R: General information on Hitachi SH math performance

Giulix giuliano.to@tin.it
Thu Aug 16 02:18:00 GMT 2001

>   The second path is to completely override the math functions in
> Currently, for libc, routines may be overridden by placing assembler
> in the appropriate machine directory (e.g. libc/machine/i386).  The name
of the
> object file must be the same as the generic C version (e.g. strcpy.o).

If I look for "strcpy" there is a file in libc/machine/sh and one in
libc/string as mentioned by you. But if I look at "divhi3" there is only one
in machine/h8500 and not one in libc. Why ?

There are difference around sh series hitachi microprocessor.  For example
SH1 have no dword mac. SH2 have dword mac. SH4 have hardware fp. I see that
libc/machine/sh files must support all the SH series. I can't test all
platform because I have only SH2 7045F model :-(          Any suggestion ?

I have tryed to compile this simple function with gcc-2.95.2 for SH:

int qem_main()
 volatile long a,b,c,d,e,f;
      b = a/b;

      return 0;

I see in dissasembler file thar the compiler use the "___sdivsi3" function.
Where this funtion is ? Is buided into compiler or is part of newlib ?

Thank you

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