unroll.c (simplify_cmp_and_jump_insns): New.

	* unroll.c (simplify_cmp_and_jump_insns): New.
	(unroll_loop): Use it.  Use simplify_gen_foo+force_operand
	instead of expand_simple_foo.

From-SVN: r57596

2 files changed, 86 insertions, 44 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index ebf0d32..c354cf9 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,5 +1,11 @@
 2002-09-27  Richard Henderson  <rth@redhat.com>
 
+	* unroll.c (simplify_cmp_and_jump_insns): New.
+	(unroll_loop): Use it.  Use simplify_gen_foo+force_operand
+	instead of expand_simple_foo.
+
+2002-09-27  Richard Henderson  <rth@redhat.com>
+
 	PR optimization/7520
 	* cfganal.c (flow_active_insn_p): New.
 	(forwarder_block_p): Use it.
diff --git a/gcc/unroll.c b/gcc/unroll.c
index c1c0059..126b5868 100644
--- a/gcc/unroll.c
+++ b/gcc/unroll.c
@@ -193,6 +193,9 @@ static int *splittable_regs_updates;
 
 /* Forward declarations.  */
 
+static rtx simplify_cmp_and_jump_insns PARAMS ((enum rtx_code,
+						enum machine_mode,
+						rtx, rtx, rtx));
 static void init_reg_map PARAMS ((struct inline_remap *, int));
 static rtx calculate_giv_inc PARAMS ((rtx, rtx, unsigned int));
 static rtx initial_reg_note_copy PARAMS ((rtx, struct inline_remap *));
@@ -843,7 +846,7 @@ unroll_loop (loop, insn_count, strength_reduce_p)
 			       &initial_value, &final_value, &increment,
 			       &mode))
 	{
-	  rtx diff;
+	  rtx diff, insn;
 	  rtx *labels;
 	  int abs_inc, neg_inc;
 	  enum rtx_code cc = loop_info->comparison_code;
@@ -875,26 +878,20 @@ unroll_loop (loop, insn_count, strength_reduce_p)
 
 	  start_sequence ();
 
+	  /* We must copy the final and initial values here to avoid
+	     improperly shared rtl.  */
+	  final_value = copy_rtx (final_value);
+	  initial_value = copy_rtx (initial_value);
+
 	  /* Final value may have form of (PLUS val1 const1_rtx).  We need
 	     to convert it into general operand, so compute the real value.  */
 
-	  if (GET_CODE (final_value) == PLUS)
-	    {
-	      final_value = expand_simple_binop (mode, PLUS,
-						 copy_rtx (XEXP (final_value, 0)),
-						 copy_rtx (XEXP (final_value, 1)),
-						 NULL_RTX, 0, OPTAB_LIB_WIDEN);
-	    }
+	  final_value = force_operand (final_value, NULL_RTX);
 	  if (!nonmemory_operand (final_value, VOIDmode))
-	    final_value = force_reg (mode, copy_rtx (final_value));
+	    final_value = force_reg (mode, final_value);
 
 	  /* Calculate the difference between the final and initial values.
 	     Final value may be a (plus (reg x) (const_int 1)) rtx.
-	     Let the following cse pass simplify this if initial value is
-	     a constant.
-
-	     We must copy the final and initial values here to avoid
-	     improperly shared rtl.
 
 	     We have to deal with for (i = 0; --i < 6;) type loops.
 	     For such loops the real final value is the first time the
@@ -907,18 +904,18 @@ unroll_loop (loop, insn_count, strength_reduce_p)
 	     so we can pretend that the overflow value is 0/~0.  */
 
 	  if (cc == NE || less_p != neg_inc)
-	    diff = expand_simple_binop (mode, MINUS, final_value,
-					copy_rtx (initial_value), NULL_RTX, 0,
-					OPTAB_LIB_WIDEN);
+	    diff = simplify_gen_binary (MINUS, mode, final_value,
+					initial_value);
 	  else
-	    diff = expand_simple_unop (mode, neg_inc ? NOT : NEG,
-				       copy_rtx (initial_value), NULL_RTX, 0);
+	    diff = simplify_gen_unary (neg_inc ? NOT : NEG, mode,
+				       initial_value, mode);
+	  diff = force_operand (diff, NULL_RTX);
 
 	  /* Now calculate (diff % (unroll * abs (increment))) by using an
 	     and instruction.  */
-	  diff = expand_simple_binop (GET_MODE (diff), AND, diff,
-				      GEN_INT (unroll_number * abs_inc - 1),
-				      NULL_RTX, 0, OPTAB_LIB_WIDEN);
+	  diff = simplify_gen_binary (AND, mode, diff,
+				      GEN_INT (unroll_number*abs_inc - 1));
+	  diff = force_operand (diff, NULL_RTX);
 
 	  /* Now emit a sequence of branches to jump to the proper precond
 	     loop entry point.  */
@@ -936,18 +933,22 @@ unroll_loop (loop, insn_count, strength_reduce_p)
 	  if (cc != NE)
 	    {
 	      rtx incremented_initval;
-	      incremented_initval = expand_simple_binop (mode, PLUS,
-							 initial_value,
-							 increment,
-							 NULL_RTX, 0,
-							 OPTAB_LIB_WIDEN);
-	      emit_cmp_and_jump_insns (incremented_initval, final_value,
-				       less_p ? GE : LE, NULL_RTX,
-				       mode, unsigned_p, labels[1]);
-	      predict_insn_def (get_last_insn (), PRED_LOOP_CONDITION,
-				TAKEN);
-	      JUMP_LABEL (get_last_insn ()) = labels[1];
-	      LABEL_NUSES (labels[1])++;
+	      enum rtx_code cmp_code;
+
+	      incremented_initval
+		= simplify_gen_binary (PLUS, mode, initial_value, increment);
+	      incremented_initval
+		= force_operand (incremented_initval, NULL_RTX);
+
+	      cmp_code = (less_p
+			  ? (unsigned_p ? GEU : GE)
+			  : (unsigned_p ? LEU : LE));
+
+	      insn = simplify_cmp_and_jump_insns (cmp_code, mode,
+						  incremented_initval,
+						  final_value, labels[1]);
+	      if (insn)
+	        predict_insn_def (insn, PRED_LOOP_CONDITION, TAKEN);
 	    }
 
 	  /* Assuming the unroll_number is 4, and the increment is 2, then
@@ -986,12 +987,12 @@ unroll_loop (loop, insn_count, strength_reduce_p)
 		  cmp_code = LE;
 		}
 
-	      emit_cmp_and_jump_insns (diff, GEN_INT (abs_inc * cmp_const),
-				       cmp_code, NULL_RTX, mode, 0, labels[i]);
-	      JUMP_LABEL (get_last_insn ()) = labels[i];
-	      LABEL_NUSES (labels[i])++;
-	      predict_insn (get_last_insn (), PRED_LOOP_PRECONDITIONING,
-			    REG_BR_PROB_BASE / (unroll_number - i));
+	      insn = simplify_cmp_and_jump_insns (cmp_code, mode, diff,
+						  GEN_INT (abs_inc*cmp_const),
+						  labels[i]);
+	      if (insn)
+	        predict_insn (insn, PRED_LOOP_PRECONDITIONING,
+			      REG_BR_PROB_BASE / (unroll_number - i));
 	    }
 
 	  /* If the increment is greater than one, then we need another branch,
@@ -1019,10 +1020,8 @@ unroll_loop (loop, insn_count, strength_reduce_p)
 		  cmp_code = GE;
 		}
 
-	      emit_cmp_and_jump_insns (diff, GEN_INT (cmp_const), cmp_code,
-				       NULL_RTX, mode, 0, labels[0]);
-	      JUMP_LABEL (get_last_insn ()) = labels[0];
-	      LABEL_NUSES (labels[0])++;
+	      simplify_cmp_and_jump_insns (cmp_code, mode, diff,
+					   GEN_INT (cmp_const), labels[0]);
 	    }
 
 	  sequence = get_insns ();
@@ -1324,6 +1323,43 @@ unroll_loop (loop, insn_count, strength_reduce_p)
     free (map->reg_map);
   free (map);
 }
+
+/* A helper function for unroll_loop.  Emit a compare and branch to 
+   satisfy (CMP OP1 OP2), but pass this through the simplifier first.
+   If the branch turned out to be conditional, return it, otherwise
+   return NULL.  */
+
+static rtx
+simplify_cmp_and_jump_insns (code, mode, op0, op1, label)
+     enum rtx_code code;
+     enum machine_mode mode;
+     rtx op0, op1, label;
+{
+  rtx t, insn;
+
+  t = simplify_relational_operation (code, mode, op0, op1);
+  if (!t)
+    {
+      enum rtx_code scode = signed_condition (code);
+      emit_cmp_and_jump_insns (op0, op1, scode, NULL_RTX, mode,
+			       code != scode, label);
+      insn = get_last_insn ();
+
+      JUMP_LABEL (insn) = label;
+      LABEL_NUSES (label) += 1;
+
+      return insn;
+    }
+  else if (t == const_true_rtx)
+    {
+      insn = emit_jump_insn (gen_jump (label));
+      emit_barrier ();
+      JUMP_LABEL (insn) = label;
+      LABEL_NUSES (label) += 1;
+    }
+
+  return NULL_RTX;
+}
 
 /* Return true if the loop can be safely, and profitably, preconditioned
    so that the unrolled copies of the loop body don't need exit tests.