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.
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.
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.
--- 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
