Turn var-tracking.c:INT_MEM_OFFSET into a function

This avoids the double evaluation mentioned in the comments and
simplifies the change to make MEM_OFFSET variable.

2017-11-01  Richard Sandiford  <richard.sandiford@linaro.org>
	    Alan Hayward  <alan.hayward@arm.com>
	    David Sherwood  <david.sherwood@arm.com>

gcc/
	* var-tracking.c (INT_MEM_OFFSET): Replace with...
	(int_mem_offset): ...this new function.
	(var_mem_set, var_mem_delete_and_set, var_mem_delete)
	(find_mem_expr_in_1pdv, dataflow_set_preserve_mem_locs)
	(same_variable_part_p, use_type, add_stores, vt_get_decl_and_offset):
	Update accordingly.

Co-Authored-By: Alan Hayward <alan.hayward@arm.com>
Co-Authored-By: David Sherwood <david.sherwood@arm.com>

From-SVN: r254309

gcc/ChangeLog

@@ -2,6 +2,17 @@
 	    Alan Hayward  <alan.hayward@arm.com>
 	    David Sherwood  <david.sherwood@arm.com>
 
+	* var-tracking.c (INT_MEM_OFFSET): Replace with...
+	(int_mem_offset): ...this new function.
+	(var_mem_set, var_mem_delete_and_set, var_mem_delete)
+	(find_mem_expr_in_1pdv, dataflow_set_preserve_mem_locs)
+	(same_variable_part_p, use_type, add_stores, vt_get_decl_and_offset):
+	Update accordingly.
+
+2017-11-01  Richard Sandiford  <richard.sandiford@linaro.org>
+	    Alan Hayward  <alan.hayward@arm.com>
+	    David Sherwood  <david.sherwood@arm.com>
+
 	* lower-subreg.c (interesting_mode_p): New function.
 	(compute_costs, find_decomposable_subregs, decompose_register)
 	(simplify_subreg_concatn, can_decompose_p, resolve_simple_move)

gcc/var-tracking.c

@@ -390,8 +390,15 @@ struct variable
 /* Pointer to the BB's information specific to variable tracking pass.  */
 #define VTI(BB) ((variable_tracking_info *) (BB)->aux)
 
-/* Macro to access MEM_OFFSET as an HOST_WIDE_INT.  Evaluates MEM twice.  */
-#define INT_MEM_OFFSET(mem) (MEM_OFFSET_KNOWN_P (mem) ? MEM_OFFSET (mem) : 0)
+/* Return MEM_OFFSET (MEM) as a HOST_WIDE_INT, or 0 if we can't.  */
+
+static inline HOST_WIDE_INT
+int_mem_offset (const_rtx mem)
+{
+  if (MEM_OFFSET_KNOWN_P (mem))
+    return MEM_OFFSET (mem);
+  return 0;
+}
 
 #if CHECKING_P && (GCC_VERSION >= 2007)
 
@@ -2336,7 +2343,7 @@ var_mem_set (dataflow_set *set, rtx loc, enum var_init_status initialized,
 	     rtx set_src)
 {
   tree decl = MEM_EXPR (loc);
-  HOST_WIDE_INT offset = INT_MEM_OFFSET (loc);
+  HOST_WIDE_INT offset = int_mem_offset (loc);
 
   var_mem_decl_set (set, loc, initialized,
 		    dv_from_decl (decl), offset, set_src, INSERT);
@@ -2354,7 +2361,7 @@ var_mem_delete_and_set (dataflow_set *set, rtx loc, bool modify,
 			enum var_init_status initialized, rtx set_src)
 {
   tree decl = MEM_EXPR (loc);
-  HOST_WIDE_INT offset = INT_MEM_OFFSET (loc);
+  HOST_WIDE_INT offset = int_mem_offset (loc);
 
   clobber_overlapping_mems (set, loc);
   decl = var_debug_decl (decl);
@@ -2375,7 +2382,7 @@ static void
 var_mem_delete (dataflow_set *set, rtx loc, bool clobber)
 {
   tree decl = MEM_EXPR (loc);
-  HOST_WIDE_INT offset = INT_MEM_OFFSET (loc);
+  HOST_WIDE_INT offset = int_mem_offset (loc);
 
   clobber_overlapping_mems (set, loc);
   decl = var_debug_decl (decl);
@@ -4618,7 +4625,7 @@ find_mem_expr_in_1pdv (tree expr, rtx val, variable_table_type *vars)
   for (node = var->var_part[0].loc_chain; node; node = node->next)
     if (MEM_P (node->loc)
 	&& MEM_EXPR (node->loc) == expr
-	&& INT_MEM_OFFSET (node->loc) == 0)
+	&& int_mem_offset (node->loc) == 0)
       {
 	where = node;
 	break;
@@ -4683,7 +4690,7 @@ dataflow_set_preserve_mem_locs (variable **slot, dataflow_set *set)
 	      /* We want to remove dying MEMs that don't refer to DECL.  */
 	      if (GET_CODE (loc->loc) == MEM
 		  && (MEM_EXPR (loc->loc) != decl
-		      || INT_MEM_OFFSET (loc->loc) != 0)
+		      || int_mem_offset (loc->loc) != 0)
 		  && mem_dies_at_call (loc->loc))
 		break;
 	      /* We want to move here MEMs that do refer to DECL.  */
@@ -4727,7 +4734,7 @@ dataflow_set_preserve_mem_locs (variable **slot, dataflow_set *set)
 
 	  if (GET_CODE (loc->loc) != MEM
 	      || (MEM_EXPR (loc->loc) == decl
-		  && INT_MEM_OFFSET (loc->loc) == 0)
+		  && int_mem_offset (loc->loc) == 0)
 	      || !mem_dies_at_call (loc->loc))
 	    {
 	      if (old_loc != loc->loc && emit_notes)
@@ -5254,7 +5261,7 @@ same_variable_part_p (rtx loc, tree expr, HOST_WIDE_INT offset)
   else if (MEM_P (loc))
     {
       expr2 = MEM_EXPR (loc);
-      offset2 = INT_MEM_OFFSET (loc);
+      offset2 = int_mem_offset (loc);
     }
   else
     return false;
@@ -5522,7 +5529,7 @@ use_type (rtx loc, struct count_use_info *cui, machine_mode *modep)
 	return MO_CLOBBER;
       else if (target_for_debug_bind (var_debug_decl (expr)))
 	return MO_CLOBBER;
-      else if (track_loc_p (loc, expr, INT_MEM_OFFSET (loc),
+      else if (track_loc_p (loc, expr, int_mem_offset (loc),
 			    false, modep, NULL)
 	       /* Multi-part variables shouldn't refer to one-part
 		  variable names such as VALUEs (never happens) or
@@ -6017,7 +6024,7 @@ add_stores (rtx loc, const_rtx expr, void *cuip)
 	      rtx xexpr = gen_rtx_SET (loc, src);
 	      if (same_variable_part_p (SET_SRC (xexpr),
 					MEM_EXPR (loc),
-					INT_MEM_OFFSET (loc)))
+					int_mem_offset (loc)))
 		mo.type = MO_COPY;
 	      else
 		mo.type = MO_SET;
@@ -9579,7 +9586,7 @@ vt_get_decl_and_offset (rtx rtl, tree *declp, HOST_WIDE_INT *offsetp)
       if (MEM_ATTRS (rtl))
 	{
 	  *declp = MEM_EXPR (rtl);
-	  *offsetp = INT_MEM_OFFSET (rtl);
+	  *offsetp = int_mem_offset (rtl);
 	  return true;
 	}
     }