target/loongarch: Split fcc register to fcc0-7 in gdbstub

Since GDB 13.1(GDB commit ea3352172), GDB LoongArch changed to use
fcc0-7 instead of fcc register. This commit partially reverts commit
2f149c759 (`target/loongarch: Update gdb_set_fpu() and gdb_get_fpu()`)
to match the behavior of GDB.

Note that it is a breaking change for GDB 13.0 or earlier, but it is
also required for GDB 13.1 or later to work.

Signed-off-by: Jiajie Chen <c@jia.je>
Acked-by: Song Gao <gaosong@loongson.cn>
Message-Id: <20230808054315.3391465-1-c@jia.je>
Signed-off-by: Song Gao <gaosong@loongson.cn>

1 files changed, 7 insertions, 9 deletions

diff --git a/target/loongarch/gdbstub.c b/target/loongarch/gdbstub.c
index e20b20f..b09804b 100644
--- a/target/loongarch/gdbstub.c
+++ b/target/loongarch/gdbstub.c
@@ -88,10 +88,9 @@ static int loongarch_gdb_get_fpu(CPULoongArchState *env,
 {
     if (0 <= n && n < 32) {
         return gdb_get_reg64(mem_buf, env->fpr[n].vreg.D(0));
-    } else if (n == 32) {
-        uint64_t val = read_fcc(env);
-        return gdb_get_reg64(mem_buf, val);
-    } else if (n == 33) {
+    } else if (32 <= n && n < 40) {
+        return gdb_get_reg8(mem_buf, env->cf[n - 32]);
+    } else if (n == 40) {
         return gdb_get_reg32(mem_buf, env->fcsr0);
     }
     return 0;
@@ -105,11 +104,10 @@ static int loongarch_gdb_set_fpu(CPULoongArchState *env,
     if (0 <= n && n < 32) {
         env->fpr[n].vreg.D(0) = ldq_p(mem_buf);
         length = 8;
-    } else if (n == 32) {
-        uint64_t val = ldq_p(mem_buf);
-        write_fcc(env, val);
-        length = 8;
-    } else if (n == 33) {
+    } else if (32 <= n && n < 40) {
+        env->cf[n - 32] = ldub_p(mem_buf);
+        length = 1;
+    } else if (n == 40) {
         env->fcsr0 = ldl_p(mem_buf);
         length = 4;
     }