From 5bcd92d0d4029f3d1d2eacc0e2bff1685545b74f Mon Sep 17 00:00:00 2001
From: Aldy Hernandez <aldyh@redhat.com>
Date: Mon, 24 Oct 2022 12:37:25 +0200
Subject: [PATCH] [PR tree-optimization/107355] Handle NANs in abs range-op
 entry.

The problem here is that the threader is coming up with a path where
the only valid result is a NAN.  When the abs op1_range entry is
trying to add the negative posibility, it attempts to get the bounds
of the working range.  NANs don't have bounds so they need to be
special cased.

	PR tree-optimization/107355

gcc/ChangeLog:

	* range-op-float.cc (foperator_abs::op1_range): Handle NAN.

gcc/testsuite/ChangeLog:

	* gcc.dg/tree-ssa/pr107355.c: New test.
---
 gcc/range-op-float.cc                    |  9 +++++++++
 gcc/testsuite/gcc.dg/tree-ssa/pr107355.c | 13 +++++++++++++
 2 files changed, 22 insertions(+)
 create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/pr107355.c

diff --git a/gcc/range-op-float.cc b/gcc/range-op-float.cc
index 8777bc70..04208c8 100644
--- a/gcc/range-op-float.cc
+++ b/gcc/range-op-float.cc
@@ -1269,6 +1269,15 @@ foperator_abs::op1_range (frange &r, tree type,
   positives.update_nan (/*sign=*/false);
   positives.intersect (lhs);
   r = positives;
+  // Add -NAN if relevant.
+  if (r.maybe_isnan ())
+    {
+      frange neg_nan;
+      neg_nan.set_nan (type, true);
+      r.union_ (neg_nan);
+    }
+  if (r.known_isnan ())
+    return true;
   // Then add the negative of each pair:
   // ABS(op1) = [5,20] would yield op1 => [-20,-5][5,20].
   r.union_ (frange (type,
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr107355.c b/gcc/testsuite/gcc.dg/tree-ssa/pr107355.c
new file mode 100644
index 0000000..4079634
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/pr107355.c
@@ -0,0 +1,13 @@
+// { dg-do compile }
+// { dg-options "-O2 -fno-guess-branch-probability -fsanitize=float-cast-overflow --param=max-jump-thread-duplication-stmts=240" }
+
+float f;
+
+void
+foo (double d)
+{
+  (char) f;
+  long l = __builtin_fabs (d);
+  (char) f;
+  (long) d;
+}
-- 
2.7.4