[PATCH 4/5] Rewrite first part of or_comparisons_1 into match.pd.

[Martin Liška <mliska at suse dot cz>]

Hi.

Next part if about transition of part of the OR patterns
into match.pd.

Patch can bootstrap on x86_64-linux-gnu and survives regression tests.

Ready to be installed?
Thanks,
Martin

>From 0cc83b72025d243e9e6ebaa9a85c68c17f9cd09a Mon Sep 17 00:00:00 2001
From: Martin Liska <mliska@suse.cz>
Date: Fri, 6 Sep 2019 12:47:01 +0200
Subject: [PATCH 4/5] Rewrite first part of or_comparisons_1 into match.pd.

gcc/ChangeLog:

2019-09-09  Martin Liska  <mliska@suse.cz>

	* gimple-fold.c (or_comparisons_1): Remove rules
	moved to ...
	* match.pd: ... here.
---
 gcc/gimple-fold.c | 87 +----------------------------------------------
 gcc/match.pd      | 29 ++++++++++++++++
 2 files changed, 30 insertions(+), 86 deletions(-)

diff --git a/gcc/gimple-fold.c b/gcc/gimple-fold.c
index f9971c004b7..e691780591c 100644
--- a/gcc/gimple-fold.c
+++ b/gcc/gimple-fold.c
@@ -6088,93 +6088,8 @@ or_comparisons_1 (enum tree_code code1, tree op1a, tree op1b,
     {
       int cmp = tree_int_cst_compare (op1b, op2b);
 
-      /* If we have (op1a != op1b), we should either be able to
-	 return that or TRUE, depending on whether the constant op1b
-	 also satisfies the other comparison against op2b.  */
-      if (code1 == NE_EXPR)
-	{
-	  bool done = true;
-	  bool val;
-	  switch (code2)
-	    {
-	    case EQ_EXPR: val = (cmp == 0); break;
-	    case NE_EXPR: val = (cmp != 0); break;
-	    case LT_EXPR: val = (cmp < 0); break;
-	    case GT_EXPR: val = (cmp > 0); break;
-	    case LE_EXPR: val = (cmp <= 0); break;
-	    case GE_EXPR: val = (cmp >= 0); break;
-	    default: done = false;
-	    }
-	  if (done)
-	    {
-	      if (val)
-		return boolean_true_node;
-	      else
-		return fold_build2 (code1, boolean_type_node, op1a, op1b);
-	    }
-	}
-      /* Likewise if the second comparison is a != comparison.  */
-      else if (code2 == NE_EXPR)
-	{
-	  bool done = true;
-	  bool val;
-	  switch (code1)
-	    {
-	    case EQ_EXPR: val = (cmp == 0); break;
-	    case NE_EXPR: val = (cmp != 0); break;
-	    case LT_EXPR: val = (cmp > 0); break;
-	    case GT_EXPR: val = (cmp < 0); break;
-	    case LE_EXPR: val = (cmp >= 0); break;
-	    case GE_EXPR: val = (cmp <= 0); break;
-	    default: done = false;
-	    }
-	  if (done)
-	    {
-	      if (val)
-		return boolean_true_node;
-	      else
-		return fold_build2 (code2, boolean_type_node, op2a, op2b);
-	    }
-	}
-
-      /* See if an equality test is redundant with the other comparison.  */
-      else if (code1 == EQ_EXPR)
-	{
-	  bool val;
-	  switch (code2)
-	    {
-	    case EQ_EXPR: val = (cmp == 0); break;
-	    case NE_EXPR: val = (cmp != 0); break;
-	    case LT_EXPR: val = (cmp < 0); break;
-	    case GT_EXPR: val = (cmp > 0); break;
-	    case LE_EXPR: val = (cmp <= 0); break;
-	    case GE_EXPR: val = (cmp >= 0); break;
-	    default:
-	      val = false;
-	    }
-	  if (val)
-	    return fold_build2 (code2, boolean_type_node, op2a, op2b);
-	}
-      else if (code2 == EQ_EXPR)
-	{
-	  bool val;
-	  switch (code1)
-	    {
-	    case EQ_EXPR: val = (cmp == 0); break;
-	    case NE_EXPR: val = (cmp != 0); break;
-	    case LT_EXPR: val = (cmp > 0); break;
-	    case GT_EXPR: val = (cmp < 0); break;
-	    case LE_EXPR: val = (cmp >= 0); break;
-	    case GE_EXPR: val = (cmp <= 0); break;
-	    default:
-	      val = false;
-	    }
-	  if (val)
-	    return fold_build2 (code1, boolean_type_node, op1a, op1b);
-	}
-
       /* Chose the less restrictive of two < or <= comparisons.  */
-      else if ((code1 == LT_EXPR || code1 == LE_EXPR)
+      if ((code1 == LT_EXPR || code1 == LE_EXPR)
 	       && (code2 == LT_EXPR || code2 == LE_EXPR))
 	{
 	  if ((cmp < 0) || (cmp == 0 && code1 == LT_EXPR))
diff --git a/gcc/match.pd b/gcc/match.pd
index 2c64c460fda..2923f5b4cbe 100644
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -2017,6 +2017,35 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
        { constant_boolean_node (false, type); })
       ))))))
 
+/* Convert (X == CST1) || (X OP2 CST2) to a known value
+   based on CST1 OP2 CST2.  Similarly for (X != CST1).  */
+
+(for code1 (eq ne)
+ (for code2 (eq ne lt gt le ge)
+  (for or (truth_or bit_ior)
+   (simplify
+    (or:c (code1 @0 INTEGER_CST@1) (code2 @0 INTEGER_CST@2))
+     (with
+      {
+       int cmp = tree_int_cst_compare (@1, @2);
+       bool val;
+       switch (code2)
+	 {
+	 case EQ_EXPR: val = (cmp == 0); break;
+	 case NE_EXPR: val = (cmp != 0); break;
+	 case LT_EXPR: val = (cmp < 0); break;
+	 case GT_EXPR: val = (cmp > 0); break;
+	 case LE_EXPR: val = (cmp <= 0); break;
+	 case GE_EXPR: val = (cmp >= 0); break;
+	 default: gcc_unreachable ();
+	 }
+      }
+      (switch
+       (if (code1 == EQ_EXPR && val) (code2 @0 @2))
+       (if (code1 == NE_EXPR && val) { constant_boolean_node (true, type); })
+       (if (code1 == NE_EXPR && !val) (code1 @0 @1))))))))
+
+
 /* We can't reassociate at all for saturating types.  */
 (if (!TYPE_SATURATING (type))
 
-- 
2.23.0