Libgcc Soft floating point functions

Question

I want to find source code implementation of these functions based on soft floating point

__aeabi_dcmpeq

__aeabi_dcmplt

__aeabi_dmul

Basically, I want to to use soft floating point implementation of libgcc as my processor based on Cortex-M4 does not have FPU. Instead of using built in library libgcc.a using -lgcc switch, I want to use the source code implementation of floating point arithmetic functions in my application and want to use only those functions that are required for my application instead of adding whole of the library. So please can any one help where these functions are lying. I see these functions are there in "ieee754-df.S" such as "aeabi_dcmpeq". Are these functions meant for Soft floating point and generic for all ARM targets? but it seems me this is not the case.

There are freeBSD implementation: web.mit.edu/freebsd/head/lib/libc/arm/aeabi/aeabi_double.c web.mit.edu/freebsd/head/lib/libc/arm/aeabi/aeabi_asm_double.S — osgx
– osgx, Commented Jun 30, 2016 at 12:23
I want to use implementation of these functions from gcc source code — user3674043
– user3674043, Commented Jun 30, 2016 at 12:51
do you use static or dynamic linking with libgcc? static linking will only keep used functions. — osgx
– osgx, Commented Jun 30, 2016 at 13:10

mirh · Accepted Answer · 2020-02-01 16:07:30Z

0

The functions are defined in libgcc in https://gcc.gnu.org/git/gitweb.cgi?p=gcc.git;a=blob;f=libgcc/config/arm/ieee754-df.S

There is softfloat implementation in NetBSD (NetBSD/src/lib/libc/softfloat/):

http://cvsweb.netbsd.org/bsdweb.cgi/src/lib/libc/arch/arm/softfloat/

http://cvsweb.netbsd.org/bsdweb.cgi/~checkout~/src/lib/libc/arch/arm/softfloat/__aeabi_dcmplt.c

edited Feb 1, 2020 at 16:07

mirh

6889 silver badges17 bronze badges

answered Jun 30, 2016 at 13:14

osgx

95.3k58 gold badges389 silver badges531 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

user3674043 Over a year ago

I pick this function " aeabi_dcmpeq" from ieee754-def.S and include it in my application, I see these errors while building the application ../src/ieee754-df.S:1096: Error: lo register required -- `str lr,[sp,#-8]!' ../src/ieee754-df.S:1099: Error: Thumb does not support conditional execution ../src/ieee754-df.S:1100: Error: Thumb does not support conditional execution. These error seems me valid as I am building it for cortex-m4. So, how can I modify it to use it for cortex-m4/armv7e-m. How GCC manipulates it for multiple architecture and for cortex-m4/armv7e-m having no FPU

user3674043 Over a year ago

have you seen my above comment?

Collectives™ on Stack Overflow

Libgcc Soft floating point functions

1 Answer 1

2 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

2 Comments

Your Answer

Sign up or log in

Post as a guest

Related