Subversion Repositories openrisc

/* ieee754-sf.S single-precision floating point support for ARM

   Copyright (C) 2003, 2004, 2005, 2007, 2008, 2009  Free Software Foundation, Inc.

   Contributed by Nicolas Pitre (nico@cam.org)

   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 3, or (at your option) any

   later version.

   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.

   Under Section 7 of GPL version 3, you are granted additional

   permissions described in the GCC Runtime Library Exception, version

   3.1, as published by the Free Software Foundation.

   You should have received a copy of the GNU General Public License and

   a copy of the GCC Runtime Library Exception along with this program;

   see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see

   .  */

/*

 * Notes:

 *

 * The goal of this code is to be as fast as possible.  This is

 * not meant to be easy to understand for the casual reader.

 *

 * Only the default rounding mode is intended for best performances.

 * Exceptions aren't supported yet, but that can be added quite easily

 * if necessary without impacting performances.

 */

#ifdef L_arm_negsf2

ARM_FUNC_START negsf2

ARM_FUNC_ALIAS aeabi_fneg negsf2

        eor     r0, r0, #0x80000000     @ flip sign bit

        RET

        FUNC_END aeabi_fneg

        FUNC_END negsf2

#endif

#ifdef L_arm_addsubsf3

ARM_FUNC_START aeabi_frsub

        eor     r0, r0, #0x80000000     @ flip sign bit of first arg

        b       1f

ARM_FUNC_START subsf3

ARM_FUNC_ALIAS aeabi_fsub subsf3

        eor     r1, r1, #0x80000000     @ flip sign bit of second arg

#if defined(__INTERWORKING_STUBS__)

        b       1f                      @ Skip Thumb-code prologue

#endif

ARM_FUNC_START addsf3

ARM_FUNC_ALIAS aeabi_fadd addsf3

1:      @ Look for zeroes, equal values, INF, or NAN.

        movs    r2, r0, lsl #1

        do_it   ne, ttt

        COND(mov,s,ne)  r3, r1, lsl #1

        teqne   r2, r3

        COND(mvn,s,ne)  ip, r2, asr #24

        COND(mvn,s,ne)  ip, r3, asr #24

        beq     LSYM(Lad_s)

        @ Compute exponent difference.  Make largest exponent in r2,

        @ corresponding arg in r0, and positive exponent difference in r3.

        mov     r2, r2, lsr #24

        rsbs    r3, r2, r3, lsr #24

        do_it   gt, ttt

        addgt   r2, r2, r3

        eorgt   r1, r0, r1

        eorgt   r0, r1, r0

        eorgt   r1, r0, r1

        do_it   lt

        rsblt   r3, r3, #0

        @ If exponent difference is too large, return largest argument

        @ already in r0.  We need up to 25 bit to handle proper rounding

        @ of 0x1p25 - 1.1.

        cmp     r3, #25

        do_it   hi

        RETc(hi)

        @ Convert mantissa to signed integer.

        tst     r0, #0x80000000

        orr     r0, r0, #0x00800000

        bic     r0, r0, #0xff000000

        do_it   ne

        rsbne   r0, r0, #0

        tst     r1, #0x80000000

        orr     r1, r1, #0x00800000

        bic     r1, r1, #0xff000000

        do_it   ne

        rsbne   r1, r1, #0

        @ If exponent == difference, one or both args were denormalized.

        @ Since this is not common case, rescale them off line.

        teq     r2, r3

        beq     LSYM(Lad_d)

LSYM(Lad_x):

        @ Compensate for the exponent overlapping the mantissa MSB added later

        sub     r2, r2, #1

        @ Shift and add second arg to first arg in r0.

        @ Keep leftover bits into r1.

        shiftop adds r0 r0 r1 asr r3 ip

        rsb     r3, r3, #32

        shift1  lsl, r1, r1, r3

        @ Keep absolute value in r0-r1, sign in r3 (the n bit was set above)

        and     r3, r0, #0x80000000

        bpl     LSYM(Lad_p)

#if defined(__thumb2__)

        negs    r1, r1

        sbc     r0, r0, r0, lsl #1

#else

        rsbs    r1, r1, #0

        rsc     r0, r0, #0

#endif

        @ Determine how to normalize the result.

LSYM(Lad_p):

        cmp     r0, #0x00800000

        bcc     LSYM(Lad_a)

        cmp     r0, #0x01000000

        bcc     LSYM(Lad_e)

        @ Result needs to be shifted right.

        movs    r0, r0, lsr #1

        mov     r1, r1, rrx

        add     r2, r2, #1

        @ Make sure we did not bust our exponent.

        cmp     r2, #254

        bhs     LSYM(Lad_o)

        @ Our result is now properly aligned into r0, remaining bits in r1.

        @ Pack final result together.

        @ Round with MSB of r1. If halfway between two numbers, round towards

        @ LSB of r0 = 0.

LSYM(Lad_e):

        cmp     r1, #0x80000000

        adc     r0, r0, r2, lsl #23

        do_it   eq

        biceq   r0, r0, #1

        orr     r0, r0, r3

        RET

        @ Result must be shifted left and exponent adjusted.

LSYM(Lad_a):

        movs    r1, r1, lsl #1

        adc     r0, r0, r0

        tst     r0, #0x00800000

        sub     r2, r2, #1

        bne     LSYM(Lad_e)

        @ No rounding necessary since r1 will always be 0 at this point.

LSYM(Lad_l):

#if __ARM_ARCH__ < 5

        movs    ip, r0, lsr #12

        moveq   r0, r0, lsl #12

        subeq   r2, r2, #12

        tst     r0, #0x00ff0000

        moveq   r0, r0, lsl #8

        subeq   r2, r2, #8

        tst     r0, #0x00f00000

        moveq   r0, r0, lsl #4

        subeq   r2, r2, #4

        tst     r0, #0x00c00000

        moveq   r0, r0, lsl #2

        subeq   r2, r2, #2

        cmp     r0, #0x00800000

        movcc   r0, r0, lsl #1

        sbcs    r2, r2, #0

#else

        clz     ip, r0

        sub     ip, ip, #8

        subs    r2, r2, ip

        shift1  lsl, r0, r0, ip

#endif

        @ Final result with sign

        @ If exponent negative, denormalize result.

        do_it   ge, et

        addge   r0, r0, r2, lsl #23

        rsblt   r2, r2, #0

        orrge   r0, r0, r3

#if defined(__thumb2__)

        do_it   lt, t

        lsrlt   r0, r0, r2

        orrlt   r0, r3, r0

#else

        orrlt   r0, r3, r0, lsr r2

#endif

        RET

        @ Fixup and adjust bit position for denormalized arguments.

        @ Note that r2 must not remain equal to 0.

LSYM(Lad_d):

        teq     r2, #0

        eor     r1, r1, #0x00800000

        do_it   eq, te

        eoreq   r0, r0, #0x00800000

        addeq   r2, r2, #1

        subne   r3, r3, #1

        b       LSYM(Lad_x)

LSYM(Lad_s):

        mov     r3, r1, lsl #1

        mvns    ip, r2, asr #24

        do_it   ne

        COND(mvn,s,ne)  ip, r3, asr #24

        beq     LSYM(Lad_i)

        teq     r2, r3

        beq     1f

        @ Result is x + 0.0 = x or 0.0 + y = y.

        teq     r2, #0

        do_it   eq

        moveq   r0, r1

        RET

1:      teq     r0, r1

        @ Result is x - x = 0.

        do_it   ne, t

        movne   r0, #0

        RETc(ne)

        @ Result is x + x = 2x.

        tst     r2, #0xff000000

        bne     2f

        movs    r0, r0, lsl #1

        do_it   cs

        orrcs   r0, r0, #0x80000000

        RET

2:      adds    r2, r2, #(2 << 24)

        do_it   cc, t

        addcc   r0, r0, #(1 << 23)

        RETc(cc)

        and     r3, r0, #0x80000000

        @ Overflow: return INF.

LSYM(Lad_o):

        orr     r0, r3, #0x7f000000

        orr     r0, r0, #0x00800000

        RET

        @ At least one of r0/r1 is INF/NAN.

        @   if r0 != INF/NAN: return r1 (which is INF/NAN)

        @   if r1 != INF/NAN: return r0 (which is INF/NAN)

        @   if r0 or r1 is NAN: return NAN

        @   if opposite sign: return NAN

        @   otherwise return r0 (which is INF or -INF)

LSYM(Lad_i):

        mvns    r2, r2, asr #24

        do_it   ne, et

        movne   r0, r1

        COND(mvn,s,eq)  r3, r3, asr #24

        movne   r1, r0

        movs    r2, r0, lsl #9

        do_it   eq, te

        COND(mov,s,eq)  r3, r1, lsl #9

        teqeq   r0, r1

        orrne   r0, r0, #0x00400000     @ quiet NAN

        RET

        FUNC_END aeabi_frsub

        FUNC_END aeabi_fadd

        FUNC_END addsf3

        FUNC_END aeabi_fsub

        FUNC_END subsf3

ARM_FUNC_START floatunsisf

ARM_FUNC_ALIAS aeabi_ui2f floatunsisf

        mov     r3, #0

        b       1f

ARM_FUNC_START floatsisf

ARM_FUNC_ALIAS aeabi_i2f floatsisf

        ands    r3, r0, #0x80000000

        do_it   mi

        rsbmi   r0, r0, #0

1:      movs    ip, r0

        do_it   eq

        RETc(eq)

        @ Add initial exponent to sign

        orr     r3, r3, #((127 + 23) << 23)

        .ifnc   ah, r0

        mov     ah, r0

        .endif

        mov     al, #0

        b       2f

        FUNC_END aeabi_i2f

        FUNC_END floatsisf

        FUNC_END aeabi_ui2f

        FUNC_END floatunsisf

ARM_FUNC_START floatundisf

ARM_FUNC_ALIAS aeabi_ul2f floatundisf

        orrs    r2, r0, r1

#if !defined (__VFP_FP__) && !defined(__SOFTFP__)

        do_it   eq, t

        mvfeqs  f0, #0.0

#else

        do_it   eq

#endif

        RETc(eq)

        mov     r3, #0

        b       1f

ARM_FUNC_START floatdisf

ARM_FUNC_ALIAS aeabi_l2f floatdisf

        orrs    r2, r0, r1

#if !defined (__VFP_FP__) && !defined(__SOFTFP__)

        do_it   eq, t

        mvfeqs  f0, #0.0

#else

        do_it   eq

#endif

        RETc(eq)

        ands    r3, ah, #0x80000000     @ sign bit in r3

        bpl     1f

#if defined(__thumb2__)

        negs    al, al

        sbc     ah, ah, ah, lsl #1

#else

        rsbs    al, al, #0

        rsc     ah, ah, #0

#endif

1:

#if !defined (__VFP_FP__) && !defined(__SOFTFP__)

        @ For hard FPA code we want to return via the tail below so that

        @ we can return the result in f0 as well as in r0 for backwards

        @ compatibility.

        str     lr, [sp, #-8]!

        adr     lr, LSYM(f0_ret)

#endif

        movs    ip, ah

        do_it   eq, tt

        moveq   ip, al

        moveq   ah, al

        moveq   al, #0

        @ Add initial exponent to sign

        orr     r3, r3, #((127 + 23 + 32) << 23)

        do_it   eq

        subeq   r3, r3, #(32 << 23)

2:      sub     r3, r3, #(1 << 23)

#if __ARM_ARCH__ < 5

        mov     r2, #23

        cmp     ip, #(1 << 16)

        do_it   hs, t

        movhs   ip, ip, lsr #16

        subhs   r2, r2, #16

        cmp     ip, #(1 << 8)

        do_it   hs, t

        movhs   ip, ip, lsr #8

        subhs   r2, r2, #8

        cmp     ip, #(1 << 4)

        do_it   hs, t

        movhs   ip, ip, lsr #4

        subhs   r2, r2, #4

        cmp     ip, #(1 << 2)

        do_it   hs, e

        subhs   r2, r2, #2

        sublo   r2, r2, ip, lsr #1

        subs    r2, r2, ip, lsr #3

#else

        clz     r2, ip

        subs    r2, r2, #8

#endif

        sub     r3, r3, r2, lsl #23

        blt     3f

        shiftop add r3 r3 ah lsl r2 ip

        shift1  lsl, ip, al, r2

        rsb     r2, r2, #32

        cmp     ip, #0x80000000

        shiftop adc r0 r3 al lsr r2 r2

        do_it   eq

        biceq   r0, r0, #1

        RET

3:      add     r2, r2, #32

        shift1  lsl, ip, ah, r2

        rsb     r2, r2, #32

        orrs    al, al, ip, lsl #1

        shiftop adc r0 r3 ah lsr r2 r2

        do_it   eq

        biceq   r0, r0, ip, lsr #31

        RET

#if !defined (__VFP_FP__) && !defined(__SOFTFP__)

LSYM(f0_ret):

        str     r0, [sp, #-4]!

        ldfs    f0, [sp], #4

        RETLDM

#endif

        FUNC_END floatdisf

        FUNC_END aeabi_l2f

        FUNC_END floatundisf

        FUNC_END aeabi_ul2f

#endif /* L_addsubsf3 */

#ifdef L_arm_muldivsf3

ARM_FUNC_START mulsf3

ARM_FUNC_ALIAS aeabi_fmul mulsf3

        @ Mask out exponents, trap any zero/denormal/INF/NAN.

        mov     ip, #0xff

        ands    r2, ip, r0, lsr #23

        do_it   ne, tt

        COND(and,s,ne)  r3, ip, r1, lsr #23

        teqne   r2, ip

        teqne   r3, ip

        beq     LSYM(Lml_s)

LSYM(Lml_x):

        @ Add exponents together

        add     r2, r2, r3

        @ Determine final sign.

        eor     ip, r0, r1

        @ Convert mantissa to unsigned integer.

        @ If power of two, branch to a separate path.

        @ Make up for final alignment.

        movs    r0, r0, lsl #9

        do_it   ne

        COND(mov,s,ne)  r1, r1, lsl #9

        beq     LSYM(Lml_1)

        mov     r3, #0x08000000

        orr     r0, r3, r0, lsr #5

        orr     r1, r3, r1, lsr #5

#if __ARM_ARCH__ < 4

        @ Put sign bit in r3, which will be restored into r0 later.

        and     r3, ip, #0x80000000

        @ Well, no way to make it shorter without the umull instruction.

        do_push {r3, r4, r5}

        mov     r4, r0, lsr #16

        mov     r5, r1, lsr #16

        bic     r0, r0, r4, lsl #16

        bic     r1, r1, r5, lsl #16

        mul     ip, r4, r5

        mul     r3, r0, r1

        mul     r0, r5, r0

        mla     r0, r4, r1, r0

        adds    r3, r3, r0, lsl #16

        adc     r1, ip, r0, lsr #16

        do_pop  {r0, r4, r5}

#else

        @ The actual multiplication.

        umull   r3, r1, r0, r1

        @ Put final sign in r0.

        and     r0, ip, #0x80000000

#endif

        @ Adjust result upon the MSB position.

        cmp     r1, #(1 << 23)

        do_it   cc, tt

        movcc   r1, r1, lsl #1

        orrcc   r1, r1, r3, lsr #31

        movcc   r3, r3, lsl #1

        @ Add sign to result.

        orr     r0, r0, r1

        @ Apply exponent bias, check for under/overflow.

        sbc     r2, r2, #127

        cmp     r2, #(254 - 1)

        bhi     LSYM(Lml_u)

        @ Round the result, merge final exponent.

        cmp     r3, #0x80000000

        adc     r0, r0, r2, lsl #23

        do_it   eq

        biceq   r0, r0, #1

        RET

        @ Multiplication by 0x1p*: let''s shortcut a lot of code.

LSYM(Lml_1):

        teq     r0, #0

        and     ip, ip, #0x80000000

        do_it   eq

        moveq   r1, r1, lsl #9

        orr     r0, ip, r0, lsr #9

        orr     r0, r0, r1, lsr #9

        subs    r2, r2, #127

        do_it   gt, tt

        COND(rsb,s,gt)  r3, r2, #255

        orrgt   r0, r0, r2, lsl #23

        RETc(gt)

        @ Under/overflow: fix things up for the code below.

        orr     r0, r0, #0x00800000

        mov     r3, #0

        subs    r2, r2, #1

LSYM(Lml_u):

        @ Overflow?

        bgt     LSYM(Lml_o)

        @ Check if denormalized result is possible, otherwise return signed 0.

        cmn     r2, #(24 + 1)

        do_it   le, t

        bicle   r0, r0, #0x7fffffff

        RETc(le)

        @ Shift value right, round, etc.

        rsb     r2, r2, #0

        movs    r1, r0, lsl #1

        shift1  lsr, r1, r1, r2

        rsb     r2, r2, #32

        shift1  lsl, ip, r0, r2

        movs    r0, r1, rrx

        adc     r0, r0, #0

        orrs    r3, r3, ip, lsl #1

        do_it   eq

        biceq   r0, r0, ip, lsr #31

        RET

        @ One or both arguments are denormalized.

        @ Scale them leftwards and preserve sign bit.

LSYM(Lml_d):

        teq     r2, #0

        and     ip, r0, #0x80000000

1:      do_it   eq, tt

        moveq   r0, r0, lsl #1

        tsteq   r0, #0x00800000

        subeq   r2, r2, #1

        beq     1b

        orr     r0, r0, ip

        teq     r3, #0

        and     ip, r1, #0x80000000

2:      do_it   eq, tt

        moveq   r1, r1, lsl #1

        tsteq   r1, #0x00800000

        subeq   r3, r3, #1

        beq     2b

        orr     r1, r1, ip

        b       LSYM(Lml_x)

LSYM(Lml_s):

        @ Isolate the INF and NAN cases away

        and     r3, ip, r1, lsr #23

        teq     r2, ip

        do_it   ne

        teqne   r3, ip

        beq     1f

        @ Here, one or more arguments are either denormalized or zero.

        bics    ip, r0, #0x80000000

        do_it   ne

        COND(bic,s,ne)  ip, r1, #0x80000000

        bne     LSYM(Lml_d)

        @ Result is 0, but determine sign anyway.

LSYM(Lml_z):

        eor     r0, r0, r1

        bic     r0, r0, #0x7fffffff

        RET

1:      @ One or both args are INF or NAN.

        teq     r0, #0x0

        do_it   ne, ett

        teqne   r0, #0x80000000

        moveq   r0, r1

        teqne   r1, #0x0

        teqne   r1, #0x80000000

        beq     LSYM(Lml_n)             @ 0 * INF or INF * 0 -> NAN

        teq     r2, ip

        bne     1f

        movs    r2, r0, lsl #9

        bne     LSYM(Lml_n)             @ NAN *  -> NAN

1:      teq     r3, ip

        bne     LSYM(Lml_i)

        movs    r3, r1, lsl #9

        do_it   ne

        movne   r0, r1

        bne     LSYM(Lml_n)             @  * NAN -> NAN

        @ Result is INF, but we need to determine its sign.

LSYM(Lml_i):

        eor     r0, r0, r1

        @ Overflow: return INF (sign already in r0).

LSYM(Lml_o):

        and     r0, r0, #0x80000000

        orr     r0, r0, #0x7f000000

        orr     r0, r0, #0x00800000

        RET

        @ Return a quiet NAN.

LSYM(Lml_n):

        orr     r0, r0, #0x7f000000

        orr     r0, r0, #0x00c00000

        RET

        FUNC_END aeabi_fmul

        FUNC_END mulsf3

ARM_FUNC_START divsf3

ARM_FUNC_ALIAS aeabi_fdiv divsf3

        @ Mask out exponents, trap any zero/denormal/INF/NAN.

        mov     ip, #0xff

        ands    r2, ip, r0, lsr #23

        do_it   ne, tt

        COND(and,s,ne)  r3, ip, r1, lsr #23

        teqne   r2, ip

        teqne   r3, ip

        beq     LSYM(Ldv_s)

LSYM(Ldv_x):

        @ Substract divisor exponent from dividend''s

        sub     r2, r2, r3

        @ Preserve final sign into ip.

        eor     ip, r0, r1

        @ Convert mantissa to unsigned integer.

        @ Dividend -> r3, divisor -> r1.

        movs    r1, r1, lsl #9

        mov     r0, r0, lsl #9

        beq     LSYM(Ldv_1)

        mov     r3, #0x10000000

        orr     r1, r3, r1, lsr #4

        orr     r3, r3, r0, lsr #4

        @ Initialize r0 (result) with final sign bit.

        and     r0, ip, #0x80000000

        @ Ensure result will land to known bit position.

        @ Apply exponent bias accordingly.

        cmp     r3, r1

        do_it   cc

        movcc   r3, r3, lsl #1

        adc     r2, r2, #(127 - 2)

        @ The actual division loop.

        mov     ip, #0x00800000

1:      cmp     r3, r1

        do_it   cs, t

        subcs   r3, r3, r1

        orrcs   r0, r0, ip

        cmp     r3, r1, lsr #1

        do_it   cs, t

        subcs   r3, r3, r1, lsr #1

        orrcs   r0, r0, ip, lsr #1

        cmp     r3, r1, lsr #2

        do_it   cs, t

        subcs   r3, r3, r1, lsr #2

        orrcs   r0, r0, ip, lsr #2

        cmp     r3, r1, lsr #3

        do_it   cs, t

        subcs   r3, r3, r1, lsr #3

        orrcs   r0, r0, ip, lsr #3

        movs    r3, r3, lsl #4

        do_it   ne

        COND(mov,s,ne)  ip, ip, lsr #4

        bne     1b

        @ Check exponent for under/overflow.

        cmp     r2, #(254 - 1)

        bhi     LSYM(Lml_u)

        @ Round the result, merge final exponent.

        cmp     r3, r1

        adc     r0, r0, r2, lsl #23

        do_it   eq

        biceq   r0, r0, #1

        RET

        @ Division by 0x1p*: let''s shortcut a lot of code.

LSYM(Ldv_1):

        and     ip, ip, #0x80000000

        orr     r0, ip, r0, lsr #9

        adds    r2, r2, #127

        do_it   gt, tt

        COND(rsb,s,gt)  r3, r2, #255

        orrgt   r0, r0, r2, lsl #23

        RETc(gt)

        orr     r0, r0, #0x00800000

        mov     r3, #0

        subs    r2, r2, #1

        b       LSYM(Lml_u)

        @ One or both arguments are denormalized.

        @ Scale them leftwards and preserve sign bit.

LSYM(Ldv_d):

        teq     r2, #0

        and     ip, r0, #0x80000000

1:      do_it   eq, tt

        moveq   r0, r0, lsl #1

        tsteq   r0, #0x00800000

        subeq   r2, r2, #1

        beq     1b

        orr     r0, r0, ip

        teq     r3, #0

        and     ip, r1, #0x80000000

2:      do_it   eq, tt

        moveq   r1, r1, lsl #1

        tsteq   r1, #0x00800000

        subeq   r3, r3, #1

        beq     2b

        orr     r1, r1, ip

        b       LSYM(Ldv_x)

        @ One or both arguments are either INF, NAN, zero or denormalized.

LSYM(Ldv_s):

        and     r3, ip, r1, lsr #23

        teq     r2, ip

        bne     1f

        movs    r2, r0, lsl #9

        bne     LSYM(Lml_n)             @ NAN /  -> NAN

        teq     r3, ip

        bne     LSYM(Lml_i)             @ INF /  -> INF

        mov     r0, r1

        b       LSYM(Lml_n)             @ INF / (INF or NAN) -> NAN

1:      teq     r3, ip

        bne     2f

        movs    r3, r1, lsl #9

        beq     LSYM(Lml_z)             @  / INF -> 0

        mov     r0, r1

        b       LSYM(Lml_n)             @  / NAN -> NAN

2:      @ If both are nonzero, we need to normalize and resume above.

        bics    ip, r0, #0x80000000

        do_it   ne

        COND(bic,s,ne)  ip, r1, #0x80000000

        bne     LSYM(Ldv_d)

        @ One or both arguments are zero.

        bics    r2, r0, #0x80000000

        bne     LSYM(Lml_i)             @  / 0 -> INF

        bics    r3, r1, #0x80000000

        bne     LSYM(Lml_z)             @ 0 /  -> 0

        b       LSYM(Lml_n)             @ 0 / 0 -> NAN

        FUNC_END aeabi_fdiv

        FUNC_END divsf3

#endif /* L_muldivsf3 */

#ifdef L_arm_cmpsf2

        @ The return value in r0 is

        @

        @   0  if the operands are equal

        @   1  if the first operand is greater than the second, or

        @      the operands are unordered and the operation is

        @      CMP, LT, LE, NE, or EQ.

        @   -1 if the first operand is less than the second, or

        @      the operands are unordered and the operation is GT

        @      or GE.

        @

        @ The Z flag will be set iff the operands are equal.

        @

        @ The following registers are clobbered by this function:

        @   ip, r0, r1, r2, r3

ARM_FUNC_START gtsf2

ARM_FUNC_ALIAS gesf2 gtsf2

        mov     ip, #-1

        b       1f

ARM_FUNC_START ltsf2

ARM_FUNC_ALIAS lesf2 ltsf2

        mov     ip, #1

        b       1f

ARM_FUNC_START cmpsf2

ARM_FUNC_ALIAS nesf2 cmpsf2

ARM_FUNC_ALIAS eqsf2 cmpsf2

        mov     ip, #1                  @ how should we specify unordered here?

1:      str     ip, [sp, #-4]!

        @ Trap any INF/NAN first.

        mov     r2, r0, lsl #1

        mov     r3, r1, lsl #1

        mvns    ip, r2, asr #24

        do_it   ne

        COND(mvn,s,ne)  ip, r3, asr #24

        beq     3f

        @ Compare values.

        @ Note that 0.0 is equal to -0.0.

2:      add     sp, sp, #4

        orrs    ip, r2, r3, lsr #1      @ test if both are 0, clear C flag

        do_it   ne

        teqne   r0, r1                  @ if not 0 compare sign

        do_it   pl

        COND(sub,s,pl)  r0, r2, r3              @ if same sign compare values, set r0

        @ Result:

        do_it   hi

        movhi   r0, r1, asr #31

        do_it   lo

        mvnlo   r0, r1, asr #31

        do_it   ne

        orrne   r0, r0, #1

        RET

        @ Look for a NAN.

3:      mvns    ip, r2, asr #24

        bne     4f

        movs    ip, r0, lsl #9

        bne     5f                      @ r0 is NAN

4:      mvns    ip, r3, asr #24

        bne     2b

        movs    ip, r1, lsl #9

        beq     2b                      @ r1 is not NAN

5:      ldr     r0, [sp], #4            @ return unordered code.

        RET

        FUNC_END gesf2

        FUNC_END gtsf2

        FUNC_END lesf2

        FUNC_END ltsf2

        FUNC_END nesf2

        FUNC_END eqsf2

        FUNC_END cmpsf2

ARM_FUNC_START aeabi_cfrcmple

        mov     ip, r0

        mov     r0, r1

        mov     r1, ip

        b       6f

ARM_FUNC_START aeabi_cfcmpeq

ARM_FUNC_ALIAS aeabi_cfcmple aeabi_cfcmpeq

        @ The status-returning routines are required to preserve all

        @ registers except ip, lr, and cpsr.

6:      do_push {r0, r1, r2, r3, lr}

        ARM_CALL cmpsf2

        @ Set the Z flag correctly, and the C flag unconditionally.

        cmp     r0, #0

        @ Clear the C flag if the return value was -1, indicating

        @ that the first operand was smaller than the second.

        do_it   mi

        cmnmi   r0, #0

        RETLDM  "r0, r1, r2, r3"

        FUNC_END aeabi_cfcmple

        FUNC_END aeabi_cfcmpeq

        FUNC_END aeabi_cfrcmple

ARM_FUNC_START  aeabi_fcmpeq

        str     lr, [sp, #-8]!

        ARM_CALL aeabi_cfcmple

        do_it   eq, e

        moveq   r0, #1  @ Equal to.

        movne   r0, #0  @ Less than, greater than, or unordered.

        RETLDM

        FUNC_END aeabi_fcmpeq

ARM_FUNC_START  aeabi_fcmplt

        str     lr, [sp, #-8]!

        ARM_CALL aeabi_cfcmple

        do_it   cc, e

        movcc   r0, #1  @ Less than.

        movcs   r0, #0  @ Equal to, greater than, or unordered.

        RETLDM

        FUNC_END aeabi_fcmplt

ARM_FUNC_START  aeabi_fcmple

        str     lr, [sp, #-8]!

        ARM_CALL aeabi_cfcmple

        do_it   ls, e

        movls   r0, #1  @ Less than or equal to.

        movhi   r0, #0  @ Greater than or unordered.

        RETLDM

        FUNC_END aeabi_fcmple

ARM_FUNC_START  aeabi_fcmpge

        str     lr, [sp, #-8]!

        ARM_CALL aeabi_cfrcmple

        do_it   ls, e

        movls   r0, #1  @ Operand 2 is less than or equal to operand 1.