util: detect RISC-V architecture

Reviewed-by: Dave Airlie <airlied@redhat.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/26018>

src/util/detect_arch.h

@@ -101,6 +101,17 @@
 #define DETECT_ARCH_HPPA 1
 #endif
 
+#if defined(__riscv)
+#define DETECT_ARCH_RISCV 1
+#if __riscv_xlen == 64
+#define DETECT_ARCH_RISCV64 1
+#elif __riscv_xlen == 32
+#define DETECT_ARCH_RISCV32 1
+#else
+#error "detect_arch: unknown target riscv xlen"
+#endif
+#endif
+
 #ifndef DETECT_ARCH_X86
 #define DETECT_ARCH_X86 0
 #endif
@@ -145,4 +156,16 @@
 #define DETECT_ARCH_HPPA 0
 #endif
 
+#ifndef DETECT_ARCH_RISCV
+#define DETECT_ARCH_RISCV 0
+#endif
+
+#ifndef DETECT_ARCH_RISCV32
+#define DETECT_ARCH_RISCV32 0
+#endif
+
+#ifndef DETECT_ARCH_RISCV64
+#define DETECT_ARCH_RISCV64 0
+#endif
+
 #endif /* UTIL_DETECT_ARCH_H_ */