flags.h, [...]: Remove flag_alias_check; optimization is now always enabled.

        * flags.h, toplev.c, calls.c, alias.c: Remove flag_alias_check;
        optimization is now always enabled.
        * calls.c (expand_call): Recognize C++ operator new as malloc-like
        function.
        * alias.c (memrefs_conflict_p): Eliminate tests now done by
        base_alias_check.
        (*_dependence): Call canon_rtx before base_alias_check.
        (init_alias_once): New function to precompute set of registers which
        can hold Pmode function arguments.
        * rtl.h: Declare init_alias_once.
        * toplev.c (compile_file): Call init_alias_once.

From-SVN: r17226

gcc/calls.c

@@ -889,11 +889,13 @@ expand_call (exp, target, ignore)
       else if (tname[0] == 'l' && tname[1] == 'o'
 	       && ! strcmp (tname, "longjmp"))
 	is_longjmp = 1;
-      /* Only recognize malloc when alias analysis is enabled.  */
-      else if (flag_alias_check
-	       && ((tname[0] == 'm' && ! strcmp(tname + 1, "alloc"))
-		   || (tname[0] == 'c' && ! strcmp(tname + 1, "alloc"))
-		   || (tname[0] == 'r' && ! strcmp(tname + 1, "ealloc"))))
+      /* XXX should have "malloc" attribute on functions instead
+	 of recognizing them by name.  */
+      else if (! strcmp (tname, "malloc")
+	       || ! strcmp (tname, "calloc")
+	       || ! strcmp (tname, "realloc")
+	       || ! strcmp (tname, "__builtin_new")
+	       || ! strcmp (tname, "__builtin_vec_new"))
 	is_malloc = 1;
     }
 

gcc/flags.h

@@ -420,10 +420,6 @@ extern int flag_gnu_linker;
 /* Tag all structures with __attribute__(packed) */
 extern int flag_pack_struct;
 
-/* 1 if alias checking is enabled: symbols do not alias each other
-   and parameters do not alias the current stack frame.  */
-extern int flag_alias_check;
-
 /* This flag is only tested if alias checking is enabled.
    0 if pointer arguments may alias each other.  True in C.
    1 if pointer arguments may not alias each other but may alias

gcc/rtl.h

@@ -1371,6 +1371,7 @@ extern int true_dependence		PROTO ((rtx, enum machine_mode, rtx,
 extern int read_dependence		PROTO ((rtx, rtx));
 extern int anti_dependence		PROTO ((rtx, rtx));
 extern int output_dependence		PROTO ((rtx, rtx));
+extern void init_alias_once		PROTO ((void));
 extern void init_alias_analysis		PROTO ((void));
 extern void end_alias_analysis		PROTO ((void));
 

gcc/toplev.c

@@ -672,9 +672,6 @@ int flag_prefix_function_name = 0;
 
 int flag_regmove = 0;
 
-/* 1 if alias checking is on (by default, when -O).  */
-int flag_alias_check = 0;
-
 /* 0 if pointer arguments may alias each other.  True in C.
    1 if pointer arguments may not alias each other but may alias
    global variables.
@@ -752,7 +749,6 @@ struct { char *string; int *variable; int on_value;} f_options[] =
   {"pack-struct", &flag_pack_struct, 1},
   {"stack-check", &flag_stack_check, 1},
   {"bytecode", &output_bytecode, 1},
-  {"alias-check", &flag_alias_check, 1},
   {"argument-alias", &flag_argument_noalias, 0},
   {"argument-noalias", &flag_argument_noalias, 1},
   {"argument-noalias-global", &flag_argument_noalias, 2},
@@ -2277,6 +2273,7 @@ compile_file (name)
   init_expr_once ();
   init_loop ();
   init_reload ();
+  init_alias_once ();
 
   if (flag_caller_saves)
     init_caller_save ();
@@ -3897,7 +3894,6 @@ main (argc, argv, envp)
 #ifdef CAN_DEBUG_WITHOUT_FP
       flag_omit_frame_pointer = 1;
 #endif
-      flag_alias_check = 1;
     }
 
   if (optimize >= 2)