ARM linux mailing lists FAQ about floating point support.
Hi,
It seems the FAQ here:
http://www.arm.linux.org.uk/mailinglists/faq.php#f4
is a bit outdated, since it does not mention that EABI solves the issue.
Regards.
Signature · 1 line
Gilles.
Quoted 7 lines · Gilles Chanteperdrix
Hi,
It seems the FAQ here:
http://www.arm.linux.org.uk/mailinglists/faq.php#f4is a bit outdated, since it does not mention that EABI solves the issue.
And just how would EABI solve the issue?
Nicolas
Quoted 10 lines · Nicolas Pitre
Quoted 6 lines · Gilles Chanteperdrix
Hi,
It seems the FAQ here:
http://www.arm.linux.org.uk/mailinglists/faq.php#f4is a bit outdated, since it does not mention that EABI solves the issue.
And just how would EABI solve the issue?
By allowing to mix soft-float and hard-float programs with only one libc?
Signature · 1 line
Gilles.
Quoted 5 lines · Gilles Chanteperdrix
Quoted 4 lines · Nicolas Pitre
Quoted 2 lines · Gilles Chanteperdrix
Hi,
Quoted 8 lines
Quoted 6 lines
Quoted 4 lines
It seems the FAQ here:
http://www.arm.linux.org.uk/mailinglists/faq.php#f4is a bit outdated, since it does not mention that EABI solves the issue.
And just how would EABI solve the issue?
By allowing to mix soft-float and hard-float programs with only one libc?
Err... How?
Nicolas
Quoted 7 lines · Nicolas Pitre
Quoted 5 lines · Gilles Chanteperdrix
Quoted 4 lines · Nicolas Pitre
Quoted 2 lines · Gilles Chanteperdrix
Hi,
Quoted 8 lines
Quoted 6 lines
Quoted 5 lines
Quoted 4 lines
It seems the FAQ here:
http://www.arm.linux.org.uk/mailinglists/faq.php#f4is a bit outdated, since it does not mention that EABI solves the issue.
And just how would EABI solve the issue?
By allowing to mix soft-float and hard-float programs with only one libc?
Err... How?
Well, I read somewhere that EABI allows mixing soft-float and hard-float code and must have assumed it was true. But you made me doubt.
But since compiling both a hard-float program and a soft-float program with the same toolchain does not produce any compilation or link-edition error, I still tend to think it is true.
I just need to run the test on actual hardware to finish checking.
Signature · 1 line
Gilles.
Quoted 7 lines · Nicolas Pitre
Quoted 5 lines · Gilles Chanteperdrix
Quoted 4 lines · Nicolas Pitre
Quoted 2 lines · Gilles Chanteperdrix
Hi,
Quoted 8 lines
Quoted 6 lines
Quoted 5 lines
Quoted 4 lines
It seems the FAQ here:
http://www.arm.linux.org.uk/mailinglists/faq.php#f4is a bit outdated, since it does not mention that EABI solves the issue.
And just how would EABI solve the issue?
By allowing to mix soft-float and hard-float programs with only one libc?
Err... How?
Right, it does not work, so, what does:
"Allows the mixing of softfloat and hardfloat code"
is supposed to mean here for instance:
http://www.eurotech-inc.com/embedded-eabi-linux.asp
Signature · 1 line
Gilles.
Quoted 15 lines · Gilles Chanteperdrix
Quoted 14 lines · Nicolas Pitre
Quoted 11 lines · Gilles Chanteperdrix
Quoted 9 lines · Nicolas Pitre
Quoted 6 lines · Gilles Chanteperdrix
Hi,
It seems the FAQ here:
http://www.arm.linux.org.uk/mailinglists/faq.php#f4is a bit outdated, since it does not mention that EABI solves the issue.
And just how would EABI solve the issue?
By allowing to mix soft-float and hard-float programs with only one libc?
Quoted 8 lines
Quoted 1 line
Err... How?
Well, I read somewhere that EABI allows mixing soft-float and hard-float code and must have assumed it was true. But you made me doubt.
But since compiling both a hard-float program and a soft-float program with the same toolchain does not produce any compilation or link-edition error, I still tend to think it is true.
Well, actually it seems that gcc can only do -mfloat-abi=softfp and surprizingly -mfloat-abi=hard is unimplemented for VFP. So in that case mixing soft and hard float objects is fine.
Nicolas
Quoted 5 lines · Gilles Chanteperdrix
Right, it does not work, so, what does:
"Allows the mixing of softfloat and hardfloat code"is supposed to mean here for instance:
http://www.eurotech-inc.com/embedded-eabi-linux.asp
As I just posted, it looks like gcc only implemented the soft-float ABI when using VFP. So if your CPU is VFP capable then using -mfloat-abi=softfp should produce actual VFP instructions while still passing function arguments around using non VFP registers.
Nicolas
Quoted 5 lines · Nicolas Pitre
Quoted 3 lines · Gilles Chanteperdrix
Right, it does not work, so, what does:
"Allows the mixing of softfloat and hardfloat code"
Quoted 7 lines
Quoted 2 lines
is supposed to mean here for instance:
http://www.eurotech-inc.com/embedded-eabi-linux.aspAs I just posted, it looks like gcc only implemented the soft-float ABI when using VFP. ?So if your CPU is VFP capable then using -mfloat-abi=softfp should produce actual VFP instructions while still passing function arguments around using non VFP registers.
Didn't latest CodeSourcery ARM toolchain (2009q1) add hardfp?
Laurent
Quoted 9 lines · Laurent Desnogues
Quoted 8 lines · Nicolas Pitre
Quoted 5 lines · Gilles Chanteperdrix
Right, it does not work, so, what does:
"Allows the mixing of softfloat and hardfloat code"is supposed to mean here for instance:
http://www.eurotech-inc.com/embedded-eabi-linux.asp
Quoted 6 lines
Quoted 4 lines
As I just posted, it looks like gcc only implemented the soft-float ABI when using VFP. ?So if your CPU is VFP capable then using -mfloat-abi=softfp should produce actual VFP instructions while still passing function arguments around using non VFP registers.
Didn't latest CodeSourcery ARM toolchain (2009q1) add hardfp?
I don't know. If so then the FAQ entry about not being able to mix hard-float and soft-float would still apply when using that mode.
Nicolas