Re: MAC instructions on H8300S [H8S/2600]

["D.Venkatasubramanian, Noida" <dvenkat at noida dot hcltech dot com>]

Hi All,

(Subsequent to earlier mails on this subject)

The test case gcc.c-torture/execute/va-arg-22.c fails:
FAIL: gcc.c-torture/execute/va-arg-22.c execution,  -O3 -fomit-frame-pointer
-funroll-all-loops -finline-functions

This failure is specific to 
Running target h8300-sim/-O2 -mint32 -ms -ms2600

The culprits were MAC-related instructions. being 
generated by the compiler. The simulator does not 
recognise these instruction and aborts. I was 
trying to add the support to the simulator.

In the file include/opcode/h8300.h, in the 
 const struct h8_opcode h8_opcodes[] definition:

The definition for ldmac and stmac should be 

  NEW_SOP(O(O_LDMAC,SL),1,2,"ldmac"),{{RS32,MD32,E}},{{0x0,0x3,MD32,RS32,E}}
EOP,
  NEW_SOP(O(O_STMAC,SL),1,2,"stmac"),{{MS32,RD32,E}},{{0x0,0x2,MS32,RD32,E}}
EOP,

where MS32 and MD32 are defined as :

#define MS32            (SRC|L_32|MACREG)
#define MD32            (DST|L_32|MACREG)

instead of :

 
NEW_SOP(O(O_LDMAC,SL),1,2,"ldmac"),{{RS32,MACREG,E}},{{0x0,0x3,MACREG,RS32,E
}} EOP,
 
NEW_SOP(O(O_STMAC,SL),1,2,"stmac"),{{MACREG,RD32,E}},{{0x0,0x2,MACREG,RD32,E
}} EOP,

This way, the simulator will be able to recognize 
that MD32 specifies a destination register and 
MS32 specifies a source register.

Could someone comment whether this is correct. 
Anyways, this change would not break anything 
that has been running until now.

Thanks and Regards,

Venky

PS : As the H8300 Simulator is totally undocumented, 
could the original author add some comments to the 
code if he could find the time. Many things remain 
unclear still.


[venkat@peacock Bug19]$ h8300-elf-gcc -v
Reading specs from
/export/venkat/gcc_release_3_3/h8300-elf/tools/lib/gcc-lib/h8300-elf/3.3/spe
cs
Configured with: /home/GCC_RELEASE/configure --target=h8300-elf
--prefix=/export/venkat/gcc_release_3_3/h8300-elf/tools --enable-languages=c
--with-newlib --with-headers=/home/GCC_RELEASE/newlib/libc/include/
Thread model: single
gcc version 3.3 20030127 (prerelease)