[Bug fortran/35418] [4.4 Regression]: Revision 132592 miscompiles 172.mgrid

["hjl dot tools at gmail dot com" <gcc-bugzilla@gcc.gnu.org>]

------- Comment #4 from hjl dot tools at gmail dot com  2008-03-02 01:11 -------
I got

  Running 172.mgrid ref base o2 default
*** Miscompare of mgrid.out, see
/export/gnu/import/rrs/spec/2000/spec/benchspec
/CFP2000/172.mgrid/run/00000002/mgrid.out.mis
Invalid run; unable to continue.  If you wish to ignore errors please use '-I'
o
r ignore_errors

Remove -ffast-math fixes the problem. -fbounds-check doesn't make
a difference. I'd like to know why

--- old/c.f.003t.original       2008-03-01 14:15:12.000000000 -0800
+++ new/c.f.003t.original       2008-03-01 14:14:53.000000000 -0800
@@ -36,39 +36,39 @@ resid (u, v, r, n, a)

   ubound.0 = (integer(kind=8)) *n;
   stride.2 = NON_LVALUE_EXPR <ubound.0>;
-  stride.2 = stride.2 >= 0 ? stride.2 : 0;
+  stride.2 = MAX_EXPR <stride.2, 0>;
   ubound.1 = (integer(kind=8)) *n;
   stride.4 = stride.2 * NON_LVALUE_EXPR <ubound.1>;
-  stride.4 = stride.4 >= 0 ? stride.4 : 0;
+  stride.4 = MAX_EXPR <stride.4, 0>;
   ubound.3 = (integer(kind=8)) *n;
   size.6 = stride.4 * NON_LVALUE_EXPR <ubound.3>;
-  size.6 = size.6 >= 0 ? size.6 : 0;
+  size.6 = MAX_EXPR <size.6, 0>;
   D.965 = size.6 - 1;
   D.966 = (bit_size_type) size.6 * 64;
   D.967 = (<unnamed-unsigned:64>) size.6 * 8;
   offset.5 = ~NON_LVALUE_EXPR <stride.2> - NON_LVALUE_EXPR <stride.4>;
   ubound.14 = (integer(kind=8)) *n;
   stride.16 = NON_LVALUE_EXPR <ubound.14>;
-  stride.16 = stride.16 >= 0 ? stride.16 : 0;
+  stride.16 = MAX_EXPR <stride.16, 0>;
   ubound.15 = (integer(kind=8)) *n;
   stride.18 = stride.16 * NON_LVALUE_EXPR <ubound.15>;
-  stride.18 = stride.18 >= 0 ? stride.18 : 0;
+  stride.18 = MAX_EXPR <stride.18, 0>;
   ubound.17 = (integer(kind=8)) *n;
   size.20 = stride.18 * NON_LVALUE_EXPR <ubound.17>;
-  size.20 = size.20 >= 0 ? size.20 : 0;
+  size.20 = MAX_EXPR <size.20, 0>;
   D.962 = size.20 - 1;
   D.963 = (bit_size_type) size.20 * 64;
   D.964 = (<unnamed-unsigned:64>) size.20 * 8;
   offset.19 = ~NON_LVALUE_EXPR <stride.16> - NON_LVALUE_EXPR <stride.18>;
   ubound.7 = (integer(kind=8)) *n;
   stride.9 = NON_LVALUE_EXPR <ubound.7>;
-  stride.9 = stride.9 >= 0 ? stride.9 : 0;
+  stride.9 = MAX_EXPR <stride.9, 0>;
   ubound.8 = (integer(kind=8)) *n;
   stride.11 = stride.9 * NON_LVALUE_EXPR <ubound.8>;
-  stride.11 = stride.11 >= 0 ? stride.11 : 0;
+  stride.11 = MAX_EXPR <stride.11, 0>;
   ubound.10 = (integer(kind=8)) *n;
   size.13 = stride.11 * NON_LVALUE_EXPR <ubound.10>;
-  size.13 = size.13 >= 0 ? size.13 : 0;
+  size.13 = MAX_EXPR <size.13, 0>;
   D.959 = size.13 - 1;
   D.960 = (bit_size_type) size.13 * 64;
   D.961 = (<unnamed-unsigned:64>) size.13 * 8;

makes such a big differece.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35418