pa reload problem

[John David Anglin]

> 
> On Fri, Dec 08, 2000 at 08:07:23PM -0500, John David Anglin wrote:
> > It is my impression that the MEM would pass as a general_operand unless
> > the volatile flag is set.  It will pass GO_IF_LEGITIMATE_ADDRESS.  Thus,
> > the general_operand test doesn't look like it will work.
> 
> Your GO_IF_LEGITIMATE_ADDRESS will accept the UNSPEC?
> The mind boggles.  Why, then, is this strange beast its own insn?

Sure looks like it:

#define GO_IF_LEGITIMATE_ADDRESS(MODE, X, ADDR)  \ 
[snip]
  /* Needed for -fPIC */                                \
  else if (GET_CODE (X) == LO_SUM                       \
           && GET_CODE (XEXP (X, 0)) == REG             \
           && REG_OK_FOR_BASE_P (XEXP (X, 0))           \
           && GET_CODE (XEXP (X, 1)) == UNSPEC)         \
    goto ADDR;                                          \
}

The comment for the insn used to load a PIC MEM says:

; We need this to make sure CSE doesn't simplify a memory load with a
; symbolic address, whose content it think it knows.  For PIC, what CSE
; think is the real value will be the address of that value.

Dave
-- 
J. David Anglin                                  dave.anglin@nrc.ca
National Research Council of Canada              (613) 990-0752 (FAX: 952-6605)