Combined compare & jump infrastructure

From-SVN: r28752

gcc/ChangeLog

+Wed Aug 18 18:20:40 1999  Bernd Schmidt  <bernds@cygnus.co.uk>
+
+	* expmed.c (emit_store_flag): If UNSIGNEDP, call unsigned_condition
+	on CODE.
+	(emit_store_flag_force): Use do_compare_rtx_and_jump.
+	(do_cmp_and_jump): Formatting fixes.
+	* expr.c (do_compare_and_jump): Renamed from compare; changed to call
+	do_compare_rtx_and_jump instead of compare_from_rtx.
+	(do_compare_rtx_and_jump): New function; mostly copied from
+	compare_from_rtx.
+	(do_jump_for_compare): Delete.
+	(expand_expr): Use do_compare_rtx_and_jump when handling MAX_EXPR and
+	MIN_EXPR.
+	(do_jump): Use do_compare_and_jump or do_compare_rtx_and_jump instead
+	of compare/do_jump_for_compare pairs.
+	(do_jump_by_parts_greater): Use do_jump_by_parts_greater_rtx.
+	(do_jump_by_parts_greater_rtx): Use do_compare_rtx_and_jump instead of
+	compare_from_rtx/do_jump_for_compare pairs.
+	(do_jump_by_parts_equality): Likewise.
+	(do_jump_by_parts_equality_rtx): Likewise.
+	* expr.h (do_compare_rtx_and_jump): Declare.
+	* optabs.c (prepare_cmp_insn): New function, contains most of the code
+	that used to be in emit_cmp_insn.
+	(cmp_available_p): New function.
+	(prepare_operand): New function.
+	(emit_cmp_and_jump_insn_1): New function, contains some code that used
+	to be in emit_cmp_insn.
+	(prepare_float_lib_cmp): Renamed from emit_float_lib_cmp; change some
+	parameters to be pointers; don't emit final compare but modify some of
+	the values pointed to by the args so the caller can perform the
+	correct comparison.
+	(expand_binop): Call emit_store_flag_force with signed forms of
+	comparison code.
+	(expand_abs): Use do_compare_rtx_and_jump instead of compare_from_rtx/
+	emit_jump_insn pair.
+	(emit_cmp_and_jump_insn): Use prepare_cmp_insn and
+	emit_cmp_and_jump_insn_1.  Call emit_queue.
+	(emit_cmp_insn): Just call emit_cmp_and_jump_insns with zero for LABEL
+	arg.
+	* flow.c (tidy_fallthru_edge): If HAVE_cc0, verify insn before a
+	jump sets cc0 before deleting it.
+	* integrate.c (expand_inline_function): Likewise.
+	* unroll.c (unroll_loop): Similar changes in several places.
+	(copy_loop_body): If HAVE_cc0, verify insn before a jump sets cc0
+	before deleting it.
+
 Wed Aug 18 06:37:44 1999  Bernd Schmidt  <bernds@cygnus.co.uk>
 
 	* Makefile.in (insn-recog.o): Update dependencies.

gcc/expmed.c

@@ -4093,6 +4093,9 @@ emit_store_flag (target, code, op0, op1, mode, unsignedp, normalizep)
   rtx last = get_last_insn ();
   rtx pattern, comparison;
 
+  if (unsignedp)
+    code = unsigned_condition (code);
+
   /* If one operand is constant, make it the second one.  Only do this
      if the other operand is not constant as well.  */
 
@@ -4492,15 +4495,10 @@ emit_store_flag_force (target, code, op0, op1, mode, unsignedp, normalizep)
     target = gen_reg_rtx (GET_MODE (target));
 
   emit_move_insn (target, const1_rtx);
-  tem = compare_from_rtx (op0, op1, code, unsignedp, mode, NULL_RTX, 0);
-  if (GET_CODE (tem) == CONST_INT)
-    return tem;
-
   label = gen_label_rtx ();
-  if (bcc_gen_fctn[(int) code] == 0)
-    abort ();
+  do_compare_rtx_and_jump (op0, op1, code, unsignedp, mode, NULL_RTX, 0,
+			   NULL_RTX, label);
 
-  emit_jump_insn ((*bcc_gen_fctn[(int) code]) (label));
   emit_move_insn (target, const0_rtx);
   emit_label (label);
 
@@ -4519,13 +4517,13 @@ emit_store_flag_force (target, code, op0, op1, mode, unsignedp, normalizep)
 static void
 do_cmp_and_jump (arg1, arg2, op, mode, label)
      rtx arg1, arg2, label;
-    enum rtx_code op;
-    enum machine_mode mode;
+     enum rtx_code op;
+     enum machine_mode mode;
 {
   /* If this mode is an integer too wide to compare properly,
      compare word by word.  Rely on cse to optimize constant cases.  */
 
-  if (GET_MODE_CLASS (mode) == MODE_INT && !can_compare_p (mode))
+  if (GET_MODE_CLASS (mode) == MODE_INT && ! can_compare_p (mode))
     {
       rtx label2 = gen_label_rtx ();
 

gcc/expr.h

@@ -801,6 +801,9 @@ extern void do_jump PROTO((tree, rtx, rtx));
 /* Generate rtl to compare two rtx's, will call emit_cmp_insn.  */
 extern rtx compare_from_rtx PROTO((rtx, rtx, enum rtx_code, int,
 				   enum machine_mode, rtx, int));
+extern void do_compare_rtx_and_jump PROTO((rtx, rtx, enum rtx_code, int,
+					   enum machine_mode, rtx, int,
+					   rtx, rtx));
 
 /* Generate a tablejump instruction (used for switch statements).  */
 extern void do_tablejump PROTO((rtx, enum machine_mode, rtx, rtx, rtx));

gcc/flow.c

@@ -1998,7 +1998,7 @@ tidy_fallthru_edge (e, b, c)
 #ifdef HAVE_cc0
       /* If this was a conditional jump, we need to also delete
 	 the insn that set cc0.  */
-      if (! simplejump_p (q) && condjump_p (q))
+      if (! simplejump_p (q) && condjump_p (q) && sets_cc0_p (PREV_INSN (q)))
 	q = PREV_INSN (q);
 #endif
 

gcc/integrate.c

@@ -1958,8 +1958,9 @@ expand_inline_function (fndecl, parms, target, ignore, type,
 	  if (condjump_p (insn) && ! simplejump_p (insn) && map->last_pc_value)
 	    {
 #ifdef HAVE_cc0
-	      /* The previous insn set cc0 for us.  So delete it.  */
-	      delete_insn (PREV_INSN (copy));
+	      /* If the previous insn set cc0 for us, delete it.  */
+	      if (sets_cc0_p (PREV_INSN (copy)))
+		delete_insn (PREV_INSN (copy));
 #endif
 
 	      /* If this is now a no-op, delete it.  */

gcc/unroll.c

@@ -339,15 +339,13 @@ unroll_loop (loop_end, insn_count, loop_start, end_insert_before,
 	}
       else if (GET_CODE (last_loop_insn) == JUMP_INSN)
 	{
+	  rtx prev = PREV_INSN (last_loop_insn);
+	  delete_insn (last_loop_insn);
 #ifdef HAVE_cc0
-	  /* The immediately preceding insn is a compare which must be
+	  /* The immediately preceding insn may be a compare which must be
 	     deleted.  */
-	  delete_insn (last_loop_insn);
-	  delete_insn (PREV_INSN (last_loop_insn));
-#else
-	  /* The immediately preceding insn may not be the compare, so don't
-	     delete it.  */
-	  delete_insn (last_loop_insn);
+	  if (sets_cc0_p (prev))
+	    delete_insn (prev);
 #endif
 	}
       return;
@@ -479,14 +477,12 @@ unroll_loop (loop_end, insn_count, loop_start, end_insert_before,
 	copy_end = PREV_INSN (PREV_INSN (last_loop_insn));
       else if (GET_CODE (last_loop_insn) == JUMP_INSN)
 	{
+	  copy_end = PREV_INSN (last_loop_insn);
 #ifdef HAVE_cc0
-	  /* The instruction immediately before the JUMP_INSN is a compare
+	  /* The instruction immediately before the JUMP_INSN may be a compare
 	     instruction which we do not want to copy.  */
-	  copy_end = PREV_INSN (PREV_INSN (last_loop_insn));
-#else
-	  /* The instruction immediately before the JUMP_INSN may not be the
-	     compare, so we must copy it.  */
-	  copy_end = PREV_INSN (last_loop_insn);
+	  if (sets_cc0_p (PREV_INSN (copy_end)))
+	    copy_end = PREV_INSN (copy_end);
 #endif
 	}
       else
@@ -520,17 +516,14 @@ unroll_loop (loop_end, insn_count, loop_start, end_insert_before,
 	}
       else if (GET_CODE (last_loop_insn) == JUMP_INSN)
 	{
+	  insert_before = last_loop_insn;
 #ifdef HAVE_cc0
-	  /* The instruction immediately before the JUMP_INSN is a compare
+	  /* The instruction immediately before the JUMP_INSN may be a compare
 	     instruction which we do not want to copy or delete.  */
-	  insert_before = PREV_INSN (last_loop_insn);
-	  copy_end = PREV_INSN (insert_before);
-#else
-	  /* The instruction immediately before the JUMP_INSN may not be the
-	     compare, so we must copy it.  */
-	  insert_before = last_loop_insn;
-	  copy_end = PREV_INSN (last_loop_insn);
+	  if (sets_cc0_p (PREV_INSN (insert_before)))
+	    insert_before = PREV_INSN (insert_before);
 #endif
+	  copy_end = PREV_INSN (insert_before);
 	}
       else
 	{
@@ -793,9 +786,9 @@ unroll_loop (loop_end, insn_count, loop_start, end_insert_before,
 	copy_end_luid--;
 
       /* If we have a target that uses cc0, then we also must not duplicate
-	 the insn that sets cc0 before the jump insn.  */
+	 the insn that sets cc0 before the jump insn, if one is present.  */
 #ifdef HAVE_cc0
-      if (GET_CODE (copy_end) == JUMP_INSN)
+      if (GET_CODE (copy_end) == JUMP_INSN && sets_cc0_p (PREV_INSN (copy_end)))
 	copy_end_luid--;
 #endif
 
@@ -1036,14 +1029,12 @@ unroll_loop (loop_end, insn_count, loop_start, end_insert_before,
 	    copy_end = PREV_INSN (PREV_INSN (last_loop_insn));
 	  else if (GET_CODE (last_loop_insn) == JUMP_INSN)
 	    {
+	      copy_end = PREV_INSN (last_loop_insn);
 #ifdef HAVE_cc0
-	      /* The immediately preceding insn is a compare which we do not
+	      /* The immediately preceding insn may be a compare which we do not
 		 want to copy.  */
-	      copy_end = PREV_INSN (PREV_INSN (last_loop_insn));
-#else
-	      /* The immediately preceding insn may not be a compare, so we
-		 must copy it.  */
-	      copy_end = PREV_INSN (last_loop_insn);
+	      if (sets_cc0_p (PREV_INSN (copy_end)))
+		copy_end = PREV_INSN (copy_end);
 #endif
 	    }
 	  else
@@ -1098,17 +1089,14 @@ unroll_loop (loop_end, insn_count, loop_start, end_insert_before,
 	    }
 	  else
 	    {
-#ifdef HAVE_cc0
-	      /* The immediately preceding insn is a compare which we do not
-		 want to copy.  */
-	      insert_before = PREV_INSN (last_loop_insn);
-	      copy_end = PREV_INSN (insert_before);
-#else
-	      /* The immediately preceding insn may not be a compare, so we
-		 must copy it.  */
 	      insert_before = last_loop_insn;
-	      copy_end = PREV_INSN (last_loop_insn);
+#ifdef HAVE_cc0
+	      /* The instruction immediately before the JUMP_INSN may be a compare
+		 instruction which we do not want to copy or delete.  */
+	      if (sets_cc0_p (PREV_INSN (insert_before)))
+		insert_before = PREV_INSN (insert_before);
 #endif
+	      copy_end = PREV_INSN (insert_before);
 	    }
 
 	  /* Set unroll type to MODULO now.  */
@@ -2089,8 +2077,9 @@ copy_loop_body (copy_start, copy_end, map, exit_label, last_iteration,
 	  if (condjump_p (insn) && !simplejump_p (insn) && map->last_pc_value)
 	    {
 #ifdef HAVE_cc0
-	      /* The previous insn set cc0 for us.  So delete it.  */
-	      delete_insn (PREV_INSN (copy));
+	      /* If the previous insn set cc0 for us, delete it.  */
+	      if (sets_cc0_p (PREV_INSN (copy)))
+		delete_insn (PREV_INSN (copy));
 #endif
 
 	      /* If this is now a no-op, delete it.  */