@@ -1082,6 +1082,14 @@ struct ppc_radix_page_info {
enum {
CACHED_FN_TYPE_NONE,
+ CACHED_FN_TYPE_F64_F64_FSTATUS,
+
+};
+
+struct cached_fn_f64_f64_fstatus {
+ float64 (*fn)(float64, float_status*);
+ float64 arg1;
+ float_status arg2;
};
struct CPUArchState {
@@ -1162,6 +1170,9 @@ struct CPUArchState {
target_ulong fpscr; /* Floating point status and control register */
int cached_fn_type;
+ union {
+ struct cached_fn_f64_f64_fstatus f64_f64_fstatus;
+ } cached_fn;
/* Internal devices resources */
ppc_tb_t *tb_env; /* Time base and decrementer */
@@ -30,8 +30,24 @@
float_flag_inexact)); \
env->cached_fn_type = CACHED_FN_TYPE_NONE; \
} while (0)
+
+#define CACHE_FN_3(env, FN, ARG1, ARG2, FIELD, TYPE) \
+ do { \
+ if (env->fpscr & FP_XX) { \
+ env->cached_fn_type = TYPE; \
+ env->cached_fn.FIELD.fn = FN; \
+ env->cached_fn.FIELD.arg1 = ARG1; \
+ env->cached_fn.FIELD.arg2 = ARG2; \
+ env->fp_status.float_exception_flags |= float_flag_inexact; \
+ } else { \
+ assert(!(env->fp_status.float_exception_flags & \
+ float_flag_inexact)); \
+ env->cached_fn_type = CACHED_FN_TYPE_NONE; \
+ } \
+ } while (0)
#else
#define CACHE_FN_NONE(env)
+#define CACHE_FN_3(env, FN, ARG1, ARG2, FIELD, TYPE)
#endif
static inline float128 float128_snan_to_qnan(float128 x)
@@ -535,6 +551,27 @@ void helper_execute_fp_cached(CPUPPCState *env)
* so no need to execute it again
*/
break;
+ case CACHED_FN_TYPE_F64_F64_FSTATUS:
+ /*
+ * execute the cached insn. At this point, float_exception_flags
+ * should have FI not set, otherwise the result will not be correct
+ */
+ assert((env->cached_fn.f64_f64_fstatus.arg2.float_exception_flags &
+ float_flag_inexact) == 0);
+ env->cached_fn.f64_f64_fstatus.fn(
+ env->cached_fn.f64_f64_fstatus.arg1,
+ &env->cached_fn.f64_f64_fstatus.arg2);
+
+ env->fpscr &= ~FP_FI;
+ /*
+ * if the cached instruction resulted in FI being set
+ * then we update fpscr with this value
+ */
+ if (env->cached_fn.f64_f64_fstatus.arg2.float_exception_flags &
+ float_flag_inexact) {
+ env->fpscr |= FP_FI | FP_XX;
+ }
+ break;
default:
g_assert_not_reached();
}
@@ -878,7 +915,8 @@ static void float_invalid_op_sqrt(CPUPPCState *env, int flags,
#define FPU_FSQRT(name, op) \
float64 helper_##name(CPUPPCState *env, float64 arg) \
{ \
- CACHE_FN_NONE(env); \
+ CACHE_FN_3(env, op, arg, env->fp_status, f64_f64_fstatus, \
+ CACHED_FN_TYPE_F64_F64_FSTATUS); \
float64 ret = op(arg, &env->fp_status); \
int flags = get_float_exception_flags(&env->fp_status); \
\
This patch adds the code necessary to cache fsqrt for usage with hardfpu in Power. It is also the first instruction to use the new cache instruction system. fsqrt is an instruction that receives two arguments, one f64 and one status, and returns f64. This info will be cached inside a new union in env, which will grow when other instructions with other signatures are added. Hardfpu in QEMU only works when the inexact is already set. So, CACHE_FN_3 will check if FP_XX is set, and set float_flag_inexact to enable the hardfpu behavior. When the instruction is later reexecuted, it will be with float_flag_inexact cleared, forcing softfloat and correctly updating the relevant flags, as is today. This implementation only works in linux-user. No test or effort was done in this patch to make it work for softmmu. Future work will be required to make it work correctly in this scenario. Signed-off-by: Víctor Colombo <victor.colombo@eldorado.org.br> --- target/ppc/cpu.h | 11 +++++++++++ target/ppc/fpu_helper.c | 40 +++++++++++++++++++++++++++++++++++++++- 2 files changed, 50 insertions(+), 1 deletion(-)