* emit-rtl.c (replace_equiv_address): New function.

	* expr.h (replace_equiv_address): New declaration.
	* explow.c (validize_mem): Call it instead of change_address and
	also call if -fforce-addr and address is constant.
	* expr.c: Replace more calls to change_address with adjust_address
	and/or replace_equiv_address or to validize_mem.
	* function.c, regmove.c, config/alpha/alpha.c: Likewise.
	* config/arm/arm.md, config/clipper/clipper.md: Likewise.
	* config/dsp16xx/dsp16xx.md, config/fr30/fr30.c: Likewise.
	* config/i370/i370.md, config/i860/i860.md: Likewise.
	* config/i960/i960.md, config/mips/mips.c: Likewise.
	* config/mips/mips.md, config/pa/pa.md: Likewise.
	* config/pdp11/pdp11.md, config/rs6000/rs6000.c: Likewise.
	* config/rs6000/rs6000.md, config/sh/sh.md: Likewise.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@43762 138bc75d-0d04-0410-961f-82ee72b054a4

22 files changed, 170 insertions, 155 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 2b66dcb05d3..dc2a6fa9010 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,20 @@
+Wed Jul  4 13:40:02 2001  Richard Kenner  <kenner@vlsi1.ultra.nyu.edu>
+
+	* emit-rtl.c (replace_equiv_address): New function.
+	* expr.h (replace_equiv_address): New declaration.
+	* explow.c (validize_mem): Call it instead of change_address and
+	also call if -fforce-addr and address is constant.
+	* expr.c: Replace more calls to change_address with adjust_address
+	and/or replace_equiv_address or to validize_mem.
+	* function.c, regmove.c, config/alpha/alpha.c: Likewise.
+	* config/arm/arm.md, config/clipper/clipper.md: Likewise.
+	* config/dsp16xx/dsp16xx.md, config/fr30/fr30.c: Likewise.
+	* config/i370/i370.md, config/i860/i860.md: Likewise.
+	* config/i960/i960.md, config/mips/mips.c: Likewise.
+	* config/mips/mips.md, config/pa/pa.md: Likewise.
+	* config/pdp11/pdp11.md, config/rs6000/rs6000.c: Likewise.
+	* config/rs6000/rs6000.md, config/sh/sh.md: Likewise.
+
 2001-07-04  Kaveh R. Ghazi  <ghazi@caip.rutgers.edu>
 
 	* bitmap.c (bitmap_union_of_diff): Don't use BITMAP_ALLOCA.
diff --git a/gcc/config/alpha/alpha.c b/gcc/config/alpha/alpha.c
index ffd378674d0..3ddd7f3d9e1 100644
--- a/gcc/config/alpha/alpha.c
+++ b/gcc/config/alpha/alpha.c
@@ -2930,8 +2930,8 @@ alpha_expand_block_move (operands)
 	}
 
       /* No appropriate mode; fall back on memory.  */
-      orig_src = change_address (orig_src, GET_MODE (orig_src),
-				 copy_addr_to_reg (XEXP (orig_src, 0)));
+      orig_src = replace_equiv_address (orig_src,
+					copy_addr_to_reg (XEXP (orig_src, 0)));
       src_align = GET_MODE_BITSIZE (GET_MODE (tmp));
     }
 
@@ -2961,9 +2961,7 @@ alpha_expand_block_move (operands)
 
       for (i = 0; i < words; ++i)
 	emit_move_insn (data_regs[nregs + i],
-			change_address (orig_src, SImode,
-					plus_constant (XEXP (orig_src, 0),
-						       ofs + i * 4)));
+			adjust_address (orig_src, SImode, ofs + i * 4));
 
       nregs += words;
       bytes -= words * 4;
@@ -3076,8 +3074,8 @@ alpha_expand_block_move (operands)
 
       /* No appropriate mode; fall back on memory.  We can speed things
 	 up by recognizing extra alignment information.  */
-      orig_dst = change_address (orig_dst, GET_MODE (orig_dst),
-				 copy_addr_to_reg (XEXP (orig_dst, 0)));
+      orig_dst = replace_equiv_address (orig_dst,
+					copy_addr_to_reg (XEXP (orig_dst, 0)));
       dst_align = GET_MODE_BITSIZE (GET_MODE (tmp));
     }
 
@@ -3229,8 +3227,7 @@ alpha_expand_block_clear (operands)
 	}
 
       /* No appropriate mode; fall back on memory.  */
-      orig_dst = change_address (orig_dst, GET_MODE (orig_dst),
-				 copy_addr_to_reg (tmp));
+      orig_dst = replace_equiv_address (orig_dst, copy_addr_to_reg (tmp));
       align = GET_MODE_BITSIZE (GET_MODE (XEXP (tmp, 0)));
     }
 
diff --git a/gcc/config/arm/arm.md b/gcc/config/arm/arm.md
index 663877de3e4..fea195483d5 100644
--- a/gcc/config/arm/arm.md
+++ b/gcc/config/arm/arm.md
@@ -4282,15 +4282,15 @@
   "TARGET_ARM"
   "
   {
-    rtx addr = XEXP (operands[1], 0);
+    rtx op1 = operands[1];
+    rtx addr = XEXP (op1, 0);
     enum rtx_code code = GET_CODE (addr);
 
     if ((code == PLUS && GET_CODE (XEXP (addr, 1)) != CONST_INT)
 	|| code == MINUS)
-      addr = force_reg (SImode, addr);
+      op1 = replace_equiv_address (operands[1], force_reg (SImode, addr));
 
-    operands[4] = change_address (operands[1], QImode,
-				  plus_constant (addr, 1));
+    operands[4] = adjust_address (op1, QImode, 1);
     operands[1] = adjust_address (operands[1], QImode, 0);
     operands[3] = gen_lowpart (QImode, operands[0]);
     operands[0] = gen_lowpart (SImode, operands[0]);
@@ -4306,15 +4306,15 @@
   "TARGET_ARM"
   "
   {
-    rtx addr = XEXP (operands[1], 0);
+    rtx op1 = operands[1];
+    rtx addr = XEXP (op1, 0);
     enum rtx_code code = GET_CODE (addr);
 
     if ((code == PLUS && GET_CODE (XEXP (addr, 1)) != CONST_INT)
 	|| code == MINUS)
-      addr = force_reg (SImode, addr);
+      op1 = replace_equiv_address (op1, force_reg (SImode, addr));
 
-    operands[4] = change_address (operands[1], QImode,
-				  plus_constant (addr, 1));
+    operands[4] = adjust_address (op1, QImode, 1);
     operands[1] = adjust_address (operands[1], QImode, 0);
     operands[3] = gen_lowpart (QImode, operands[0]);
     operands[0] = gen_lowpart (SImode, operands[0]);
@@ -4332,11 +4332,12 @@
   {
     HOST_WIDE_INT value = INTVAL (operands[1]);
     rtx addr = XEXP (operands[0], 0);
+    rtx op0 = operands[0];
     enum rtx_code code = GET_CODE (addr);
 
     if ((code == PLUS && GET_CODE (XEXP (addr, 1)) != CONST_INT)
 	|| code == MINUS)
-      addr = force_reg (SImode, addr);
+      op0 = replace_equiv_address (op0, force_reg (SImode, addr));
 
     operands[1] = gen_reg_rtx (SImode);
     if (BYTES_BIG_ENDIAN)
@@ -4362,8 +4363,7 @@
 	  }
       }
 
-    operands[3] = change_address (operands[0], QImode,
-				  plus_constant (addr, 1));
+    operands[3] = adjust_address (op0, QImode, 1);
     operands[0] = adjust_address (operands[0], QImode, 0);
   }"
 )
@@ -4550,18 +4550,16 @@
           if (GET_CODE (operands[0]) == MEM
 	      && !memory_address_p (GET_MODE (operands[0]),
 				    XEXP (operands[0], 0)))
-	    {
-	      rtx temp = copy_to_reg (XEXP (operands[0], 0));
-	      operands[0] = change_address (operands[0], VOIDmode, temp);
-	    }
+	    operands[0]
+	      = replace_equiv_address (operands[0],
+				       copy_to_reg (XEXP (operands[0], 0)));
    
           if (GET_CODE (operands[1]) == MEM
 	      && !memory_address_p (GET_MODE (operands[1]),
 				    XEXP (operands[1], 0)))
-	    {
-	      rtx temp = copy_to_reg (XEXP (operands[1], 0));
-	      operands[1] = change_address (operands[1], VOIDmode, temp);
-	    }
+	    operands[1]
+	      = replace_equiv_address (operands[1],
+				       copy_to_reg (XEXP (operands[1], 0)));
         }
       /* Handle loading a large integer during reload */
       else if (GET_CODE (operands[1]) == CONST_INT
@@ -4850,17 +4848,15 @@
           if (GET_CODE (operands[0]) == MEM
 	      && !memory_address_p (GET_MODE (operands[0]),
 		  		     XEXP (operands[0], 0)))
-	    {
-	      rtx temp = copy_to_reg (XEXP (operands[0], 0));
-	      operands[0] = change_address (operands[0], VOIDmode, temp);
-	    }
+	    operands[0]
+	      = replace_equiv_address (operands[0],
+				       copy_to_reg (XEXP (operands[0], 0)));
           if (GET_CODE (operands[1]) == MEM
 	      && !memory_address_p (GET_MODE (operands[1]),
 				    XEXP (operands[1], 0)))
-	    {
-	       rtx temp = copy_to_reg (XEXP (operands[1], 0));
-	       operands[1] = change_address (operands[1], VOIDmode, temp);
-	    }
+	     operands[1]
+	       = replace_equiv_address (operands[1],
+					copy_to_reg (XEXP (operands[1], 0)));
         }
       /* Handle loading a large integer during reload */
       else if (GET_CODE (operands[1]) == CONST_INT
diff --git a/gcc/config/clipper/clipper.md b/gcc/config/clipper/clipper.md
index 95f402ed7bd..2d2a504d6b8 100644
--- a/gcc/config/clipper/clipper.md
+++ b/gcc/config/clipper/clipper.md
@@ -531,8 +531,8 @@
   operands[6] = addr0;
   operands[7] = addr1;
 
-  operands[0] = change_address (operands[0], VOIDmode, addr0);
-  operands[1] = change_address (operands[1], VOIDmode, addr1);
+  operands[0] = replace_equiv_address (operands[0], addr0);
+  operands[1] = replace_equiv_address (operands[1], addr1);
 
   if (GET_CODE (operands[2]) != CONST_INT)
     operands[2] = force_reg (SImode, operands[2]);
diff --git a/gcc/config/dsp16xx/dsp16xx.md b/gcc/config/dsp16xx/dsp16xx.md
index 2d821b5504a..4e851554b27 100644
--- a/gcc/config/dsp16xx/dsp16xx.md
+++ b/gcc/config/dsp16xx/dsp16xx.md
@@ -1131,8 +1131,8 @@
   operands[5] = addr0;
   operands[6] = addr1;
 
-  operands[0] = change_address (operands[0], VOIDmode, addr0);
-  operands[1] = change_address (operands[1], VOIDmode, addr1);
+  operands[0] = replace_equiv_address (operands[0], VOIDmode, addr0);
+  operands[1] = replace_equiv_address (operands[1], VOIDmode, addr1);
 }")
 
 (define_insn ""
diff --git a/gcc/config/fr30/fr30.c b/gcc/config/fr30/fr30.c
index 0c18c652e11..8fcad88314a 100644
--- a/gcc/config/fr30/fr30.c
+++ b/gcc/config/fr30/fr30.c
@@ -1007,7 +1007,7 @@ fr30_move_double (operands)
 	  if (reverse)
 	    {
 	      emit_insn (gen_rtx_SET (VOIDmode, dest1,
-				      change_address (src, SImode, addr)));
+				      adjust_address (src, SImode, 0)));
 	      emit_insn (gen_rtx_SET (SImode, dest0,
 				      gen_rtx_REG (SImode, REGNO (addr))));
 	      emit_insn (gen_rtx_SET (SImode, dest0,
@@ -1021,7 +1021,7 @@ fr30_move_double (operands)
 	  else
 	    {
 	      emit_insn (gen_rtx_SET (VOIDmode, dest0,
-				      change_address (src, SImode, addr)));
+				      adjust_address (src, SImode, 0)));
 	      emit_insn (gen_rtx_SET (SImode, dest1,
 				      gen_rtx_REG (SImode, REGNO (addr))));
 	      emit_insn (gen_rtx_SET (SImode, dest1,
@@ -1058,8 +1058,7 @@ fr30_move_double (operands)
       src0 = operand_subword (src, 0, TRUE, mode);
       src1 = operand_subword (src, 1, TRUE, mode);
       
-      emit_insn (gen_rtx_SET (VOIDmode,
-			      change_address (dest, SImode, addr),
+      emit_insn (gen_rtx_SET (VOIDmode, adjust_address (dest, SImode, 0),
 			      src0));
 
       if (REGNO (addr) == STACK_POINTER_REGNUM
diff --git a/gcc/config/i370/i370.md b/gcc/config/i370/i370.md
index 7ef666e4323..c0d05e6e791 100644
--- a/gcc/config/i370/i370.md
+++ b/gcc/config/i370/i370.md
@@ -1380,21 +1380,6 @@ check_label_emit ();
    ""
    "
 {
-/*
-  XXX bogus, i think, unless change_address has a side effet we need
-  rtx op0;
-
-  op0 = XEXP (operands[0], 0);
-  if (GET_CODE (op0) == REG
-      || (GET_CODE (op0) == PLUS && GET_CODE (XEXP (op0, 0)) == REG
-	  && GET_CODE (XEXP (op0, 1)) == CONST_INT
-	  && (unsigned) INTVAL (XEXP (op0, 1)) < 4096))
-    op0 = operands[0];
-  else
-    op0 = change_address (operands[0], VOIDmode,
-			  copy_to_mode_reg (SImode, op0));
-
-*/
   {
         /* implementation suggested by  Richard Henderson <rth@cygnus.com> */
         rtx reg1 = gen_reg_rtx (DImode);
@@ -1442,8 +1427,7 @@ check_label_emit ();
 	  && (unsigned) INTVAL (XEXP (op0, 1)) < 4096))
     op0 = operands[0];
   else
-    op0 = change_address (operands[0], VOIDmode,
-			  copy_to_mode_reg (SImode, op0));
+    op0 = replace_equiv_address (operands[0], copy_to_mode_reg (SImode, op0));
 
   op1 = XEXP (operands[1], 0);
   if (GET_CODE (op1) == REG
@@ -1452,8 +1436,7 @@ check_label_emit ();
 	  && (unsigned) INTVAL (XEXP (op1, 1)) < 4096))
     op1 = operands[1];
   else
-    op1 = change_address (operands[1], VOIDmode,
-			  copy_to_mode_reg (SImode, op1));
+    op1 = replace_equiv_address (operands[1], copy_to_mode_reg (SImode, op1));
 
   if (GET_CODE (operands[2]) == CONST_INT && INTVAL (operands[2]) < 256)
     emit_insn (gen_rtx_PARALLEL (VOIDmode,
diff --git a/gcc/config/i860/i860.md b/gcc/config/i860/i860.md
index beeabe6927b..eda051c5b57 100644
--- a/gcc/config/i860/i860.md
+++ b/gcc/config/i860/i860.md
@@ -1022,8 +1022,8 @@
   operands[7] = copy_to_mode_reg (SImode, XEXP (operands[0], 0));
   operands[8] = copy_to_mode_reg (SImode, XEXP (operands[1], 0));
 
-  operands[0] = change_address (operands[0], VOIDmode, operands[7]);
-  operands[1] = change_address (operands[1], VOIDmode, operands[8]);
+  operands[0] = replace_equiv_address (operands[0], operands[7]);
+  operands[1] = replace_equiv_address (operands[1], operands[8]);
 }")
 
 (define_insn ""
@@ -2127,8 +2127,9 @@ fmul.ss %1,%0,%4\;fmul.ss %3,%4,%0\";
   /* Make sure the address is just one reg and will stay that way.  */
   if (! call_insn_operand (operands[0], QImode))
     operands[0]
-      = change_address (operands[0], VOIDmode,
-			copy_to_mode_reg (Pmode, XEXP (operands[0], 0)));
+      = replace_equiv_address (operands[0],
+			       copy_to_mode_reg (Pmode,
+						 XEXP (operands[0], 0)));
   if (INTVAL (operands[1]) > 0)
     {
       emit_move_insn (arg_pointer_rtx, stack_pointer_rtx);
@@ -2195,8 +2196,9 @@ fmul.ss %1,%0,%4\;fmul.ss %3,%4,%0\";
   /* Make sure the address is just one reg and will stay that way.  */
   if (! call_insn_operand (operands[1], QImode))
     operands[1]
-      = change_address (operands[1], VOIDmode,
-			copy_to_mode_reg (Pmode, XEXP (operands[1], 0)));
+      = replace_equiv_address (operands[1],
+			       copy_to_mode_reg (Pmode,
+						 XEXP (operands[1], 0)));
   if (INTVAL (operands[2]) > 0)
     {
       emit_move_insn (arg_pointer_rtx, stack_pointer_rtx);
diff --git a/gcc/config/i960/i960.md b/gcc/config/i960/i960.md
index 341d13c540c..282297d5a7d 100644
--- a/gcc/config/i960/i960.md
+++ b/gcc/config/i960/i960.md
@@ -1004,7 +1004,7 @@
 {
   int regno;
   int count;
-  rtx from;
+  int offset = 0;
 
   if (GET_CODE (operands[0]) != MEM
       || GET_CODE (operands[1]) != REG
@@ -1016,30 +1016,29 @@
     FAIL;
 
   regno = REGNO (operands[1]);
-  from = memory_address (SImode, XEXP (operands[0], 0));
   while (count >= 4 && ((regno & 3) == 0))
     {
-      emit_move_insn (change_address (operands[0], TImode, from),
+      emit_move_insn (adjust_address (operands[0], TImode, offset),
 		      gen_rtx_REG (TImode, regno));
       count -= 4;
       regno += 4;
-      from = memory_address (TImode, plus_constant (from, 16));
+      offset += 16;
     }
   while (count >= 2 && ((regno & 1) == 0))
     {
-      emit_move_insn (change_address (operands[0], DImode, from),
+      emit_move_insn (adjust_address (operands[0], DImode, offset),
 		      gen_rtx_REG (DImode, regno));
       count -= 2;
       regno += 2;
-      from = memory_address (DImode, plus_constant (from, 8));
+      offset += 8;
     }
   while (count > 0)
     {
-      emit_move_insn (change_address (operands[0], SImode, from),
+      emit_move_insn (adjust_address (operands[0], SImode, offset),
 		      gen_rtx_REG (SImode, regno));
       count -= 1;
       regno += 1;
-      from = memory_address (SImode, plus_constant (from, 4));
+      offset += 4;
     }
   DONE;
 }")
diff --git a/gcc/config/mips/mips.c b/gcc/config/mips/mips.c
index 0a614d90098..37cb19bc31b 100644
--- a/gcc/config/mips/mips.c
+++ b/gcc/config/mips/mips.c
@@ -3248,11 +3248,11 @@ block_move_loop (dest_reg, src_reg, bytes, align, orig_dest, orig_src)
      rtx src_reg;		/* register holding source address */
      unsigned int bytes;	/* # bytes to move */
      int align;			/* alignment */
-     rtx orig_dest;		/* original dest for change_address */
+     rtx orig_dest;		/* original dest */
      rtx orig_src;		/* original source for making a reg note */
 {
-  rtx dest_mem = change_address (orig_dest, BLKmode, dest_reg);
-  rtx src_mem = change_address (orig_src, BLKmode, src_reg);
+  rtx dest_mem = replace_equiv_address (orig_dest, dest_reg);
+  rtx src_mem = replace_equiv_address (orig_src, src_reg);
   rtx align_rtx = GEN_INT (align);
   rtx label;
   rtx final_src;
@@ -3383,10 +3383,10 @@ expand_block_move (operands)
     move_by_pieces (orig_dest, orig_src, bytes, align * BITS_PER_WORD);
 	
   else if (constp && bytes <= (unsigned)2 * MAX_MOVE_BYTES)
-    emit_insn (gen_movstrsi_internal (change_address (orig_dest, BLKmode,
-						      dest_reg),
-				      change_address (orig_src, BLKmode,
-						      src_reg),
+    emit_insn (gen_movstrsi_internal (replace_equiv_address (orig_dest,
+							     dest_reg),
+				      replace_equiv_address (orig_src,
+							     src_reg),
 				      bytes_rtx, align_rtx));
 
   else if (constp && align >= (unsigned) UNITS_PER_WORD && optimize)
@@ -3433,10 +3433,10 @@ expand_block_move (operands)
 
       /* Bytes at the end of the loop.  */
       if (leftover)
-	emit_insn (gen_movstrsi_internal (change_address (orig_dest, BLKmode,
-							  dest_reg),
-					  change_address (orig_src, BLKmode,
-							  src_reg),
+	emit_insn (gen_movstrsi_internal (replace_equiv_address (orig_dest,
+								 dest_reg),
+					  replace_equiv_address (orig_src,
+								 src_reg),
 					  GEN_INT (leftover),
 					  GEN_INT (align)));
     }
diff --git a/gcc/config/mips/mips.md b/gcc/config/mips/mips.md
index bba9645b4eb..c55c128f331 100644
--- a/gcc/config/mips/mips.md
+++ b/gcc/config/mips/mips.md
@@ -5066,7 +5066,7 @@ move\\t%0,%z4\\n\\
 	{
 	  rtx memword, offword, hi_word, lo_word;
 	  rtx addr = find_replacement (&XEXP (operands[1], 0));
-	  rtx op1 = change_address (operands[1], VOIDmode, addr);
+	  rtx op1 = replace_equiv_address (operands[1], addr);
 
 	  scratch = gen_rtx_REG (SImode, REGNO (scratch));
 	  memword = adjust_address (op1, SImode, 0);
@@ -5146,7 +5146,7 @@ move\\t%0,%z4\\n\\
 	{
 	  rtx scratch, memword, offword, hi_word, lo_word;
 	  rtx addr = find_replacement (&XEXP (operands[0], 0));
-	  rtx op0 = change_address (operands[0], VOIDmode, addr);
+	  rtx op0 = replace_equiv_address (operands[0], addr);
 
 	  scratch = gen_rtx_REG (SImode, REGNO (operands[2]));
 	  memword = adjust_address (op0, SImode, 0);
diff --git a/gcc/config/pa/pa.md b/gcc/config/pa/pa.md
index ab587b391b6..59b4c766fa2 100644
--- a/gcc/config/pa/pa.md
+++ b/gcc/config/pa/pa.md
@@ -2814,11 +2814,11 @@
   
   /* Fall through means we're going to use our block move pattern.  */
   operands[0]
-    = change_address (operands[0], VOIDmode,
-		      copy_to_mode_reg (SImode, XEXP (operands[0], 0)));
+    = replace_equiv_address (operands[0],
+			     copy_to_mode_reg (SImode, XEXP (operands[0], 0)));
   operands[1]
-    = change_address (operands[1], VOIDmode,
-		      copy_to_mode_reg (SImode, XEXP (operands[1], 0)));
+    = replace_equiv_address (operands[1],
+			     copy_to_mode_reg (SImode, XEXP (operands[1], 0)));
   operands[4] = gen_reg_rtx (SImode);
   operands[5] = gen_reg_rtx (SImode);
   operands[6] = gen_reg_rtx (SImode);
diff --git a/gcc/config/pdp11/pdp11.md b/gcc/config/pdp11/pdp11.md
index 93fac95be81..98a10c01e48 100644
--- a/gcc/config/pdp11/pdp11.md
+++ b/gcc/config/pdp11/pdp11.md
@@ -696,11 +696,11 @@
   "
 {
   operands[0]
-    = change_address (operands[0], VOIDmode,
-		      copy_to_mode_reg (Pmode, XEXP (operands[0], 0)));
+    = replace_equiv_address (operands[0],
+			     copy_to_mode_reg (Pmode, XEXP (operands[0], 0)));
   operands[1]
-    = change_address (operands[1], VOIDmode,
-		      copy_to_mode_reg (Pmode, XEXP (operands[1], 0)));
+    = replace_equiv_address (operands[1],
+			     copy_to_mode_reg (Pmode, XEXP (operands[1], 0)));
 
   operands[5] = XEXP (operands[0], 0);
   operands[6] = XEXP (operands[1], 0);
diff --git a/gcc/config/rs6000/rs6000.c b/gcc/config/rs6000/rs6000.c
index b9f2348c5ef..2f35583bb34 100644
--- a/gcc/config/rs6000/rs6000.c
+++ b/gcc/config/rs6000/rs6000.c
@@ -1866,14 +1866,16 @@ rs6000_emit_move (dest, source, mode)
       if (GET_CODE (operands[0]) == MEM
 	  && GET_CODE (XEXP (operands[0], 0)) != REG
 	  && ! reload_in_progress)
-	operands[0] = change_address (operands[0], TImode,
-				      copy_addr_to_reg (XEXP (operands[0], 0)));
+	operands[0]
+	  = replace_equiv_address (operands[0],
+				   copy_addr_to_reg (XEXP (operands[0], 0)));
 
       if (GET_CODE (operands[1]) == MEM
 	  && GET_CODE (XEXP (operands[1], 0)) != REG
 	  && ! reload_in_progress)
-	operands[1] = change_address (operands[1], TImode,
-				      copy_addr_to_reg (XEXP (operands[1], 0)));
+	operands[1]
+	  = replace_equiv_address (operands[1],
+				   copy_addr_to_reg (XEXP (operands[1], 0)));
       break;
 
     default:
diff --git a/gcc/config/rs6000/rs6000.md b/gcc/config/rs6000/rs6000.md
index 5be801da94b..e23e289ec33 100644
--- a/gcc/config/rs6000/rs6000.md
+++ b/gcc/config/rs6000/rs6000.md
@@ -1,6 +1,6 @@
 ;; Machine description for IBM RISC System 6000 (POWER) for GNU C compiler
 ;; Copyright (C) 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 
-;; 1999, 2000 Free Software Foundation, Inc.
+;; 1999, 2000, 2001 Free Software Foundation, Inc.
 ;; Contributed by Richard Kenner (kenner@vlsi1.ultra.nyu.edu)
 
 ;; This file is part of GNU CC.
@@ -8257,7 +8257,7 @@ operands[2] = GEN_INT (INTVAL (operands[1]) >> 32);
 {
   int regno;
   int count;
-  rtx from;
+  rtx op1;
   int i;
 
   /* Support only loading a constant number of fixed-point registers from
@@ -8275,13 +8275,13 @@ operands[2] = GEN_INT (INTVAL (operands[1]) >> 32);
   regno = REGNO (operands[0]);
 
   operands[3] = gen_rtx_PARALLEL (VOIDmode, rtvec_alloc (count));
-  from = force_reg (SImode, XEXP (operands[1], 0));
+  op1 = replace_equiv_address (operands[1],
+			       force_reg (SImode, XEXP (operands[1], 0)));
 
   for (i = 0; i < count; i++)
     XVECEXP (operands[3], 0, i)
       = gen_rtx_SET (VOIDmode, gen_rtx_REG (SImode, regno + i),
-		     change_address (operands[1], SImode,
-				     plus_constant (from, i * 4)));
+		     adjust_address (op1, SImode, i * 4));
 }")
 
 (define_insn ""
@@ -8354,6 +8354,7 @@ operands[2] = GEN_INT (INTVAL (operands[1]) >> 32);
   int regno;
   int count;
   rtx to;
+  rtx op0;
   int i;
 
   /* Support only storing a constant number of fixed-point registers to
@@ -8372,18 +8373,17 @@ operands[2] = GEN_INT (INTVAL (operands[1]) >> 32);
 
   operands[3] = gen_rtx_PARALLEL (VOIDmode, rtvec_alloc (count + 1));
   to = force_reg (SImode, XEXP (operands[0], 0));
+  op0 = replace_equiv_address (operands[0], to);
 
   XVECEXP (operands[3], 0, 0)
-    = gen_rtx_SET (VOIDmode, change_address (operands[0], SImode, to),
-		   operands[1]);
+    = gen_rtx_SET (VOIDmode, op0, operands[1]);
   XVECEXP (operands[3], 0, 1) = gen_rtx_CLOBBER (VOIDmode,
 						 gen_rtx_SCRATCH (SImode));
 
   for (i = 1; i < count; i++)
     XVECEXP (operands[3], 0, i + 1)
       = gen_rtx_SET (VOIDmode,
-		     change_address (operands[0], SImode,
-				     plus_constant (to, i * 4)),
+		     adjust_address (op0, SImode, i * 4),
 		     gen_rtx_REG (SImode, regno + i));
 }")
 
diff --git a/gcc/config/sh/sh.md b/gcc/config/sh/sh.md
index eb3c88b0c61..c625b702a05 100644
--- a/gcc/config/sh/sh.md
+++ b/gcc/config/sh/sh.md
@@ -5028,7 +5028,7 @@
   emit_insn (gen_movsi (shift_reg, operands[3]));
   addr_target = copy_addr_to_reg (plus_constant (orig_address, size - 1));
 
-  operands[0] = change_address (operands[0], QImode, addr_target);
+  operands[0] = replace_equiv_address (operands[0], addr_target);
   emit_insn (gen_movqi (operands[0], gen_rtx_SUBREG (QImode, shift_reg, 0)));
 
   while (size -= 1)
diff --git a/gcc/emit-rtl.c b/gcc/emit-rtl.c
index 861e73bf3ad..deca99b7459 100644
--- a/gcc/emit-rtl.c
+++ b/gcc/emit-rtl.c
@@ -1601,6 +1601,7 @@ change_address (memref, mode, addr)
   MEM_COPY_ATTRIBUTES (new, memref);
   return new;
 }
+
 /* Return a memory reference like MEMREF, but with its mode changed
    to MODE and its address offset by OFFSET bytes.  */
 
@@ -1615,6 +1616,21 @@ adjust_address (memref, mode, offset)
   return
     change_address (memref, mode, plus_constant (XEXP (memref, 0), offset));
 }
+
+/* Return a memory reference like MEMREF, but with its address changed to
+   ADDR.  The caller is asserting that the actual piece of memory pointed
+   to is the same, just the form of the address is being changed, such as
+   by putting something into a register.  */
+
+rtx
+replace_equiv_address (memref, addr)
+     rtx memref;
+     rtx addr;
+{
+  /* For now, this is just a wrapper for change_address, but eventually
+     will do memref tracking.  */
+  return change_address (memref, VOIDmode, addr);
+}
 
 /* Return a newly created CODE_LABEL rtx with a unique label number.  */
 
diff --git a/gcc/explow.c b/gcc/explow.c
index 1acb834709a..68394598271 100644
--- a/gcc/explow.c
+++ b/gcc/explow.c
@@ -610,10 +610,12 @@ validize_mem (ref)
 {
   if (GET_CODE (ref) != MEM)
     return ref;
-  if (memory_address_p (GET_MODE (ref), XEXP (ref, 0)))
+  if (! (flag_force_addr && CONSTANT_ADDRESS_P (XEXP (ref, 0)))
+      && memory_address_p (GET_MODE (ref), XEXP (ref, 0)))
     return ref;
+
   /* Don't alter REF itself, since that is probably a stack slot.  */
-  return change_address (ref, GET_MODE (ref), XEXP (ref, 0));
+  return replace_equiv_address (ref, XEXP (ref, 0));
 }
 
 /* Given REF, either a MEM or a REG, and T, either the type of X or
diff --git a/gcc/expr.c b/gcc/expr.c
index 6eb90a643f0..3264aca2080 100644
--- a/gcc/expr.c
+++ b/gcc/expr.c
@@ -1879,8 +1879,7 @@ move_block_from_reg (regno, x, nregs, size)
   if (size <= UNITS_PER_WORD
       && (mode = mode_for_size (size * BITS_PER_UNIT, MODE_INT, 0)) != BLKmode)
     {
-      emit_move_insn (change_address (x, mode, NULL),
-		      gen_rtx_REG (mode, regno));
+      emit_move_insn (adjust_address (x, mode, 0), gen_rtx_REG (mode, regno));
       return;
     }
 
@@ -2746,13 +2745,13 @@ emit_move_insn (x, y)
 	   && ! push_operand (x, GET_MODE (x)))
 	  || (flag_force_addr
 	      && CONSTANT_ADDRESS_P (XEXP (x, 0)))))
-    x = change_address (x, VOIDmode, XEXP (x, 0));
+    x = validize_mem (x);
 
   if (GET_CODE (y) == MEM
       && (! memory_address_p (GET_MODE (y), XEXP (y, 0))
 	  || (flag_force_addr
 	      && CONSTANT_ADDRESS_P (XEXP (y, 0)))))
-    y = change_address (y, VOIDmode, XEXP (y, 0));
+    y = validize_mem (y);
 
   if (mode == BLKmode)
     abort ();
@@ -3752,9 +3751,9 @@ expand_assignment (to, from, want_value, suggest_reg)
 	      if (GET_CODE (XEXP (temp, 0)) == REG)
 	        to_rtx = temp;
 	      else
-		to_rtx = change_address (to_rtx, mode1,
-				         force_reg (GET_MODE (XEXP (temp, 0)),
-						    XEXP (temp, 0)));
+		to_rtx = (replace_equiv_address
+			  (to_rtx, force_reg (GET_MODE (XEXP (temp, 0)),
+					      XEXP (temp, 0))));
 	      bitpos = 0;
 	    }
 
@@ -5331,14 +5330,13 @@ store_field (target, bitsize, bitpos, mode, exp, value_mode,
 		&& GET_CODE (XEXP (addr, 1)) == CONST_INT
 		&& (XEXP (addr, 0) == virtual_incoming_args_rtx
 		    || XEXP (addr, 0) == virtual_stack_vars_rtx)))
-	addr = copy_to_reg (addr);
+	target = replace_equiv_address (target, copy_to_reg (addr));
 
       /* Now build a reference to just the desired component.  */
 
-      to_rtx = copy_rtx (change_address (target, mode,
-					 plus_constant (addr,
-							(bitpos
-							 / BITS_PER_UNIT))));
+      to_rtx = copy_rtx (adjust_address (target, mode,
+					 bitpos / BITS_PER_UNIT));
+
       MEM_SET_IN_STRUCT_P (to_rtx, 1);
       /* If the address of the structure varies, then it might be on
 	 the stack.  And, stack slots may be shared across scopes.
@@ -5683,13 +5681,12 @@ save_noncopied_parts (lhs, list)
 						| TYPE_QUAL_CONST)),
 			 0, 1, 1);
 
-	if (! memory_address_p (TYPE_MODE (part_type), XEXP (target, 0)))
-	  target = change_address (target, TYPE_MODE (part_type), NULL_RTX);
 	parts = tree_cons (to_be_saved,
 			   build (RTL_EXPR, part_type, NULL_TREE,
-				  (tree) target),
+				  (tree) validize_mem (target)),
 			   parts);
-	store_expr (TREE_PURPOSE (parts), RTL_EXPR_RTL (TREE_VALUE (parts)), 0);
+	store_expr (TREE_PURPOSE (parts),
+		    RTL_EXPR_RTL (TREE_VALUE (parts)), 0);
       }
   return parts;
 }
@@ -6342,12 +6339,13 @@ expand_expr (exp, target, tmode, modifier)
 	    abort ();
 	  addr = XEXP (DECL_RTL (exp), 0);
 	  if (GET_CODE (addr) == MEM)
-	    addr = change_address (addr, Pmode,
-				   fix_lexical_addr (XEXP (addr, 0), exp));
+	    addr
+	      = replace_equiv_address (addr,
+				       fix_lexical_addr (XEXP (addr, 0), exp));
 	  else
 	    addr = fix_lexical_addr (addr, exp);
 
-	  temp = change_address (DECL_RTL (exp), mode, addr);
+	  temp = replace_equiv_address (DECL_RTL (exp), addr);
 	}
 
       /* This is the case of an array whose size is to be determined
@@ -6356,8 +6354,7 @@ expand_expr (exp, target, tmode, modifier)
 
       else if (GET_CODE (DECL_RTL (exp)) == MEM
 	       && GET_CODE (XEXP (DECL_RTL (exp), 0)) == REG)
-	temp = change_address (DECL_RTL (exp), GET_MODE (DECL_RTL (exp)),
-			       XEXP (DECL_RTL (exp), 0));
+	temp = validize_mem (DECL_RTL (exp));
 
       /* If DECL_RTL is memory, we are in the normal case and either
 	 the address is not valid or it is not a register and -fforce-addr
@@ -6371,8 +6368,8 @@ expand_expr (exp, target, tmode, modifier)
 				       XEXP (DECL_RTL (exp), 0))
 		   || (flag_force_addr
 		       && GET_CODE (XEXP (DECL_RTL (exp), 0)) != REG)))
-	temp = change_address (DECL_RTL (exp), VOIDmode,
-			       copy_rtx (XEXP (DECL_RTL (exp), 0)));
+	temp = replace_equiv_address (DECL_RTL (exp),
+				      copy_rtx (XEXP (DECL_RTL (exp), 0)));
 
       /* If we got something, return it.  But first, set the alignment
 	 if the address is a register.  */
@@ -6441,8 +6438,8 @@ expand_expr (exp, target, tmode, modifier)
 	  && (! memory_address_p (mode, XEXP (TREE_CST_RTL (exp), 0))
 	      || (flag_force_addr
 		  && GET_CODE (XEXP (TREE_CST_RTL (exp), 0)) != REG)))
-	return change_address (TREE_CST_RTL (exp), VOIDmode,
-			       copy_rtx (XEXP (TREE_CST_RTL (exp), 0)));
+	return replace_equiv_address (TREE_CST_RTL (exp),
+				      copy_rtx (XEXP (TREE_CST_RTL (exp), 0)));
       return TREE_CST_RTL (exp);
 
     case EXPR_WITH_FILE_LOCATION:
@@ -6491,8 +6488,9 @@ expand_expr (exp, target, tmode, modifier)
 	    }
 	  if (temp == 0 || GET_CODE (temp) != MEM)
 	    abort ();
-	  return change_address (temp, mode,
-				 fix_lexical_addr (XEXP (temp, 0), exp));
+	  return
+	    replace_equiv_address (temp,
+				   fix_lexical_addr (XEXP (temp, 0), exp));
 	}
       if (SAVE_EXPR_RTL (exp) == 0)
 	{
@@ -6747,13 +6745,9 @@ expand_expr (exp, target, tmode, modifier)
 
 	  if (modifier != EXPAND_CONST_ADDRESS
 	      && modifier != EXPAND_INITIALIZER
-	      && modifier != EXPAND_SUM
-	      && (! memory_address_p (GET_MODE (constructor),
-				      XEXP (constructor, 0))
-		  || (flag_force_addr
-		      && GET_CODE (XEXP (constructor, 0)) != REG)))
-	    constructor = change_address (constructor, VOIDmode,
-					  XEXP (constructor, 0));
+	      && modifier != EXPAND_SUM)
+	    constructor = validize_mem (constructor);
+
 	  return constructor;
 	}
       else
@@ -7095,9 +7089,10 @@ expand_expr (exp, target, tmode, modifier)
 		if (GET_CODE (XEXP (temp, 0)) == REG)
 		  op0 = temp;
 		else
-		  op0 = change_address (op0, mode1,
-					force_reg (GET_MODE (XEXP (temp, 0)),
-						   XEXP (temp, 0)));
+		  op0 = (replace_equiv_address
+			 (op0,
+			  force_reg (GET_MODE (XEXP (temp, 0)),
+				     XEXP (temp, 0))));
 		bitpos = 0;
 	      }
 
@@ -9400,7 +9395,7 @@ expand_increment (exp, post, ignore)
 		      : copy_to_reg (XEXP (op0, 0)));
 	  rtx temp, result;
 
-	  op0 = change_address (op0, VOIDmode, addr);
+	  op0 = replace_equiv_address (op0, addr);
 	  temp = force_reg (GET_MODE (op0), op0);
 	  if (! (*insn_data[icode].operand[2].predicate) (op1, mode))
 	    op1 = force_reg (mode, op1);
diff --git a/gcc/expr.h b/gcc/expr.h
index 9dff8e931a8..0e8f875113b 100644
--- a/gcc/expr.h
+++ b/gcc/expr.h
@@ -1154,6 +1154,12 @@ extern rtx change_address PARAMS ((rtx, enum machine_mode, rtx));
    to MODE and its address offset by OFFSET bytes.  */
 extern rtx adjust_address PARAMS ((rtx, enum machine_mode, HOST_WIDE_INT));
 
+/* Return a memory reference like MEMREF, but with its address changed to
+   ADDR.  The caller is asserting that the actual piece of memory pointed
+   to is the same, just the form of the address is being changed, such as
+   by putting something into a register.  */
+extern rtx replace_equiv_address PARAMS ((rtx, rtx));
+
 /* Return a memory reference like MEMREF, but which is known to have a
    valid address.  */
 extern rtx validize_mem PARAMS ((rtx));
diff --git a/gcc/function.c b/gcc/function.c
index 8ab0037fcf3..4e0c4f8c265 100644
--- a/gcc/function.c
+++ b/gcc/function.c
@@ -2617,7 +2617,7 @@ fixup_stack_1 (x, insn)
 	  seq = gen_sequence ();
 	  end_sequence ();
 	  emit_insn_before (seq, insn);
-	  return change_address (x, VOIDmode, temp);
+	  return replace_equiv_address (x, temp);
 	}
       return x;
     }
diff --git a/gcc/regmove.c b/gcc/regmove.c
index 85ca4efaa7d..5d3f18eba84 100644
--- a/gcc/regmove.c
+++ b/gcc/regmove.c
@@ -2458,8 +2458,9 @@ combine_stack_adjustments_for_block (bb)
 	      && ! reg_mentioned_p (stack_pointer_rtx, src)
 	      && memory_address_p (GET_MODE (dest), stack_pointer_rtx)
 	      && validate_change (insn, &SET_DEST (set),
-				  change_address (dest, VOIDmode,
-						  stack_pointer_rtx), 0))
+				  replace_equiv_address (dest,
+							 stack_pointer_rtx),
+				  0))
 	    {
 	      if (last_sp_set == bb->head)
 		bb->head = NEXT_INSN (last_sp_set);