ccmp.c (ccmp_tree_comparison_p): New function.

2017-06-29  Steve Ellcey  <sellcey@cavium.com>

	* ccmp.c (ccmp_tree_comparison_p): New function.
	(ccmp_candidate_p): Update to use above function.
	(get_compare_parts): New function.
	(expand_ccmp_next): Update to use new functions.
	(expand_ccmp_expr_1): Take tree arg instead of gimple, update to use
	new functions.
	(expand_ccmp_expr): Pass tree instead of gimple to expand_ccmp_expr_1,
	take mode as argument.
	* ccmp.h (expand_ccmp_expr): Add mode as argument.
	* expr.c (expand_expr_real_1): Pass mode as argument.

From-SVN: r249805

gcc/ChangeLog

+2017-06-29  Steve Ellcey  <sellcey@cavium.com>
+
+	* ccmp.c (ccmp_tree_comparison_p): New function.
+	(ccmp_candidate_p): Update to use above function.
+	(get_compare_parts): New function.
+	(expand_ccmp_next): Update to use new functions.
+	(expand_ccmp_expr_1): Take tree arg instead of gimple, update to use
+	new functions.
+	(expand_ccmp_expr): Pass tree instead of gimple to expand_ccmp_expr_1,
+	take mode as argument.
+	* ccmp.h (expand_ccmp_expr): Add mode as argument.
+	* expr.c (expand_expr_real_1): Pass mode as argument.
+
 2017-06-29  Segher Boessenkool  <segher@kernel.crashing.org>
 
 	* combine.c (combine_instructions): Print insns to dump_file, together

gcc/ccmp.c

@@ -38,6 +38,29 @@ along with GCC; see the file COPYING3.  If not see
 #include "ccmp.h"
 #include "predict.h"
 
+/* Check whether T is a simple boolean variable or a SSA name
+   set by a comparison operator in the same basic block.  */
+static bool
+ccmp_tree_comparison_p (tree t, basic_block bb)
+{
+  gimple *g = get_gimple_for_ssa_name (t);
+  tree_code tcode;
+
+  /* If we have a boolean variable allow it and generate a compare
+     to zero reg when expanding.  */
+  if (!g)
+    return (TREE_CODE (TREE_TYPE (t)) == BOOLEAN_TYPE);
+
+  /* Check to see if SSA name is set by a comparison operator in
+     the same basic block.  */ 
+  if (!is_gimple_assign (g))
+    return false;
+  if (bb != gimple_bb (g))
+    return false;
+  tcode = gimple_assign_rhs_code (g);
+  return TREE_CODE_CLASS (tcode) == tcc_comparison;
+}
+
 /* The following functions expand conditional compare (CCMP) instructions.
    Here is a short description about the over all algorithm:
      * ccmp_candidate_p is used to identify the CCMP candidate
@@ -71,49 +94,69 @@ along with GCC; see the file COPYING3.  If not see
 static bool
 ccmp_candidate_p (gimple *g)
 {
-  tree rhs = gimple_assign_rhs_to_tree (g);
+  tree rhs;
   tree lhs, op0, op1;
   gimple *gs0, *gs1;
-  tree_code tcode, tcode0, tcode1;
-  tcode = TREE_CODE (rhs);
+  tree_code tcode;
+  basic_block bb;
+
+  if (!g)
+    return false;
 
+  rhs = gimple_assign_rhs_to_tree (g);
+  tcode = TREE_CODE (rhs);
   if (tcode != BIT_AND_EXPR && tcode != BIT_IOR_EXPR)
     return false;
 
   lhs = gimple_assign_lhs (g);
   op0 = TREE_OPERAND (rhs, 0);
   op1 = TREE_OPERAND (rhs, 1);
+  bb = gimple_bb (g);
 
   if ((TREE_CODE (op0) != SSA_NAME) || (TREE_CODE (op1) != SSA_NAME)
       || !has_single_use (lhs))
     return false;
 
-  gs0 = get_gimple_for_ssa_name (op0);
-  gs1 = get_gimple_for_ssa_name (op1);
-  if (!gs0 || !gs1 || !is_gimple_assign (gs0) || !is_gimple_assign (gs1)
-      /* g, gs0 and gs1 must be in the same basic block, since current stage
-	 is out-of-ssa.  We can not guarantee the correctness when forwording
-	 the gs0 and gs1 into g whithout DATAFLOW analysis.  */
-      || gimple_bb (gs0) != gimple_bb (gs1)
-      || gimple_bb (gs0) != gimple_bb (g))
-    return false;
+  gs0 = get_gimple_for_ssa_name (op0); /* gs0 may be NULL */
+  gs1 = get_gimple_for_ssa_name (op1); /* gs1 may be NULL */
 
-  tcode0 = gimple_assign_rhs_code (gs0);
-  tcode1 = gimple_assign_rhs_code (gs1);
-  if (TREE_CODE_CLASS (tcode0) == tcc_comparison
-      && TREE_CODE_CLASS (tcode1) == tcc_comparison)
+  if (ccmp_tree_comparison_p (op0, bb) && ccmp_tree_comparison_p (op1, bb))
     return true;
-  if (TREE_CODE_CLASS (tcode0) == tcc_comparison
-      && ccmp_candidate_p (gs1))
+  if (ccmp_tree_comparison_p (op0, bb) && ccmp_candidate_p (gs1))
     return true;
-  else if (TREE_CODE_CLASS (tcode1) == tcc_comparison
-	   && ccmp_candidate_p (gs0))
+  if (ccmp_tree_comparison_p (op1, bb) && ccmp_candidate_p (gs0))
     return true;
   /* We skip ccmp_candidate_p (gs1) && ccmp_candidate_p (gs0) since
-     there is no way to set the CC flag.  */
+     there is no way to set and maintain the CC flag on both sides of
+     the logical operator at the same time.  */
   return false;
 }
 
+/* Extract the comparison we want to do from the tree.  */
+void
+get_compare_parts (tree t, int *up, rtx_code *rcode,
+		   tree *rhs1, tree *rhs2)
+{
+  tree_code code;
+  gimple *g = get_gimple_for_ssa_name (t);
+  if (g)
+    {
+      *up = TYPE_UNSIGNED (TREE_TYPE (gimple_assign_rhs1 (g)));
+      code = gimple_assign_rhs_code (g);
+      *rcode = get_rtx_code (code, *up);
+      *rhs1 = gimple_assign_rhs1 (g);
+      *rhs2 = gimple_assign_rhs2 (g);
+    }
+  else
+    {
+      /* If g is not a comparison operator create a compare to zero.  */
+      *up = 1;
+      *rcode = NE;
+      *rhs1 = t;
+      *rhs2 = build_zero_cst (TREE_TYPE (t));
+    }
+}
+
 /* PREV is a comparison with the CC register which represents the
    result of the previous CMP or CCMP.  The function expands the
    next compare based on G which is ANDed/ORed with the previous
@@ -121,20 +164,16 @@ ccmp_candidate_p (gimple *g)
    PREP_SEQ returns all insns to prepare opearands for compare.
    GEN_SEQ returns all compare insns.  */
 static rtx
-expand_ccmp_next (gimple *g, tree_code code, rtx prev,
+expand_ccmp_next (tree op, tree_code code, rtx prev,
 		  rtx_insn **prep_seq, rtx_insn **gen_seq)
 {
   rtx_code rcode;
-  int unsignedp = TYPE_UNSIGNED (TREE_TYPE (gimple_assign_rhs1 (g)));
-
-  gcc_assert (code == BIT_AND_EXPR || code == BIT_IOR_EXPR);
-
-  rcode = get_rtx_code (gimple_assign_rhs_code (g), unsignedp);
+  int unsignedp;
+  tree rhs1, rhs2;
 
+  get_compare_parts(op, &unsignedp, &rcode, &rhs1, &rhs2);
   return targetm.gen_ccmp_next (prep_seq, gen_seq, prev, rcode,
-				gimple_assign_rhs1 (g),
-				gimple_assign_rhs2 (g),
-				get_rtx_code (code, 0));
+				rhs1, rhs2, get_rtx_code (code, 0));
 }
 
 /* Expand conditional compare gimple G.  A typical CCMP sequence is like:
@@ -153,39 +192,42 @@ expand_ccmp_expr_1 (gimple *g, rtx_insn **prep_seq, rtx_insn **gen_seq)
 {
   tree exp = gimple_assign_rhs_to_tree (g);
   tree_code code = TREE_CODE (exp);
-  gimple *gs0 = get_gimple_for_ssa_name (TREE_OPERAND (exp, 0));
-  gimple *gs1 = get_gimple_for_ssa_name (TREE_OPERAND (exp, 1));
+  basic_block bb = gimple_bb (g);
+
+  tree op0 = TREE_OPERAND (exp, 0);
+  tree op1 = TREE_OPERAND (exp, 1);
+  gimple *gs0 = get_gimple_for_ssa_name (op0);
+  gimple *gs1 = get_gimple_for_ssa_name (op1);
   rtx tmp;
-  tree_code code0 = gimple_assign_rhs_code (gs0);
-  tree_code code1 = gimple_assign_rhs_code (gs1);
 
   gcc_assert (code == BIT_AND_EXPR || code == BIT_IOR_EXPR);
-  gcc_assert (gs0 && gs1 && is_gimple_assign (gs0) && is_gimple_assign (gs1));
 
-  if (TREE_CODE_CLASS (code0) == tcc_comparison)
+  if (ccmp_tree_comparison_p (op0, bb))
     {
-      if (TREE_CODE_CLASS (code1) == tcc_comparison)
+      if (ccmp_tree_comparison_p (op1, bb))
 	{
 	  int unsignedp0, unsignedp1;
 	  rtx_code rcode0, rcode1;
+	  tree logical_op0_rhs1, logical_op0_rhs2;
+	  tree logical_op1_rhs1, logical_op1_rhs2;
 	  int speed_p = optimize_insn_for_speed_p ();
+
 	  rtx tmp2 = NULL_RTX, ret = NULL_RTX, ret2 = NULL_RTX;
 	  unsigned cost1 = MAX_COST;
 	  unsigned cost2 = MAX_COST;
 
-	  unsignedp0 = TYPE_UNSIGNED (TREE_TYPE (gimple_assign_rhs1 (gs0)));
-	  unsignedp1 = TYPE_UNSIGNED (TREE_TYPE (gimple_assign_rhs1 (gs1)));
-	  rcode0 = get_rtx_code (code0, unsignedp0);
-	  rcode1 = get_rtx_code (code1, unsignedp1);
+	  get_compare_parts (op0, &unsignedp0, &rcode0,
+			     &logical_op0_rhs1, &logical_op0_rhs2);
+
+	  get_compare_parts (op1, &unsignedp1, &rcode1,
+			     &logical_op1_rhs1, &logical_op1_rhs2);
 
 	  rtx_insn *prep_seq_1, *gen_seq_1;
 	  tmp = targetm.gen_ccmp_first (&prep_seq_1, &gen_seq_1, rcode0,
-					gimple_assign_rhs1 (gs0),
-					gimple_assign_rhs2 (gs0));
-
+					logical_op0_rhs1, logical_op0_rhs2);
 	  if (tmp != NULL)
 	    {
-	      ret = expand_ccmp_next (gs1, code, tmp, &prep_seq_1, &gen_seq_1);
+	      ret = expand_ccmp_next (op1, code, tmp, &prep_seq_1, &gen_seq_1);
 	      cost1 = seq_cost (prep_seq_1, speed_p);
 	      cost1 += seq_cost (gen_seq_1, speed_p);
 	    }
@@ -197,27 +239,22 @@ expand_ccmp_expr_1 (gimple *g, rtx_insn **prep_seq, rtx_insn **gen_seq)
 	  rtx_insn *prep_seq_2, *gen_seq_2;
 	  if (tmp == NULL || cost1 < COSTS_N_INSNS (25))
 	    tmp2 = targetm.gen_ccmp_first (&prep_seq_2, &gen_seq_2, rcode1,
-					   gimple_assign_rhs1 (gs1),
-					   gimple_assign_rhs2 (gs1));
-
+					   logical_op1_rhs1, logical_op1_rhs2);
 	  if (!tmp && !tmp2)
 	    return NULL_RTX;
-
 	  if (tmp2 != NULL)
 	    {
-	      ret2 = expand_ccmp_next (gs0, code, tmp2, &prep_seq_2,
+	      ret2 = expand_ccmp_next (op0, code, tmp2, &prep_seq_2,
 				       &gen_seq_2);
 	      cost2 = seq_cost (prep_seq_2, speed_p);
 	      cost2 += seq_cost (gen_seq_2, speed_p);
 	    }
-
 	  if (cost2 < cost1)
 	    {
 	      *prep_seq = prep_seq_2;
 	      *gen_seq = gen_seq_2;
 	      return ret2;
 	    }
-
 	  *prep_seq = prep_seq_1;
 	  *gen_seq = gen_seq_1;
 	  return ret;
@@ -227,28 +264,18 @@ expand_ccmp_expr_1 (gimple *g, rtx_insn **prep_seq, rtx_insn **gen_seq)
 	  tmp = expand_ccmp_expr_1 (gs1, prep_seq, gen_seq);
 	  if (!tmp)
 	    return NULL_RTX;
-
-	  return expand_ccmp_next (gs0, code, tmp, prep_seq, gen_seq);
+	  return expand_ccmp_next (op0, code, tmp, prep_seq, gen_seq);
 	}
     }
   else
     {
       gcc_assert (gimple_assign_rhs_code (gs0) == BIT_AND_EXPR
                   || gimple_assign_rhs_code (gs0) == BIT_IOR_EXPR);
-
-      if (TREE_CODE_CLASS (gimple_assign_rhs_code (gs1)) == tcc_comparison)
-	{
-	  tmp = expand_ccmp_expr_1 (gs0, prep_seq, gen_seq);
-	  if (!tmp)
-	    return NULL_RTX;
-
-	  return expand_ccmp_next (gs1, code, tmp, prep_seq, gen_seq);
-	}
-      else
-	{
-	  gcc_assert (gimple_assign_rhs_code (gs1) == BIT_AND_EXPR
-		      || gimple_assign_rhs_code (gs1) == BIT_IOR_EXPR);
-	}
+      gcc_assert (ccmp_tree_comparison_p (op1, bb));
+      tmp = expand_ccmp_expr_1 (gs0, prep_seq, gen_seq);
+      if (!tmp)
+	return NULL_RTX;
+      return expand_ccmp_next (op1, code, tmp, prep_seq, gen_seq);
     }
 
   return NULL_RTX;
@@ -258,7 +285,7 @@ expand_ccmp_expr_1 (gimple *g, rtx_insn **prep_seq, rtx_insn **gen_seq)
    Return NULL_RTX if G is not a legal candidate or expand fail.
    Otherwise return the target.  */
 rtx
-expand_ccmp_expr (gimple *g)
+expand_ccmp_expr (gimple *g, machine_mode mode)
 {
   rtx_insn *last;
   rtx tmp;
@@ -275,7 +302,6 @@ expand_ccmp_expr (gimple *g)
     {
       insn_code icode;
       machine_mode cc_mode = CCmode;
-      tree lhs = gimple_assign_lhs (g);
       rtx_code cmp_code = GET_CODE (tmp);
 
 #ifdef SELECT_CC_MODE
@@ -284,7 +310,6 @@ expand_ccmp_expr (gimple *g)
       icode = optab_handler (cstore_optab, cc_mode);
       if (icode != CODE_FOR_nothing)
 	{
-	  machine_mode mode = TYPE_MODE (TREE_TYPE (lhs));
 	  rtx target = gen_reg_rtx (mode);
 
 	  emit_insn (prep_seq);
@@ -300,4 +325,3 @@ expand_ccmp_expr (gimple *g)
   delete_insns_since (last);
   return NULL_RTX;
 }
-

gcc/ccmp.h

@@ -20,6 +20,6 @@ along with GCC; see the file COPYING3.  If not see
 #ifndef GCC_CCMP_H
 #define GCC_CCMP_H
 
-extern rtx expand_ccmp_expr (gimple *);
+extern rtx expand_ccmp_expr (gimple *, machine_mode);
 
 #endif  /* GCC_CCMP_H  */

gcc/expr.c

@@ -9776,7 +9776,7 @@ expand_expr_real_1 (tree exp, rtx target, machine_mode tmode,
 	      if (targetm.gen_ccmp_first)
 		{
 		  gcc_checking_assert (targetm.gen_ccmp_next != NULL);
-		  r = expand_ccmp_expr (g);
+		  r = expand_ccmp_expr (g, mode);
 		  if (r)
 		    break;
 		}