On Tue, Sep 6, 2016 at 5:06 PM, Jakub Jelinek <ja...@redhat.com> wrote:
> On Mon, Sep 05, 2016 at 08:58:12PM +0200, Uros Bizjak wrote:
>> ... perhaps we can emit a warning here and expand the builtin as a
>> call? This way, we will mirror the case when builtin requires some
>> ISA, e.g.:
>>
>> void foo ()
>> {
>> __builtin_ia32_stmxcsr();
>> }
>>
>> $ gcc -S -mno-sse dd.c
>> dd.c: In function ‘foo’:
>> dd.c:3:3: warning: implicit declaration of function
>> ‘__builtin_ia32_stmxcsr’ [-Wimplicit-function-declaration]
>> __builtin_ia32_stmxcsr();
>> ^~~~~~~~~~~~~~~~~~~~~~
>
> I'm not sure it is a good idea to emit a warning, we are in the backend
> and we don't know what kind of warning/error the FE would emit if the
> builtin isn't implicitly prototyped. E.g. C++ would certainly error out,
> C with -pedantic-errors would too, etc., it is simply too hard to replicate
> such behavior this late.
OK.
> Using expand_call works too (only tested on the testcases so far, but can test
> it fully), just had to add some expected warnings for the return and
> argument type -Wpsabi stuff.
Yes, this is what compiling testcase without using #pragmas warns.
> 2016-09-05 Jakub Jelinek <ja...@redhat.com>
>
> PR target/69255
> * config/i386/i386.c (ix86_expand_builtin): For builtin with
> unsupported or unknown ISA, use expand_call.
>
> * gcc.target/i386/pr69255-1.c: New test.
> * gcc.target/i386/pr69255-2.c: New test.
> * gcc.target/i386/pr69255-3.c: New test.
OK for mainline and release branches.
Thanks,
Uros.
> --- gcc/config/i386/i386.c.jj 2016-09-05 19:27:03.287671306 +0200
> +++ gcc/config/i386/i386.c 2016-09-06 16:55:35.524605779 +0200
> @@ -36107,7 +36107,7 @@ ix86_expand_builtin (tree exp, rtx targe
> error ("%qE needs isa option %s", fndecl, opts);
> free (opts);
> }
> - return const0_rtx;
> + return expand_call (exp, target, ignore);
> }
>
> switch (fcode)
> --- gcc/testsuite/gcc.target/i386/pr69255-1.c.jj 2016-09-06
> 16:54:01.793783159 +0200
> +++ gcc/testsuite/gcc.target/i386/pr69255-1.c 2016-09-06 16:59:53.317370510
> +0200
> @@ -0,0 +1,17 @@
> +/* PR target/69255 */
> +/* { dg-do compile } */
> +/* { dg-options "-mno-avx512f" } */
> +
> +#pragma GCC target "avx512vl"
> +#pragma GCC target "no-avx512vl"
> +__attribute__ ((__vector_size__ (32))) long long a;
> +__attribute__ ((__vector_size__ (16))) int b;
> +
> +void
> +foo (const long long *p)
> +{
> + a = __builtin_ia32_gather3siv4di (a, p, b, 1, 1); /* { dg-error "needs
> isa option -m32 -mavx512vl" } */
> +}
> +
> +/* { dg-warning "AVX vector return without AVX enabled changes the ABI" "" {
> target *-*-* } 13 } */
> +/* { dg-warning "AVX vector argument without AVX enabled changes the ABI" ""
> { target *-*-* } 13 } */
> --- gcc/testsuite/gcc.target/i386/pr69255-2.c.jj 2016-09-06
> 16:54:01.793783159 +0200
> +++ gcc/testsuite/gcc.target/i386/pr69255-2.c 2016-09-06 17:00:04.229233625
> +0200
> @@ -0,0 +1,17 @@
> +/* PR target/69255 */
> +/* { dg-do compile } */
> +/* { dg-options "-mno-avx512f" } */
> +
> +#pragma GCC target "avx512vl"
> +#pragma GCC target ""
> +__attribute__ ((__vector_size__ (32))) long long a;
> +__attribute__ ((__vector_size__ (16))) int b;
> +
> +void
> +foo (const long long *p)
> +{
> + __builtin_ia32_gather3siv4di (a, p, b, 1, 1); /* { dg-error
> "needs isa option -m32 -mavx512vl" } */
> +}
> +
> +/* { dg-warning "AVX vector return without AVX enabled changes the ABI" "" {
> target *-*-* } 13 } */
> +/* { dg-warning "AVX vector argument without AVX enabled changes the ABI" ""
> { target *-*-* } 13 } */
> --- gcc/testsuite/gcc.target/i386/pr69255-3.c.jj 2016-09-06
> 16:54:01.794783146 +0200
> +++ gcc/testsuite/gcc.target/i386/pr69255-3.c 2016-09-06 17:00:14.915099574
> +0200
> @@ -0,0 +1,17 @@
> +/* PR target/69255 */
> +/* { dg-do compile } */
> +/* { dg-options "-mno-avx512f" } */
> +
> +#pragma GCC target "avx512vl"
> +#pragma GCC target ""
> +__attribute__ ((__vector_size__ (32))) long long a;
> +__attribute__ ((__vector_size__ (16))) int b;
> +
> +void
> +foo (const long long *p, __attribute__ ((__vector_size__ (32))) long long *q)
> +{
> + *q = __builtin_ia32_gather3siv4di (a, p, b, 1, 1); /* { dg-error "needs
> isa option -m32 -mavx512vl" } */
> +}
> +
> +/* { dg-warning "AVX vector return without AVX enabled changes the ABI" "" {
> target *-*-* } 13 } */
> +/* { dg-warning "AVX vector argument without AVX enabled changes the ABI" ""
> { target *-*-* } 13 } */
>
>
> Jakub
