Signed-off-by: Laurent Vivier <laurent@vivier.eu>
---
target/m68k/fpu_helper.c | 106 +++++++++++++++++++++++++++++++++++++++++++++++
target/m68k/helper.h | 3 ++
target/m68k/translate.c | 9 ++++
3 files changed, 118 insertions(+)
diff --git a/target/m68k/fpu_helper.c b/target/m68k/fpu_helper.c
index 715b9be..88957fa 100644
--- a/target/m68k/fpu_helper.c
+++ b/target/m68k/fpu_helper.c
@@ -771,3 +771,109 @@ void HELPER(frem)(CPUM68KState *env, FPReg *res, FPReg *val0, FPReg *val1)
make_quotient(env, dst, sign);
res->d = ldouble_to_floatx80(dst, &env->fp_status);
}
+
+void HELPER(fgetexp)(CPUM68KState *env, FPReg *res, FPReg *val)
+{
+ int32_t exp;
+
+ if (floatx80_is_infinity(val->d)) {
+ res->d = floatx80_default_nan(NULL);
+ /* FIXME: set the OPERR bit int he FPSR */
+ return;
+ }
+ if (floatx80_is_zero(val->d)) {
+ *res = *val;
+ return;
+ }
+ if (floatx80_is_zero_or_denormal(val->d)) {
+ res->d = int32_to_floatx80(-16384, &env->fp_status);
+ return;
+ }
+
+ if (floatx80_is_any_nan(val->d)) {
+ res->d = floatx80_default_nan(NULL);
+ return;
+ }
+
+ exp = (val->l.upper & 0x7fff) - 0x3fff;
+
+ res->d = int32_to_floatx80(exp, &env->fp_status);
+}
+
+void HELPER(fgetman)(CPUM68KState *env, FPReg *res, FPReg *val)
+{
+ if (floatx80_is_infinity(val->d)) {
+ res->d = floatx80_default_nan(NULL);
+ /* FIXME: set the OPERR bit int he FPSR */
+ return;
+ }
+ if (floatx80_is_zero(val->d) ||
+ floatx80_is_any_nan(val->d)) {
+ *res = *val;
+ return;
+ }
+
+ res->l.upper = (val->l.upper & 0x8000) | 0x3fff;
+ if (floatx80_is_zero_or_denormal(val->d)) {
+ res->l.lower = val->l.lower << 1;
+ } else {
+ res->l.lower = val->l.lower;
+ }
+}
+
+void HELPER(fscale)(CPUM68KState *env, FPReg *res, FPReg *val0, FPReg *val1)
+{
+ int rounding_mode;
+ int32_t scale;
+ int32_t exp;
+
+ if (floatx80_is_infinity(val0->d)) {
+ res->d = floatx80_default_nan(NULL);
+ /* FIXME: set the OPERR bit in the FPSR */
+ return;
+ }
+ if (floatx80_is_any_nan(val0->d)) {
+ res->d = floatx80_default_nan(NULL);
+ return;
+ }
+ if (floatx80_is_infinity(val1->d) ||
+ floatx80_is_zero_or_denormal(val1->d)) {
+ *res = *val1;
+ return;
+ }
+ if (floatx80_is_zero(val0->d)) {
+ res->d = floatx80_round(val1->d, &env->fp_status);
+ return;
+ }
+
+ rounding_mode = get_float_rounding_mode(&env->fp_status);
+ set_float_rounding_mode(float_round_to_zero, &env->fp_status);
+ scale = floatx80_to_int32(val0->d, &env->fp_status);
+ set_float_rounding_mode(rounding_mode, &env->fp_status);
+
+ if (scale >= 16384) {
+ if (floatx80_is_neg(val1->d)) {
+ res->d = floatx80_chs(floatx80_infinity);
+ } else {
+ res->d = floatx80_infinity;
+ }
+ /* FIXME: set OVFL in FPSR */
+ return;
+ }
+ if (scale <= -16384) {
+ if (floatx80_is_neg(val1->d)) {
+ res->d = floatx80_chs(floatx80_zero);
+ } else {
+ res->d = floatx80_zero;
+ }
+ /* FIXME: set UNFL in FPSR */
+ return;
+ }
+
+ exp = (val1->l.upper & 0x7fff) + scale;
+
+ res->l.upper = (val1->l.upper & 0x8000) | (exp & 0x7fff);
+ res->l.lower = val1->l.lower;
+
+ res->d = floatx80_round(res->d, &env->fp_status);
+}
diff --git a/target/m68k/helper.h b/target/m68k/helper.h
index 889978e..a6be815 100644
--- a/target/m68k/helper.h
+++ b/target/m68k/helper.h
@@ -79,6 +79,9 @@ DEF_HELPER_3(fcos, void, env, fp, fp)
DEF_HELPER_4(fsincos, void, env, fp, fp, fp)
DEF_HELPER_4(fmod, void, env, fp, fp, fp)
DEF_HELPER_4(frem, void, env, fp, fp, fp)
+DEF_HELPER_3(fgetexp, void, env, fp, fp)
+DEF_HELPER_3(fgetman, void, env, fp, fp)
+DEF_HELPER_4(fscale, void, env, fp, fp, fp)
DEF_HELPER_3(mac_move, void, env, i32, i32)
DEF_HELPER_3(macmulf, i64, env, i32, i32)
diff --git a/target/m68k/translate.c b/target/m68k/translate.c
index fe9e0bf..348f4fb 100644
--- a/target/m68k/translate.c
+++ b/target/m68k/translate.c
@@ -4718,6 +4718,12 @@ DISAS_INSN(fpu)
case 0x1d: /* fcos */
gen_helper_fcos(cpu_env, cpu_dest, cpu_src);
break;
+ case 0x1e: /* fgetexp */
+ gen_helper_fgetexp(cpu_env, cpu_dest, cpu_src);
+ break;
+ case 0x1f: /* fgetman */
+ gen_helper_fgetman(cpu_env, cpu_dest, cpu_src);
+ break;
case 0x20: /* fdiv */
gen_helper_fdiv(cpu_env, cpu_dest, cpu_src, cpu_dest);
break;
@@ -4754,6 +4760,9 @@ DISAS_INSN(fpu)
case 0x25: /* frem */
gen_helper_frem(cpu_env, cpu_dest, cpu_src, cpu_dest);
break;
+ case 0x26: /* fscale */
+ gen_helper_fscale(cpu_env, cpu_dest, cpu_src, cpu_dest);
+ break;
case 0x27: /* fsglmul */
gen_helper_fsglmul(cpu_env, cpu_dest, cpu_src, cpu_dest);
break;
--
2.9.4
On 07/03/2017 09:23 AM, Laurent Vivier wrote:
> +void HELPER(fgetman)(CPUM68KState *env, FPReg *res, FPReg *val)
> +{
> + if (floatx80_is_infinity(val->d)) {
> + res->d = floatx80_default_nan(NULL);
> + /* FIXME: set the OPERR bit int he FPSR */
> + return;
> + }
> + if (floatx80_is_zero(val->d) ||
> + floatx80_is_any_nan(val->d)) {
> + *res = *val;
> + return;
> + }
> +
> + res->l.upper = (val->l.upper & 0x8000) | 0x3fff;
> + if (floatx80_is_zero_or_denormal(val->d)) {
> + res->l.lower = val->l.lower << 1;
Surely you have to do more than this for denormals? There may be more than one
leading zero bit in the mant. Do you actually need to re-normalize? Or does
real hardware produce a so-called "unnormal" in this situation?
r~
Le 03/07/2017 à 21:26, Richard Henderson a écrit :
> On 07/03/2017 09:23 AM, Laurent Vivier wrote:
>> +void HELPER(fgetman)(CPUM68KState *env, FPReg *res, FPReg *val)
>> +{
>> + if (floatx80_is_infinity(val->d)) {
>> + res->d = floatx80_default_nan(NULL);
>> + /* FIXME: set the OPERR bit int he FPSR */
>> + return;
>> + }
>> + if (floatx80_is_zero(val->d) ||
>> + floatx80_is_any_nan(val->d)) {
>> + *res = *val;
>> + return;
>> + }
>> +
>> + res->l.upper = (val->l.upper & 0x8000) | 0x3fff;
>> + if (floatx80_is_zero_or_denormal(val->d)) {
>> + res->l.lower = val->l.lower << 1;
>
> Surely you have to do more than this for denormals? There may be more
> than one leading zero bit in the mant. Do you actually need to
> re-normalize? Or does real hardware produce a so-called "unnormal" in
> this situation?
I don't know. Do you have test values I can try on real hardware to know?
I've tried:
fmove.x #0x000056789ABCDEF12345,%fp0
fgetman.x %fp0,%fp6
fp0 1.135643728339893804160017756766172e-4932 (raw
0x0000000056789abcdef12345)
fp6 1.3511111111108837373479679699883604 (raw
0x3fff0000acf13579bde2468a)
fmove.x #0x000086789ABCDEF12345,%fp0
fgetman.x %fp0,%fp6
fp0 1.7660380676734113365842698475140006e-4932 (raw
0x0000000086789abcdef12345)
fp6 1.0505555555554418686739839849941802 (raw
0x3fff000086789abcdef12345)
fmove.x #0x000000000ABCDEF12345,%fp0
fgetman.x %fp0,%fp6
fp0 2.1518178707571747286191852003521627e-4938 (raw
0x0000000000000abcdef12345)
fp6 1.342222103012886691431049257516861 (raw
0x3fff0000abcdef1234500000)
So I guess the mantissa must be shifted to left until we have a 1 in the
explicit integer part bit?
Thanks,
Laurent
On 07/03/2017 12:50 PM, Laurent Vivier wrote: > fmove.x #0x000000000ABCDEF12345,%fp0 > fgetman.x %fp0,%fp6 > fp0 2.1518178707571747286191852003521627e-4938 (raw > 0x0000000000000abcdef12345) > fp6 1.342222103012886691431049257516861 (raw > 0x3fff0000abcdef1234500000) This one shows exactly what I was thinking about. > So I guess the mantissa must be shifted to left until we have a 1 in the > explicit integer part bit? Yes. Please try fgetexp on this same input. I suspect the answer is -16384 - clz64(val->l.lower). Otherwise the behaviour of fgetman above doesn't make sense. r~
Le 03/07/2017 à 22:31, Richard Henderson a écrit : > On 07/03/2017 12:50 PM, Laurent Vivier wrote: >> fmove.x #0x000000000ABCDEF12345,%fp0 >> fgetman.x %fp0,%fp6 >> fp0 2.1518178707571747286191852003521627e-4938 (raw >> 0x0000000000000abcdef12345) >> fp6 1.342222103012886691431049257516861 (raw >> 0x3fff0000abcdef1234500000) > > This one shows exactly what I was thinking about. > >> So I guess the mantissa must be shifted to left until we have a 1 in the >> explicit integer part bit? > > Yes. > > Please try fgetexp on this same input. fmove.x #0x000000000ABCDEF12345,%fp0 fgetexp.x %fp0,%fp6 fp0 (raw 0x0000000000000abcdef12345) fp6 -16403 > I suspect the answer is -16384 - clz64(val->l.lower). It looks like -16383 - clz64(val->l.lower) fmove.x #0x000056789ABCDEF12345,%fp0 fgetexp.x %fp0,%fp6 fp0 (raw 0x0000000056789abcdef12345) fp6 -16384 fmove.x #0x000086789ABCDEF12345,%fp0 fgetexp.x %fp0,%fp6 fp0 (raw 0x0000000086789abcdef12345) fp6 -16383 Thanks, Laurent
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