diff mbox series

[PUSHED] Fix PR97315 (part 2 of 2)

Message ID 79b7d4c5-a6fd-8661-7e03-7c5f2156f27c@redhat.com
State New
Headers show
Series [PUSHED] Fix PR97315 (part 2 of 2) | expand

Commit Message

Aldy Hernandez Oct. 8, 2020, 9:36 a.m. UTC 
This fixes the second testcase in the PR.

I've tested Andrew's patch and pushed it.

Aldy

     gcc/ChangeLog:

             PR tree-optimization/97315
             * range-op.cc (value_range_with_overflow): Change any
             non-overflow calculation in which both bounds are
             overflow/underflow to be undefined.

     gcc/testsuite/ChangeLog:

             * gcc.dg/pr97315-2.c: New test.
diff mbox series

Patch

diff --git a/gcc/range-op.cc b/gcc/range-op.cc
index 87c6d82f2ac..22bc23c1bbf 100644
--- a/gcc/range-op.cc
+++ b/gcc/range-op.cc
@@ -287,6 +287,15 @@  value_range_with_overflow (irange &r, tree type,
      }
    else
      {
+      // If both bounds either underflowed or overflowed, then the result
+      // is undefined.
+      if ((min_ovf == wi::OVF_OVERFLOW && max_ovf == wi::OVF_OVERFLOW)
+	  || (min_ovf == wi::OVF_UNDERFLOW && max_ovf == wi::OVF_UNDERFLOW))
+	{
+	  r.set_undefined ();
+	  return;
+	}
+
        // If overflow does not wrap, saturate to [MIN, MAX].
        wide_int new_lb, new_ub;
        if (min_ovf == wi::OVF_UNDERFLOW)
diff --git a/gcc/testsuite/gcc.dg/pr97315-2.c 
b/gcc/testsuite/gcc.dg/pr97315-2.c
new file mode 100644
index 00000000000..5dd1b6a3fc7
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr97315-2.c
@@ -0,0 +1,11 @@ 
+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+
+void c(int);
+
+int a;
+void b()
+{
+  if (a >= 2147483647)
+    c(a + 1);
+}