Add helpers for reading/writing the 68881 FPSR register so that
changes in floating point exception state can be seen by the
application.
Signed-off-by: Keith Packard <kei...@keithp.com>
---
target/m68k/cpu.h | 2 ++
target/m68k/fpu_helper.c | 72 ++++++++++++++++++++++++++++++++++++++++
target/m68k/helper.c | 4 +--
target/m68k/helper.h | 2 ++
target/m68k/translate.c | 4 +--
5 files changed, 80 insertions(+), 4 deletions(-)
diff --git a/target/m68k/cpu.h b/target/m68k/cpu.h
index b741c50a8f..1e491fda77 100644
--- a/target/m68k/cpu.h
+++ b/target/m68k/cpu.h
@@ -173,6 +173,8 @@ struct ArchCPU {
CPUM68KState env;
};
+uint32_t cpu_m68k_get_fpsr(CPUM68KState *env);
+void cpu_m68k_set_fpsr(CPUM68KState *env, uint32_t val);
#ifndef CONFIG_USER_ONLY
void m68k_cpu_do_interrupt(CPUState *cpu);
diff --git a/target/m68k/fpu_helper.c b/target/m68k/fpu_helper.c
index ab120b5f59..542ce1790a 100644
--- a/target/m68k/fpu_helper.c
+++ b/target/m68k/fpu_helper.c
@@ -164,6 +164,78 @@ void HELPER(set_fpcr)(CPUM68KState *env, uint32_t val)
cpu_m68k_set_fpcr(env, val);
}
+/* Convert host exception flags to cpu_m68k form. */
+static inline int cpu_m68k_exceptbits_from_host(int host_bits)
+{
+ int target_bits = 0;
+
+ if (host_bits & float_flag_invalid) {
+ target_bits |= 0x80;
+ }
+ if (host_bits & float_flag_overflow) {
+ target_bits |= 0x40;
+ }
+ if (host_bits & (float_flag_underflow | float_flag_output_denormal)) {
+ target_bits |= 0x20;
+ }
+ if (host_bits & float_flag_divbyzero) {
+ target_bits |= 0x10;
+ }
+ if (host_bits & float_flag_inexact) {
+ target_bits |= 0x08;
+ }
+ return target_bits;
+}
+
+/* Convert cpu_m68k exception flags to target form. */
+static inline int cpu_m68k_exceptbits_to_host(int target_bits)
+{
+ int host_bits = 0;
+
+ if (target_bits & 0x80) {
+ host_bits |= float_flag_invalid;
+ }
+ if (target_bits & 0x40) {
+ host_bits |= float_flag_overflow;
+ }
+ if (target_bits & 0x20) {
+ host_bits |= float_flag_underflow;
+ }
+ if (target_bits & 0x10) {
+ host_bits |= float_flag_divbyzero;
+ }
+ if (target_bits & 0x08) {
+ host_bits |= float_flag_inexact;
+ }
+ return host_bits;
+}
+
+uint32_t HELPER(get_fpsr)(CPUM68KState *env)
+{
+ int host_flags = get_float_exception_flags(&env->fp_status);
+ int target_flags = cpu_m68k_exceptbits_from_host(host_flags);
+ int except = (env->fpsr & ~(0xf8)) | target_flags;
+ return except;
+}
+
+uint32_t cpu_m68k_get_fpsr(CPUM68KState *env)
+{
+ return HELPER(get_fpsr)(env);
+}
+
+void HELPER(set_fpsr)(CPUM68KState *env, uint32_t val)
+{
+ env->fpsr = val;
+
+ int host_flags = cpu_m68k_exceptbits_to_host((int) env->fpsr);
+ set_float_exception_flags(host_flags, &env->fp_status);
+}
+
+void cpu_m68k_set_fpsr(CPUM68KState *env, uint32_t val)
+{
+ return HELPER(set_fpsr)(env, val);
+}
+
#define PREC_BEGIN(prec) \
do { \
FloatX80RoundPrec old = \
diff --git a/target/m68k/helper.c b/target/m68k/helper.c
index 0a1544cd68..beab4b96bc 100644
--- a/target/m68k/helper.c
+++ b/target/m68k/helper.c
@@ -118,7 +118,7 @@ static int m68k_fpu_gdb_get_reg(CPUM68KState *env,
GByteArray *mem_buf, int n)
case 8: /* fpcontrol */
return gdb_get_reg32(mem_buf, env->fpcr);
case 9: /* fpstatus */
- return gdb_get_reg32(mem_buf, env->fpsr);
+ return gdb_get_reg32(mem_buf, cpu_m68k_get_fpsr(env));
case 10: /* fpiar, not implemented */
return gdb_get_reg32(mem_buf, 0);
}
@@ -137,7 +137,7 @@ static int m68k_fpu_gdb_set_reg(CPUM68KState *env, uint8_t
*mem_buf, int n)
cpu_m68k_set_fpcr(env, ldl_p(mem_buf));
return 4;
case 9: /* fpstatus */
- env->fpsr = ldl_p(mem_buf);
+ cpu_m68k_set_fpsr(env, ldl_p(mem_buf));
return 4;
case 10: /* fpiar, not implemented */
return 4;
diff --git a/target/m68k/helper.h b/target/m68k/helper.h
index 2bbe0dc032..95aa5e53bb 100644
--- a/target/m68k/helper.h
+++ b/target/m68k/helper.h
@@ -54,6 +54,8 @@ DEF_HELPER_4(fsdiv, void, env, fp, fp, fp)
DEF_HELPER_4(fddiv, void, env, fp, fp, fp)
DEF_HELPER_4(fsgldiv, void, env, fp, fp, fp)
DEF_HELPER_FLAGS_3(fcmp, TCG_CALL_NO_RWG, void, env, fp, fp)
+DEF_HELPER_2(set_fpsr, void, env, i32)
+DEF_HELPER_1(get_fpsr, i32, env)
DEF_HELPER_FLAGS_2(set_fpcr, TCG_CALL_NO_RWG, void, env, i32)
DEF_HELPER_FLAGS_2(ftst, TCG_CALL_NO_RWG, void, env, fp)
DEF_HELPER_3(fconst, void, env, fp, i32)
diff --git a/target/m68k/translate.c b/target/m68k/translate.c
index d037c57453..360d054162 100644
--- a/target/m68k/translate.c
+++ b/target/m68k/translate.c
@@ -4718,7 +4718,7 @@ static void gen_load_fcr(DisasContext *s, TCGv res, int
reg)
tcg_gen_movi_i32(res, 0);
break;
case M68K_FPSR:
- tcg_gen_ld_i32(res, cpu_env, offsetof(CPUM68KState, fpsr));
+ gen_helper_get_fpsr(res, cpu_env);
break;
case M68K_FPCR:
tcg_gen_ld_i32(res, cpu_env, offsetof(CPUM68KState, fpcr));
@@ -4732,7 +4732,7 @@ static void gen_store_fcr(DisasContext *s, TCGv val, int
reg)
case M68K_FPIAR:
break;
case M68K_FPSR:
- tcg_gen_st_i32(val, cpu_env, offsetof(CPUM68KState, fpsr));
+ gen_helper_set_fpsr(cpu_env, val);
break;
case M68K_FPCR:
gen_helper_set_fpcr(cpu_env, val);
--
2.40.1
