[PATCH v1 5/6] RISC-V: Add the Zicsr extension

[Palmer Dabbelt <palmer@rivosinc.com>]

Recent versions of binutils default to an ISA spec version that doesn't
include Zicsr as part of I, so Linux has recently started passing this
in -march.

Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
---
 target-riscv.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/target-riscv.c b/target-riscv.c
index 5076bbaf..afd6fafa 100644
--- a/target-riscv.c
+++ b/target-riscv.c
@@ -17,6 +17,7 @@
 #define RISCV_EMBD	(1 << 9)
 #define RISCV_FPU	(RISCV_FLOAT|RISCV_DOUBLE|RISCV_FDIV)
 #define RISCV_GENERIC	(RISCV_MUL|RISCV_DIV|RISCV_ATOMIC|RISCV_FPU)
+#define RISCV_ZICSR	(1 << 10)
 
 static unsigned int riscv_flags;
 
@@ -34,9 +35,10 @@ static void parse_march_riscv(const char *arg)
 	}, extensions[] = {
 		{ "m",		RISCV_MUL|RISCV_DIV },
 		{ "a",		RISCV_ATOMIC },
-		{ "f",		RISCV_FLOAT|RISCV_FDIV },
-		{ "d",		RISCV_DOUBLE|RISCV_FDIV },
+		{ "f",		RISCV_FLOAT|RISCV_FDIV|RISCV_ZICSR },
+		{ "d",		RISCV_DOUBLE|RISCV_FDIV|RISCV_ZICSR },
 		{ "c",		RISCV_COMP },
+		{ "_zicsr",	RISCV_ZICSR },
 	};
 	int i;
 
@@ -128,6 +130,8 @@ static void predefine_riscv(const struct target *self)
 		predefine("__riscv_mul", 1, "1");
 	if ((riscv_flags & RISCV_MUL) && (riscv_flags & RISCV_DIV))
 		predefine("__riscv_muldiv", 1, "1");
+	if (riscv_flags & RISCV_ZICSR)
+		predefine("__riscv_zicsr", 1, "1");
 
 	if (cmodel)
 		predefine_strong("__riscv_cmodel_%s", cmodel);
-- 
2.34.1