re PR rtl-optimization/69570 (if-conversion bug on i?86)

PR rtl-optimization/69570
	* ifcvt.c (bb_ok_for_noce_convert_multiple_sets): Return true only
	if there is more than one set, not if there is a single set.

	* g++.dg/opt/pr69570.C: New test.

From-SVN: r233033

gcc/ChangeLog

@@ -1,3 +1,9 @@
+2016-02-01  Jakub Jelinek  <jakub@redhat.com>
+
+	PR rtl-optimization/69570
+	* ifcvt.c (bb_ok_for_noce_convert_multiple_sets): Return true only
+	if there is more than one set, not if there is a single set.
+
 2016-02-01  Richard Henderson  <rth@redhat.com>
 
 	PR rtl-opt/69535

gcc/ifcvt.c

@@ -3295,7 +3295,7 @@ bb_ok_for_noce_convert_multiple_sets (basic_block test_bb,
   if (count > limit)
     return false;
 
-  return count > 0;
+  return count > 1;
 }
 
 /* Given a simple IF-THEN-JOIN or IF-THEN-ELSE-JOIN block, attempt to convert

gcc/testsuite/ChangeLog

@@ -1,3 +1,8 @@
+2016-02-01  Jakub Jelinek  <jakub@redhat.com>
+
+	PR rtl-optimization/69570
+	* g++.dg/opt/pr69570.C: New test.
+
 2016-02-01  Richard Henderson  <rth@redhat.com>
 
 	* gcc.dg/pr69535.c: New test.

gcc/testsuite/g++.dg/opt/pr69570.C

@@ -0,0 +1,70 @@
+// PR rtl-optimization/69570
+// { dg-do run }
+// { dg-options "-O2" }
+// { dg-additional-options "-fpic" { target fpic } }
+// { dg-additional-options "-march=i686" { target ia32 } }
+
+template <typename T> inline const T &
+min (const T &a, const T &b)
+{
+  if (b < a)
+    return b;
+  return a;
+}
+
+template <typename T> inline const T &
+max (const T &a, const T &b)
+{
+  if (a < b)
+    return b;
+  return a;
+}
+
+static inline void
+foo (unsigned x, unsigned y, unsigned z, double &h, double &s, double &l)
+{
+  double r = x / 255.0;
+  double g = y / 255.0;
+  double b = z / 255.0;
+  double m = max (r, max (g, b));
+  double n = min (r, min (g, b));
+  double d = m - n;
+  double e = m + n;
+  h = 0.0, s = 0.0, l = e / 2.0;
+  if (d > 0.0)
+    {
+      s = l > 0.5 ? d / (2.0 - e) : d / e;
+      if (m == r && m != g)
+        h = (g - b) / d + (g < b ? 6.0 : 0.0);
+      if (m == g && m != b)
+        h = (b - r) / d + 2.0;
+      if (m == b && m != r)
+        h = (r - g) / d + 4.0;
+      h /= 6.0;
+    }
+}
+
+__attribute__ ((noinline, noclone))
+void bar (unsigned x[3], double y[3])
+{
+  double h, s, l;
+  foo (x[0], x[1], x[2], h, s, l);
+  y[0] = h;
+  y[1] = s;
+  y[2] = l;
+}
+
+int
+main ()
+{
+  unsigned x[3] = { 0, 128, 0 };
+  double y[3];
+
+  bar (x, y);
+  if (__builtin_fabs (y[0] - 0.33333) > 0.001
+      || __builtin_fabs (y[1] - 1) > 0.001
+      || __builtin_fabs (y[2] - 0.25098) > 0.001)
+    __builtin_abort ();
+
+  return 0;
+}