1; \

	vaddubm	v7, v5, v3; \

	vcmpgtub	v8, v8, v2; \

	vsel	v5, v7, v5, v8; \

	vcmpequb.	v7, v5, v4;

/*

 * Get 16 bytes for unaligned case.

 * reg1: Vector to hold next 16 bytes.

 * reg2: Address to read from.

 * reg3: Permute control vector.

 * v8: Tmp vector used to mask unwanted bytes.

 * v9: Tmp vector,0 when null is found on first 16 bytes

 */

#ifdef __LITTLE_ENDIAN__

#define GET16BYTES(reg1, reg2, reg3) \

	lvx	reg1, 0, reg2; \

	vspltisb	v8, -1; \

	vperm	v8, v8, reg1, reg3; \

	vcmpequb.	v8, v0, v8; \

	beq	cr6, 1f; \

	vspltisb	v9, 0; \

	b	2f; \

	.align 4; \

1: \

	addi	r6, reg2, 16; \

	lvx	v9, 0, r6; \

2: \

	vperm	reg1, v9, reg1, reg3;

#else

#define GET16BYTES(reg1, reg2, reg3) \

	lvx	reg1, 0, reg2; \

	vspltisb	 v8, -1; \

	vperm	v8, reg1, v8,  reg3; \

	vcmpequb.	v8, v0, v8; \

	beq	cr6, 1f; \

	vspltisb	v9, 0; \

	b	2f; \

	.align 4; \

1: \

	addi	r6, reg2, 16; \

	lvx	v9, 0, r6; \

2: \

	vperm	reg1, reg1, v9, reg3;

#endif

/* Check null in v4, v5 and convert to lower.  */

#define CHECKNULLANDCONVERT() \

	vcmpequb.	v7, v0, v5; \

	beq	cr6, 3f; \

	vcmpequb.	v7, v0, v4; \

	beq	cr6, 3f; \

	b	L(null_found); \

	.align  4; \

3: \

	TOLOWER()

#ifdef _ARCH_PWR8

#  define VCLZD_V8_v7	vclzd	v8, v7;

#  define MFVRD_R3_V1	mfvrd	r3, v1;

#  define VSUBUDM_V9_V8	vsubudm	v9, v9, v8;

#  define VPOPCNTD_V8_V8	vpopcntd v8, v8;

#  define VADDUQM_V7_V8	vadduqm	v9, v7, v8;

#else

#  define VCLZD_V8_v7	.long	0x11003fc2

#  define MFVRD_R3_V1	.long	0x7c230067

#  define VSUBUDM_V9_V8	.long	0x112944c0

#  define VPOPCNTD_V8_V8	.long	0x110047c3

#  define VADDUQM_V7_V8	.long	0x11274100

#endif

	.machine  power7

ENTRY (__STRCASECMP)

#ifdef USE_AS_STRNCASECMP

	CALL_MCOUNT 3

#else

	CALL_MCOUNT 2

#endif

#define rRTN	r3	/* Return value */

#define rSTR1	r10	/* 1st string */

#define rSTR2	r4	/* 2nd string */

#define rCHAR1	r6	/* Byte read from 1st string */

#define rCHAR2	r7	/* Byte read from 2nd string */

#define rADDR1	r8	/* Address of tolower(rCHAR1) */

#define rADDR2	r12	/* Address of tolower(rCHAR2) */

#define rLWR1	r8	/* Word tolower(rCHAR1) */

#define rLWR2	r12	/* Word tolower(rCHAR2) */

#define rTMP	r9

#define rLOC	r11	/* Default locale address */

	cmpd	cr7, rRTN, rSTR2

	/* Get locale address.  */

	ld 	rTMP, __libc_tsd_LOCALE@got@tprel(r2)

	add 	rLOC, rTMP, __libc_tsd_LOCALE@tls

	ld	rLOC, 0(rLOC)

	mr	rSTR1, rRTN

	li	rRTN, 0

	beqlr	cr7

#ifdef USE_AS_STRNCASECMP

	cmpdi	cr7, r5, 0

	beq	cr7, L(retnull)

	cmpdi	cr7, r5, 16

	blt	cr7, L(bytebybyte)

#endif

	vspltisb	v0, 0

	vspltisb	v8, -1

	/* Check for null in initial characters.

	   Check max of 16 char depending on the alignment.

	   If null is present, proceed byte by byte.  */

	lvx	v4, 0, rSTR1

#ifdef  __LITTLE_ENDIAN__

	lvsr	v10, 0, rSTR1	/* Compute mask.  */

	vperm	v9, v8, v4, v10	/* Mask bits that are not part of string.  */

#else

	lvsl	v10, 0, rSTR1

	vperm	v9, v4, v8, v10

#endif

	vcmpequb.	v9, v0, v9	/* Check for null bytes.  */

	bne	cr6, L(bytebybyte)

	lvx	v5, 0, rSTR2

	/* Calculate alignment.  */

#ifdef __LITTLE_ENDIAN__

	lvsr	v6, 0, rSTR2

	vperm	v9, v8, v5, v6	/* Mask bits that are not part of string.  */

#else

	lvsl	v6, 0, rSTR2

	vperm	v9, v5, v8, v6

#endif

	vcmpequb.	v9, v0, v9	/* Check for null bytes.  */

	bne	cr6, L(bytebybyte)

	/* Check if locale has non ascii characters.  */

	ld	rTMP, 0(rLOC)

	addi r6, rTMP,LOCALE_DATA_VALUES+_NL_CTYPE_NONASCII_CASE*SIZEOF_VALUES

	lwz	rTMP, 0(r6)

	cmpdi	cr7, rTMP, 1

	beq	cr7, L(bytebybyte)

	/* Load vector registers with values used for TOLOWER.  */

	/* Load v1 = 0xbf, v2 = 0x19 v3 = 0x20 in each byte.  */

	vspltisb	v3, 2

	vspltisb	v9, 4

	vsl	v3, v3, v9

	vaddubm	v1, v3, v3

	vnor	v1, v1, v1

	vspltisb	v2, 7

	vsububm	v2, v3, v2

	andi.	rADDR1, rSTR1, 0xF

	beq	cr0, L(align)

	addi	r6, rSTR1, 16

	lvx	v9, 0, r6

	/* Compute 16 bytes from previous two loads.  */

#ifdef __LITTLE_ENDIAN__

	vperm	v4, v9, v4, v10

#else

	vperm	v4, v4, v9, v10

#endif

L(align):

	andi.	rADDR2, rSTR2, 0xF

	beq	cr0, L(align1)

	addi	r6, rSTR2, 16

	lvx	v9, 0, r6

	/* Compute 16 bytes from previous two loads.  */

#ifdef __LITTLE_ENDIAN__

	vperm	v5, v9, v5, v6

#else

	vperm	v5, v5, v9, v6

#endif

L(align1):

	CHECKNULLANDCONVERT()

	blt	cr6, L(match)

	b	L(different)

	.align 	4

L(match):

	clrldi	r6, rSTR1, 60

	subfic	r7, r6, 16

#ifdef USE_AS_STRNCASECMP

	sub	r5, r5, r7

#endif

	add	rSTR1, rSTR1, r7

	add	rSTR2, rSTR2, r7

	andi.	rADDR2, rSTR2, 0xF

	addi	rSTR1, rSTR1, -16

	addi	rSTR2, rSTR2, -16

	beq	cr0, L(aligned)

#ifdef __LITTLE_ENDIAN__

	lvsr	v6, 0, rSTR2

#else

	lvsl	v6, 0, rSTR2

#endif

	/* There are 2 loops depending on the input alignment.

	   Each loop gets 16 bytes from s1 and s2, check for null,

	   convert to lowercase and compare. Loop till difference

	   or null occurs. */

L(s1_align):

	addi	rSTR1, rSTR1, 16

	addi	rSTR2, rSTR2, 16

#ifdef USE_AS_STRNCASECMP

	cmpdi	cr7, r5, 16

	blt	cr7, L(bytebybyte)

	addi	r5, r5, -16

#endif

	lvx	v4, 0, rSTR1

	GET16BYTES(v5, rSTR2, v6)

	CHECKNULLANDCONVERT()

	blt	cr6, L(s1_align)

	b	L(different)

	.align 	4

L(aligned):

	addi	rSTR1, rSTR1, 16

	addi	rSTR2, rSTR2, 16

#ifdef USE_AS_STRNCASECMP

	cmpdi	cr7, r5, 16

	blt	cr7, L(bytebybyte)

	addi	r5, r5, -16

#endif

	lvx	v4, 0, rSTR1

	lvx	v5, 0, rSTR2

	CHECKNULLANDCONVERT()

	blt	cr6, L(aligned)

	/* Calculate and return the difference. */

L(different):

	vaddubm	v1, v3, v3

	vcmpequb	v7, v0, v7

#ifdef __LITTLE_ENDIAN__

	/* Count trailing zero.  */

	vspltisb	v8, -1

	VADDUQM_V7_V8

	vandc	v8, v9, v7

	VPOPCNTD_V8_V8

	vspltb	v6, v8, 15

	vcmpequb.	v6, v6, v1

	blt	cr6, L(shift8)

#else

	/* Count leading zero.  */

	VCLZD_V8_v7

	vspltb	v6, v8, 7

	vcmpequb.	v6, v6, v1

	blt	cr6, L(shift8)

	vsro	v8, v8, v1

#endif

	b	L(skipsum)

	.align  4

L(shift8):

	vsumsws		v8, v8, v0

L(skipsum):

#ifdef __LITTLE_ENDIAN__

	/* Shift registers based on leading zero count.  */

	vsro	v6, v5, v8

	vsro	v7, v4, v8

	/* Merge and move to GPR.  */

	vmrglb	v6, v6, v7

	vslo	v1, v6, v1

	MFVRD_R3_V1

	/* Place the characters that are different in first position.  */

	sldi	rSTR2, rRTN, 56

	srdi	rSTR2, rSTR2, 56

	sldi	rSTR1, rRTN, 48

	srdi	rSTR1, rSTR1, 56

#else

	vslo	v6, v5, v8

	vslo	v7, v4, v8

	vmrghb	v1, v6, v7

	MFVRD_R3_V1

	srdi	rSTR2, rRTN, 48

	sldi	rSTR2, rSTR2, 56

	srdi	rSTR2, rSTR2, 56

	srdi	rSTR1, rRTN, 56

#endif

	subf  	rRTN, rSTR1, rSTR2

	extsw 	rRTN, rRTN

	blr

	.align  4

	/* OK. We've hit the end of the string. We need to be careful that

	   we don't compare two strings as different because of junk beyond

	   the end of the strings...  */

L(null_found):

	vaddubm	v10, v3, v3

#ifdef __LITTLE_ENDIAN__

	/* Count trailing zero.  */

	vspltisb	v8, -1

	VADDUQM_V7_V8

	vandc	v8, v9, v7

	VPOPCNTD_V8_V8

	vspltb	v6, v8, 15

	vcmpequb.	v6, v6, v10

	blt	cr6, L(shift_8)

#else

	/* Count leading zero.  */

	VCLZD_V8_v7

	vspltb	v6, v8, 7

	vcmpequb.	v6, v6, v10

	blt	cr6, L(shift_8)

	vsro	v8, v8, v10

#endif

	b	L(skipsum1)

	.align  4

L(shift_8):

	vsumsws	v8, v8, v0

L(skipsum1):

	/* Calculate shift count based on count of zero.  */

	vspltisb	v10, 7

	vslb	v10, v10, v10

	vsldoi	v9, v0, v10, 1

	VSUBUDM_V9_V8

	vspltisb	v8, 8

	vsldoi	v8, v0, v8, 1

	VSUBUDM_V9_V8

	/* Shift and remove junk after null character.  */

#ifdef __LITTLE_ENDIAN__

	vslo	v5, v5, v9

	vslo	v4, v4, v9

#else

	vsro	v5, v5, v9

	vsro	v4, v4, v9

#endif

	/* Convert and compare 16 bytes.  */

	TOLOWER()

	blt	cr6, L(retnull)

	b	L(different)

	.align  4

L(retnull):

	li	rRTN, 0

	blr

	.align  4

L(bytebybyte):

	/* Unrolling loop for POWER: loads are done with 'lbz' plus

	offset and string descriptors are only updated in the end

	of loop unrolling. */

	ld	rLOC, LOCALE_CTYPE_TOLOWER(rLOC)

	lbz	rCHAR1, 0(rSTR1)	/* Load char from s1 */

	lbz	rCHAR2, 0(rSTR2)	/* Load char from s2 */

#ifdef USE_AS_STRNCASECMP

	rldicl	rTMP, r5, 62, 2

	cmpdi	cr7, rTMP, 0

	beq	cr7, L(lessthan4)

	mtctr	rTMP

#endif

L(loop):

	cmpdi	rCHAR1, 0		/* *s1 == '\0' ? */

	sldi	rADDR1, rCHAR1, 2	/* Calculate address for tolower(*s1) */

	sldi	rADDR2, rCHAR2, 2	/* Calculate address for tolower(*s2) */

	lwzx	rLWR1, rLOC, rADDR1	/* Load tolower(*s1) */

	lwzx	rLWR2, rLOC, rADDR2	/* Load tolower(*s2) */

	cmpw	cr1, rLWR1, rLWR2	/* r = tolower(*s1) == tolower(*s2) ? */

	crorc	4*cr1+eq,eq,4*cr1+eq	/* (*s1 != '\0') || (r == 1) */

	beq	cr1, L(done)

	lbz	rCHAR1, 1(rSTR1)

	lbz	rCHAR2, 1(rSTR2)

	cmpdi	rCHAR1, 0

	sldi	rADDR1, rCHAR1, 2

	sldi	rADDR2, rCHAR2, 2

	lwzx	rLWR1, rLOC, rADDR1

	lwzx	rLWR2, rLOC, rADDR2

	cmpw	cr1, rLWR1, rLWR2

	crorc	4*cr1+eq,eq,4*cr1+eq

	beq	cr1, L(done)

	lbz	rCHAR1, 2(rSTR1)

	lbz	rCHAR2, 2(rSTR2)

	cmpdi	rCHAR1, 0

	sldi	rADDR1, rCHAR1, 2

	sldi	rADDR2, rCHAR2, 2

	lwzx	rLWR1, rLOC, rADDR1

	lwzx	rLWR2, rLOC, rADDR2

	cmpw	cr1, rLWR1, rLWR2

	crorc	4*cr1+eq,eq,4*cr1+eq

	beq	cr1, L(done)

	lbz	rCHAR1, 3(rSTR1)

	lbz	rCHAR2, 3(rSTR2)

	cmpdi	rCHAR1, 0

	/* Increment both string descriptors */

	addi	rSTR1, rSTR1, 4

	addi	rSTR2, rSTR2, 4

	sldi	rADDR1, rCHAR1, 2

	sldi	rADDR2, rCHAR2, 2

	lwzx	rLWR1, rLOC, rADDR1

	lwzx	rLWR2, rLOC, rADDR2

	cmpw	cr1, rLWR1, rLWR2

	crorc	4*cr1+eq,eq,4*cr1+eq

	beq     cr1, L(done)

	lbz	rCHAR1, 0(rSTR1)	/* Load char from s1 */

	lbz	rCHAR2, 0(rSTR2)	/* Load char from s2 */

#ifdef USE_AS_STRNCASECMP

	bdnz	L(loop)

#else

	b	L(loop)

#endif

#ifdef USE_AS_STRNCASECMP

L(lessthan4):

	clrldi	r5, r5, 62

	cmpdi	cr7, r5, 0

	beq	cr7, L(retnull)

	mtctr	r5

L(loop1):

	cmpdi	rCHAR1, 0

	sldi	rADDR1, rCHAR1, 2

	sldi	rADDR2, rCHAR2, 2

	lwzx	rLWR1, rLOC, rADDR1

	lwzx	rLWR2, rLOC, rADDR2

	cmpw	cr1, rLWR1, rLWR2

	crorc	4*cr1+eq,eq,4*cr1+eq

	beq	cr1, L(done)

	addi	rSTR1, rSTR1, 1

	addi	rSTR2, rSTR2, 1

	lbz	rCHAR1, 0(rSTR1)

	lbz	rCHAR2, 0(rSTR2)

	bdnz	L(loop1)

#endif

L(done):

	subf	r0, rLWR2, rLWR1

	extsw	rRTN, r0

	blr

END (__STRCASECMP)

weak_alias (__STRCASECMP, STRCASECMP)

libc_hidden_builtin_def (__STRCASECMP)