F28377D (FPU: LUF, LVF Flags are Invalid for the EINVF32 and EISQRTF32 Instructions) errata and C compiler

Colombo Carlo

Hello Champs ,

please customer is using C compiler and F28377D .

now they see on page 19-20 of sprz412f this errtata (FPU: LUF, LVF Flags are Invalid for the EINVF32 and EISQRTF32 Instructions).

question is : is the CCS C compiler aware of this issue and skip these instructions , or sent warnings during compiling if this could be an issue ?

we have online a asm workaround , but what about C ?

should they check the assmbler output line by line ?

any suggestion on how to be safe in C ?

thank you

bye

Carlo

over 8 years ago

0 Vishal_Coelho over 8 years ago

TI__Mastermind 20850 points

Carlo,

I will check with SDO to see if this is comprehended (or even if it needs to be) by the C compiler.

This is a concern only if you are looking for underflows and overflows as a result of these 2 operations. Typically the operands should be checked before running these instructions.

0 Archaeologist over 8 years ago

TI__Guru* 84225 points

The C compiler can only generate these instructions when using the __einvf32 and __eisqrtf32 intrinsics, and does not make use of the LUF or LVF flags.

0 Anna Youssefi over 7 years ago in reply to Archaeologist

TI__Intellectual 2560 points

Please note that the compiler’s standard C math library routines for sqrt call the __eisqrtf() intrinsic if FPU32 is enabled.

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F28377D (FPU: LUF, LVF Flags are Invalid for the EINVF32 and EISQRTF32 Instructions) errata and C compiler