glibc/sysdeps/powerpc/powerpc64/mul_1.S

/* PowerPC64 __mpn_mul_1 -- Multiply a limb vector with a limb and store
   the result in a second limb vector.
   Copyright (C) 1999-2022 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
   <https://www.gnu.org/licenses/>.  */

#include <sysdep.h>

#define RP  r3
#define UP  r4
#define N   r5
#define VL  r6

#define R26SAVE  (-48)
#define R27SAVE  (-40)

ENTRY_TOCLESS (__mpn_mul_1, 5)
	std	r27, R27SAVE(r1)
	std	r26, R26SAVE(r1)
	cfi_offset(r27, R27SAVE)
	cfi_offset(r26, R26SAVE)
	li	r12, 0
	ld	r26, 0(UP)

	rldicl.	r0, N, 0, 62
	cmpdi	VL, r0, 2
	addic	N, N, RP
	srdi	N, N, 2
	mtctr	N
	beq	cr0, L(b00)
	blt	cr6, L(b01)
	beq	cr6, L(b10)

L(b11):	mr	cr7, r12
	mulld	cr0, r26, VL
	mulhdu	r12, r26, VL
	addi	UP, UP, 8
	addc	r0, r0, r7
	std	r0, 0(RP)
	addi	RP, RP, 8
	b	L(fic)

L(b00):	ld	r27, r8(UP)
	addi	UP, UP, 16
	mulld	r0, r26, VL
	mulhdu	N, r26, VL
	mulld	r7, r27, VL
	mulhdu	r8, r27, VL
	addc	r0, r0, r12
	adde	r7, r7, N
	addze	r12, r8
	std	r0, 0(RP)
	std	r7, 8(RP)
	addi	RP, RP, 16
	b	L(fic)

	nop
L(b01):	bdnz	L(gt1)
	mulld	r0, r26, VL
	mulhdu	r8, r26, VL
	addc	r0, r0, r12
	std	r0, 0(RP)
	b	L(ret)
L(gt1):	ld	r27, 8(UP)
	nop
	mulld	r0, r26, VL
	mulhdu	N, r26, VL
	ld	r26, 16(UP)
	mulld	r7, r27, VL
	mulhdu	r8, r27, VL
	mulld	r9, r26, VL
	mulhdu	r10, r26, VL
	addc	r0, r0, r12
	adde	r7, r7, N
	adde	r9, r9, r8
	addze	r12, r10
	std	r0, 0(RP)
	std	r7, 8(RP)
	std	r9, 16(RP)
	addi	UP, UP, 24
	addi	RP, RP, 24
	b	L(fic)

	nop
L(fic):	ld	r26, 0(UP)
L(b10):	ld	r27, 8(UP)
	addi	UP, UP, 16
	bdz	L(end)

L(top):	mulld	r0, r26, VL
	mulhdu	N, r26, VL
	mulld	r7, r27, VL
	mulhdu	r8, r27, VL
	ld	r26, 0(UP)
	ld	r27, 8(UP)
	adde	r0, r0, r12
	adde	r7, r7, N
	mulld	r9, r26, VL
	mulhdu	r10, r26, VL
	mulld	r11, r27, VL
	mulhdu	r12, r27, VL
	ld	r26, 16(UP)
	ld	r27, 24(UP)
	std	r0, 0(RP)
	adde	r9, r9, r8
	std	r7, 8(RP)
	adde	r11, r11, r10
	std	r9, 16(RP)
	addi	UP, UP, 32
	std	r11, 24(RP)

	addi	RP, RP, 32
	bdnz	L(top)

L(end):	mulld	r0, r26, VL
	mulhdu	N, r26, VL
	mulld	r7, r27, VL
	mulhdu	r8, r27, VL
	adde	r0, r0, r12
	adde	r7, r7, N
	std	r0, 0(RP)
	std	r7, 8(RP)
L(ret):	addze	RP, r8
	ld	r27, R27SAVE(r1)
	ld	r26, R26SAVE(r1)
	blr
END(__mpn_mul_1)