How to generate a PC- relative load instruction.

sumanth <sumanth.gundapneni@xxxxxxxxxxxxxxxxxx> · Thu, 09 Apr 2009 16:48:02 +0530

Hi,

   How can I  generate a load instruction with pc-relative accessing of 
"global" variables.
   As far as I know I need to modify GO_IF_LEGITIMATE_ADDRESS
   X is an RTX ; 1. GET_CODE (X) == PC     + offset
                          2. GET_CODE (X) == LABEL_REF  or  GET_CODE 
(X) == SYMBOL_REF
  and split the label to PC + offset (if possible)  .

 The problem here is how can I keep data in PC + offset and tell my 
compiler. The only reference is in arm  as far as I know.
 Its some thing like
  "a = 10 " is a global variable  and i need to load its address it in 
to register r0.
 120    ld r0(destination), pc ,#4
 124    0x2345678e
 value 10 is in 0x2345678e

Can any one help me in this regard .

Thanks in advance.

Thanks,
Sumanth