tree.c (real_minus_onep): New function to test for -1.0.

	* tree.c (real_minus_onep): New function to test for -1.0.
	* fold-const.c (fold) [MULT_EXPR]:  Optimize -1.0*x into -x.

	* gcc.dg/fnegate-1.c: New test case.

From-SVN: r54149

2 files changed, 117 insertions, 0 deletions

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 8e06317..5f2d0b7 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,7 @@
+2002-06-01  Roger Sayle  <roger@eyesopen.com>
+
+	* gcc.dg/fnegate-1.c: New test case.
+
 2002-05-30  Osku Salerma  <osku@iki.fi>
 
 	* gcc.c-torture/execute/mayalias-1.c: New file.
diff --git a/gcc/testsuite/gcc.dg/fnegate-1.c b/gcc/testsuite/gcc.dg/fnegate-1.c
new file mode 100644
index 0000000..ad0f4e0
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/fnegate-1.c
@@ -0,0 +1,113 @@
+/* Copyright (C) 2002 Free Software Foundation.
+  
+   Test floating point negation produces the expected results.
+  
+   Written by Roger Sayle, 21st May 2002.  */
+
+/* { dg-do run } */
+/* { dg-options "-O2 -ffast-math" } */
+
+extern void abort ();
+
+
+double
+dneg (double x)
+{
+  return -x;
+}
+
+double
+dmult (double x)
+{
+  return -1.0 * x;
+}
+
+double
+ddiv (double x)
+{
+  return x / -1.0;
+}
+
+
+float
+fneg (float x)
+{
+  return -x;
+}
+
+float
+fmult (float x)
+{
+  return -1.0f * x;
+}
+
+float
+fdiv (float x)
+{
+  return x / -1.0f;
+}
+
+
+void
+ftest(float src, float dst)
+{
+  if (fneg (src) != dst)
+    abort ();
+
+  if (src != fneg (dst))
+    abort ();
+
+  if (fmult (src) != dst)
+    abort ();
+
+  if (src != fmult (dst))
+    abort ();
+
+  if (fdiv (src) != dst)
+    abort ();
+
+  if (src != fdiv(dst))
+    abort ();
+}
+
+void
+dtest(double src, double dst)
+{
+  if (dneg (src) != dst)
+    abort ();
+
+  if (src != dneg (dst))
+    abort ();
+
+  if (dmult (src) != dst)
+    abort ();
+
+  if (src != dmult (dst))
+    abort ();
+
+  if (ddiv (src) != dst)
+    abort ();
+
+  if (src != ddiv(dst))
+    abort ();
+}
+
+
+int
+main ()
+{
+  ftest (1.0f, -1.0f);
+  ftest (2.0f, -2.0f);
+  ftest (-3.0f, 3.0f);
+  ftest (0.0f, -0.0f);
+  ftest (-0.0f, 0.0f);
+
+  dtest (1.0, -1.0);
+  dtest (2.0, -2.0);
+  dtest (-3.0, 3.0);
+  dtest (0.0, -0.0);
+  dtest (-0.0, 0.0);
+
+  return 0;
+}
+