match.pd: Add flag_unsafe_math_optimizations check before deciding on the widest...

2019-09-09  Barnaby Wilks  <barnaby.wilks@arm.com>

	* match.pd: Add flag_unsafe_math_optimizations check
	before deciding on the widest type in a binary math operation.

	* gcc.dg/fold-binary-math-casts.c: New test.

From-SVN: r275518

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 6c567aa8717ee34e29d42ab9b7d9d87eac24d63b..b58b92ad114524f61f71be10032c4bbd2fce03a8 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2019-09-09  Barnaby Wilks  <barnaby.wilks@arm.com>
+
+       * match.pd: Add flag_unsafe_math_optimizations check
+       before deciding on the widest type in a binary math operation.
+
 2019-09-09  Martin Liska  <mliska@suse.cz>
 
        * config/i386/i386.opt: Update comment of removed

diff --git a/gcc/match.pd b/gcc/match.pd
index 1d13543a6159dc94ce1ff1112c0bfc6b0d588638..5b2d95dfa9d8feef7e7248c0364909fc061da3ab 100644 (file)
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -5040,10 +5040,18 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
              && newtype == type
              && types_match (newtype, type))
            (op (convert:newtype @1) (convert:newtype @2))
-           (with { if (TYPE_PRECISION (ty1) > TYPE_PRECISION (newtype))
+           (with
+             {
+               if (!flag_unsafe_math_optimizations)
+                 {
+                   if (TYPE_PRECISION (ty1) > TYPE_PRECISION (newtype))
                      newtype = ty1;
+
                    if (TYPE_PRECISION (ty2) > TYPE_PRECISION (newtype))
-                     newtype = ty2; }
+                     newtype = ty2;
+                 }
+             }
+
               /* Sometimes this transformation is safe (cannot
                  change results through affecting double rounding
                  cases) and sometimes it is not.  If NEWTYPE is

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index ec2872b97df9708d5b7301cc1f83bc4655cd93ca..6129f911f31e8e180988a01ee9e799829d2e920e 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,7 @@
+2019-09-09  Barnaby Wilks  <barnaby.wilks@arm.com>
+
+       * gcc.dg/fold-binary-math-casts.c: New test.
+
 2019-09-09  Jakub Jelinek  <jakub@redhat.com>
 
        PR target/87853

diff --git a/gcc/testsuite/gcc.dg/fold-binary-math-casts.c b/gcc/testsuite/gcc.dg/fold-binary-math-casts.c
new file mode 100644 (file)
index 0000000..53c247f
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/fold-binary-math-casts.c
@@ -0,0 +1,58 @@
+/* { dg-do compile } */
+/* { dg-options "-Ofast -fdump-tree-optimized" } */
+
+#include <math.h>
+
+float
+f (float x, float y)
+{
+  double z = 1.0 / x;
+  return z * y;
+}
+
+float
+g (float x, float y)
+{
+  double a = 1.0 / x;
+  double b = 1.0 / y;
+  long double k = x*x*x*x*x*x;
+
+  return a + b - k;
+}
+
+float
+h (float x)
+{
+  double a = x * 2.0;
+  double b = a / 3.5f;
+  return a + b;
+}
+
+float
+i (float y, float z)
+{
+  return pow (y, 2.0) / (double) (y + z);
+}
+
+float
+j (float x, float y)
+{
+  double t = 4.0 * x;
+  double z = t + y;
+  return z;
+}
+
+float
+k (float a)
+{
+  return 1.0 / sqrtf (a);
+}
+
+float
+l (float a)
+{
+  return (double) a * (a / 2.0);
+}
+
+/* { dg-final { scan-tree-dump-not "\\(double\\)" "optimized" } } */
+/* { dg-final { scan-tree-dump-not "\\(float\\)" "optimized" } } */