F28377D (FPU: LUF, LVF Flags are Invalid for the EINVF32 and EISQRTF32 Instructions) errata and C compiler: No changes ?

Hideaki Nambu

Mastermind 9125 points

Hello,

I'm studying errata and the titled thread https://e2e.ti.com/support/development_tools/compiler/f/343/t/473778 .

" The C compiler can only generate these instructions when using the __einvf32 and __eisqrtf32 intrinsics ... "

This is a part of the conclusion of the thread. Is it true still now and future ?

over 7 years ago

0 Anna Youssefi over 7 years ago

TI__Intellectual 2560 points

Nothing has changed. However, the thread did not mention that the compiler’s standard C math library routines for sqrt call the __eisqrtf() intrinsic if FPU32 is enabled. I have updated the thread. I will also check with the C2000 group to see if an updated errata was issued on this topic.

0 Hideaki Nambu over 7 years ago in reply to Anna Youssefi

Mastermind 9125 points

Anna,
Thank you for your response.
So, could you please double-check my customer's action items ?

My customer' code:
- Makes sure that "Divide by Positive value" before the calculation.
- Does not care overflow/underflow.
- Disables PIEIER12.7/8.

In the case I think *no action items for the errata*. Is it correct ?

- - -
It is all my convenience, but a careful reply is highly appreciated for this question.

0 Anna Youssefi over 7 years ago in reply to Hideaki Nambu

TI__Intellectual 2560 points

This is best answered by the C2000 group. I will ask them to respond.

0 Vishal_Coelho over 7 years ago in reply to Hideaki Nambu

TI__Mastermind 20850 points

Hideaki Nambu said:
My customer' code:
- Makes sure that "Divide by Positive value" before the calculation.
- Does not care overflow/underflow.
- Disables PIEIER12.7/8.

This is essentially correct. One thing i would caution you on is make sure the positive value lies in the normal range of floating point numbers (i.e. its not a subnormal/denorm number). I will update the errata with the caveat that Anna mentioned (about the std C library).

0 Hideaki Nambu over 7 years ago in reply to Vishal_Coelho

Mastermind 9125 points

Vishal, Anna,
I appreciate your response. Very clear.

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F28377D (FPU: LUF, LVF Flags are Invalid for the EINVF32 and EISQRTF32 Instructions) errata and C compiler: No changes ?