target/m68k: implement ftanh
Using local m68k floatx80_tanh() and floatx80_etoxm1()
[copied from previous:
Written by Andreas Grabher for Previous, NeXT Computer Emulator.]
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20180312202728.23790-10-laurent@vivier.eu>
diff --git a/target/m68k/softfloat.c b/target/m68k/softfloat.c
index 5ce8413..4ce5783 100644
--- a/target/m68k/softfloat.c
+++ b/target/m68k/softfloat.c
@@ -2367,3 +2367,369 @@
return a;
}
+
+/*----------------------------------------------------------------------------
+ | e to x minus 1
+ *----------------------------------------------------------------------------*/
+
+floatx80 floatx80_etoxm1(floatx80 a, float_status *status)
+{
+ flag aSign;
+ int32_t aExp;
+ uint64_t aSig;
+
+ int8_t user_rnd_mode, user_rnd_prec;
+
+ int32_t compact, n, j, m, m1;
+ floatx80 fp0, fp1, fp2, fp3, l2, sc, onebysc;
+
+ aSig = extractFloatx80Frac(a);
+ aExp = extractFloatx80Exp(a);
+ aSign = extractFloatx80Sign(a);
+
+ if (aExp == 0x7FFF) {
+ if ((uint64_t) (aSig << 1)) {
+ return propagateFloatx80NaNOneArg(a, status);
+ }
+ if (aSign) {
+ return packFloatx80(aSign, one_exp, one_sig);
+ }
+ return packFloatx80(0, floatx80_infinity.high,
+ floatx80_infinity.low);
+ }
+
+ if (aExp == 0 && aSig == 0) {
+ return packFloatx80(aSign, 0, 0);
+ }
+
+ user_rnd_mode = status->float_rounding_mode;
+ user_rnd_prec = status->floatx80_rounding_precision;
+ status->float_rounding_mode = float_round_nearest_even;
+ status->floatx80_rounding_precision = 80;
+
+ if (aExp >= 0x3FFD) { /* |X| >= 1/4 */
+ compact = floatx80_make_compact(aExp, aSig);
+
+ if (compact <= 0x4004C215) { /* |X| <= 70 log2 */
+ fp0 = a;
+ fp1 = a;
+ fp0 = floatx80_mul(fp0, float32_to_floatx80(
+ make_float32(0x42B8AA3B), status),
+ status); /* 64/log2 * X */
+ n = floatx80_to_int32(fp0, status); /* int(64/log2*X) */
+ fp0 = int32_to_floatx80(n, status);
+
+ j = n & 0x3F; /* J = N mod 64 */
+ m = n / 64; /* NOTE: this is really arithmetic right shift by 6 */
+ if (n < 0 && j) {
+ /* arithmetic right shift is division and
+ * round towards minus infinity
+ */
+ m--;
+ }
+ m1 = -m;
+ /*m += 0x3FFF; // biased exponent of 2^(M) */
+ /*m1 += 0x3FFF; // biased exponent of -2^(-M) */
+
+ fp2 = fp0; /* N */
+ fp0 = floatx80_mul(fp0, float32_to_floatx80(
+ make_float32(0xBC317218), status),
+ status); /* N * L1, L1 = lead(-log2/64) */
+ l2 = packFloatx80(0, 0x3FDC, LIT64(0x82E308654361C4C6));
+ fp2 = floatx80_mul(fp2, l2, status); /* N * L2, L1+L2 = -log2/64 */
+ fp0 = floatx80_add(fp0, fp1, status); /* X + N*L1 */
+ fp0 = floatx80_add(fp0, fp2, status); /* R */
+
+ fp1 = floatx80_mul(fp0, fp0, status); /* S = R*R */
+ fp2 = float32_to_floatx80(make_float32(0x3950097B),
+ status); /* A6 */
+ fp2 = floatx80_mul(fp2, fp1, status); /* fp2 is S*A6 */
+ fp3 = floatx80_mul(float32_to_floatx80(make_float32(0x3AB60B6A),
+ status), fp1, status); /* fp3 is S*A5 */
+ fp2 = floatx80_add(fp2, float64_to_floatx80(
+ make_float64(0x3F81111111174385), status),
+ status); /* fp2 IS A4+S*A6 */
+ fp3 = floatx80_add(fp3, float64_to_floatx80(
+ make_float64(0x3FA5555555554F5A), status),
+ status); /* fp3 is A3+S*A5 */
+ fp2 = floatx80_mul(fp2, fp1, status); /* fp2 IS S*(A4+S*A6) */
+ fp3 = floatx80_mul(fp3, fp1, status); /* fp3 IS S*(A3+S*A5) */
+ fp2 = floatx80_add(fp2, float64_to_floatx80(
+ make_float64(0x3FC5555555555555), status),
+ status); /* fp2 IS A2+S*(A4+S*A6) */
+ fp3 = floatx80_add(fp3, float32_to_floatx80(
+ make_float32(0x3F000000), status),
+ status); /* fp3 IS A1+S*(A3+S*A5) */
+ fp2 = floatx80_mul(fp2, fp1,
+ status); /* fp2 IS S*(A2+S*(A4+S*A6)) */
+ fp1 = floatx80_mul(fp1, fp3,
+ status); /* fp1 IS S*(A1+S*(A3+S*A5)) */
+ fp2 = floatx80_mul(fp2, fp0,
+ status); /* fp2 IS R*S*(A2+S*(A4+S*A6)) */
+ fp0 = floatx80_add(fp0, fp1,
+ status); /* fp0 IS R+S*(A1+S*(A3+S*A5)) */
+ fp0 = floatx80_add(fp0, fp2, status); /* fp0 IS EXP(R) - 1 */
+
+ fp0 = floatx80_mul(fp0, exp_tbl[j],
+ status); /* 2^(J/64)*(Exp(R)-1) */
+
+ if (m >= 64) {
+ fp1 = float32_to_floatx80(exp_tbl2[j], status);
+ onebysc = packFloatx80(1, m1 + 0x3FFF, one_sig); /* -2^(-M) */
+ fp1 = floatx80_add(fp1, onebysc, status);
+ fp0 = floatx80_add(fp0, fp1, status);
+ fp0 = floatx80_add(fp0, exp_tbl[j], status);
+ } else if (m < -3) {
+ fp0 = floatx80_add(fp0, float32_to_floatx80(exp_tbl2[j],
+ status), status);
+ fp0 = floatx80_add(fp0, exp_tbl[j], status);
+ onebysc = packFloatx80(1, m1 + 0x3FFF, one_sig); /* -2^(-M) */
+ fp0 = floatx80_add(fp0, onebysc, status);
+ } else { /* -3 <= m <= 63 */
+ fp1 = exp_tbl[j];
+ fp0 = floatx80_add(fp0, float32_to_floatx80(exp_tbl2[j],
+ status), status);
+ onebysc = packFloatx80(1, m1 + 0x3FFF, one_sig); /* -2^(-M) */
+ fp1 = floatx80_add(fp1, onebysc, status);
+ fp0 = floatx80_add(fp0, fp1, status);
+ }
+
+ sc = packFloatx80(0, m + 0x3FFF, one_sig);
+
+ status->float_rounding_mode = user_rnd_mode;
+ status->floatx80_rounding_precision = user_rnd_prec;
+
+ a = floatx80_mul(fp0, sc, status);
+
+ float_raise(float_flag_inexact, status);
+
+ return a;
+ } else { /* |X| > 70 log2 */
+ if (aSign) {
+ fp0 = float32_to_floatx80(make_float32(0xBF800000),
+ status); /* -1 */
+
+ status->float_rounding_mode = user_rnd_mode;
+ status->floatx80_rounding_precision = user_rnd_prec;
+
+ a = floatx80_add(fp0, float32_to_floatx80(
+ make_float32(0x00800000), status),
+ status); /* -1 + 2^(-126) */
+
+ float_raise(float_flag_inexact, status);
+
+ return a;
+ } else {
+ status->float_rounding_mode = user_rnd_mode;
+ status->floatx80_rounding_precision = user_rnd_prec;
+
+ return floatx80_etox(a, status);
+ }
+ }
+ } else { /* |X| < 1/4 */
+ if (aExp >= 0x3FBE) {
+ fp0 = a;
+ fp0 = floatx80_mul(fp0, fp0, status); /* S = X*X */
+ fp1 = float32_to_floatx80(make_float32(0x2F30CAA8),
+ status); /* B12 */
+ fp1 = floatx80_mul(fp1, fp0, status); /* S * B12 */
+ fp2 = float32_to_floatx80(make_float32(0x310F8290),
+ status); /* B11 */
+ fp1 = floatx80_add(fp1, float32_to_floatx80(
+ make_float32(0x32D73220), status),
+ status); /* B10 */
+ fp2 = floatx80_mul(fp2, fp0, status);
+ fp1 = floatx80_mul(fp1, fp0, status);
+ fp2 = floatx80_add(fp2, float32_to_floatx80(
+ make_float32(0x3493F281), status),
+ status); /* B9 */
+ fp1 = floatx80_add(fp1, float64_to_floatx80(
+ make_float64(0x3EC71DE3A5774682), status),
+ status); /* B8 */
+ fp2 = floatx80_mul(fp2, fp0, status);
+ fp1 = floatx80_mul(fp1, fp0, status);
+ fp2 = floatx80_add(fp2, float64_to_floatx80(
+ make_float64(0x3EFA01A019D7CB68), status),
+ status); /* B7 */
+ fp1 = floatx80_add(fp1, float64_to_floatx80(
+ make_float64(0x3F2A01A01A019DF3), status),
+ status); /* B6 */
+ fp2 = floatx80_mul(fp2, fp0, status);
+ fp1 = floatx80_mul(fp1, fp0, status);
+ fp2 = floatx80_add(fp2, float64_to_floatx80(
+ make_float64(0x3F56C16C16C170E2), status),
+ status); /* B5 */
+ fp1 = floatx80_add(fp1, float64_to_floatx80(
+ make_float64(0x3F81111111111111), status),
+ status); /* B4 */
+ fp2 = floatx80_mul(fp2, fp0, status);
+ fp1 = floatx80_mul(fp1, fp0, status);
+ fp2 = floatx80_add(fp2, float64_to_floatx80(
+ make_float64(0x3FA5555555555555), status),
+ status); /* B3 */
+ fp3 = packFloatx80(0, 0x3FFC, LIT64(0xAAAAAAAAAAAAAAAB));
+ fp1 = floatx80_add(fp1, fp3, status); /* B2 */
+ fp2 = floatx80_mul(fp2, fp0, status);
+ fp1 = floatx80_mul(fp1, fp0, status);
+
+ fp2 = floatx80_mul(fp2, fp0, status);
+ fp1 = floatx80_mul(fp1, a, status);
+
+ fp0 = floatx80_mul(fp0, float32_to_floatx80(
+ make_float32(0x3F000000), status),
+ status); /* S*B1 */
+ fp1 = floatx80_add(fp1, fp2, status); /* Q */
+ fp0 = floatx80_add(fp0, fp1, status); /* S*B1+Q */
+
+ status->float_rounding_mode = user_rnd_mode;
+ status->floatx80_rounding_precision = user_rnd_prec;
+
+ a = floatx80_add(fp0, a, status);
+
+ float_raise(float_flag_inexact, status);
+
+ return a;
+ } else { /* |X| < 2^(-65) */
+ sc = packFloatx80(1, 1, one_sig);
+ fp0 = a;
+
+ if (aExp < 0x0033) { /* |X| < 2^(-16382) */
+ fp0 = floatx80_mul(fp0, float64_to_floatx80(
+ make_float64(0x48B0000000000000), status),
+ status);
+ fp0 = floatx80_add(fp0, sc, status);
+
+ status->float_rounding_mode = user_rnd_mode;
+ status->floatx80_rounding_precision = user_rnd_prec;
+
+ a = floatx80_mul(fp0, float64_to_floatx80(
+ make_float64(0x3730000000000000), status),
+ status);
+ } else {
+ status->float_rounding_mode = user_rnd_mode;
+ status->floatx80_rounding_precision = user_rnd_prec;
+
+ a = floatx80_add(fp0, sc, status);
+ }
+
+ float_raise(float_flag_inexact, status);
+
+ return a;
+ }
+ }
+}
+
+/*----------------------------------------------------------------------------
+ | Hyperbolic tangent
+ *----------------------------------------------------------------------------*/
+
+floatx80 floatx80_tanh(floatx80 a, float_status *status)
+{
+ flag aSign, vSign;
+ int32_t aExp, vExp;
+ uint64_t aSig, vSig;
+
+ int8_t user_rnd_mode, user_rnd_prec;
+
+ int32_t compact;
+ floatx80 fp0, fp1;
+ uint32_t sign;
+
+ aSig = extractFloatx80Frac(a);
+ aExp = extractFloatx80Exp(a);
+ aSign = extractFloatx80Sign(a);
+
+ if (aExp == 0x7FFF) {
+ if ((uint64_t) (aSig << 1)) {
+ return propagateFloatx80NaNOneArg(a, status);
+ }
+ return packFloatx80(aSign, one_exp, one_sig);
+ }
+
+ if (aExp == 0 && aSig == 0) {
+ return packFloatx80(aSign, 0, 0);
+ }
+
+ user_rnd_mode = status->float_rounding_mode;
+ user_rnd_prec = status->floatx80_rounding_precision;
+ status->float_rounding_mode = float_round_nearest_even;
+ status->floatx80_rounding_precision = 80;
+
+ compact = floatx80_make_compact(aExp, aSig);
+
+ if (compact < 0x3FD78000 || compact > 0x3FFFDDCE) {
+ /* TANHBORS */
+ if (compact < 0x3FFF8000) {
+ /* TANHSM */
+ status->float_rounding_mode = user_rnd_mode;
+ status->floatx80_rounding_precision = user_rnd_prec;
+
+ a = floatx80_move(a, status);
+
+ float_raise(float_flag_inexact, status);
+
+ return a;
+ } else {
+ if (compact > 0x40048AA1) {
+ /* TANHHUGE */
+ sign = 0x3F800000;
+ sign |= aSign ? 0x80000000 : 0x00000000;
+ fp0 = float32_to_floatx80(make_float32(sign), status);
+ sign &= 0x80000000;
+ sign ^= 0x80800000; /* -SIGN(X)*EPS */
+
+ status->float_rounding_mode = user_rnd_mode;
+ status->floatx80_rounding_precision = user_rnd_prec;
+
+ a = floatx80_add(fp0, float32_to_floatx80(make_float32(sign),
+ status), status);
+
+ float_raise(float_flag_inexact, status);
+
+ return a;
+ } else {
+ fp0 = packFloatx80(0, aExp + 1, aSig); /* Y = 2|X| */
+ fp0 = floatx80_etox(fp0, status); /* FP0 IS EXP(Y) */
+ fp0 = floatx80_add(fp0, float32_to_floatx80(
+ make_float32(0x3F800000),
+ status), status); /* EXP(Y)+1 */
+ sign = aSign ? 0x80000000 : 0x00000000;
+ fp1 = floatx80_div(float32_to_floatx80(make_float32(
+ sign ^ 0xC0000000), status), fp0,
+ status); /* -SIGN(X)*2 / [EXP(Y)+1] */
+ fp0 = float32_to_floatx80(make_float32(sign | 0x3F800000),
+ status); /* SIGN */
+
+ status->float_rounding_mode = user_rnd_mode;
+ status->floatx80_rounding_precision = user_rnd_prec;
+
+ a = floatx80_add(fp1, fp0, status);
+
+ float_raise(float_flag_inexact, status);
+
+ return a;
+ }
+ }
+ } else { /* 2**(-40) < |X| < (5/2)LOG2 */
+ fp0 = packFloatx80(0, aExp + 1, aSig); /* Y = 2|X| */
+ fp0 = floatx80_etoxm1(fp0, status); /* FP0 IS Z = EXPM1(Y) */
+ fp1 = floatx80_add(fp0, float32_to_floatx80(make_float32(0x40000000),
+ status),
+ status); /* Z+2 */
+
+ vSign = extractFloatx80Sign(fp1);
+ vExp = extractFloatx80Exp(fp1);
+ vSig = extractFloatx80Frac(fp1);
+
+ fp1 = packFloatx80(vSign ^ aSign, vExp, vSig);
+
+ status->float_rounding_mode = user_rnd_mode;
+ status->floatx80_rounding_precision = user_rnd_prec;
+
+ a = floatx80_div(fp0, fp1, status);
+
+ float_raise(float_flag_inexact, status);
+
+ return a;
+ }
+}
