On 9/6/19 12:47 PM, Richard Earnshaw (lists) wrote:
> On 06/09/2019 11:28, Bernd Edlinger wrote:
>> Hi!
>>
>> It was pointed out in the PR that the test case fails on big endian
>> targets.
>>
>> This is probably obvious, since the test case scans the assembler
>> output for vld1.32, vst1.32, vldr and vstr, but these are never
>> generated for -mbig-endian.
>>
>> So added dg-require-effective-target arm_little_endian.
>>
>>
>> Is it OK for trunk?
>>
>>
>> Thanks
>> Bernd.
>>
>
> I think this test needs further work - there's opportunity for the compiler
> to optimize it by placement of both a and x, since it can see both
> definitions. Note that vldr is safe on 32-bit (or higher) aligned objects,
> so if GCC can see the definition it can use that information (the actual
> rather than the declared placement) in its optimizations.
>
> Changing the global to extern, or making it a pointer and dereferencing that
> is probably enough.
>
done.
> Finally, the test is really just a memory copy operation. There's no real
> reason why it has to use the vector registers for this at all. I think if
> you want to force them, you'll need to do some operations on the values as
> well so that the compiler has to place the values in the vector registers
> rather than anywhere it sees fit.
>
Okay, nailed the test case down, to use neon registers.
Is it OK now?
Thanks
Bernd.
2019-09-06 Bernd Edlinger <bernd.edlin...@hotmail.de>
* gcc.target/arm/pr91603.c: Add dg-require-effective-target
arm_little_endian. Force value in neon register.
Index: gcc/testsuite/gcc.target/arm/pr91603.c
===================================================================
--- gcc/testsuite/gcc.target/arm/pr91603.c (revision 275409)
+++ gcc/testsuite/gcc.target/arm/pr91603.c (working copy)
@@ -1,5 +1,6 @@
/* { dg-do compile } */
/* { dg-require-effective-target arm_neon_ok } */
+/* { dg-require-effective-target arm_little_endian } */
/* { dg-options "-O3" } */
/* { dg-add-options arm_neon } */
@@ -6,7 +7,7 @@
typedef __simd64_int32_t int32x2_t;
typedef __attribute__((aligned (1))) int32x2_t unalignedvec;
-unalignedvec a = {11, 13};
+extern unalignedvec a;
void foo(unalignedvec *);
@@ -13,7 +14,9 @@ void foo(unalignedvec *);
void test()
{
unalignedvec x = a;
+ __asm__ ("@ value in %h0": "=w"(x) : "0"(x));
foo (&x);
+ __asm__ ("@ value in %h0": "=w"(x) : "0"(x));
a = x;
}
