arch/sh/lib/udiv_qrnnd.S

Source file repositories/reference/linux-study-clean/arch/sh/lib/udiv_qrnnd.S

File Facts

System
Linux kernel
Corpus path
arch/sh/lib/udiv_qrnnd.S
Extension
.S
Size
1111 bytes
Lines
61
Domain
Architecture Layer
Bucket
arch/sh
Inferred role
Architecture Layer: arch/sh
Status
atlas-only

Why This File Exists

CPU and platform-specific kernel glue: boot entry, traps, syscall entry, interrupts, page tables, context switch, and low-level barriers.

Dependency Surface

Detected Declarations

Annotated Snippet

Copyright (C) 1994, 1995, 1997, 1998, 1999, 2000, 2001, 2002, 2003,
   2004, 2005, 2006
   Free Software Foundation, Inc.
*/

!! libgcc routines for the Renesas / SuperH SH CPUs.
!! Contributed by Steve Chamberlain.
!! sac@cygnus.com

!! ashiftrt_r4_x, ___ashrsi3, ___ashlsi3, ___lshrsi3 routines
!! recoded in assembly by Toshiyasu Morita
!! tm@netcom.com

/* SH2 optimizations for ___ashrsi3, ___ashlsi3, ___lshrsi3 and
   ELF local label prefixes by J"orn Rennecke
   amylaar@cygnus.com  */

	/* r0: rn r1: qn */ /* r0: n1 r4: n0 r5: d r6: d1 */ /* r2: __m */
	/* n1 < d, but n1 might be larger than d1.  */
	.global __udiv_qrnnd_16
	.balign 8
__udiv_qrnnd_16:
	div0u
	cmp/hi r6,r0
	bt .Lots
	.rept 16
	div1 r6,r0 
	.endr
	extu.w r0,r1
	bt 0f
	add r6,r0
0:	rotcl r1
	mulu.w r1,r5
	xtrct r4,r0
	swap.w r0,r0
	sts macl,r2
	cmp/hs r2,r0
	sub r2,r0
	bt 0f
	addc r5,r0
	add #-1,r1
	bt 0f
1:	add #-1,r1
	rts
	add r5,r0
	.balign 8
.Lots:
	sub r5,r0
	swap.w r4,r1
	xtrct r0,r1
	clrt
	mov r1,r0
	addc r5,r0
	mov #-1,r1
	bf/s 1b
	 shlr16 r1
0:	rts
	 nop

Annotation

Implementation Notes