From: Aldy Hernandez <aldyh@redhat.com>
To: GCC patches <gcc-patches@gcc.gnu.org>
Cc: Andrew MacLeod <amacleod@redhat.com>, Aldy Hernandez <aldyh@redhat.com>
Subject: [COMMITTED] A false UNORDERED_<cond> means neither operand can be a NAN.
Date: Thu, 20 Oct 2022 18:46:33 +0200 [thread overview]
Message-ID: <20221020164633.256422-1-aldyh@redhat.com> (raw)
The false side of UNORDERED_<cond> means neither operand can be a NAN.
Adjust all the op[12]_range entries for the UNORDERED operators such
that a known NAN on one operands means the other operands is
undefined.
gcc/ChangeLog:
* range-op-float.cc (foperator_unordered_le::op1_range): Adjust
false side with a NAN operand.
(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.
(foperator_unordered_equal::op1_range): Same.
---
gcc/range-op-float.cc | 51 ++++++++++++++++++++++++++++++++++---------
1 file changed, 41 insertions(+), 10 deletions(-)
diff --git a/gcc/range-op-float.cc b/gcc/range-op-float.cc
index a9e74c86877..0cb07c2ec29 100644
--- a/gcc/range-op-float.cc
+++ b/gcc/range-op-float.cc
@@ -1351,7 +1351,11 @@ foperator_unordered_le::op1_range (frange &r, tree type,
break;
case BRS_FALSE:
- if (build_gt (r, type, op2))
+ // A false UNORDERED_LE means both operands are !NAN, so it's
+ // impossible for op2 to be a NAN.
+ if (op2.known_isnan ())
+ r.set_undefined ();
+ else if (build_gt (r, type, op2))
r.clear_nan ();
break;
@@ -1375,7 +1379,11 @@ foperator_unordered_le::op2_range (frange &r,
break;
case BRS_FALSE:
- if (build_lt (r, type, op1))
+ // A false UNORDERED_LE means both operands are !NAN, so it's
+ // impossible for op1 to be a NAN.
+ if (op1.known_isnan ())
+ r.set_undefined ();
+ else if (build_lt (r, type, op1))
r.clear_nan ();
break;
@@ -1434,7 +1442,11 @@ foperator_unordered_gt::op1_range (frange &r,
break;
case BRS_FALSE:
- if (build_le (r, type, op2))
+ // A false UNORDERED_GT means both operands are !NAN, so it's
+ // impossible for op2 to be a NAN.
+ if (op2.known_isnan ())
+ r.set_undefined ();
+ else if (build_le (r, type, op2))
r.clear_nan ();
break;
@@ -1458,7 +1470,11 @@ foperator_unordered_gt::op2_range (frange &r,
break;
case BRS_FALSE:
- if (build_ge (r, type, op1))
+ // A false UNORDERED_GT means both operands are !NAN, so it's
+ // impossible for op1 to be a NAN.
+ if (op1.known_isnan ())
+ r.set_undefined ();
+ else if (build_ge (r, type, op1))
r.clear_nan ();
break;
@@ -1517,7 +1533,11 @@ foperator_unordered_ge::op1_range (frange &r,
break;
case BRS_FALSE:
- if (build_lt (r, type, op2))
+ // A false UNORDERED_GE means both operands are !NAN, so it's
+ // impossible for op2 to be a NAN.
+ if (op2.known_isnan ())
+ r.set_undefined ();
+ else if (build_lt (r, type, op2))
r.clear_nan ();
break;
@@ -1540,7 +1560,11 @@ foperator_unordered_ge::op2_range (frange &r, tree type,
break;
case BRS_FALSE:
- if (build_gt (r, type, op1))
+ // A false UNORDERED_GE means both operands are !NAN, so it's
+ // impossible for op1 to be a NAN.
+ if (op1.known_isnan ())
+ r.set_undefined ();
+ else if (build_gt (r, type, op1))
r.clear_nan ();
break;
@@ -1606,10 +1630,17 @@ foperator_unordered_equal::op1_range (frange &r, tree type,
break;
case BRS_FALSE:
- // The false side indictates !NAN and not equal. We can at least
- // represent !NAN.
- r.set_varying (type);
- r.clear_nan ();
+ // A false UNORDERED_EQ means both operands are !NAN, so it's
+ // impossible for op2 to be a NAN.
+ if (op2.known_isnan ())
+ r.set_undefined ();
+ else
+ {
+ // The false side indictates !NAN and not equal. We can at least
+ // represent !NAN.
+ r.set_varying (type);
+ r.clear_nan ();
+ }
break;
default:
--
2.37.3
reply other threads:[~2022-10-20 16:46 UTC|newest]
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