stupid.c: Die die die.

	* stupid.c: Die die die.
	* Makefile.in (OBJS): Remove stupid.o.
	(stupid.o): Likewise.

	* except.c (emit_eh_context): Don't emit USEs for stupid.
	* explow.c (probe_stack_range): Likewise.
	* flags.h (obey_regdecls): Remove.
	* flow.c (find_basic_blocks): Don't run try_merge_blocks
	when not optimizing.
	(life_analysis): Limit data collection when not optimizing.
	(mark_regs_live_at_end): Always mark the return value registers.
	(mark_used_regs): Remove dummy RETURN case.
	(print_rtl_with_bb): Don't consult obey_regdecls.
	* function.c (use_variable, use_variable_after): Remove.
	(assign_parms): Consult optimize not obey_regdecls.
	(expand_function_start): Don't emit USEs for stupid.
	(expand_function_end): Likewise.
	* global.c (build_insn_chain): Export.
	* integrate.c (expand_inline_function): Kill return-value USE
	handling code.
	* jump.c (jump_optimize_1): Do simple jump optimizations and
	dead code elimination.
	(calculate_can_reach_end): Remove check_deleted argument.
	(delete_insn): Patch out insns even when not optimizing.
	* local-alloc.c (block_alloc): Don't do tying when not optimizing.
	* rtl.h (use_variable, use_variable_after): Remove declarations.
	(build_insn_chain): Declare.
	* stmt.c (expand_value_return): Don't emit USEs for stupid.
	(expand_end_bindings): Likewise.
	(expand_decl): Likewise.  Consult optimize not obey_regdecls.
	* toplev.c (obey_regdecls): Remove.
	(rest_of_compilation): Don't set it.  Kill stupid in favour of
	flow1, local-alloc, and reload.
	(main): Don't set obey_regdecls.

	* config/nextstep.c (handle_pragma): Likewise.

	* alpha/alpha.md (allocate_stack): Don't emit USEs for stupid.

	* arm/arm.h (CONDITIONAL_REGISTER_USAGE): Don't fix reg 0 for stupid.

From-SVN: r31499

gcc/ChangeLog

+2000-01-19  Richard Henderson  <rth@cygnus.com>
+
+	* stupid.c: Die die die.
+	* Makefile.in (OBJS): Remove stupid.o.
+	(stupid.o): Likewise.
+
+	* except.c (emit_eh_context): Don't emit USEs for stupid.
+	* explow.c (probe_stack_range): Likewise.
+	* flags.h (obey_regdecls): Remove.
+	* flow.c (find_basic_blocks): Don't run try_merge_blocks
+	when not optimizing.
+	(life_analysis): Limit data collection when not optimizing.
+	(mark_regs_live_at_end): Always mark the return value registers.
+	(mark_used_regs): Remove dummy RETURN case.
+	(print_rtl_with_bb): Don't consult obey_regdecls.
+	* function.c (use_variable, use_variable_after): Remove.
+	(assign_parms): Consult optimize not obey_regdecls.
+	(expand_function_start): Don't emit USEs for stupid.
+	(expand_function_end): Likewise.
+	* global.c (build_insn_chain): Export.
+	* integrate.c (expand_inline_function): Kill return-value USE
+	handling code.
+	* jump.c (jump_optimize_1): Do simple jump optimizations and
+	dead code elimination.
+	(calculate_can_reach_end): Remove check_deleted argument.
+	(delete_insn): Patch out insns even when not optimizing.
+	* local-alloc.c (block_alloc): Don't do tying when not optimizing.
+	* rtl.h (use_variable, use_variable_after): Remove declarations.
+	(build_insn_chain): Declare.
+	* stmt.c (expand_value_return): Don't emit USEs for stupid.
+	(expand_end_bindings): Likewise.
+	(expand_decl): Likewise.  Consult optimize not obey_regdecls.
+	* toplev.c (obey_regdecls): Remove.
+	(rest_of_compilation): Don't set it.  Kill stupid in favour of
+	flow1, local-alloc, and reload.
+	(main): Don't set obey_regdecls.
+
+	* config/nextstep.c (handle_pragma): Likewise.
+
+	* alpha/alpha.md (allocate_stack): Don't emit USEs for stupid.
+
+	* arm/arm.h (CONDITIONAL_REGISTER_USAGE): Don't fix reg 0 for stupid.
+
 2000-01-18  Kaveh R. Ghazi  <ghazi@caip.rutgers.edu>
 
 	* alpha-protos.h: PROTO -> PARAMS.

gcc/Makefile.in

@@ -667,7 +667,7 @@ OBJS = diagnostic.o \
  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 stupid.o combine.o varray.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 \
@@ -1546,8 +1546,6 @@ integrate.o : integrate.c $(CONFIG_H) system.h $(RTL_H) $(TREE_H) flags.h \
 jump.o : jump.c $(CONFIG_H) system.h $(RTL_H) flags.h hard-reg-set.h $(REGS_H) \
    insn-config.h insn-flags.h $(RECOG_H) $(EXPR_H) real.h except.h function.h \
    toplev.h insn-attr.h
-stupid.o : stupid.c $(CONFIG_H) system.h $(RTL_H) $(REGS_H) hard-reg-set.h \
-   $(BASIC_BLOCK_H) insn-config.h reload.h flags.h function.h toplev.h
 
 simplify-rtx.o : simplify-rtx.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 \

gcc/config/alpha/alpha.md

@@ -5116,8 +5116,6 @@
       emit_insn (gen_adddi3 (tmp, tmp, GEN_INT(-8192)));
       emit_insn (gen_cmpdi (tmp, want));
       emit_jump_insn (gen_bgtu (loop_label));
-      if (obey_regdecls)
-	gen_rtx_USE (VOIDmode, tmp);
 
       memref = gen_rtx_MEM (DImode, want);
       MEM_VOLATILE_P (memref) = 1;

gcc/config/arm/arm.h

@@ -736,14 +736,8 @@ extern const char * structure_size_string;
 #define SUBTARGET_CONDITIONAL_REGISTER_USAGE
 #endif
 
-/* If doing stupid life analysis, avoid a bug causing a return value r0 to be
-   trampled.  This effectively reduces the number of available registers by 1.
-   XXX It is a hack, I know.
-   XXX Is this still needed?  */
 #define CONDITIONAL_REGISTER_USAGE  \
 {							\
-  if (obey_regdecls)					\
-    fixed_regs[0] = 1;					\
   if (TARGET_SOFT_FLOAT)				\
     {							\
       int regno;					\

gcc/config/nextstep.c

@@ -61,13 +61,13 @@ handle_pragma (p_getc, p_ungetc, pname)
 
   if (strcmp (pname, "CC_OPT_ON") == 0)
     {
-      optimize = 1, obey_regdecls = 0;
+      optimize = 1;
       warning ("optimization turned on");
       retval = 1;
     }
   else if (strcmp (pname, "CC_OPT_OFF") == 0)
     {
-      optimize = 0, obey_regdecls = 1;
+      optimize = 0;
       warning ("optimization turned off");
       retval = 1;
     }
@@ -76,13 +76,7 @@ handle_pragma (p_getc, p_ungetc, pname)
       extern int initial_optimize_flag;
 
       if (optimize != initial_optimize_flag)
-	{
-	  if (initial_optimize_flag)
-	    obey_regdecls = 0;
-	  else
-	    obey_regdecls = 1;
-	  optimize = initial_optimize_flag;
-	}
+	optimize = initial_optimize_flag;
       warning ("optimization level restored");
       retval = 1;
     }

gcc/except.c

@@ -2364,14 +2364,6 @@ emit_eh_context ()
 	    end_sequence ();
 
 	    emit_insns_before (insns, insn);
-
-            /* At -O0, we must make the context register stay alive so
-               that the stupid.c register allocator doesn't get confused. */
-            if (obey_regdecls != 0)
-              {
-                insns = gen_rtx_USE (GET_MODE (XEXP (reg,0)), XEXP (reg,0));
-                emit_insn_before (insns, get_last_insn ());
-              }
 	  }
       }
 }

gcc/explow.c

@@ -1556,10 +1556,6 @@ probe_stack_range (first, size)
       emit_note (NULL_PTR, NOTE_INSN_LOOP_END);
       emit_label (end_lab);
 
-      /* If will be doing stupid optimization, show test_addr is still live. */
-      if (obey_regdecls)
-	emit_insn (gen_rtx_USE (VOIDmode, test_addr));
-
       emit_stack_probe (last_addr);
     }
 }

gcc/flags.h

@@ -57,11 +57,6 @@ extern int optimize;
 
 extern int optimize_size;
 
-/* Nonzero means do stupid register allocation.  -noreg.
-   Currently, this is 1 if `optimize' is 0.  */
-
-extern int obey_regdecls;
-
 /* Don't print functions as they are compiled and don't print
    times taken by the various passes.  -quiet.  */
 

gcc/flow.c

@@ -436,7 +436,8 @@ find_basic_blocks (f, nregs, file, do_cleanup)
       delete_unreachable_blocks ();
       move_stray_eh_region_notes ();
       record_active_eh_regions (f);
-      try_merge_blocks ();
+      if (optimize)
+	try_merge_blocks ();
     }
 
   /* Mark critical edges.  */
@@ -2447,9 +2448,14 @@ life_analysis (f, nregs, file, remove_dead_code)
   /* We want alias analysis information for local dead store elimination.  */
   init_alias_analysis ();
 
-  flags = PROP_FINAL;
-  if (! remove_dead_code)
-    flags &= ~(PROP_SCAN_DEAD_CODE | PROP_KILL_DEAD_CODE);
+  if (! optimize)
+    flags = PROP_DEATH_NOTES | PROP_REG_INFO;
+  else
+    {
+      flags = PROP_FINAL;
+      if (! remove_dead_code)
+	flags &= ~(PROP_SCAN_DEAD_CODE | PROP_KILL_DEAD_CODE);
+    }
   life_analysis_1 (f, nregs, flags);
 
   if (! reload_completed)
@@ -2835,15 +2841,9 @@ mark_regs_live_at_end (set)
     }
 
   /* Mark function return value.  */
-  /* ??? Only do this after reload.  Consider a non-void function that
-     omits a return statement.  Across that edge we'll have the return
-     register live, and no set for it.  Thus the return register will
-     be live back through the CFG to the entry, and thus we die.  A
-     possible solution is to emit a clobber at exits without returns.  */
 
   type = TREE_TYPE (DECL_RESULT (current_function_decl));
-  if (reload_completed
-      && type != void_type_node)
+  if (type != void_type_node)
     {
       rtx outgoing;
 
@@ -4643,12 +4643,6 @@ mark_used_regs (needed, live, x, flags, insn)
       }
       break;
 
-    case RETURN:
-      /* ??? This info should have been gotten from mark_regs_live_at_end,
-	 as applied to the EXIT block, and propagated along the edge that
-	 connects this block to the EXIT.  */
-      break;
-
     case ASM_OPERANDS:
     case UNSPEC_VOLATILE:
     case TRAP_IF:
@@ -5112,8 +5106,7 @@ print_rtl_with_bb (outf, rtx_first)
 
 	  if (in_bb_p[INSN_UID(tmp_rtx)] == NOT_IN_BB
 	      && GET_CODE (tmp_rtx) != NOTE
-	      && GET_CODE (tmp_rtx) != BARRIER
-	      && ! obey_regdecls)
+	      && GET_CODE (tmp_rtx) != BARRIER)
 	    fprintf (outf, ";; Insn is not within a basic block\n");
 	  else if (in_bb_p[INSN_UID(tmp_rtx)] == IN_MULTIPLE_BB)
 	    fprintf (outf, ";; Insn is in multiple basic blocks\n");

gcc/function.c

@@ -3916,45 +3916,6 @@ delete_handlers ()
     }
 }
 
-/* Output a USE for any register use in RTL.
-   This is used with -noreg to mark the extent of lifespan
-   of any registers used in a user-visible variable's DECL_RTL.  */
-
-void
-use_variable (rtl)
-     rtx rtl;
-{
-  if (GET_CODE (rtl) == REG)
-    /* This is a register variable.  */
-    emit_insn (gen_rtx_USE (VOIDmode, rtl));
-  else if (GET_CODE (rtl) == MEM
-	   && GET_CODE (XEXP (rtl, 0)) == REG
-	   && (REGNO (XEXP (rtl, 0)) < FIRST_VIRTUAL_REGISTER
-	       || REGNO (XEXP (rtl, 0)) > LAST_VIRTUAL_REGISTER)
-	   && XEXP (rtl, 0) != current_function_internal_arg_pointer)
-    /* This is a variable-sized structure.  */
-    emit_insn (gen_rtx_USE (VOIDmode, XEXP (rtl, 0)));
-}
-
-/* Like use_variable except that it outputs the USEs after INSN
-   instead of at the end of the insn-chain.  */
-
-void
-use_variable_after (rtl, insn)
-     rtx rtl, insn;
-{
-  if (GET_CODE (rtl) == REG)
-    /* This is a register variable.  */
-    emit_insn_after (gen_rtx_USE (VOIDmode, rtl), insn);
-  else if (GET_CODE (rtl) == MEM
-	   && GET_CODE (XEXP (rtl, 0)) == REG
-	   && (REGNO (XEXP (rtl, 0)) < FIRST_VIRTUAL_REGISTER
-	       || REGNO (XEXP (rtl, 0)) > LAST_VIRTUAL_REGISTER)
-	   && XEXP (rtl, 0) != current_function_internal_arg_pointer)
-    /* This is a variable-sized structure.  */
-    emit_insn_after (gen_rtx_USE (VOIDmode, XEXP (rtl, 0)), insn);
-}
-
 int
 max_parm_reg_num ()
 {
@@ -4495,7 +4456,8 @@ assign_parms (fndecl)
 	    }
 	  DECL_RTL (parm) = stack_parm;
 	}
-      else if (! ((obey_regdecls && ! DECL_REGISTER (parm)
+      else if (! ((! optimize
+		   && ! DECL_REGISTER (parm)
 		   && ! DECL_INLINE (fndecl))
 		  /* layout_decl may set this.  */
 		  || TREE_ADDRESSABLE (parm)
@@ -4579,7 +4541,8 @@ assign_parms (fndecl)
 	  /* If we were passed a pointer but the actual value
 	     can safely live in a register, put it in one.  */
 	  if (passed_pointer && TYPE_MODE (TREE_TYPE (parm)) != BLKmode
-	      && ! ((obey_regdecls && ! DECL_REGISTER (parm)
+	      && ! ((! optimize
+		     && ! DECL_REGISTER (parm)
 		     && ! DECL_INLINE (fndecl))
 		    /* layout_decl may set this.  */
 		    || TREE_ADDRESSABLE (parm)
@@ -6064,32 +6027,19 @@ expand_function_start (subr, parms_have_cleanups)
      as opposed to parm setup.  */
   emit_note (NULL_PTR, NOTE_INSN_FUNCTION_BEG);
 
-  /* If doing stupid allocation, mark parms as born here.  */
-
   if (GET_CODE (get_last_insn ()) != NOTE)
     emit_note (NULL_PTR, NOTE_INSN_DELETED);
   parm_birth_insn = get_last_insn ();
 
-  if (obey_regdecls)
-    {
-      for (i = LAST_VIRTUAL_REGISTER + 1; i < max_parm_reg; i++)
-	use_variable (regno_reg_rtx[i]);
-
-      if (current_function_internal_arg_pointer != virtual_incoming_args_rtx)
-	use_variable (current_function_internal_arg_pointer);
-    }
-
   context_display = 0;
   if (current_function_needs_context)
     {
       /* Fetch static chain values for containing functions.  */
       tem = decl_function_context (current_function_decl);
-      /* If not doing stupid register allocation copy the static chain
-	 pointer into a pseudo.  If we have small register classes, copy
-	 the value from memory if static_chain_incoming_rtx is a REG.  If
-	 we do stupid register allocation, we use the stack address
-	 generated above.  */
-      if (tem && ! obey_regdecls)
+      /* Copy the static chain pointer into a pseudo.  If we have
+	 small register classes, copy the value from memory if
+	 static_chain_incoming_rtx is a REG.  */
+      if (tem)
 	{
 	  /* If the static chain originally came in a register, put it back
 	     there, then move it out in the next insn.  The reason for
@@ -6349,27 +6299,6 @@ expand_function_end (filename, line, end_bindings)
      until next function's body starts.  */
   immediate_size_expand--;
 
-  /* If doing stupid register allocation,
-     mark register parms as dying here.  */
-
-  if (obey_regdecls)
-    {
-      rtx tem;
-      for (i = LAST_VIRTUAL_REGISTER + 1; i < max_parm_reg; i++)
-	use_variable (regno_reg_rtx[i]);
-
-      /* Likewise for the regs of all the SAVE_EXPRs in the function.  */
-
-      for (tem = save_expr_regs; tem; tem = XEXP (tem, 1))
-	{
-	  use_variable (XEXP (tem, 0));
-	  use_variable_after (XEXP (tem, 0), parm_birth_insn);
-	}
-
-      if (current_function_internal_arg_pointer != virtual_incoming_args_rtx)
-	use_variable (current_function_internal_arg_pointer);
-    }
-
   clear_pending_stack_adjust ();
   do_pending_stack_adjust ();
 
@@ -6488,7 +6417,6 @@ expand_function_end (filename, line, end_bindings)
 		  GET_MODE (DECL_RTL (DECL_RESULT (current_function_decl))));
       emit_move_insn (real_decl_result,
 		      DECL_RTL (DECL_RESULT (current_function_decl)));
-      emit_insn (gen_rtx_USE (VOIDmode, real_decl_result));
 
       /* The delay slot scheduler assumes that current_function_return_rtx
 	 holds the hard register containing the return value, not a temporary
@@ -6522,7 +6450,6 @@ expand_function_end (filename, line, end_bindings)
       REG_FUNCTION_VALUE_P (outgoing) = 1;
 
       emit_move_insn (outgoing, value_address);
-      use_variable (outgoing);
     }
 
   /* If this is an implementation of __throw, do what's necessary to 

gcc/global.c

@@ -305,7 +305,6 @@ static void dump_conflicts	PARAMS ((FILE *));
 static void reg_becomes_live	PARAMS ((rtx, rtx, void *));
 static void reg_dies		PARAMS ((int, enum machine_mode,
 				       struct insn_chain *));
-static void build_insn_chain	PARAMS ((rtx));
 
 /* Perform allocation of pseudo-registers not allocated by local_alloc.
    FILE is a file to output debugging information on,
@@ -1757,7 +1756,7 @@ reg_dies (regno, mode, chain)
 
 /* Walk the insns of the current function and build reload_insn_chain,
    and record register life information.  */
-static void
+void
 build_insn_chain (first)
      rtx first;
 {

gcc/integrate.c

@@ -1099,13 +1099,6 @@ expand_inline_function (fndecl, parms, target, ignore, type,
 	  pattern = PATTERN (insn);
 	  set = single_set (insn);
 	  copy = 0;
-	  if (GET_CODE (pattern) == USE
-	      && GET_CODE (XEXP (pattern, 0)) == REG
-	      && REG_FUNCTION_VALUE_P (XEXP (pattern, 0)))
-	    /* The (USE (REG n)) at return from the function should
-	       be ignored since we are changing (REG n) into
-	       inline_target.  */
-	    break;
 
 	  /* If the inline fn needs eh context, make sure that
 	     the current fn has one. */

gcc/jump.c

@@ -112,7 +112,7 @@ static void delete_barrier_successors	PARAMS ((rtx));
 static void mark_all_labels		PARAMS ((rtx, int));
 static rtx delete_unreferenced_labels	PARAMS ((rtx));
 static void delete_noop_moves		PARAMS ((rtx));
-static int calculate_can_reach_end	PARAMS ((rtx, int, int));
+static int calculate_can_reach_end	PARAMS ((rtx, int));
 static int duplicate_loop_exit_test	PARAMS ((rtx));
 static void find_cross_jump		PARAMS ((rtx, rtx, int, rtx *, rtx *));
 static void do_cross_jump		PARAMS ((rtx, rtx, rtx));
@@ -232,24 +232,8 @@ jump_optimize_1 (f, cross_jump, noop_moves, after_regscan, mark_labels_only)
 
   last_insn = delete_unreferenced_labels (f);
 
-  if (optimize == 0)
-    {
-      /* CAN_REACH_END is persistent for each function.  Once set it should
-	 not be cleared.  This is especially true for the case where we
-	 delete the NOTE_FUNCTION_END note.  CAN_REACH_END is cleared by
-	 the front-end before compiling each function.  */
-      if (calculate_can_reach_end (last_insn, 1, 0))
-	can_reach_end = 1;
-
-      /* Zero the "deleted" flag of all the "deleted" insns.  */
-      for (insn = f; insn; insn = NEXT_INSN (insn))
-	INSN_DELETED_P (insn) = 0;
-      
-      goto end;
-    }
-
 #ifdef HAVE_return
-  if (HAVE_return)
+  if (optimize && HAVE_return)
     {
       /* If we fall through to the epilogue, see if we can insert a RETURN insn
 	 in front of it.  If the machine allows it at this point (we might be
@@ -275,7 +259,7 @@ jump_optimize_1 (f, cross_jump, noop_moves, after_regscan, mark_labels_only)
      This helps some of the optimizations below by having less insns
      being jumped around.  */
 
-  if (! reload_completed && after_regscan)
+  if (optimize && ! reload_completed && after_regscan)
     for (insn = f; insn; insn = next)
       {
 	rtx set = single_set (insn);
@@ -389,6 +373,9 @@ jump_optimize_1 (f, cross_jump, noop_moves, after_regscan, mark_labels_only)
 		}
 	    }
 
+	  if (! optimize)
+	    continue;
+
 	  /* If a jump references the end of the function, try to turn
 	     it into a RETURN insn, possibly a conditional one.  */
 	  if (JUMP_LABEL (insn) != 0
@@ -986,7 +973,7 @@ jump_optimize_1 (f, cross_jump, noop_moves, after_regscan, mark_labels_only)
 	     CALL_INSN, which some machines, such as the ARC, can do, but
 	     this is a very minor optimization.  */
 	  if (this_is_condjump && ! this_is_simplejump
-	      && cse_not_expected && optimize > 0 && ! reload_completed
+	      && cse_not_expected && ! reload_completed
 	      && BRANCH_COST > 2
 	      && can_reverse_comparison_p (XEXP (SET_SRC (PATTERN (insn)), 0),
 					   insn))
@@ -2008,8 +1995,6 @@ jump_optimize_1 (f, cross_jump, noop_moves, after_regscan, mark_labels_only)
 #endif
 	  else
 	    {
-	      /* Detect a jump to a jump.  */
-
 	      /* Look for   if (foo) bar; else break;  */
 	      /* The insns look like this:
 		 insn = condjump label1;
@@ -2300,7 +2285,7 @@ jump_optimize_1 (f, cross_jump, noop_moves, after_regscan, mark_labels_only)
      not be cleared.  This is especially true for the case where we
      delete the NOTE_FUNCTION_END note.  CAN_REACH_END is cleared by
      the front-end before compiling each function.  */
-  if (calculate_can_reach_end (last_insn, 0, 1))
+  if (calculate_can_reach_end (last_insn, optimize != 0))
     can_reach_end = 1;
 
 end:
@@ -2711,9 +2696,8 @@ delete_noop_moves (f)
    if we find it.  */
 
 static int
-calculate_can_reach_end (last, check_deleted, delete_final_note)
+calculate_can_reach_end (last, delete_final_note)
      rtx last;
-     int check_deleted;
      int delete_final_note;
 {
   rtx insn = last;
@@ -2751,9 +2735,7 @@ calculate_can_reach_end (last, check_deleted, delete_final_note)
   /* See if we backed up to the appropriate type of note.  */
   if (insn != NULL_RTX
       && GET_CODE (insn) == NOTE
-      && NOTE_LINE_NUMBER (insn) == NOTE_INSN_FUNCTION_END
-      && (check_deleted == 0
-	  || ! INSN_DELETED_P (insn)))
+      && NOTE_LINE_NUMBER (insn) == NOTE_INSN_FUNCTION_END)
     {
       if (delete_final_note)
 	delete_insn (insn);
@@ -4320,8 +4302,7 @@ delete_insn (insn)
 
   /* Don't delete user-declared labels.  Convert them to special NOTEs
      instead.  */
-  if (was_code_label && LABEL_NAME (insn) != 0
-      && optimize && ! dont_really_delete)
+  if (was_code_label && LABEL_NAME (insn) != 0 && ! dont_really_delete)
     {
       PUT_CODE (insn, NOTE);
       NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED_LABEL;
@@ -4347,7 +4328,7 @@ delete_insn (insn)
 
   /* Patch out INSN (and the barrier if any) */
 
-  if (optimize && ! dont_really_delete)
+  if (! dont_really_delete)
     {
       if (prev)
 	{

gcc/local-alloc.c

@@ -1110,7 +1110,8 @@ block_alloc (b)
 
 	     If tying is done, WIN is set nonzero.  */
 
-	  if (recog_data.n_operands > 1
+	  if (optimize
+	      && recog_data.n_operands > 1
 	      && recog_data.constraints[0][0] == '='
 	      && recog_data.constraints[0][1] != '&')
 	    {
@@ -1194,7 +1195,8 @@ block_alloc (b)
 	     destination register won't have had a quantity number
 	     assigned, since that would prevent combining.  */
 
-	  if (GET_CODE (PATTERN (insn)) == CLOBBER
+	  if (optimize
+	      && GET_CODE (PATTERN (insn)) == CLOBBER
 	      && (r0 = XEXP (PATTERN (insn), 0),
 		  GET_CODE (r0) == REG)
 	      && (link = find_reg_note (insn, REG_LIBCALL, NULL_RTX)) != 0

gcc/rtl.h

@@ -1503,12 +1503,10 @@ extern void record_excess_regs		PARAMS ((rtx, rtx, rtx *));
 extern void reposition_prologue_and_epilogue_notes	PARAMS ((rtx));
 extern void thread_prologue_and_epilogue_insns		PARAMS ((rtx));
 extern int prologue_epilogue_contains			PARAMS ((rtx));
-extern void use_variable				PARAMS ((rtx));
 extern HOST_WIDE_INT get_frame_size			PARAMS ((void));
 extern void preserve_rtl_expr_result			PARAMS ((rtx));
 extern void mark_temp_addr_taken			PARAMS ((rtx));
 extern void update_temp_slot_address			PARAMS ((rtx, rtx));
-extern void use_variable_after				PARAMS ((rtx, rtx));
 extern void purge_addressof				PARAMS ((rtx));
 
 /* In reload.c */
@@ -1562,6 +1560,7 @@ extern void dump_global_regs		PARAMS ((FILE *));
 #ifdef HARD_CONST
 extern void retry_global_alloc		PARAMS ((int, HARD_REG_SET));
 #endif
+extern void build_insn_chain		PARAMS ((rtx));
 
 /* In regclass.c */
 extern int reg_classes_intersect_p	PARAMS ((enum reg_class, enum reg_class));

gcc/stmt.c

@@ -2722,8 +2722,6 @@ expand_value_return (val)
 	emit_move_insn (return_reg, val);
     }
 
-  diddle_return_value (USE);
-
   /* Does any pending block have cleanups?  */
 
   while (block && block->data.block.cleanups == 0)
@@ -3689,14 +3687,6 @@ expand_end_bindings (vars, mark_ends, dont_jump_in)
     /* Get rid of the beginning-mark if we don't make an end-mark.  */
     NOTE_LINE_NUMBER (thisblock->data.block.first_insn) = NOTE_INSN_DELETED;
 
-  /* If doing stupid register allocation, make sure lives of all
-     register variables declared here extend thru end of scope.  */
-
-  if (obey_regdecls)
-    for (decl = vars; decl; decl = TREE_CHAIN (decl))
-      if (TREE_CODE (decl) == VAR_DECL && DECL_RTL (decl))
-	use_variable (DECL_RTL (decl));
-
   /* Restore the temporary level of TARGET_EXPRs.  */
   target_temp_slot_level = thisblock->data.block.block_target_temp_slot_level;
 
@@ -3757,7 +3747,7 @@ expand_decl (decl)
 		&& TREE_CODE (type) == REAL_TYPE)
 	   && ! TREE_THIS_VOLATILE (decl)
 	   && ! TREE_ADDRESSABLE (decl)
-	   && (DECL_REGISTER (decl) || ! obey_regdecls)
+	   && (DECL_REGISTER (decl) || optimize)
 	   /* if -fcheck-memory-usage, check all variables.  */
 	   && ! current_function_check_memory_usage)
     {
@@ -3889,15 +3879,7 @@ expand_decl (decl)
   if (TREE_READONLY (decl))
     RTX_UNCHANGING_P (DECL_RTL (decl)) = 1;
 #endif
-
-  /* If doing stupid register allocation, make sure life of any
-     register variable starts here, at the start of its scope.  */
-
-  if (obey_regdecls)
-    use_variable (DECL_RTL (decl));
 }
-
-
 
 /* Emit code to perform the initialization of a declaration DECL.  */
 

gcc/toplev.c

@@ -362,11 +362,6 @@ int pedantic = 0;
 
 int in_system_header = 0;
 
-/* Nonzero means do stupid register allocation.
-   Currently, this is 1 if `optimize' is 0.  */
-
-int obey_regdecls = 0;
-
 /* Don't print functions as they are compiled and don't print
    times taken by the various passes.  -quiet.  */
 
@@ -3207,13 +3202,6 @@ rest_of_compilation (decl)
 	ggc_collect ();
     }
 
-  /* Now we choose between stupid (pcc-like) register allocation
-     (if we got the -noreg switch and not -opt)
-     and smart register allocation.  */
-
-  if (optimize > 0)		/* Stupid allocation probably won't work */
-    obey_regdecls = 0;		/* if optimizations being done.  */
-
   regclass_init ();
 
   /* Print function header into flow dump now
@@ -3222,34 +3210,23 @@ rest_of_compilation (decl)
   if (flow_dump)
     open_dump_file (".08.flow", decl_printable_name (decl, 2));
   
-  if (obey_regdecls)
-    {
-      TIMEVAR (flow_time,
-	       {
-		 regclass (insns, max_reg_num (), NULL);
-		 stupid_life_analysis (insns, max_reg_num (),
-				       rtl_dump_file);
-	       });
-    }
-  else
-    {
-      /* Do control and data flow analysis,
-	 and write some of the results to dump file.  */
+  /* Do control and data flow analysis; wrote some of the results to
+     the dump file.  */
 
-      TIMEVAR
-	(flow_time,
-	 {
-	   find_basic_blocks (insns, max_reg_num (), rtl_dump_file, 1);
-	   calculate_loop_depth (rtl_dump_file);
-	   life_analysis (insns, max_reg_num (), rtl_dump_file, 1);
-	 });
+  TIMEVAR
+    (flow_time,
+     {
+       find_basic_blocks (insns, max_reg_num (), rtl_dump_file, 1);
+       if (optimize)
+	 calculate_loop_depth (rtl_dump_file);
+       life_analysis (insns, max_reg_num (), rtl_dump_file, 1);
+     });
 
-      if (warn_uninitialized || extra_warnings)
-	{
-	  uninitialized_vars_warning (DECL_INITIAL (decl));
-          if (extra_warnings)
-	    setjmp_args_warning ();
-	}
+  if (warn_uninitialized || extra_warnings)
+    {
+      uninitialized_vars_warning (DECL_INITIAL (decl));
+      if (extra_warnings)
+	setjmp_args_warning ();
     }
 
   /* Dump rtl after flow analysis.  */
@@ -3344,24 +3321,20 @@ rest_of_compilation (decl)
   if (local_reg_dump)
     open_dump_file (".12.lreg", decl_printable_name (decl, 2));
 
-  /* Unless we did stupid register allocation,
-     allocate pseudo-regs that are used only within 1 basic block. 
+  /* Allocate pseudo-regs that are used only within 1 basic block. 
 
      RUN_JUMP_AFTER_RELOAD records whether or not we need to rerun the
      jump optimizer after register allocation and reloading are finished.  */
 
-  if (!obey_regdecls)
-    TIMEVAR (local_alloc_time,
-	     {
-	       /* We recomputed reg usage as part of updating the rest
-		  of life info during sched.  */
-	       if (! flag_schedule_insns)
-		 recompute_reg_usage (insns, ! optimize_size);
-	       regclass (insns, max_reg_num (), rtl_dump_file);
-	       rebuild_label_notes_after_reload = local_alloc ();
-	     });
-  else
-    rebuild_label_notes_after_reload = 0;
+  TIMEVAR (local_alloc_time,
+	   {
+	     /* We recomputed reg usage as part of updating the rest
+		of life info during sched.  */
+	     if (! flag_schedule_insns)
+	       recompute_reg_usage (insns, ! optimize_size);
+	     regclass (insns, max_reg_num (), rtl_dump_file);
+	     rebuild_label_notes_after_reload = local_alloc ();
+	   });
 
   /* Dump rtl code after allocating regs within basic blocks.  */
 
@@ -3381,19 +3354,20 @@ rest_of_compilation (decl)
   if (global_reg_dump)
     open_dump_file (".13.greg", decl_printable_name (decl, 2));
 
-  /* Unless we did stupid register allocation,
-     allocate remaining pseudo-regs, then do the reload pass
-     fixing up any insns that are invalid.  */
+  /* If optimizing, allocate remaining pseudo-regs.  Do the reload
+     pass fixing up any insns that are invalid.  */
 
   TIMEVAR (global_alloc_time,
 	   {
-	     if (!obey_regdecls)
+	     if (optimize)
 	       failure = global_alloc (rtl_dump_file);
 	     else
-	       failure = reload (insns, 0, rtl_dump_file);
+	       {
+		 build_insn_chain (insns);
+		 failure = reload (insns, 0, rtl_dump_file);
+	       }
 	   });
 
-
   if (failure)
     goto exit_rest_of_compilation;
 
@@ -3507,10 +3481,8 @@ rest_of_compilation (decl)
     = optimize > 0 && only_leaf_regs_used () && leaf_function_p ();
 #endif
 
-  /* One more attempt to remove jumps to .+1
-     left by dead-store-elimination.
-     Also do cross-jumping this time
-     and delete no-op move insns.  */
+  /* One more attempt to remove jumps to .+1 left by dead-store elimination. 
+     Also do cross-jumping this time and delete no-op move insns.  */
 
   if (optimize > 0)
     {
@@ -4573,8 +4545,6 @@ main (argc, argv)
 	}
     }
 
-  obey_regdecls = (optimize == 0);
-
   if (optimize >= 1)
     {
       flag_defer_pop = 1;