learning

[Ulrich Weigand]

David Welch wrote:

>(insn 6 5 7 (set (reg/v:SI 23)
>        (mem/f:SI (reg/f:SI 25) [2 x+0 S4 A32])) -1 (insn_list 5 (nil))
>    (expr_list:REG_DEAD (reg/f:SI 25)
>        (nil)))

>Anyway, what do the /v and /f, etc mean in say reg/v:SI? 

reg/v: Register represents a user-level variable
reg/f: Register holds a pointer
mem/f: Memory reference to a scalar value

See: 
http://gcc.gnu.org/onlinedocs/gccint/Flags.html#Flags

>And of course the big question, what kind of instruction or 
>expression is it looking for here? 

Reg 25 holds a memory address; load the SImode value from 
memory at this address, and place it into reg 23.

(If *this* insn is not recognized, you have serious problems ...)

See:
http://gcc.gnu.org/onlinedocs/gccint/Regs-and-Memory.html#Regs%20and%20Memory
http://gcc.gnu.org/onlinedocs/gccint/Side-Effects.html#Side%20Effects

>Is there something other than the GCCint that I should be 
>reading or referencing?

These issues are all documented in the internals manual.

Bye,
Ulrich 

-- 
  Dr. Ulrich Weigand
  weigand@informatik.uni-erlangen.de