Resolves: https://gitlab.com/qemu-project/qemu/-/issues/2488
Signed-off-by: Richard Henderson <richard.hender...@linaro.org>
---
target/m68k/helper.h | 1 +
target/m68k/fpu_helper.c | 100 +++++++++++++++++++++++++++++++++++++++
target/m68k/translate.c | 27 +++++++++--
3 files changed, 125 insertions(+), 3 deletions(-)
diff --git a/target/m68k/helper.h b/target/m68k/helper.h
index 2c71361451..21af6adb39 100644
--- a/target/m68k/helper.h
+++ b/target/m68k/helper.h
@@ -127,6 +127,7 @@ DEF_HELPER_3(chk, void, env, s32, s32)
DEF_HELPER_4(chk2, void, env, s32, s32, s32)
DEF_HELPER_FLAGS_3(load_pdr_to_fx80, TCG_CALL_NO_RWG, void, env, fp, tl)
+DEF_HELPER_FLAGS_4(store_fx80_to_pdr, TCG_CALL_NO_RWG, void, env, tl, fp, int)
#if !defined(CONFIG_USER_ONLY)
DEF_HELPER_3(ptest, void, env, i32, i32)
diff --git a/target/m68k/fpu_helper.c b/target/m68k/fpu_helper.c
index dd80943153..6f37a165e2 100644
--- a/target/m68k/fpu_helper.c
+++ b/target/m68k/fpu_helper.c
@@ -886,3 +886,103 @@ void HELPER(load_pdr_to_fx80)(CPUM68KState *env, FPReg
*res, target_ulong addr)
res->d = floatx80_div(res->d, fexp, &env->fp_status);
}
}
+
+static floatx80 floatx80_scale10i(floatx80 x, int e, float_status *status)
+{
+ floatx80 t;
+ if (e >= 0) {
+ t = floatx80_exp10i(e, status);
+ t = floatx80_mul(x, t, status);
+ } else {
+ t = floatx80_exp10i(-e, status);
+ t = floatx80_div(x, t, status);
+ }
+ return t;
+}
+
+void HELPER(store_fx80_to_pdr)(CPUM68KState *env, target_ulong addr,
+ FPReg *srcp, int kfactor)
+{
+ floatx80 t, x = srcp->d;
+ int len, exp2, exp10;
+ uint64_t res_lo;
+ uint32_t res_hi;
+ int64_t y;
+
+ res_lo = x.low;
+ exp2 = x.high & 0x7fff;
+ if (unlikely(exp2 == 0x7fff)) {
+ /* NaN and Inf */
+ res_hi = (uint32_t)x.high << 16;
+ goto done;
+ }
+
+ /* Copy the sign bit to the output, and then x = abs(x). */
+ res_hi = (x.high & 0x8000u) << 16;
+ x.high &= 0x7fff;
+
+ if (exp2 == 0) {
+ if (res_lo == 0) {
+ /* +/- 0 */
+ goto done;
+ }
+ /* denormal */
+ exp2 = -0x3fff - clz64(res_lo);
+ } else {
+ exp2 -= 0x3fff;
+ }
+
+ /*
+ * Begin with an approximation of log2(x) via the base 2 exponent.
+ * Adjust, so that we compute the value scaled by 10**17, which will
+ * allows an integer to be extracted to match the output digits.
+ */
+ exp10 = (exp2 * 30102) / 100000;
+ while (1) {
+ /* kfactor controls the number of output digits */
+ if (kfactor <= 0) {
+ /* kfactor is number of digits right of the decimal point. */
+ len = exp10 - kfactor;
+ } else {
+ /* kfactor is number of significant digits */
+ len = kfactor;
+ }
+ len = MIN(MAX(len, 1), 17);
+
+ /*
+ * Scale, so that we have the requested number of digits
+ * left of the decimal point. Convert to integer, which
+ * handles the rounding (and may force adjustment of exp10).
+ */
+ t = floatx80_scale10i(x, len - 1 - exp10, &env->fp_status);
+ y = floatx80_to_int64(t, &env->fp_status);
+ if (y < i64_pow10[len - 1]) {
+ exp10--;
+ } else if (y < i64_pow10[len]) {
+ break;
+ } else {
+ exp10++;
+ }
+ }
+
+ /* Output the mantissa. */
+ res_hi |= y / i64_pow10[len - 1];
+ res_lo = 0;
+ for (int i = 1; i < len; ++i) {
+ int64_t d = (y / i64_pow10[len - 1 - i]) % 10;
+ res_lo |= d << (64 - i * 4);
+ }
+
+ /* Output the exponent. */
+ if (exp10 < 0) {
+ res_hi |= 0x40000000;
+ exp10 = -exp10;
+ }
+ for (int i = 24; exp10; i -= 4, exp10 /= 10) {
+ res_hi |= (exp10 % 10) << i;
+ }
+
+ done:
+ cpu_stl_be_data_ra(env, addr, res_hi, GETPC());
+ cpu_stq_be_data_ra(env, addr + 4, res_lo, GETPC());
+}
diff --git a/target/m68k/translate.c b/target/m68k/translate.c
index 59e7d27393..fb5ecce0c3 100644
--- a/target/m68k/translate.c
+++ b/target/m68k/translate.c
@@ -119,6 +119,8 @@ typedef struct DisasContext {
int done_mac;
int writeback_mask;
TCGv writeback[8];
+ uint16_t insn;
+ uint16_t ext;
bool ss_active;
} DisasContext;
@@ -671,6 +673,7 @@ static inline int ext_opsize(int ext, int pos)
case 4: return OS_WORD;
case 5: return OS_DOUBLE;
case 6: return OS_BYTE;
+ case 7: return OS_PACKED; /* store, dynamic k-factor */
default:
g_assert_not_reached();
}
@@ -1010,11 +1013,25 @@ static void gen_store_fp(DisasContext *s, int opsize,
TCGv addr, TCGv_ptr fp,
tcg_gen_qemu_st_i64(t64, tmp, index, MO_TEUQ);
break;
case OS_PACKED:
+ if (!m68k_feature(s->env, M68K_FEATURE_FPU_PACKED_DECIMAL)) {
+ gen_exception(s, s->base.pc_next, EXCP_FP_UNIMP);
+ break;
+ }
/*
- * unimplemented data type on 68040/ColdFire
- * FIXME if needed for another FPU
+ * For stores we must recover k-factor, either from an
+ * immediate or the low 7 bits of a D register.
*/
- gen_exception(s, s->base.pc_next, EXCP_FP_UNIMP);
+ switch ((s->ext >> 10) & 7) {
+ case 3:
+ tcg_gen_movi_i32(tmp, sextract32(s->ext, 0, 7));
+ break;
+ case 7:
+ tcg_gen_sextract_i32(tmp, DREG(s->ext, 4), 0, 7);
+ break;
+ default:
+ g_assert_not_reached();
+ }
+ gen_helper_store_fx80_to_pdr(tcg_env, addr, fp, tmp);
break;
default:
g_assert_not_reached();
@@ -4940,6 +4957,8 @@ DISAS_INSN(fpu)
TCGv_ptr cpu_src, cpu_dest;
ext = read_im16(env, s);
+ s->ext = ext;
+
opmode = ext & 0x7f;
switch ((ext >> 13) & 7) {
case 0:
@@ -6042,6 +6061,8 @@ static void m68k_tr_translate_insn(DisasContextBase
*dcbase, CPUState *cpu)
CPUM68KState *env = cpu_env(cpu);
uint16_t insn = read_im16(env, dc);
+ dc->insn = insn;
+ dc->ext = 0;
opcode_table[insn](env, dc, insn);
do_writebacks(dc);
--
2.43.0
