--- /dev/null
+/*
+ * TriCore emulation for qemu: fpu helper.
+ *
+ * Copyright (c) 2016 Bastian Koppelmann University of Paderborn
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "qemu/osdep.h"
+#include "cpu.h"
+#include "exec/helper-proto.h"
+
+#define ADD_NAN 0x7cf00001
+#define DIV_NAN 0x7fc00008
+#define MUL_NAN 0x7fc00002
+#define FPU_FS PSW_USB_C
+#define FPU_FI PSW_USB_V
+#define FPU_FV PSW_USB_SV
+#define FPU_FZ PSW_USB_AV
+#define FPU_FU PSW_USB_SAV
+
+/* we don't care about input_denormal */
+static inline uint8_t f_get_excp_flags(CPUTriCoreState *env)
+{
+ return get_float_exception_flags(&env->fp_status)
+ & (float_flag_invalid
+ | float_flag_overflow
+ | float_flag_underflow
+ | float_flag_output_denormal
+ | float_flag_divbyzero
+ | float_flag_inexact);
+}
+
+static inline bool f_is_denormal(float32 arg)
+{
+ return float32_is_zero_or_denormal(arg) && !float32_is_zero(arg);
+}
+
+static void f_update_psw_flags(CPUTriCoreState *env, uint8_t flags)
+{
+ uint8_t some_excp = 0;
+ set_float_exception_flags(0, &env->fp_status);
+
+ if (flags & float_flag_invalid) {
+ env->FPU_FI = 1 << 31;
+ some_excp = 1;
+ }
+
+ if (flags & float_flag_overflow) {
+ env->FPU_FV = 1 << 31;
+ some_excp = 1;
+ }
+
+ if (flags & float_flag_underflow || flags & float_flag_output_denormal) {
+ env->FPU_FU = 1 << 31;
+ some_excp = 1;
+ }
+
+ if (flags & float_flag_divbyzero) {
+ env->FPU_FZ = 1 << 31;
+ some_excp = 1;
+ }
+
+ if (flags & float_flag_inexact || flags & float_flag_output_denormal) {
+ env->PSW |= 1 << 26;
+ some_excp = 1;
+ }
+
+ env->FPU_FS = some_excp;
+}
+
+#define FADD_SUB(op) \
+uint32_t helper_f##op(CPUTriCoreState *env, uint32_t r1, uint32_t r2) \
+{ \
+ float32 arg1 = make_float32(r1); \
+ float32 arg2 = make_float32(r2); \
+ uint32_t flags; \
+ float32 f_result; \
+ \
+ f_result = float32_##op(arg2, arg1, &env->fp_status); \
+ flags = f_get_excp_flags(env); \
+ if (flags) { \
+ /* If the output is a NaN, but the inputs aren't, \
+ we return a unique value. */ \
+ if ((flags & float_flag_invalid) \
+ && !float32_is_any_nan(arg1) \
+ && !float32_is_any_nan(arg2)) { \
+ f_result = ADD_NAN; \
+ } \
+ f_update_psw_flags(env, flags); \
+ } else { \
+ env->FPU_FS = 0; \
+ } \
+ return (uint32_t)f_result; \
+}
+FADD_SUB(add)
+FADD_SUB(sub)
+
+uint32_t helper_fmul(CPUTriCoreState *env, uint32_t r1, uint32_t r2)
+{
+ uint32_t flags;
+ float32 arg1 = make_float32(r1);
+ float32 arg2 = make_float32(r2);
+ float32 f_result;
+
+ f_result = float32_mul(arg1, arg2, &env->fp_status);
+
+ flags = f_get_excp_flags(env);
+ if (flags) {
+ /* If the output is a NaN, but the inputs aren't,
+ we return a unique value. */
+ if ((flags & float_flag_invalid)
+ && !float32_is_any_nan(arg1)
+ && !float32_is_any_nan(arg2)) {
+ f_result = MUL_NAN;
+ }
+ f_update_psw_flags(env, flags);
+ } else {
+ env->FPU_FS = 0;
+ }
+ return (uint32_t)f_result;
+
+}
+
+uint32_t helper_fdiv(CPUTriCoreState *env, uint32_t r1, uint32_t r2)
+{
+ uint32_t flags;
+ float32 arg1 = make_float32(r1);
+ float32 arg2 = make_float32(r2);
+ float32 f_result;
+
+ f_result = float32_div(arg1, arg2 , &env->fp_status);
+
+ flags = f_get_excp_flags(env);
+ if (flags) {
+ /* If the output is a NaN, but the inputs aren't,
+ we return a unique value. */
+ if ((flags & float_flag_invalid)
+ && !float32_is_any_nan(arg1)
+ && !float32_is_any_nan(arg2)) {
+ f_result = DIV_NAN;
+ }
+ f_update_psw_flags(env, flags);
+ } else {
+ env->FPU_FS = 0;
+ }
+
+ return (uint32_t)f_result;
+}
+
+uint32_t helper_fcmp(CPUTriCoreState *env, uint32_t r1, uint32_t r2)
+{
+ uint32_t result, flags;
+ float32 arg1 = make_float32(r1);
+ float32 arg2 = make_float32(r2);
+
+ set_flush_inputs_to_zero(0, &env->fp_status);
+
+ result = 1 << (float32_compare_quiet(arg1, arg2, &env->fp_status) + 1);
+ result |= f_is_denormal(arg1) << 4;
+ result |= f_is_denormal(arg2) << 5;
+
+ flags = f_get_excp_flags(env);
+ if (flags) {
+ f_update_psw_flags(env, flags);
+ } else {
+ env->FPU_FS = 0;
+ }
+
+ set_flush_inputs_to_zero(1, &env->fp_status);
+ return result;
+}
+
+uint32_t helper_ftoi(CPUTriCoreState *env, uint32_t arg)
+{
+ float32 f_arg = make_float32(arg);
+ int32_t result, flags;
+
+ result = float32_to_int32(f_arg, &env->fp_status);
+
+ flags = f_get_excp_flags(env);
+ if (flags) {
+ if (float32_is_any_nan(f_arg)) {
+ result = 0;
+ }
+ f_update_psw_flags(env, flags);
+ } else {
+ env->FPU_FS = 0;
+ }
+ return (uint32_t)result;
+}
+
+uint32_t helper_itof(CPUTriCoreState *env, uint32_t arg)
+{
+ float32 f_result;
+ uint32_t flags;
+ f_result = int32_to_float32(arg, &env->fp_status);
+
+ flags = f_get_excp_flags(env);
+ if (flags) {
+ f_update_psw_flags(env, flags);
+ } else {
+ env->FPU_FS = 0;
+ }
+ return (uint32_t)f_result;
+}
Code Review / kvmfornfv.git / blobdiff