Value Range Propagation Patch -- Part 1 of 2

[John Wehle]

This patch implements a value range propagation pass.
This patch passes make bootstrap and make check on FreeBSD-3.4 x86,
IBM AIX 4.3, Solaris 2.5.1 SPARC, and Solaris 2.5.1 x86.

ChangeLog:

Sun Apr  2 01:42:03 EST 2000  John Wehle  (john@feith.com)

	* Makefile.in (vrp.o): New rule.
	(OBJS): Add vrp.o.
	* rtl.h (value_range_prop): New declaration.
	* toplev.c (enum dump_file_index): Add vrp entry.
	(struct dump_file): Likewise.
	(vrp_time): New global variable.
	(compile_file): Initialize and print vrp_time.
	(rest_of_compilation): Call value_range_prop when optimizing.

Enjoy!

-- John Wehle
------------------8<------------------------8<------------------------
*** gcc/Makefile.in.ORIGINAL	Sat Apr  1 18:25:30 2000
--- gcc/Makefile.in	Sat Apr  1 22:06:53 2000
*************** OBJS = diagnostic.o \
*** 673,679 ****
   function.o stmt.o except.o expr.o calls.o expmed.o explow.o optabs.o real.o \
   builtins.o intl.o varasm.o rtl.o print-rtl.o rtlanal.o emit-rtl.o genrtl.o \
   dbxout.o sdbout.o dwarfout.o dwarf2out.o xcoffout.o bitmap.o alias.o gcse.o \
!  integrate.o jump.o cse.o loop.o unroll.o flow.o combine.o varray.o \
   regclass.o regmove.o local-alloc.o global.o reload.o reload1.o caller-save.o \
   insn-peep.o reorg.o haifa-sched.o final.o recog.o reg-stack.o \
   insn-opinit.o insn-recog.o insn-extract.o insn-output.o insn-emit.o lcm.o \
--- 673,679 ----
   function.o stmt.o except.o expr.o calls.o expmed.o explow.o optabs.o real.o \
   builtins.o intl.o varasm.o rtl.o print-rtl.o rtlanal.o emit-rtl.o genrtl.o \
   dbxout.o sdbout.o dwarfout.o dwarf2out.o xcoffout.o bitmap.o alias.o gcse.o \
!  vrp.o integrate.o jump.o cse.o loop.o unroll.o flow.o combine.o varray.o \
   regclass.o regmove.o local-alloc.o global.o reload.o reload1.o caller-save.o \
   insn-peep.o reorg.o haifa-sched.o final.o recog.o reg-stack.o \
   insn-opinit.o insn-recog.o insn-extract.o insn-output.o insn-emit.o lcm.o \
*************** simplify-rtx.o : simplify-rtx.c $(CONFIG
*** 1571,1576 ****
--- 1571,1579 ----
     output.h function.h cselib.h ggc.h $(srcdir)/../include/obstack.h
  cse.o : cse.c $(CONFIG_H) system.h $(RTL_H) $(REGS_H) hard-reg-set.h flags.h \
     real.h insn-config.h $(RECOG_H) $(EXPR_H) toplev.h output.h function.h ggc.h
+ vrp.o : vrp.c $(CONFIG_H) system.h toplev.h $(RTL_H) $(TREE_H) $(REGS_H) \
+    flags.h real.h insn-config.h $(RECOG_H) $(BASIC_BLOCK_H) output.h \
+    function.h expr.h
  gcse.o : gcse.c $(CONFIG_H) system.h $(RTL_H) $(REGS_H) hard-reg-set.h \
     flags.h real.h insn-config.h $(RECOG_H) $(EXPR_H) $(BASIC_BLOCK_H) \
     function.h output.h toplev.h
*** gcc/rtl.h.ORIGINAL	Sat Apr  1 18:26:13 2000
--- gcc/rtl.h	Sat Apr  1 22:08:08 2000
*************** extern rtx expand_mult_highpart		PARAMS 
*** 1612,1617 ****
--- 1612,1622 ----
  						unsigned HOST_WIDE_INT, rtx,
  						int, int));
  
+ /* In vrp.c */
+ #ifdef BUFSIZ
+ extern int value_range_prop		PARAMS ((rtx, int, FILE *));
+ #endif
+ 
  /* In gcse.c */
  #ifdef BUFSIZ
  extern int gcse_main			PARAMS ((rtx, FILE *));
*** gcc/toplev.c.ORIGINAL	Sat Apr  1 18:26:30 2000
--- gcc/toplev.c	Sat Apr  1 22:16:23 2000
*************** enum dump_file_index
*** 256,261 ****
--- 256,262 ----
    DFI_addressof,
    DFI_ssa,
    DFI_ussa,
+   DFI_vrp,
    DFI_gcse,
    DFI_loop,
    DFI_cse2,
*************** struct dump_file_info dump_file[DFI_MAX]
*** 288,293 ****
--- 289,295 ----
    { "addressof", 'F', 0, 0, 0 },
    { "ssa",	'e', 1, 0, 0 },
    { "ussa",	'e', 1, 0, 0 },	/* Yes, duplicate enable switch.  */
+   { "vrp",	'V', 1, 0, 0 },
    { "gcse",	'G', 1, 0, 0 },
    { "loop",	'L', 1, 0, 0 },
    { "cse2",	't', 1, 0, 0 },
*************** int varconst_time;
*** 1400,1405 ****
--- 1402,1408 ----
  int integration_time;
  int jump_time;
  int cse_time;
+ int vrp_time;
  int gcse_time;
  int loop_time;
  int cse2_time;
*************** compile_file (name)
*** 2149,2154 ****
--- 2152,2158 ----
    integration_time = 0;
    jump_time = 0;
    cse_time = 0;
+   vrp_time = 0;
    gcse_time = 0;
    loop_time = 0;
    cse2_time = 0;
*************** compile_file (name)
*** 2549,2554 ****
--- 2553,2559 ----
        print_time ("integration", integration_time);
        print_time ("jump", jump_time);
        print_time ("cse", cse_time);
+       print_time ("vrp", vrp_time);
        print_time ("gcse", gcse_time);
        print_time ("loop", loop_time);
        print_time ("cse2", cse2_time);
*************** rest_of_compilation (decl)
*** 3033,3038 ****
--- 3038,3069 ----
        /* Life analysis used in SSA adds log_links but these shouldn't
  	 be there until the flow stage, so clear them away.  */
        clear_log_links (insns);
+ 
+       if (ggc_p)
+ 	ggc_collect ();
+     }
+ 
+   /* Perform value range propagation.  */
+ 
+   if (optimize > 0)
+     {
+       open_dump_file (DFI_vrp, decl);
+ 
+       TIMEVAR (vrp_time, tem = value_range_prop (insns, 1, rtl_dump_file));
+ 
+       /* If value range propagation altered any jumps, rerun jump
+ 	 optimizations to clean things up.  */
+       if (tem)
+ 	TIMEVAR (jump_time, jump_optimize (insns, !JUMP_CROSS_JUMP,
+ 					   !JUMP_NOOP_MOVES,
+ 					   !JUMP_AFTER_REGSCAN));
+ 
+       /* Value range propagation may make some instructions trivially dead.
+ 	 Run this after jump optmizations remove all the unreachable code
+ 	 so that unreachable code will not keep values live.  */
+       TIMEVAR (vrp_time, delete_trivially_dead_insns (insns, max_reg_num ()));
+ 
+       close_dump_file (DFI_vrp, print_rtl, insns);
  
        if (ggc_p)
  	ggc_collect ();
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|   Feith Systems  |   Voice: 1-215-646-8000  |  Email: john@feith.com  |
|    John Wehle    |     Fax: 1-215-540-5495  |                         |
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