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Altera_Forum
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19 years ago

How to use fpu custom instruction ?

I work on a NIOSII with a fpu provided by Altera (taking into account +, -, *, and / operations on float). So when I write C code : A + B (where A and B are float type), assembler code use custom ins...
Altera_Forum's avatar
Altera_Forum
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19 years ago

I recommend turning on the objdump file generation in the Nios II IDE (under the preferences). By specifying -save-temps you are getting the assembler output, however the custom instructions for those floating point operations don't get pulled in until link time (so you'll see them in the objdump).

So here's the order:

1) Compiler creates the assembly and object files (containing calls to the generic math libraries)

2) During linking the linker figures out if the library should be pulled in or a custom library/hardware

3) After linking completes you have an elf and the objdump file is created based on it.

I hope that helps clarify the issue.