OpenBLAS/kernel/arm64/dnrm2.S

/*******************************************************************************
Copyright (c) 2015, The OpenBLAS Project
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ARE DISCLAIMED. IN NO EVENT SHALL THE OPENBLAS PROJECT OR CONTRIBUTORS BE
LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*******************************************************************************/

#define ASSEMBLER
#include "common.h"

#define	N	x0	/* vector length */
#define	X	x1	/* X vector address */
#define	INC_X	x2	/* X stride */
#define I	x5	/* loop variable */

/*******************************************************************************
* Macro definitions
*******************************************************************************/

#define TMPF	d6
#define SSQ	d0
#define TMPVF	{v6.d}[0]
#define SZ	8

/******************************************************************************/

.macro KERNEL_F1
	ldr	TMPF, [X], #SZ
	fmul	TMPF, TMPF, TMPF
	fadd	SSQ, SSQ, TMPF
.endm

.macro KERNEL_F8
	ld1	{v1.2d, v2.2d}, [X], #32
	fmla	v0.2d, v1.2d, v1.2d
	fmla	v5.2d, v2.2d, v2.2d
	ld1	{v3.2d, v4.2d}, [X], #32
	fmla	v0.2d, v3.2d, v3.2d
	fmla	v5.2d, v4.2d, v4.2d
	PRFM	PLDL1KEEP, [X, #1024]
.endm

.macro nrm2_kernel_F8_FINALIZE
	fadd	v0.2d, v0.2d, v5.2d
	faddp	SSQ, v0.2d
.endm

.macro INIT_S
	lsl	INC_X, INC_X, #3
	ld1	TMPVF, [X], INC_X
	fmul	SSQ, TMPF, TMPF
.endm

.macro KERNEL_S1
	ld1	TMPVF, [X], INC_X
	fmul	TMPF, TMPF, TMPF
	fadd	SSQ, SSQ, TMPF
.endm

/*******************************************************************************
* End of macro definitions
*******************************************************************************/

	PROLOGUE

	fmov	SSQ, xzr
	fmov	d5, SSQ

	cmp	N, xzr
	ble	nrm2_kernel_zero
	cmp	INC_X, xzr
	ble	nrm2_kernel_zero
	cmp	INC_X, #1
	bne	nrm2_kernel_S_BEGIN

nrm2_kernel_F_BEGIN:

	asr	I, N, #3
	cmp	I, xzr
	beq	nrm2_kernel_F1_INIT

nrm2_kernel_F8:

	KERNEL_F8

	subs	I, I, #1
	bne	nrm2_kernel_F8

	nrm2_kernel_F8_FINALIZE

nrm2_kernel_F1:

	ands	I, N, #7
	ble	nrm2_kernel_L999

nrm2_kernel_F10:

	KERNEL_F1

	subs    I, I, #1
        bne     nrm2_kernel_F10

	b	nrm2_kernel_L999

nrm2_kernel_F1_INIT:

	b	nrm2_kernel_F1

nrm2_kernel_S_BEGIN:

	INIT_S

	subs	N, N, #1
	ble	nrm2_kernel_L999

	asr	I, N, #2
	cmp	I, xzr
	ble	nrm2_kernel_S1

nrm2_kernel_S4:

	KERNEL_S1
	KERNEL_S1
	KERNEL_S1
	KERNEL_S1

	subs	I, I, #1
	bne	nrm2_kernel_S4

nrm2_kernel_S1:

	ands	I, N, #3
	ble	nrm2_kernel_L999

nrm2_kernel_S10:

	KERNEL_S1

	subs    I, I, #1
	bne     nrm2_kernel_S10

nrm2_kernel_L999:
	fsqrt	SSQ, SSQ
	ret

nrm2_kernel_zero:
	ret

	EPILOGUE