[gcc r15-2436] aarch64: Add march flags for +fp8 arch extensions

[Richard Sandiford via Gcc-cvs]

https://gcc.gnu.org/g:72ebbc3b2bb9bb3649f1222f731a9b4d0197499e

commit r15-2436-g72ebbc3b2bb9bb3649f1222f731a9b4d0197499e
Author: Claudio Bantaloukas <claudio.bantalou...@arm.com>
Date:   Wed Jul 31 14:42:39 2024 +0100

    aarch64: Add march flags for +fp8 arch extensions
    
    This introduces the relevant flags to enable access to the fpmr register 
and fp8 intrinsics, which will be added subsequently.
    
    gcc/ChangeLog:
    
            * config/aarch64/aarch64-option-extensions.def (fp8): New.
            * config/aarch64/aarch64.h (TARGET_FP8): Likewise.
            * doc/invoke.texi (AArch64 Options): Document new -march flags
            and extensions.
    
    gcc/testsuite/ChangeLog:
    
            * gcc.target/aarch64/acle/fp8.c: New test.

Diff:
---
 gcc/config/aarch64/aarch64-option-extensions.def |  2 ++
 gcc/config/aarch64/aarch64.h                     |  3 +++
 gcc/doc/invoke.texi                              |  2 ++
 gcc/testsuite/gcc.target/aarch64/acle/fp8.c      | 20 ++++++++++++++++++++
 4 files changed, 27 insertions(+)

diff --git a/gcc/config/aarch64/aarch64-option-extensions.def 
b/gcc/config/aarch64/aarch64-option-extensions.def
index 42ec0eec31e2..6998627f3774 100644
--- a/gcc/config/aarch64/aarch64-option-extensions.def
+++ b/gcc/config/aarch64/aarch64-option-extensions.def
@@ -232,6 +232,8 @@ AARCH64_OPT_EXTENSION("the", THE, (), (), (), "the")
 
 AARCH64_OPT_EXTENSION("gcs", GCS, (), (), (), "gcs")
 
+AARCH64_OPT_EXTENSION("fp8", FP8, (SIMD), (), (), "fp8")
+
 #undef AARCH64_OPT_FMV_EXTENSION
 #undef AARCH64_OPT_EXTENSION
 #undef AARCH64_FMV_FEATURE
diff --git a/gcc/config/aarch64/aarch64.h b/gcc/config/aarch64/aarch64.h
index b7e330438d9b..2e75c6b81e20 100644
--- a/gcc/config/aarch64/aarch64.h
+++ b/gcc/config/aarch64/aarch64.h
@@ -463,6 +463,9 @@ constexpr auto AARCH64_FL_DEFAULT_ISA_MODE ATTRIBUTE_UNUSED
                                 && (aarch64_tune_params.extra_tuning_flags \
                                     & AARCH64_EXTRA_TUNE_AVOID_PRED_RMW))
 
+/* fp8 instructions are enabled through +fp8.  */
+#define TARGET_FP8 AARCH64_HAVE_ISA (FP8)
+
 /* Standard register usage.  */
 
 /* 31 64-bit general purpose registers R0-R30:
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index 86f9b5d1fe5e..ef2213b4e841 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -21849,6 +21849,8 @@ Enable support for Armv9.4-a Guarded Control Stack 
extension.
 Enable support for Armv8.9-a/9.4-a translation hardening extension.
 @item rcpc3
 Enable the RCpc3 (Release Consistency) extension.
+@item fp8
+Enable the fp8 (8-bit floating point) extension.
 
 @end table
 
diff --git a/gcc/testsuite/gcc.target/aarch64/acle/fp8.c 
b/gcc/testsuite/gcc.target/aarch64/acle/fp8.c
new file mode 100644
index 000000000000..459442be1557
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/acle/fp8.c
@@ -0,0 +1,20 @@
+/* Test the fp8 ACLE intrinsics family.  */
+/* { dg-do compile } */
+/* { dg-options "-O1 -march=armv8-a" } */
+
+#include <arm_acle.h>
+
+#ifdef __ARM_FEATURE_FP8
+#error "__ARM_FEATURE_FP8 feature macro defined."
+#endif
+
+#pragma GCC push_options
+#pragma GCC target("arch=armv9.4-a+fp8")
+
+/* We do not define __ARM_FEATURE_FP8 until all
+   relevant features have been added. */
+#ifdef __ARM_FEATURE_FP8
+#error "__ARM_FEATURE_FP8 feature macro defined."
+#endif
+
+#pragma GCC pop_options