Re: ORDERED_EXPR in invert_tree_comparison

[Marc Glisse <marc.glisse@inria.fr>]

[-- Attachment #1: Type: TEXT/PLAIN, Size: 1050 bytes --]

On Thu, 2 Aug 2012, Richard Guenther wrote:

> On Wed, Aug 1, 2012 at 9:21 PM, Marc Glisse <marc.glisse@inria.fr> wrote:
>> Hello,
>>
>> an opinion on this?
>>
>> (I just noticed: I'll update the list in the comment visible at the top of
>> the patch if this gets in).
>
> It looks ok to me but I am no floating-point expert.  Can you add a testcase?
>
> Ok with that change.

Here again with a testcase. The -O is not necessary for the optimization 
to happen, but it seemed wrong to me not to include it. I wondered about 
adding an explicit -ftrapping-math, for documentation purposes.

I am redoing the bootstrap+regtest, then I'll commit if I don't hear 
protests about the testcase.

gcc/ChangeLog
2012-06-15  Marc Glisse  <marc.glisse@inria.fr>

 	PR tree-optimization/53805
 	* fold-const.c (invert_tree_comparison): Do invert ORDERED_EXPR and
 	UNORDERED_EXPR for floating point.

gcc/testsuite/ChangeLog
2012-06-15  Marc Glisse  <marc.glisse@inria.fr>

 	PR tree-optimization/53805
 	* gcc.dg/fold-notunord.c: New testcase.

-- 
Marc Glisse

[-- Attachment #2: Type: TEXT/PLAIN, Size: 1972 bytes --]

Index: gcc/testsuite/gcc.dg/fold-notunord.c
===================================================================
--- gcc/testsuite/gcc.dg/fold-notunord.c	(revision 0)
+++ gcc/testsuite/gcc.dg/fold-notunord.c	(revision 0)
@@ -0,0 +1,10 @@
+/* { dg-do compile } */
+/* { dg-options "-O -fdump-tree-optimized" } */
+
+int f (double d)
+{
+  return !__builtin_isnan (d);
+}
+
+/* { dg-final { scan-tree-dump " ord " "optimized" } } */
+/* { dg-final { cleanup-tree-dump "optimized" } } */

Property changes on: gcc/testsuite/gcc.dg/fold-notunord.c
___________________________________________________________________
Added: svn:eol-style
   + native
Added: svn:keywords
   + Author Date Id Revision URL

Index: gcc/fold-const.c
===================================================================
--- gcc/fold-const.c	(revision 190071)
+++ gcc/fold-const.c	(working copy)
@@ -2087,26 +2087,28 @@ static tree
 pedantic_non_lvalue_loc (location_t loc, tree x)
 {
   if (pedantic_lvalues)
     return non_lvalue_loc (loc, x);
 
   return protected_set_expr_location_unshare (x, loc);
 }
 \f
 /* Given a tree comparison code, return the code that is the logical inverse.
    It is generally not safe to do this for floating-point comparisons, except
-   for EQ_EXPR and NE_EXPR, so we return ERROR_MARK in this case.  */
+   for EQ_EXPR, NE_EXPR, ORDERED_EXPR and UNORDERED_EXPR, so we return
+   ERROR_MARK in this case.  */
 
 enum tree_code
 invert_tree_comparison (enum tree_code code, bool honor_nans)
 {
-  if (honor_nans && flag_trapping_math && code != EQ_EXPR && code != NE_EXPR)
+  if (honor_nans && flag_trapping_math && code != EQ_EXPR && code != NE_EXPR
+      && code != ORDERED_EXPR && code != UNORDERED_EXPR)
     return ERROR_MARK;
 
   switch (code)
     {
     case EQ_EXPR:
       return NE_EXPR;
     case NE_EXPR:
       return EQ_EXPR;
     case GT_EXPR:
       return honor_nans ? UNLE_EXPR : LE_EXPR;