On Tue, 2021-05-18 at 16:49 -0400, Michael Meissner wrote:
> [PATCH] Fix vec-splati-runnable.c test.
>
hi,
> I noticed that the vec-splati-runnable.c did not have an abort after one
> of the tests. If the test was run with optimization, the optimizer could
> delete some of the tests and throw off the count.
>
> I have bootstraped this on LE power9 and BE power8 systems. There were no
> regressions in the tests. Can I check this into the trunk?
>
> I do not expect to back port this to GCC 11 unless we will be back porting the
> future patches that add support for the XXSPLITW, XXSPLTIDP, and XXSPLTI32DX
> instructions.
>
> gcc/testsuite/
> 2021-05-18 Michael Meissner <meiss...@linux.ibm.com>
>
> * gcc.target/powerpc/vec-splati-runnable.c: Run test with -O2
> optimization. Do not check what XXSPLTIDP generates if the value
> is undefined.
> ---
> .../gcc.target/powerpc/vec-splati-runnable.c | 29 ++++++-------------
> 1 file changed, 9 insertions(+), 20 deletions(-)
>
> diff --git a/gcc/testsuite/gcc.target/powerpc/vec-splati-runnable.c
> b/gcc/testsuite/gcc.target/powerpc/vec-splati-runnable.c
> index e84ce77a21d..a135279b1d7 100644
> --- a/gcc/testsuite/gcc.target/powerpc/vec-splati-runnable.c
> +++ b/gcc/testsuite/gcc.target/powerpc/vec-splati-runnable.c
> @@ -1,7 +1,7 @@
> /* { dg-do run { target { power10_hw } } } */
> /* { dg-do link { target { ! power10_hw } } } */
> /* { dg-require-effective-target power10_ok } */
> -/* { dg-options "-mdejagnu-cpu=power10 -save-temps" } */
> +/* { dg-options "-mdejagnu-cpu=power10 -save-temps -O2" } */
> #include <altivec.h>
>
> #define DEBUG 0
> @@ -12,6 +12,8 @@
>
> extern void abort (void);
>
> +volatile vector double vresult_d_undefined;
> +
> int
> main (int argc, char *argv [])
> {
> @@ -85,25 +87,12 @@ main (int argc, char *argv [])
> #endif
> }
>
> - /* This test will generate a "note" to the user that the argument
> - is subnormal. It is not an error, but results are not defined. */
> - vresult_d = (vector double) { 2.0, 3.0 };
> - expected_vresult_d = (vector double) { 6.6E-42f, 6.6E-42f };
> -
> - vresult_d = vec_splatid (6.6E-42f);
> -
> - /* Although the instruction says the results are not defined, it does seem
> - to work, at least on Mambo. But no guarentees! */
> - if (!vec_all_eq (vresult_d, expected_vresult_d)) {
> -#if DEBUG
> - printf("ERROR, vec_splati (6.6E-42f)\n");
> - for(i = 0; i < 2; i++)
> - printf(" vresult_d[%i] = %e, expected_vresult_d[%i] = %e\n",
> - i, vresult_d[i], i, expected_vresult_d[i]);
> -#else
> - ;
> -#endif
> - }
> + /* This test will generate a "note" to the user that the argument is
> + subnormal. It is not an error, but results are not defined. Because
> this
> + is undefined, we cannot check that any value is correct. Just store it
> in
as in undefined-behavior..?
> + a volatile variable so the XXSPLTIDP instruction gets generated and the
> + warning message printed. */
> + vresult_d_undefined = vec_splatid (6.6E-42f);
This does not look like it adds an abort() call as I would have
expected per the patch description.
So this looks like it still calls vec_splatid(), but instead assigns
result to a variable name vresult_d_undefined. Also removes some
DEBUG code, which is fine. So just the vec_all_eq() call is removed?
I'm not certain I see how that will change the results, just the -O2
optimization makes the difference?
I may be missing something...
Thanks,
-Will
>
> /* Vector splat immediate */
> vsrc_a_int = (vector int) { 2, 3, 4, 5 };
> --
> 2.31.1
>
