m68hc11.c (m68hc11_check_z_replacement): Take into account pre/post increment decrement for 68HC12.

	* config/m68hc11/m68hc11.c (m68hc11_check_z_replacement): Take
	into account pre/post increment decrement for 68HC12.
	Fix other problems in replacement and fix call to reg_mentioned_p.

From-SVN: r41848

gcc/ChangeLog

 2001-05-04  Stephane Carrez  <Stephane.Carrez@worldnet.fr>
 
+	* config/m68hc11/m68hc11.c (m68hc11_check_z_replacement): Take
+	into account pre/post increment decrement for 68HC12.
+	Fix other problems in replacement and fix call to reg_mentioned_p.
+
+2001-05-04  Stephane Carrez  <Stephane.Carrez@worldnet.fr>
+
 	* config/m68hc11/larith.asm (L_regs_frame): New for _.frame.
 	Put the soft registers in bss for 68HC12.
 	(L_regs_d3_4): New for _.d3 and _.d4.

gcc/config/m68hc11/m68hc11.c

@@ -3851,6 +3851,7 @@ m68hc11_check_z_replacement (insn, info)
   int this_insn_uses_ix;
   int this_insn_uses_iy;
   int this_insn_uses_z;
+  int this_insn_uses_z_in_dst;
   int this_insn_uses_d;
   rtx body;
   int z_dies_here;
@@ -3954,10 +3955,13 @@ m68hc11_check_z_replacement (insn, info)
 	{
 	  if (!reg_mentioned_p (z_reg, src))
 	    {
-	      if (insn == info->first)
+              /* Z reg is used before being set.  Treat this as
+                 a new sequence of Z register replacement.  */
+	      if (insn != info->first)
 		{
-		  info->must_load_z = 0;
+                  return 0;
 		}
+              info->must_load_z = 0;
 	    }
 	  info->z_set_count++;
 	  info->z_value = src;
@@ -3977,9 +3981,23 @@ m68hc11_check_z_replacement (insn, info)
 
       /* If z is used as an address operand (like (MEM (reg z))),
          we can't replace it with d.  */
-      if (this_insn_uses_z && !Z_REG_P (src))
+      if (this_insn_uses_z && !Z_REG_P (src)
+          && !(m68hc11_arith_operator (src, GET_MODE (src))
+               && Z_REG_P (XEXP (src, 0))
+               && !reg_mentioned_p (z_reg, XEXP (src, 1))
+               && insn == info->first
+               && dead_register_here (insn, d_reg)))
 	info->can_use_d = 0;
-      this_insn_uses_z |= reg_mentioned_p (z_reg, dst);
+
+      this_insn_uses_z_in_dst = reg_mentioned_p (z_reg, dst);
+      if (TARGET_M6812 && !z_dies_here
+          && ((this_insn_uses_z && side_effects_p (src))
+              || (this_insn_uses_z_in_dst && side_effects_p (dst))))
+        {
+          info->need_save_z = 1;
+          info->z_set_count++;
+        }
+      this_insn_uses_z |= this_insn_uses_z_in_dst;
 
       if (this_insn_uses_z && this_insn_uses_ix && this_insn_uses_iy)
 	{
@@ -3996,6 +4014,9 @@ m68hc11_check_z_replacement (insn, info)
 	  return 0;
 	}
 
+      if (this_insn_uses_ix && X_REG_P (dst) && GET_MODE (dst) == SImode)
+        info->can_use_d = 0;
+
       if (info->x_used == 0 && this_insn_uses_ix)
 	{
 	  if (info->y_used)
@@ -4058,7 +4079,7 @@ m68hc11_check_z_replacement (insn, info)
 	      return 0;
 	    }
 	  info->x_used = 1;
-	  if (z_dies_here && !reg_mentioned_p (src, ix_reg)
+	  if (z_dies_here && !reg_mentioned_p (ix_reg, src)
 	      && GET_CODE (dst) == REG && REGNO (dst) == HARD_X_REGNUM)
 	    {
 	      info->need_save_z = 0;
@@ -4069,6 +4090,13 @@ m68hc11_check_z_replacement (insn, info)
 	      info->must_restore_reg = 0;
 	      return 0;
 	    }
+          if (rtx_equal_p (src, z_reg) && rtx_equal_p (dst, ix_reg))
+            {
+              info->regno = HARD_X_REGNUM;
+              info->must_restore_reg = 0;
+              info->must_save_reg = 0;
+              return 0;
+            }
 	}
       if (info->y_used == 0 && this_insn_uses_iy)
 	{
@@ -4129,7 +4157,7 @@ m68hc11_check_z_replacement (insn, info)
 	      return 0;
 	    }
 	  info->y_used = 1;
-	  if (z_dies_here && !reg_mentioned_p (src, iy_reg)
+	  if (z_dies_here && !reg_mentioned_p (iy_reg, src)
 	      && GET_CODE (dst) == REG && REGNO (dst) == HARD_Y_REGNUM)
 	    {
 	      info->need_save_z = 0;
@@ -4140,6 +4168,13 @@ m68hc11_check_z_replacement (insn, info)
 	      info->must_restore_reg = 0;
 	      return 0;
 	    }
+          if (rtx_equal_p (src, z_reg) && rtx_equal_p (dst, iy_reg))
+            {
+              info->regno = HARD_Y_REGNUM;
+              info->must_restore_reg = 0;
+              info->must_save_reg = 0;
+              return 0;
+            }
 	}
       if (z_dies_here)
 	{
@@ -4193,6 +4228,9 @@ m68hc11_check_z_replacement (insn, info)
 	      if (Z_REG_P (dst))
 		info->z_set_count++;
 	    }
+          if (TARGET_M6812 && uses_z && side_effects_p (x))
+            info->need_save_z = 1;
+
 	  if (z_clobber)
 	    info->need_save_z = 0;
 	}