Re: mode dependent constants in gcc

Re: mode dependent constants in gcc

[Soubhik Bhattacharya]

u can force this using addl constraints (CONST_OK_FOR_LETTER_P)......
see sparc.md for example.

--soubhik.

----------------------
Hi,
 I am working for gcc z80 port.
 In z80 the valid constants range depends on the
 instruction that involves the constants.
  If it is an 8 bit operation, the valid range is
       -128 to 127 and it differs in the
 16 bit operations.
  But in gcc I am not able to figure out how to
 handle this. The macro LEGITIMATE_CONSTANT
 checks for the valid constant range.
 But actually if I say
   some mode dependent check, it does n't work.
 May be because constants can pass any mode.
  Could you please tell me how to handle this.
 If I am assuming something wrong please let me know. thanks and regards
V.Brahmaiah

mode dependent constants in gcc

[brahmaiah vallabhaneni]

Hi,
 I am working for gcc z80 port.
 In z80 the valid constants range depends on the
 instruction that involves the constants.

  If it is an 8 bit operation, the valid range is
       -128 to 127 and it differs in the 
 16 bit operations.

  But in gcc I am not able to figure out how to
 handle this. The macro LEGITIMATE_CONSTANT 
 checks for the valid constant range.
 But actually if I say 

   some mode dependent check, it does n't work. 
 May be because constants can pass any mode.


  Could you please tell me how to handle this.
 If I am assuming something wrong please let me 
know.


thanks and regards

V.Brahmaiah








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