gcc-4.3.1/gcc/config/arm/lib1funcs.asm

@ libgcc routines for ARM cpu.
@ Division routines, written by Richard Earnshaw, (rearnsha@armltd.co.uk)

/* Copyright 1995, 1996, 1998, 1999, 2000, 2003, 2004, 2005, 2007
   Free Software Foundation, Inc.

This file is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by the
Free Software Foundation; either version 2, or (at your option) any
later version.

In addition to the permissions in the GNU General Public License, the
Free Software Foundation gives you unlimited permission to link the
compiled version of this file into combinations with other programs,
and to distribute those combinations without any restriction coming
from the use of this file.  (The General Public License restrictions
do apply in other respects; for example, they cover modification of
the file, and distribution when not linked into a combine
executable.)

This file 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
General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; see the file COPYING.  If not, write to
the Free Software Foundation, 51 Franklin Street, Fifth Floor,
Boston, MA 02110-1301, USA.  */

/* An executable stack is *not* required for these functions.  */
#if defined(__ELF__) && defined(__linux__)
.section .note.GNU-stack,"",%progbits
.previous
#endif

/* ------------------------------------------------------------------------ */

/* We need to know what prefix to add to function names.  */

#ifndef __USER_LABEL_PREFIX__
#error  __USER_LABEL_PREFIX__ not defined
#endif

/* ANSI concatenation macros.  */

#define CONCAT1(a, b) CONCAT2(a, b)
#define CONCAT2(a, b) a ## b

/* Use the right prefix for global labels.  */

#define SYM(x) CONCAT1 (__USER_LABEL_PREFIX__, x)

#ifdef __ELF__
#ifdef __thumb__
#define __PLT__  /* Not supported in Thumb assembler (for now).  */
#elif defined __vxworks && !defined __PIC__
#define __PLT__ /* Not supported by the kernel loader.  */
#else
#define __PLT__ (PLT)
#endif
#define TYPE(x) .type SYM(x),function
#define SIZE(x) .size SYM(x), . - SYM(x)
#define LSYM(x) .x
#else
#define __PLT__
#define TYPE(x)
#define SIZE(x)
#define LSYM(x) x
#endif

/* Function end macros.  Variants for interworking.  */

#if defined(__ARM_ARCH_2__)
# define __ARM_ARCH__ 2
#endif

#if defined(__ARM_ARCH_3__)
# define __ARM_ARCH__ 3
#endif

#if defined(__ARM_ARCH_3M__) || defined(__ARM_ARCH_4__) \
	|| defined(__ARM_ARCH_4T__)
/* We use __ARM_ARCH__ set to 4 here, but in reality it's any processor with
   long multiply instructions.  That includes v3M.  */
# define __ARM_ARCH__ 4
#endif
	
#if defined(__ARM_ARCH_5__) || defined(__ARM_ARCH_5T__) \
	|| defined(__ARM_ARCH_5E__) || defined(__ARM_ARCH_5TE__) \
	|| defined(__ARM_ARCH_5TEJ__)
# define __ARM_ARCH__ 5
#endif

#if defined(__ARM_ARCH_6__) || defined(__ARM_ARCH_6J__) \
	|| defined(__ARM_ARCH_6K__) || defined(__ARM_ARCH_6Z__) \
	|| defined(__ARM_ARCH_6ZK__) || defined(__ARM_ARCH_6T2__)
# define __ARM_ARCH__ 6
#endif

#if defined(__ARM_ARCH_7__) || defined(__ARM_ARCH_7A__) \
	|| defined(__ARM_ARCH_7R__) || defined(__ARM_ARCH_7M__)
# define __ARM_ARCH__ 7
#endif

#ifndef __ARM_ARCH__
#error Unable to determine architecture.
#endif

/* How to return from a function call depends on the architecture variant.  */

#if (__ARM_ARCH__ > 4) || defined(__ARM_ARCH_4T__)

# define RET		bx	lr
# define RETc(x)	bx##x	lr

/* Special precautions for interworking on armv4t.  */
# if (__ARM_ARCH__ == 4)

/* Always use bx, not ldr pc.  */
#  if (defined(__thumb__) || defined(__THUMB_INTERWORK__))
#    define __INTERWORKING__
#   endif /* __THUMB__ || __THUMB_INTERWORK__ */

/* Include thumb stub before arm mode code.  */
#  if defined(__thumb__) && !defined(__THUMB_INTERWORK__)
#   define __INTERWORKING_STUBS__
#  endif /* __thumb__ && !__THUMB_INTERWORK__ */

#endif /* __ARM_ARCH == 4 */

#else

# define RET		mov	pc, lr
# define RETc(x)	mov##x	pc, lr

#endif

.macro	cfi_pop		advance, reg, cfa_offset
#ifdef __ELF__
	.pushsection	.debug_frame
	.byte	0x4		/* DW_CFA_advance_loc4 */
	.4byte	\advance
	.byte	(0xc0 | \reg)	/* DW_CFA_restore */
	.byte	0xe		/* DW_CFA_def_cfa_offset */
	.uleb128 \cfa_offset
	.popsection
#endif
.endm
.macro	cfi_push	advance, reg, offset, cfa_offset
#ifdef __ELF__
	.pushsection	.debug_frame
	.byte	0x4		/* DW_CFA_advance_loc4 */
	.4byte	\advance
	.byte	(0x80 | \reg)	/* DW_CFA_offset */
	.uleb128 (\offset / -4)
	.byte	0xe		/* DW_CFA_def_cfa_offset */
	.uleb128 \cfa_offset
	.popsection
#endif
.endm
.macro cfi_start	start_label, end_label
#ifdef __ELF__
	.pushsection	.debug_frame
LSYM(Lstart_frame):
	.4byte	LSYM(Lend_cie) - LSYM(Lstart_cie) @ Length of CIE
LSYM(Lstart_cie):
        .4byte	0xffffffff	@ CIE Identifier Tag
        .byte	0x1	@ CIE Version
        .ascii	"\0"	@ CIE Augmentation
        .uleb128 0x1	@ CIE Code Alignment Factor
        .sleb128 -4	@ CIE Data Alignment Factor
        .byte	0xe	@ CIE RA Column
        .byte	0xc	@ DW_CFA_def_cfa
        .uleb128 0xd
        .uleb128 0x0

	.align 2
LSYM(Lend_cie):
	.4byte	LSYM(Lend_fde)-LSYM(Lstart_fde)	@ FDE Length
LSYM(Lstart_fde):
	.4byte	LSYM(Lstart_frame)	@ FDE CIE offset
	.4byte	\start_label	@ FDE initial location
	.4byte	\end_label-\start_label	@ FDE address range
	.popsection
#endif
.endm
.macro cfi_end	end_label
#ifdef __ELF__
	.pushsection	.debug_frame
	.align	2
LSYM(Lend_fde):
	.popsection
\end_label:
#endif
.endm

/* Don't pass dirn, it's there just to get token pasting right.  */

.macro	RETLDM	regs=, cond=, unwind=, dirn=ia
#if defined (__INTERWORKING__)
	.ifc "\regs",""
	ldr\cond	lr, [sp], #8
	.else
# if defined(__thumb2__)
	pop\cond	{\regs, lr}
# else
	ldm\cond\dirn	sp!, {\regs, lr}
# endif
	.endif
	.ifnc "\unwind", ""
	/* Mark LR as restored.  */
97:	cfi_pop 97b - \unwind, 0xe, 0x0
	.endif
	bx\cond	lr
#else
	/* Caller is responsible for providing IT instruction.  */
	.ifc "\regs",""
	ldr\cond	pc, [sp], #8
	.else
# if defined(__thumb2__)
	pop\cond	{\regs, pc}
# else
	ldm\cond\dirn	sp!, {\regs, pc}
# endif
	.endif
#endif
.endm

/* The Unified assembly syntax allows the same code to be assembled for both
   ARM and Thumb-2.  However this is only supported by recent gas, so define
   a set of macros to allow ARM code on older assemblers.  */
#if defined(__thumb2__)
.macro do_it cond, suffix=""
	it\suffix	\cond
.endm
.macro shift1 op, arg0, arg1, arg2
	\op	\arg0, \arg1, \arg2
.endm
#define do_push	push
#define do_pop	pop
#define COND(op1, op2, cond) op1 ## op2 ## cond
/* Perform an arithmetic operation with a variable shift operand.  This
   requires two instructions and a scratch register on Thumb-2.  */
.macro shiftop name, dest, src1, src2, shiftop, shiftreg, tmp
	\shiftop \tmp, \src2, \shiftreg
	\name \dest, \src1, \tmp
.endm
#else
.macro do_it cond, suffix=""
.endm
.macro shift1 op, arg0, arg1, arg2
	mov	\arg0, \arg1, \op \arg2
.endm
#define do_push	stmfd sp!,
#define do_pop	ldmfd sp!,
#define COND(op1, op2, cond) op1 ## cond ## op2
.macro shiftop name, dest, src1, src2, shiftop, shiftreg, tmp
	\name \dest, \src1, \src2, \shiftop \shiftreg
.endm
#endif

.macro ARM_LDIV0 name
	str	lr, [sp, #-8]!
98:	cfi_push 98b - __\name, 0xe, -0x8, 0x8
	bl	SYM (__div0) __PLT__
	mov	r0, #0			@ About as wrong as it could be.
	RETLDM	unwind=98b
.endm


.macro THUMB_LDIV0 name
	push	{ r1, lr }
98:	cfi_push 98b - __\name, 0xe, -0x4, 0x8
	bl	SYM (__div0)
	mov	r0, #0			@ About as wrong as it could be.
#if defined (__INTERWORKING__)
	pop	{ r1, r2 }
	bx	r2
#else
	pop	{ r1, pc }
#endif
.endm

.macro FUNC_END name
	SIZE (__\name)
.endm

.macro DIV_FUNC_END name
	cfi_start	__\name, LSYM(Lend_div0)
LSYM(Ldiv0):
#ifdef __thumb__
	THUMB_LDIV0 \name
#else
	ARM_LDIV0 \name
#endif
	cfi_end	LSYM(Lend_div0)
	FUNC_END \name
.endm

.macro THUMB_FUNC_START name
	.globl	SYM (\name)
	TYPE	(\name)
	.thumb_func
SYM (\name):
.endm

/* Function start macros.  Variants for ARM and Thumb.  */

#ifdef __thumb__
#define THUMB_FUNC .thumb_func
#define THUMB_CODE .force_thumb
# if defined(__thumb2__)
#define THUMB_SYNTAX .syntax divided
# else
#define THUMB_SYNTAX
# endif
#else
#define THUMB_FUNC
#define THUMB_CODE
#define THUMB_SYNTAX
#endif

.macro FUNC_START name
	.text
	.globl SYM (__\name)
	TYPE (__\name)
	.align 0
	THUMB_CODE
	THUMB_FUNC
	THUMB_SYNTAX
SYM (__\name):
.endm

/* Special function that will always be coded in ARM assembly, even if
   in Thumb-only compilation.  */

#if defined(__thumb2__)

/* For Thumb-2 we build everything in thumb mode.  */
.macro ARM_FUNC_START name
       FUNC_START \name
       .syntax unified
.endm
#define EQUIV .thumb_set
.macro  ARM_CALL name
	bl	__\name
.endm

#elif defined(__INTERWORKING_STUBS__)

.macro	ARM_FUNC_START name
	FUNC_START \name
	bx	pc
	nop
	.arm
/* A hook to tell gdb that we've switched to ARM mode.  Also used to call
   directly from other local arm routines.  */
_L__\name:		
.endm
#define EQUIV .thumb_set
/* Branch directly to a function declared with ARM_FUNC_START.
   Must be called in arm mode.  */
.macro  ARM_CALL name
	bl	_L__\name
.endm

#else /* !(__INTERWORKING_STUBS__ || __thumb2__) */

.macro	ARM_FUNC_START name
	.text
	.globl SYM (__\name)
	TYPE (__\name)
	.align 0
	.arm
SYM (__\name):
.endm
#define EQUIV .set
.macro  ARM_CALL name
	bl	__\name
.endm

#endif

.macro	FUNC_ALIAS new old
	.globl	SYM (__\new)
#if defined (__thumb__)
	.thumb_set	SYM (__\new), SYM (__\old)
#else
	.set	SYM (__\new), SYM (__\old)
#endif
.endm

.macro	ARM_FUNC_ALIAS new old
	.globl	SYM (__\new)
	EQUIV	SYM (__\new), SYM (__\old)
#if defined(__INTERWORKING_STUBS__)
	.set	SYM (_L__\new), SYM (_L__\old)
#endif
.endm

#ifdef __ARMEB__
#define xxh r0
#define xxl r1
#define yyh r2
#define yyl r3
#else
#define xxh r1
#define xxl r0
#define yyh r3
#define yyl r2
#endif	

#ifdef __thumb__
/* Register aliases.  */

work		.req	r4	@ XXXX is this safe ?
dividend	.req	r0
divisor		.req	r1
overdone	.req	r2
result		.req	r2
curbit		.req	r3
#endif
#if 0
ip		.req	r12
sp		.req	r13
lr		.req	r14
pc		.req	r15
#endif

/* ------------------------------------------------------------------------ */
/*		Bodies of the division and modulo routines.		    */
/* ------------------------------------------------------------------------ */	
.macro ARM_DIV_BODY dividend, divisor, result, curbit

#if __ARM_ARCH__ >= 5 && ! defined (__OPTIMIZE_SIZE__)

	clz	\curbit, \dividend
	clz	\result, \divisor
	sub	\curbit, \result, \curbit
	rsbs	\curbit, \curbit, #31
	addne	\curbit, \curbit, \curbit, lsl #1
	mov	\result, #0
	addne	pc, pc, \curbit, lsl #2
	nop
	.set	shift, 32
	.rept	32
	.set	shift, shift - 1
	cmp	\dividend, \divisor, lsl #shift
	adc	\result, \result, \result
	subcs	\dividend, \dividend, \divisor, lsl #shift
	.endr

#else /* __ARM_ARCH__ < 5 || defined (__OPTIMIZE_SIZE__) */
#if __ARM_ARCH__ >= 5

	clz	\curbit, \divisor
	clz	\result, \dividend
	sub	\result, \curbit, \result
	mov	\curbit, #1
	mov	\divisor, \divisor, lsl \result
	mov	\curbit, \curbit, lsl \result
	mov	\result, #0
	
#else /* __ARM_ARCH__ < 5 */

	@ Initially shift the divisor left 3 bits if possible,
	@ set curbit accordingly.  This allows for curbit to be located
	@ at the left end of each 4-bit nibbles in the division loop
	@ to save one loop in most cases.
	tst	\divisor, #0xe0000000
	moveq	\divisor, \divisor, lsl #3
	moveq	\curbit, #8
	movne	\curbit, #1

	@ Unless the divisor is very big, shift it up in multiples of
	@ four bits, since this is the amount of unwinding in the main
	@ division loop.  Continue shifting until the divisor is 
	@ larger than the dividend.
1:	cmp	\divisor, #0x10000000
	cmplo	\divisor, \dividend
	movlo	\divisor, \divisor, lsl #4
	movlo	\curbit, \curbit, lsl #4
	blo	1b

	@ For very big divisors, we must shift it a bit at a time, or
	@ we will be in danger of overflowing.
1:	cmp	\divisor, #0x80000000
	cmplo	\divisor, \dividend
	movlo	\divisor, \divisor, lsl #1
	movlo	\curbit, \curbit, lsl #1
	blo	1b

	mov	\result, #0

#endif /* __ARM_ARCH__ < 5 */

	@ Division loop
1:	cmp	\dividend, \divisor
	subhs	\dividend, \dividend, \divisor
	orrhs	\result,   \result,   \curbit
	cmp	\dividend, \divisor,  lsr #1
	subhs	\dividend, \dividend, \divisor, lsr #1
	orrhs	\result,   \result,   \curbit,  lsr #1
	cmp	\dividend, \divisor,  lsr #2
	subhs	\dividend, \dividend, \divisor, lsr #2
	orrhs	\result,   \result,   \curbit,  lsr #2
	cmp	\dividend, \divisor,  lsr #3
	subhs	\dividend, \dividend, \divisor, lsr #3
	orrhs	\result,   \result,   \curbit,  lsr #3
	cmp	\dividend, #0			@ Early termination?
	movnes	\curbit,   \curbit,  lsr #4	@ No, any more bits to do?
	movne	\divisor,  \divisor, lsr #4
	bne	1b

#endif /* __ARM_ARCH__ < 5 || defined (__OPTIMIZE_SIZE__) */

.endm
/* ------------------------------------------------------------------------ */	
.macro ARM_DIV2_ORDER divisor, order

#if __ARM_ARCH__ >= 5

	clz	\order, \divisor
	rsb	\order, \order, #31

#else

	cmp	\divisor, #(1 << 16)
	movhs	\divisor, \divisor, lsr #16
	movhs	\order, #16
	movlo	\order, #0

	cmp	\divisor, #(1 << 8)
	movhs	\divisor, \divisor, lsr #8
	addhs	\order, \order, #8

	cmp	\divisor, #(1 << 4)
	movhs	\divisor, \divisor, lsr #4
	addhs	\order, \order, #4

	cmp	\divisor, #(1 << 2)
	addhi	\order, \order, #3
	addls	\order, \order, \divisor, lsr #1

#endif

.endm
/* ------------------------------------------------------------------------ */
.macro ARM_MOD_BODY dividend, divisor, order, spare

#if __ARM_ARCH__ >= 5 && ! defined (__OPTIMIZE_SIZE__)

	clz	\order, \divisor
	clz	\spare, \dividend
	sub	\order, \order, \spare
	rsbs	\order, \order, #31
	addne	pc, pc, \order, lsl #3
	nop
	.set	shift, 32
	.rept	32
	.set	shift, shift - 1
	cmp	\dividend, \divisor, lsl #shift
	subcs	\dividend, \dividend, \divisor, lsl #shift
	.endr

#else /* __ARM_ARCH__ < 5 || defined (__OPTIMIZE_SIZE__) */
#if __ARM_ARCH__ >= 5

	clz	\order, \divisor
	clz	\spare, \dividend
	sub	\order, \order, \spare
	mov	\divisor, \divisor, lsl \order
	
#else /* __ARM_ARCH__ < 5 */

	mov	\order, #0

	@ Unless the divisor is very big, shift it up in multiples of
	@ four bits, since this is the amount of unwinding in the main
	@ division loop.  Continue shifting until the divisor is 
	@ larger than the dividend.
1:	cmp	\divisor, #0x10000000
	cmplo	\divisor, \dividend
	movlo	\divisor, \divisor, lsl #4
	addlo	\order, \order, #4
	blo	1b

	@ For very big divisors, we must shift it a bit at a time, or
	@ we will be in danger of overflowing.
1:	cmp	\divisor, #0x80000000
	cmplo	\divisor, \dividend
	movlo	\divisor, \divisor, lsl #1
	addlo	\order, \order, #1
	blo	1b

#endif /* __ARM_ARCH__ < 5 */

	@ Perform all needed substractions to keep only the reminder.
	@ Do comparisons in batch of 4 first.
	subs	\order, \order, #3		@ yes, 3 is intended here
	blt	2f

1:	cmp	\dividend, \divisor
	subhs	\dividend, \dividend, \divisor
	cmp	\dividend, \divisor,  lsr #1
	subhs	\dividend, \dividend, \divisor, lsr #1
	cmp	\dividend, \divisor,  lsr #2
	subhs	\dividend, \dividend, \divisor, lsr #2
	cmp	\dividend, \divisor,  lsr #3
	subhs	\dividend, \dividend, \divisor, lsr #3
	cmp	\dividend, #1
	mov	\divisor, \divisor, lsr #4
	subges	\order, \order, #4
	bge	1b

	tst	\order, #3
	teqne	\dividend, #0
	beq	5f

	@ Either 1, 2 or 3 comparison/substractions are left.
2:	cmn	\order, #2
	blt	4f
	beq	3f
	cmp	\dividend, \divisor
	subhs	\dividend, \dividend, \divisor
	mov	\divisor,  \divisor,  lsr #1
3:	cmp	\dividend, \divisor
	subhs	\dividend, \dividend, \divisor
	mov	\divisor,  \divisor,  lsr #1
4:	cmp	\dividend, \divisor
	subhs	\dividend, \dividend, \divisor
5:

#endif /* __ARM_ARCH__ < 5 || defined (__OPTIMIZE_SIZE__) */

.endm
/* ------------------------------------------------------------------------ */
.macro THUMB_DIV_MOD_BODY modulo
	@ Load the constant 0x10000000 into our work register.
	mov	work, #1
	lsl	work, #28
LSYM(Loop1):
	@ Unless the divisor is very big, shift it up in multiples of
	@ four bits, since this is the amount of unwinding in the main
	@ division loop.  Continue shifting until the divisor is 
	@ larger than the dividend.
	cmp	divisor, work
	bhs	LSYM(Lbignum)
	cmp	divisor, dividend
	bhs	LSYM(Lbignum)
	lsl	divisor, #4
	lsl	curbit,  #4
	b	LSYM(Loop1)
LSYM(Lbignum):
	@ Set work to 0x80000000
	lsl	work, #3
LSYM(Loop2):
	@ For very big divisors, we must shift it a bit at a time, or
	@ we will be in danger of overflowing.
	cmp	divisor, work
	bhs	LSYM(Loop3)
	cmp	divisor, dividend
	bhs	LSYM(Loop3)
	lsl	divisor, #1
	lsl	curbit,  #1
	b	LSYM(Loop2)
LSYM(Loop3):
	@ Test for possible subtractions ...
  .if \modulo
	@ ... On the final pass, this may subtract too much from the dividend, 
	@ so keep track of which subtractions are done, we can fix them up 
	@ afterwards.
	mov	overdone, #0
	cmp	dividend, divisor
	blo	LSYM(Lover1)
	sub	dividend, dividend, divisor
LSYM(Lover1):
	lsr	work, divisor, #1
	cmp	dividend, work
	blo	LSYM(Lover2)
	sub	dividend, dividend, work
	mov	ip, curbit
	mov	work, #1
	ror	curbit, work
	orr	overdone, curbit
	mov	curbit, ip
LSYM(Lover2):
	lsr	work, divisor, #2
	cmp	dividend, work
	blo	LSYM(Lover3)
	sub	dividend, dividend, work
	mov	ip, curbit
	mov	work, #2
	ror	curbit, work
	orr	overdone, curbit
	mov	curbit, ip
LSYM(Lover3):
	lsr	work, divisor, #3
	cmp	dividend, work
	blo	LSYM(Lover4)
	sub	dividend, dividend, work
	mov	ip, curbit
	mov	work, #3
	ror	curbit, work
	orr	overdone, curbit
	mov	curbit, ip
LSYM(Lover4):
	mov	ip, curbit
  .else
	@ ... and note which bits are done in the result.  On the final pass,
	@ this may subtract too much from the dividend, but the result will be ok,
	@ since the "bit" will have been shifted out at the bottom.
	cmp	dividend, divisor
	blo	LSYM(Lover1)
	sub	dividend, dividend, divisor
	orr	result, result, curbit
LSYM(Lover1):
	lsr	work, divisor, #1
	cmp	dividend, work
	blo	LSYM(Lover2)
	sub	dividend, dividend, work
	lsr	work, curbit, #1
	orr	result, work
LSYM(Lover2):
	lsr	work, divisor, #2
	cmp	dividend, work
	blo	LSYM(Lover3)
	sub	dividend, dividend, work
	lsr	work, curbit, #2
	orr	result, work
LSYM(Lover3):
	lsr	work, divisor, #3
	cmp	dividend, work
	blo	LSYM(Lover4)
	sub	dividend, dividend, work
	lsr	work, curbit, #3
	orr	result, work
LSYM(Lover4):
  .endif
	
	cmp	dividend, #0			@ Early termination?
	beq	LSYM(Lover5)
	lsr	curbit,  #4			@ No, any more bits to do?
	beq	LSYM(Lover5)
	lsr	divisor, #4
	b	LSYM(Loop3)
LSYM(Lover5):
  .if \modulo
	@ Any subtractions that we should not have done will be recorded in
	@ the top three bits of "overdone".  Exactly which were not needed
	@ are governed by the position of the bit, stored in ip.
	mov	work, #0xe
	lsl	work, #28
	and	overdone, work
	beq	LSYM(Lgot_result)
	
	@ If we terminated early, because dividend became zero, then the 
	@ bit in ip will not be in the bottom nibble, and we should not
	@ perform the additions below.  We must test for this though
	@ (rather relying upon the TSTs to prevent the additions) since
	@ the bit in ip could be in the top two bits which might then match
	@ with one of the smaller RORs.
	mov	curbit, ip
	mov	work, #0x7
	tst	curbit, work
	beq	LSYM(Lgot_result)
	
	mov	curbit, ip
	mov	work, #3
	ror	curbit, work
	tst	overdone, curbit
	beq	LSYM(Lover6)
	lsr	work, divisor, #3
	add	dividend, work
LSYM(Lover6):
	mov	curbit, ip
	mov	work, #2
	ror	curbit, work
	tst	overdone, curbit
	beq	LSYM(Lover7)
	lsr	work, divisor, #2
	add	dividend, work
LSYM(Lover7):
	mov	curbit, ip
	mov	work, #1
	ror	curbit, work
	tst	overdone, curbit
	beq	LSYM(Lgot_result)
	lsr	work, divisor, #1
	add	dividend, work
  .endif
LSYM(Lgot_result):
.endm	
/* ------------------------------------------------------------------------ */
/*		Start of the Real Functions				    */
/* ------------------------------------------------------------------------ */
#ifdef L_udivsi3

	FUNC_START udivsi3
	FUNC_ALIAS aeabi_uidiv udivsi3

#ifdef __thumb__

	cmp	divisor, #0
	beq	LSYM(Ldiv0)
	mov	curbit, #1
	mov	result, #0
	
	push	{ work }
	cmp	dividend, divisor
	blo	LSYM(Lgot_result)

	THUMB_DIV_MOD_BODY 0
	
	mov	r0, result
	pop	{ work }
	RET

#else /* ARM version.  */

	subs	r2, r1, #1
	RETc(eq)
	bcc	LSYM(Ldiv0)
	cmp	r0, r1
	bls	11f
	tst	r1, r2
	beq	12f
	
	ARM_DIV_BODY r0, r1, r2, r3
	
	mov	r0, r2
	RET	

11:	moveq	r0, #1
	movne	r0, #0
	RET

12:	ARM_DIV2_ORDER r1, r2

	mov	r0, r0, lsr r2
	RET

#endif /* ARM version */

	DIV_FUNC_END udivsi3

FUNC_START aeabi_uidivmod
#ifdef __thumb__
	push	{r0, r1, lr}
	bl	SYM(__udivsi3)
	POP	{r1, r2, r3}
	mul	r2, r0
	sub	r1, r1, r2
	bx	r3
#else
	stmfd	sp!, { r0, r1, lr }
	bl	SYM(__udivsi3)
	ldmfd	sp!, { r1, r2, lr }
	mul	r3, r2, r0
	sub	r1, r1, r3
	RET
#endif
	FUNC_END aeabi_uidivmod
	
#endif /* L_udivsi3 */
/* ------------------------------------------------------------------------ */
#ifdef L_umodsi3

	FUNC_START umodsi3

#ifdef __thumb__

	cmp	divisor, #0
	beq	LSYM(Ldiv0)
	mov	curbit, #1
	cmp	dividend, divisor
	bhs	LSYM(Lover10)
	RET	

LSYM(Lover10):
	push	{ work }

	THUMB_DIV_MOD_BODY 1
	
	pop	{ work }
	RET
	
#else  /* ARM version.  */
	
	subs	r2, r1, #1			@ compare divisor with 1
	bcc	LSYM(Ldiv0)
	cmpne	r0, r1				@ compare dividend with divisor
	moveq   r0, #0
	tsthi	r1, r2				@ see if divisor is power of 2
	andeq	r0, r0, r2
	RETc(ls)

	ARM_MOD_BODY r0, r1, r2, r3
	
	RET	

#endif /* ARM version.  */
	
	DIV_FUNC_END umodsi3

#endif /* L_umodsi3 */
/* ------------------------------------------------------------------------ */
#ifdef L_divsi3

	FUNC_START divsi3	
	FUNC_ALIAS aeabi_idiv divsi3

#ifdef __thumb__
	cmp	divisor, #0
	beq	LSYM(Ldiv0)
	
	push	{ work }
	mov	work, dividend
	eor	work, divisor		@ Save the sign of the result.
	mov	ip, work
	mov	curbit, #1
	mov	result, #0
	cmp	divisor, #0
	bpl	LSYM(Lover10)
	neg	divisor, divisor	@ Loops below use unsigned.
LSYM(Lover10):
	cmp	dividend, #0
	bpl	LSYM(Lover11)
	neg	dividend, dividend
LSYM(Lover11):
	cmp	dividend, divisor
	blo	LSYM(Lgot_result)

	THUMB_DIV_MOD_BODY 0
	
	mov	r0, result
	mov	work, ip
	cmp	work, #0
	bpl	LSYM(Lover12)
	neg	r0, r0
LSYM(Lover12):
	pop	{ work }
	RET

#else /* ARM version.  */
	
	cmp	r1, #0
	eor	ip, r0, r1			@ save the sign of the result.
	beq	LSYM(Ldiv0)
	rsbmi	r1, r1, #0			@ loops below use unsigned.
	subs	r2, r1, #1			@ division by 1 or -1 ?
	beq	10f
	movs	r3, r0
	rsbmi	r3, r0, #0			@ positive dividend value
	cmp	r3, r1
	bls	11f
	tst	r1, r2				@ divisor is power of 2 ?
	beq	12f

	ARM_DIV_BODY r3, r1, r0, r2
	
	cmp	ip, #0
	rsbmi	r0, r0, #0
	RET	

10:	teq	ip, r0				@ same sign ?
	rsbmi	r0, r0, #0
	RET	

11:	movlo	r0, #0
	moveq	r0, ip, asr #31
	orreq	r0, r0, #1
	RET

12:	ARM_DIV2_ORDER r1, r2

	cmp	ip, #0
	mov	r0, r3, lsr r2
	rsbmi	r0, r0, #0
	RET

#endif /* ARM version */
	
	DIV_FUNC_END divsi3

FUNC_START aeabi_idivmod
#ifdef __thumb__
	push	{r0, r1, lr}
	bl	SYM(__divsi3)
	POP	{r1, r2, r3}
	mul	r2, r0
	sub	r1, r1, r2
	bx	r3
#else
	stmfd	sp!, { r0, r1, lr }
	bl	SYM(__divsi3)
	ldmfd	sp!, { r1, r2, lr }
	mul	r3, r2, r0
	sub	r1, r1, r3
	RET
#endif
	FUNC_END aeabi_idivmod
	
#endif /* L_divsi3 */
/* ------------------------------------------------------------------------ */
#ifdef L_modsi3

	FUNC_START modsi3

#ifdef __thumb__

	mov	curbit, #1
	cmp	divisor, #0
	beq	LSYM(Ldiv0)
	bpl	LSYM(Lover10)
	neg	divisor, divisor		@ Loops below use unsigned.
LSYM(Lover10):
	push	{ work }
	@ Need to save the sign of the dividend, unfortunately, we need
	@ work later on.  Must do this after saving the original value of
	@ the work register, because we will pop this value off first.
	push	{ dividend }
	cmp	dividend, #0
	bpl	LSYM(Lover11)
	neg	dividend, dividend
LSYM(Lover11):
	cmp	dividend, divisor
	blo	LSYM(Lgot_result)

	THUMB_DIV_MOD_BODY 1
		
	pop	{ work }
	cmp	work, #0
	bpl	LSYM(Lover12)
	neg	dividend, dividend
LSYM(Lover12):
	pop	{ work }
	RET	

#else /* ARM version.  */
	
	cmp	r1, #0
	beq	LSYM(Ldiv0)
	rsbmi	r1, r1, #0			@ loops below use unsigned.
	movs	ip, r0				@ preserve sign of dividend
	rsbmi	r0, r0, #0			@ if negative make positive
	subs	r2, r1, #1			@ compare divisor with 1
	cmpne	r0, r1				@ compare dividend with divisor
	moveq	r0, #0
	tsthi	r1, r2				@ see if divisor is power of 2
	andeq	r0, r0, r2
	bls	10f

	ARM_MOD_BODY r0, r1, r2, r3

10:	cmp	ip, #0
	rsbmi	r0, r0, #0
	RET	

#endif /* ARM version */
	
	DIV_FUNC_END modsi3

#endif /* L_modsi3 */
/* ------------------------------------------------------------------------ */
#ifdef L_dvmd_tls

	FUNC_START div0
	FUNC_ALIAS aeabi_idiv0 div0
	FUNC_ALIAS aeabi_ldiv0 div0

	RET

	FUNC_END aeabi_ldiv0
	FUNC_END aeabi_idiv0
	FUNC_END div0
	
#endif /* L_divmodsi_tools */
/* ------------------------------------------------------------------------ */
#ifdef L_dvmd_lnx
@ GNU/Linux division-by zero handler.  Used in place of L_dvmd_tls

/* Constant taken from <asm/signal.h>.  */
#define SIGFPE	8

	ARM_FUNC_START div0

	do_push	{r1, lr}
	mov	r0, #SIGFPE
	bl	SYM(raise) __PLT__
	RETLDM	r1

	FUNC_END div0
	
#endif /* L_dvmd_lnx */

/* ------------------------------------------------------------------------ */
#ifdef L_muldi3

/* ------------------------------------------------------------------------ */
/* Dword multiplication operation.

   The THUMB ISA lacks an instruction to compute the higher half of the
   64-bit result from a 32-bit by 32-bit multiplication.  This makes 64-bit
   multiplication difficult to implement efficiently.  The ARM ISAs after V3M
   have UMULL and MLA which can be used to implement 64-bit muliplication
   efficiently.  On a target that support both ARM V3M+ and THUMB ISA's (but
   not THUMB2), we want to use the ARM version of _muldi3 in the THUMB libgcc.

   We do not need to use the ARM version for THUMB2 targets as the THUMB2
   targets also support MLA and UMULL. */

/* We cannot use the faster version for following situations:

   -ARM architetures older than V3M lack the UMULL instruction.
   -Target is ARMV6M, which does not run ARM code.
*/

#undef USE_FAST_MULDI3
#if (__ARM_ARCH__ > 3 || defined(__ARM_ARCH_3M__)) && !defined(__ARM_ARCH_6M__)
#define USE_FAST_MULDI3
#endif

/* Force using ARM code if it is possible except for THUMB2 target. */
#if defined(USE_FAST_MULDI3) && !defined(__thumb2__)
	ARM_FUNC_START muldi3
	ARM_FUNC_ALIAS aeabi_lmul muldi3
#else
	FUNC_START muldi3
	FUNC_ALIAS aeabi_lmul muldi3
#endif

#if defined(USE_FAST_MULDI3)
	/* Fast version for ARM with umull and THUMB2.  */
	mul	xxh, yyl
	mla	yyh, xxl, yyh, xxh
	umull	xxl, xxh, yyl, xxl
	add	xxh, yyh
	RET
#else
	/* Slow version for both THUMB and older ARMs lacking umull. */
	mul	xxh, yyl		/* xxh := AH*BL */
	push	{r4, r5, r6, r7}
	mul	yyh, xxl		/* yyh := AL*BH */
	ldr	r4, .L_mask
	lsr	r5, xxl, #16		/* r5 := (AL>>16) */
	lsr	r6, yyl, #16		/* r6 := (BL>>16) */
	lsr	r7, xxl, #16		/* r7 := (AL>>16) */
	mul	r5, r6			/* r5 = (AL>>16) * (BL>>16) */
	and	xxl, r4			/* xxl = AL & 0xffff */
	and	yyl, r4			/* yyl = BL & 0xffff */
	add	xxh, yyh		/* xxh = AH*BL+AL*BH */
	mul	r6, xxl			/* r6 = (AL&0xffff) * (BL>>16) */
	mul	r7, yyl			/* r7 = (AL>>16) * (BL&0xffff) */
	add	xxh, r5
	mul	xxl, yyl		/* xxl = (AL&0xffff) * (BL&0xffff) */
	mov	r4, #0	
	adds	r6, r7			/* partial sum to result[47:16]. */
	adc	r4, r4			/* carry to result[48]. */
	lsr	yyh, r6, #16
	lsl	r4, r4, #16
	lsl	yyl, r6, #16
	add	xxh, r4
	adds	xxl, yyl
	adc	xxh, yyh
	pop	{r4, r5, r6, r7}
	RET
	.align	2
.L_mask:
	.word	65535
#endif

	FUNC_END muldi3
#endif

/* ------------------------------------------------------------------------ */
/* Dword shift operations.  */
/* All the following Dword shift variants rely on the fact that
	shft xxx, Reg
   is in fact done as
	shft xxx, (Reg & 255)
   so for Reg value in (32...63) and (-1...-31) we will get zero (in the
   case of logical shifts) or the sign (for asr).  */

#ifdef __ARMEB__
#define al	r1
#define ah	r0
#else
#define al	r0
#define ah	r1
#endif

/* Prevent __aeabi double-word shifts from being produced on SymbianOS.  */
#ifndef __symbian__

#ifdef L_lshrdi3

	FUNC_START lshrdi3
	FUNC_ALIAS aeabi_llsr lshrdi3
	
#ifdef __thumb__
	lsr	al, r2
	mov	r3, ah
	lsr	ah, r2
	mov	ip, r3
	sub	r2, #32
	lsr	r3, r2
	orr	al, r3
	neg	r2, r2
	mov	r3, ip
	lsl	r3, r2
	orr	al, r3
	RET
#else
	subs	r3, r2, #32
	rsb	ip, r2, #32
	movmi	al, al, lsr r2
	movpl	al, ah, lsr r3
	orrmi	al, al, ah, lsl ip
	mov	ah, ah, lsr r2
	RET
#endif
	FUNC_END aeabi_llsr
	FUNC_END lshrdi3

#endif
	
#ifdef L_ashrdi3
	
	FUNC_START ashrdi3
	FUNC_ALIAS aeabi_lasr ashrdi3
	
#ifdef __thumb__
	lsr	al, r2
	mov	r3, ah
	asr	ah, r2
	sub	r2, #32
	@ If r2 is negative at this point the following step would OR
	@ the sign bit into all of AL.  That's not what we want...
	bmi	1f
	mov	ip, r3
	asr	r3, r2
	orr	al, r3
	mov	r3, ip
1:
	neg	r2, r2
	lsl	r3, r2
	orr	al, r3
	RET
#else
	subs	r3, r2, #32
	rsb	ip, r2, #32
	movmi	al, al, lsr r2
	movpl	al, ah, asr r3
	orrmi	al, al, ah, lsl ip
	mov	ah, ah, asr r2
	RET
#endif

	FUNC_END aeabi_lasr
	FUNC_END ashrdi3

#endif

#ifdef L_ashldi3

	FUNC_START ashldi3
	FUNC_ALIAS aeabi_llsl ashldi3
	
#ifdef __thumb__
	lsl	ah, r2
	mov	r3, al
	lsl	al, r2
	mov	ip, r3
	sub	r2, #32
	lsl	r3, r2
	orr	ah, r3
	neg	r2, r2
	mov	r3, ip
	lsr	r3, r2
	orr	ah, r3
	RET
#else
	subs	r3, r2, #32
	rsb	ip, r2, #32
	movmi	ah, ah, lsl r2
	movpl	ah, al, lsl r3
	orrmi	ah, ah, al, lsr ip
	mov	al, al, lsl r2
	RET
#endif
	FUNC_END aeabi_llsl
	FUNC_END ashldi3

#endif

#endif /* __symbian__ */

#if ((__ARM_ARCH__ > 5) && !defined(__ARM_ARCH_6M__)) \
    || defined(__ARM_ARCH_5E__) || defined(__ARM_ARCH_5TE__) \
    || defined(__ARM_ARCH_5TEJ__)
#define HAVE_ARM_CLZ 1
#endif

#ifdef L_clzsi2
#if defined(__ARM_ARCH_6M__)
FUNC_START clzsi2
	mov	r1, #28
	mov	r3, #1
	lsl	r3, r3, #16
	cmp	r0, r3 /* 0x10000 */
	bcc	2f
	lsr	r0, r0, #16
	sub	r1, r1, #16
2:	lsr	r3, r3, #8
	cmp	r0, r3 /* #0x100 */
	bcc	2f
	lsr	r0, r0, #8
	sub	r1, r1, #8
2:	lsr	r3, r3, #4
	cmp	r0, r3 /* #0x10 */
	bcc	2f
	lsr	r0, r0, #4
	sub	r1, r1, #4
2:	adr	r2, 1f
	ldrb	r0, [r2, r0]
	add	r0, r0, r1
	bx lr
.align 2
1:
.byte 4, 3, 2, 2, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0
	FUNC_END clzsi2
#else
ARM_FUNC_START clzsi2
# if defined(HAVE_ARM_CLZ)
	clz	r0, r0
	RET
# else
	mov	r1, #28
	cmp	r0, #0x10000
	do_it	cs, t
	movcs	r0, r0, lsr #16
	subcs	r1, r1, #16
	cmp	r0, #0x100
	do_it	cs, t
	movcs	r0, r0, lsr #8
	subcs	r1, r1, #8
	cmp	r0, #0x10
	do_it	cs, t
	movcs	r0, r0, lsr #4
	subcs	r1, r1, #4
	adr	r2, 1f
	ldrb	r0, [r2, r0]
	add	r0, r0, r1
	bx lr
.align 2
1:
.byte 4, 3, 2, 2, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0
# endif /* !HAVE_ARM_CLZ */
	FUNC_END clzsi2
#endif
#endif /* L_clzsi2 */

#ifdef L_clzdi2
#if !defined(HAVE_ARM_CLZ)

# if defined(__ARM_ARCH_6M__)
FUNC_START clzdi2
	push	{r4, lr}
# else
ARM_FUNC_START clzdi2
	do_push	{r4, lr}
# endif
	cmp	xxh, #0
	bne	1f
# ifdef __ARMEB__
	mov	r0, xxl
	bl	__clzsi2
	add	r0, r0, #32
	b 2f
1:
	bl	__clzsi2
# else
	bl	__clzsi2
	add	r0, r0, #32
	b 2f
1:
	mov	r0, xxh
	bl	__clzsi2
# endif
2:
# if defined(__ARM_ARCH_6M__)
	pop	{r4, pc}
# else
	RETLDM	r4
# endif
	FUNC_END clzdi2

#else /* HAVE_ARM_CLZ */

ARM_FUNC_START clzdi2
	cmp	xxh, #0
	do_it	eq, et
	clzeq	r0, xxl
	clzne	r0, xxh
	addeq	r0, r0, #32
	RET
	FUNC_END clzdi2

#endif
#endif /* L_clzdi2 */

/* ------------------------------------------------------------------------ */
/* These next two sections are here despite the fact that they contain Thumb 
   assembler because their presence allows interworked code to be linked even
   when the GCC library is this one.  */
		
/* Do not build the interworking functions when the target architecture does 
   not support Thumb instructions.  (This can be a multilib option).  */
#if defined __ARM_ARCH_4T__ || defined __ARM_ARCH_5T__\
      || defined __ARM_ARCH_5TE__ || defined __ARM_ARCH_5TEJ__ \
      || __ARM_ARCH__ >= 6

#if defined L_call_via_rX

/* These labels & instructions are used by the Arm/Thumb interworking code. 
   The address of function to be called is loaded into a register and then 
   one of these labels is called via a BL instruction.  This puts the 
   return address into the link register with the bottom bit set, and the 
   code here switches to the correct mode before executing the function.  */
	
	.text
	.align 0
        .force_thumb

.macro call_via register
	THUMB_FUNC_START _call_via_\register

	bx	\register
	nop

	SIZE	(_call_via_\register)
.endm

	call_via r0
	call_via r1
	call_via r2
	call_via r3
	call_via r4
	call_via r5
	call_via r6
	call_via r7
	call_via r8
	call_via r9
	call_via sl
	call_via fp
	call_via ip
	call_via sp
	call_via lr

#endif /* L_call_via_rX */

/* Don't bother with the old interworking routines for Thumb-2.  */
/* ??? Maybe only omit these on v7m.  */
#ifndef __thumb2__

#if defined L_interwork_call_via_rX

/* These labels & instructions are used by the Arm/Thumb interworking code,
   when the target address is in an unknown instruction set.  The address 
   of function to be called is loaded into a register and then one of these
   labels is called via a BL instruction.  This puts the return address 
   into the link register with the bottom bit set, and the code here 
   switches to the correct mode before executing the function.  Unfortunately
   the target code cannot be relied upon to return via a BX instruction, so
   instead we have to store the resturn address on the stack and allow the
   called function to return here instead.  Upon return we recover the real
   return address and use a BX to get back to Thumb mode.

   There are three variations of this code.  The first,
   _interwork_call_via_rN(), will push the return address onto the
   stack and pop it in _arm_return().  It should only be used if all
   arguments are passed in registers.

   The second, _interwork_r7_call_via_rN(), instead stores the return
   address at [r7, #-4].  It is the caller's responsibility to ensure
   that this address is valid and contains no useful data.

   The third, _interwork_r11_call_via_rN(), works in the same way but
   uses r11 instead of r7.  It is useful if the caller does not really
   need a frame pointer.  */
	
	.text
	.align 0

	.code   32
	.globl _arm_return
LSYM(Lstart_arm_return):
	cfi_start	LSYM(Lstart_arm_return) LSYM(Lend_arm_return)
	cfi_push	0, 0xe, -0x8, 0x8
	nop	@ This nop is for the benefit of debuggers, so that
		@ backtraces will use the correct unwind information.
_arm_return:
	RETLDM	unwind=LSYM(Lstart_arm_return)
	cfi_end	LSYM(Lend_arm_return)

	.globl _arm_return_r7
_arm_return_r7:
	ldr	lr, [r7, #-4]
	bx	lr

	.globl _arm_return_r11
_arm_return_r11:
	ldr	lr, [r11, #-4]
	bx	lr

.macro interwork_with_frame frame, register, name, return
	.code	16

	THUMB_FUNC_START \name

	bx	pc
	nop

	.code	32
	tst	\register, #1
	streq	lr, [\frame, #-4]
	adreq	lr, _arm_return_\frame
	bx	\register

	SIZE	(\name)
.endm

.macro interwork register
	.code	16

	THUMB_FUNC_START _interwork_call_via_\register

	bx	pc
	nop

	.code	32
	.globl LSYM(Lchange_\register)
LSYM(Lchange_\register):
	tst	\register, #1
	streq	lr, [sp, #-8]!
	adreq	lr, _arm_return
	bx	\register

	SIZE	(_interwork_call_via_\register)

	interwork_with_frame r7,\register,_interwork_r7_call_via_\register
	interwork_with_frame r11,\register,_interwork_r11_call_via_\register
.endm
	
	interwork r0
	interwork r1
	interwork r2
	interwork r3
	interwork r4
	interwork r5
	interwork r6
	interwork r7
	interwork r8
	interwork r9
	interwork sl
	interwork fp
	interwork ip
	interwork sp
	
	/* The LR case has to be handled a little differently...  */
	.code 16

	THUMB_FUNC_START _interwork_call_via_lr

	bx 	pc
	nop
	
	.code 32
	.globl .Lchange_lr
.Lchange_lr:
	tst	lr, #1
	stmeqdb	r13!, {lr, pc}
	mov	ip, lr
	adreq	lr, _arm_return
	bx	ip
	
	SIZE	(_interwork_call_via_lr)
	
#endif /* L_interwork_call_via_rX */
#endif /* !__thumb2__ */
#endif /* Arch supports thumb.  */

#ifndef __symbian__
#include "ieee754-df.S"
#include "ieee754-sf.S"
#include "bpabi.S"
#endif /* __symbian__ */