aarch64: PR target/115457 Implement missing __ARM_FEATURE_BF16 macro

The ACLE asks the user to test for __ARM_FEATURE_BF16 before using the
<arm_bf16.h> header but GCC doesn't set this up.
LLVM does, so this is an inconsistency between the compilers.

This patch enables that macro for TARGET_BF16_FP.
Bootstrapped and tested on aarch64-none-linux-gnu.

gcc/

	PR target/115457
	* config/aarch64/aarch64-c.cc (aarch64_update_cpp_builtins):
	Define __ARM_FEATURE_BF16 for TARGET_BF16_FP.

gcc/testsuite/

	PR target/115457
	* gcc.target/aarch64/acle/bf16_feature.c: New test.

Signed-off-by: Kyrylo Tkachov <ktkachov@nvidia.com>
(cherry picked from commit c10942134fa759843ac1ed1424b86fcb8e6368ba)

diff --git a/gcc/config/aarch64/aarch64-c.cc b/gcc/config/aarch64/aarch64-c.cc
index a4c407724a783b856ac8f90fd4677e4d98a14023..b31b967c140dc42d0495ab198e848cbd78048784 100644 (file)
--- a/gcc/config/aarch64/aarch64-c.cc
+++ b/gcc/config/aarch64/aarch64-c.cc
@@ -200,6 +200,8 @@ aarch64_update_cpp_builtins (cpp_reader *pfile)
                        "__ARM_FEATURE_BF16_VECTOR_ARITHMETIC", pfile);
   aarch64_def_or_undef (TARGET_BF16_FP,
                        "__ARM_FEATURE_BF16_SCALAR_ARITHMETIC", pfile);
+  aarch64_def_or_undef (TARGET_BF16_FP,
+                       "__ARM_FEATURE_BF16", pfile);
   aarch64_def_or_undef (TARGET_LS64,
                        "__ARM_FEATURE_LS64", pfile);
   aarch64_def_or_undef (AARCH64_ISA_RCPC, "__ARM_FEATURE_RCPC", pfile);

diff --git a/gcc/testsuite/gcc.target/aarch64/acle/bf16_feature.c b/gcc/testsuite/gcc.target/aarch64/acle/bf16_feature.c
new file mode 100644 (file)
index 0000000..96584b4
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/acle/bf16_feature.c
@@ -0,0 +1,10 @@
+/* { dg-do compile } */
+
+#pragma GCC target "+bf16"
+#ifndef __ARM_FEATURE_BF16
+#error "__ARM_FEATURE_BF16 is not defined but should be!"
+#endif
+
+void
+foo (void) {}
+