From: sunyuechi <sunyue...@iscas.ac.cn>
This patch is derived from "config/riscv: detect presence of Zbc
extension with modifications".
The RISC-V C api defines architecture extension test macros
These let us detect whether the V extension is supported on the
compiler and -march we're building with. The C api also defines V
intrinsics we can use rather than inline assembly on newer versions of
GCC (14.1.0+) and Clang (18.1.0+).
If the V extension and intrinsics are both present and we can detect
the V extension at runtime, we define a flag, RTE_RISCV_FEATURE_V.
Signed-off-by: sunyuechi <sunyue...@iscas.ac.cn>
---
config/riscv/meson.build | 25 +++++++++++++++++++++++++
1 file changed, 25 insertions(+)
diff --git a/config/riscv/meson.build b/config/riscv/meson.build
index 7562c6cb99..e3694cf2e6 100644
--- a/config/riscv/meson.build
+++ b/config/riscv/meson.build
@@ -119,6 +119,31 @@ foreach flag: arch_config['machine_args']
endif
endforeach
+# check if we can do buildtime detection of extensions supported by the target
+riscv_extension_macros = false
+if (cc.get_define('__riscv_arch_test', args: machine_args) == '1')
+ message('Detected architecture extension test macros')
+ riscv_extension_macros = true
+else
+ warning('RISC-V architecture extension test macros not available. Build-time
detection of extensions not possible')
+endif
+
+# detect extensions
+# Requires intrinsics available in GCC 14.1.0+ and Clang 18.1.0+
+if (riscv_extension_macros and
+ (cc.get_define('__riscv_vector', args: machine_args) != ''))
+ if ((cc.get_id() == 'gcc' and cc.version().version_compare('>=14.1.0'))
+ or (cc.get_id() == 'clang' and cc.version().version_compare('>=18.1.0')))
+ if (cc.compiles('''#include <riscv_vector.h>
+ int main(void) { size_t vl = __riscv_vsetvl_e32m1(1); }''', args:
machine_args))
+ message('Compiling with the V extension')
+ machine_args += ['-DRTE_RISCV_FEATURE_V']
+ endif
+ else
+ warning('Detected V extension but cannot use because intrinsics are not
available (present in GCC 14.1.0+ and Clang 18.1.0+)')
+ endif
+endif
+
# apply flags
foreach flag: dpdk_flags
if flag.length() > 0
--
2.49.0
