[COMMITTED] Always check result from build_<COND> in range-op-float.cc

[COMMITTED] Always check result from build_<COND> in range-op-float.cc

[Aldy Hernandez]

A result of false from build_<COND> in range-ops means the result is
final and needs no further adjustments.  This patch documents this,
and changes all uses to check the result.  There should be no change
in functionality.

gcc/ChangeLog:

	* range-op-float.cc (build_le): Document result.
	(build_lt): Same.
	(build_ge): Same.
	(foperator_ge::op2_range): Check result of build_*.
	(foperator_unordered_le::op1_range): Same.
	(foperator_unordered_le::op2_range): Same.
	(foperator_unordered_gt::op1_range): Same.
	(foperator_unordered_gt::op2_range): Same.
	(foperator_unordered_ge::op1_range): Same.
	(foperator_unordered_ge::op2_range): Same.
---
 gcc/range-op-float.cc | 47 ++++++++++++++++++++++++-------------------
 1 file changed, 26 insertions(+), 21 deletions(-)

diff --git a/gcc/range-op-float.cc b/gcc/range-op-float.cc
index e7334794b0d..0605a908684 100644
--- a/gcc/range-op-float.cc
+++ b/gcc/range-op-float.cc
@@ -239,7 +239,9 @@ frange_add_zeros (frange &r, tree type)
     }
 }
 
-// Build a range that is <= VAL and store it in R.
+// Build a range that is <= VAL and store it in R.  Return TRUE if
+// further changes may be needed for R, or FALSE if R is in its final
+// form.
 
 static bool
 build_le (frange &r, tree type, const frange &val)
@@ -255,7 +257,9 @@ build_le (frange &r, tree type, const frange &val)
   return true;
 }
 
-// Build a range that is < VAL and store it in R.
+// Build a range that is < VAL and store it in R.  Return TRUE if
+// further changes may be needed for R, or FALSE if R is in its final
+// form.
 
 static bool
 build_lt (frange &r, tree type, const frange &val)
@@ -277,7 +281,9 @@ build_lt (frange &r, tree type, const frange &val)
   return true;
 }
 
-// Build a range that is >= VAL and store it in R.
+// Build a range that is >= VAL and store it in R.  Return TRUE if
+// further changes may be needed for R, or FALSE if R is in its final
+// form.
 
 static bool
 build_ge (frange &r, tree type, const frange &val)
@@ -293,7 +299,9 @@ build_ge (frange &r, tree type, const frange &val)
   return true;
 }
 
-// Build a range that is > VAL and store it in R.
+// Build a range that is > VAL and store it in R.  Return TRUE if
+// further changes may be needed for R, or FALSE if R is in its final
+// form.
 
 static bool
 build_gt (frange &r, tree type, const frange &val)
@@ -979,11 +987,8 @@ foperator_ge::op2_range (frange &r, tree type,
       // The TRUE side of NAN >= x is unreachable.
       if (op1.known_isnan ())
 	r.set_undefined ();
-      else
-	{
-	  build_le (r, type, op1);
-	  r.clear_nan ();
-	}
+      else if (build_le (r, type, op1))
+	r.clear_nan ();
       break;
 
     case BRS_FALSE:
@@ -1354,8 +1359,8 @@ foperator_unordered_le::op1_range (frange &r, tree type,
       break;
 
     case BRS_FALSE:
-      build_gt (r, type, op2);
-      r.clear_nan ();
+      if (build_gt (r, type, op2))
+	r.clear_nan ();
       break;
 
     default:
@@ -1378,8 +1383,8 @@ foperator_unordered_le::op2_range (frange &r,
       break;
 
     case BRS_FALSE:
-      build_lt (r, type, op1);
-      r.clear_nan ();
+      if (build_lt (r, type, op1))
+	r.clear_nan ();
       break;
 
     default:
@@ -1437,8 +1442,8 @@ foperator_unordered_gt::op1_range (frange &r,
       break;
 
     case BRS_FALSE:
-      build_le (r, type, op2);
-      r.clear_nan ();
+      if (build_le (r, type, op2))
+	r.clear_nan ();
       break;
 
     default:
@@ -1461,8 +1466,8 @@ foperator_unordered_gt::op2_range (frange &r,
       break;
 
     case BRS_FALSE:
-      build_ge (r, type, op1);
-      r.clear_nan ();
+      if (build_ge (r, type, op1))
+	r.clear_nan ();
       break;
 
     default:
@@ -1520,8 +1525,8 @@ foperator_unordered_ge::op1_range (frange &r,
       break;
 
     case BRS_FALSE:
-      build_lt (r, type, op2);
-      r.clear_nan ();
+      if (build_lt (r, type, op2))
+	r.clear_nan ();
       break;
 
     default:
@@ -1543,8 +1548,8 @@ foperator_unordered_ge::op2_range (frange &r, tree type,
       break;
 
     case BRS_FALSE:
-      build_gt (r, type, op1);
-      r.clear_nan ();
+      if (build_gt (r, type, op1))
+	r.clear_nan ();
       break;
 
     default:
-- 
2.37.3