pa reload problem

[John David Anglin]

> On Wed, Dec 06, 2000 at 03:41:06PM -0500, John David Anglin wrote:
> > >     (expr_list:REG_EQUIV (mem/u:SI (lo_sum:SI (reg/f:SI 309)
> > > 		(unspec:SI[
> > > 			(symbol_ref:SI ("constructor_max_index"))
> > > 		    ]  0)) 0)
> 
> This appears to be the same sort of bug as in compile/20001205-1.c
> except that an unspec is involved instead of an asm_operands.
> 
> I wonder if the best solution is to avoid local-alloc creating
> REG_EQUIV notes for every little thing under the sun.  Allow
> only general_operand or something.

I am testing the following.  The bootstrap has gone well past the above
point.  Maybe some generalization of this would work in general or
some similar control could be added to local-alloc regarding the creation
of REG_EQUIV notes.  This method works well here because there are no
valid substitutions of PIC mem's on the PA as far as I am aware.  Another
method might be to scan the insn list and check that the substitution is
valid for all the insns that use the register before deciding that a
REG_EQUIV note should be added.

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

2000-12-06  John David Anglin  <dave@hiauly1.hia.nrc.ca>

	* pa.h (PIC_ADDRESS_P): Define macro to recognize PIC address.
	* reload1.c (reload): Don't set reg_equiv_mem if PIC_ADDRESS_P
	is defined and true.

--- config/pa/pa.h.orig	Sat Dec  2 02:43:02 2000
+++ config/pa/pa.h	Wed Dec  6 17:27:21 2000
@@ -1091,6 +1091,14 @@
    || GET_CODE (X) == HIGH) 						\
    && (reload_in_progress || reload_completed || ! symbolic_expression_p (X)))
 
+/* Recognize a PIC address.  */
+
+#define PIC_ADDRESS_P(X)			\
+   (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)	\
+
 /* Include all constant integers and constant doubles, but not
    floating-point, except for floating-point zero.
 
--- reload1.c.orig	Thu Nov 30 17:39:21 2000
+++ reload1.c	Wed Dec  6 17:18:27 2000
@@ -881,8 +881,14 @@
 	  {
 	    rtx x = eliminate_regs (reg_equiv_memory_loc[i], 0, NULL_RTX);
 
+#ifndef PIC_ADDRESS_P
 	    if (strict_memory_address_p (GET_MODE (regno_reg_rtx[i]),
 					 XEXP (x, 0)))
+#else
+	    if (strict_memory_address_p (GET_MODE (regno_reg_rtx[i]),
+					 XEXP (x, 0))
+		&& ! PIC_ADDRESS_P (XEXP (x, 0)))
+#endif
 	      reg_equiv_mem[i] = x, reg_equiv_address[i] = 0;
 	    else if (CONSTANT_P (XEXP (x, 0))
 		     || (GET_CODE (XEXP (x, 0)) == REG