[PATCH] Fix up 20181120-1.c testcase on big-endian (PR rtl-optimization/85925, take 2)

[Jakub Jelinek]

Hi!

On Wed, Nov 21, 2018 at 12:07:51PM -0600, Segher Boessenkool wrote:
> > Admittedly, it might be better if the initializer was 0x1010101 or say
> > 0x4030201 because on big endian in particular 0x10101 has the top 15 bits
> > all zero and thus that is what is in u.f1, so if the bug can be reproduced
> > with the combine.c + rtlanal.c fix reverted with 0x4030201, it would be
> > better to use that value (in both spots).
> 
> Yeah good point.

I've now managed to test this with a cross to armv7hl (scped to an arm box)
with and without the rtlanal.c + combine.c change reverted and on
powerpc64-linux as example of big-endian, on armv7hl it still fails with
the changes reverted, otherwise it succeeds on both.  The test also needs
32-bit int target (previously just 17-bit or more, so I've added effective
target).

Ok for trunk and release branches?

2018-11-21  Jakub Jelinek  <ja...@redhat.com>

        PR rtl-optimization/85925
        * gcc.c-torture/execute/20181120-1.c: Require effective target
        int32plus.
        (u): New variable.
        (main): Compare d against u.f1 rather than 0x101.  Use 0x4030201
        instead of 0x10101.

--- gcc/testsuite/gcc.c-torture/execute/20181120-1.c.jj 2018-11-21 
17:39:47.963671708 +0100
+++ gcc/testsuite/gcc.c-torture/execute/20181120-1.c    2018-11-21 
20:07:45.804556443 +0100
@@ -1,4 +1,5 @@
 /* PR rtl-optimization/85925 */
+/* { dg-require-effective-target int32plus } */
 /* Testcase by <s...@gcc.gnu.org> */
 
 int a, c, d;
@@ -9,17 +10,18 @@ union U1 {
   unsigned f0;
   unsigned f1 : 15;
 };
+volatile union U1 u = { 0x4030201 };
 
 int main (void)
 {
   for (c = 0; c <= 1; c++) {
-    union U1 f = {0x10101};
+    union U1 f = {0x4030201};
     if (c == 1)
       b;
     *e = f.f1;
   }
 
-  if (d != 0x101)
+  if (d != u.f1)
     __builtin_abort ();
 
   return 0;


        Jakub