aboutsummaryrefslogtreecommitdiff
path: root/fpu
diff options
context:
space:
mode:
Diffstat (limited to 'fpu')
-rw-r--r--fpu/softfloat.c319
1 files changed, 145 insertions, 174 deletions
diff --git a/fpu/softfloat.c b/fpu/softfloat.c
index ae4ba6de51..616c6cef07 100644
--- a/fpu/softfloat.c
+++ b/fpu/softfloat.c
@@ -560,6 +560,25 @@ static bool is_qnan(FloatClass c)
return c == float_class_qnan;
}
+static FloatParts return_nan(FloatParts a, float_status *s)
+{
+ switch (a.cls) {
+ case float_class_snan:
+ s->float_exception_flags |= float_flag_invalid;
+ a.cls = float_class_msnan;
+ /* fall through */
+ case float_class_qnan:
+ if (s->default_nan_mode) {
+ a.cls = float_class_dnan;
+ }
+ break;
+
+ default:
+ g_assert_not_reached();
+ }
+ return a;
+}
+
static FloatParts pick_nan(FloatParts a, FloatParts b, float_status *s)
{
if (is_snan(a.cls) || is_snan(b.cls)) {
@@ -1175,6 +1194,132 @@ float64 float64_div(float64 a, float64 b, float_status *status)
return float64_round_pack_canonical(pr, status);
}
+/*
+ * Rounds the floating-point value `a' to an integer, and returns the
+ * result as a floating-point value. The operation is performed
+ * according to the IEC/IEEE Standard for Binary Floating-Point
+ * Arithmetic.
+ */
+
+static FloatParts round_to_int(FloatParts a, int rounding_mode, float_status *s)
+{
+ if (is_nan(a.cls)) {
+ return return_nan(a, s);
+ }
+
+ switch (a.cls) {
+ case float_class_zero:
+ case float_class_inf:
+ case float_class_qnan:
+ /* already "integral" */
+ break;
+ case float_class_normal:
+ if (a.exp >= DECOMPOSED_BINARY_POINT) {
+ /* already integral */
+ break;
+ }
+ if (a.exp < 0) {
+ bool one;
+ /* all fractional */
+ s->float_exception_flags |= float_flag_inexact;
+ switch (rounding_mode) {
+ case float_round_nearest_even:
+ one = a.exp == -1 && a.frac > DECOMPOSED_IMPLICIT_BIT;
+ break;
+ case float_round_ties_away:
+ one = a.exp == -1 && a.frac >= DECOMPOSED_IMPLICIT_BIT;
+ break;
+ case float_round_to_zero:
+ one = false;
+ break;
+ case float_round_up:
+ one = !a.sign;
+ break;
+ case float_round_down:
+ one = a.sign;
+ break;
+ default:
+ g_assert_not_reached();
+ }
+
+ if (one) {
+ a.frac = DECOMPOSED_IMPLICIT_BIT;
+ a.exp = 0;
+ } else {
+ a.cls = float_class_zero;
+ }
+ } else {
+ uint64_t frac_lsb = DECOMPOSED_IMPLICIT_BIT >> a.exp;
+ uint64_t frac_lsbm1 = frac_lsb >> 1;
+ uint64_t rnd_even_mask = (frac_lsb - 1) | frac_lsb;
+ uint64_t rnd_mask = rnd_even_mask >> 1;
+ uint64_t inc;
+
+ switch (rounding_mode) {
+ case float_round_nearest_even:
+ inc = ((a.frac & rnd_even_mask) != frac_lsbm1 ? frac_lsbm1 : 0);
+ break;
+ case float_round_ties_away:
+ inc = frac_lsbm1;
+ break;
+ case float_round_to_zero:
+ inc = 0;
+ break;
+ case float_round_up:
+ inc = a.sign ? 0 : rnd_mask;
+ break;
+ case float_round_down:
+ inc = a.sign ? rnd_mask : 0;
+ break;
+ default:
+ g_assert_not_reached();
+ }
+
+ if (a.frac & rnd_mask) {
+ s->float_exception_flags |= float_flag_inexact;
+ a.frac += inc;
+ a.frac &= ~rnd_mask;
+ if (a.frac & DECOMPOSED_OVERFLOW_BIT) {
+ a.frac >>= 1;
+ a.exp++;
+ }
+ }
+ }
+ break;
+ default:
+ g_assert_not_reached();
+ }
+ return a;
+}
+
+float16 float16_round_to_int(float16 a, float_status *s)
+{
+ FloatParts pa = float16_unpack_canonical(a, s);
+ FloatParts pr = round_to_int(pa, s->float_rounding_mode, s);
+ return float16_round_pack_canonical(pr, s);
+}
+
+float32 float32_round_to_int(float32 a, float_status *s)
+{
+ FloatParts pa = float32_unpack_canonical(a, s);
+ FloatParts pr = round_to_int(pa, s->float_rounding_mode, s);
+ return float32_round_pack_canonical(pr, s);
+}
+
+float64 float64_round_to_int(float64 a, float_status *s)
+{
+ FloatParts pa = float64_unpack_canonical(a, s);
+ FloatParts pr = round_to_int(pa, s->float_rounding_mode, s);
+ return float64_round_pack_canonical(pr, s);
+}
+
+float64 float64_trunc_to_int(float64 a, float_status *s)
+{
+ FloatParts pa = float64_unpack_canonical(a, s);
+ FloatParts pr = round_to_int(pa, float_round_to_zero, s);
+ return float64_round_pack_canonical(pr, s);
+}
+
/*----------------------------------------------------------------------------
| Takes a 64-bit fixed-point value `absZ' with binary point between bits 6
| and 7, and returns the properly rounded 32-bit integer corresponding to the
@@ -2906,87 +3051,6 @@ float128 float32_to_float128(float32 a, float_status *status)
}
/*----------------------------------------------------------------------------
-| Rounds the single-precision floating-point value `a' to an integer, and
-| returns the result as a single-precision floating-point value. The
-| operation is performed according to the IEC/IEEE Standard for Binary
-| Floating-Point Arithmetic.
-*----------------------------------------------------------------------------*/
-
-float32 float32_round_to_int(float32 a, float_status *status)
-{
- flag aSign;
- int aExp;
- uint32_t lastBitMask, roundBitsMask;
- uint32_t z;
- a = float32_squash_input_denormal(a, status);
-
- aExp = extractFloat32Exp( a );
- if ( 0x96 <= aExp ) {
- if ( ( aExp == 0xFF ) && extractFloat32Frac( a ) ) {
- return propagateFloat32NaN(a, a, status);
- }
- return a;
- }
- if ( aExp <= 0x7E ) {
- if ( (uint32_t) ( float32_val(a)<<1 ) == 0 ) return a;
- status->float_exception_flags |= float_flag_inexact;
- aSign = extractFloat32Sign( a );
- switch (status->float_rounding_mode) {
- case float_round_nearest_even:
- if ( ( aExp == 0x7E ) && extractFloat32Frac( a ) ) {
- return packFloat32( aSign, 0x7F, 0 );
- }
- break;
- case float_round_ties_away:
- if (aExp == 0x7E) {
- return packFloat32(aSign, 0x7F, 0);
- }
- break;
- case float_round_down:
- return make_float32(aSign ? 0xBF800000 : 0);
- case float_round_up:
- return make_float32(aSign ? 0x80000000 : 0x3F800000);
- }
- return packFloat32( aSign, 0, 0 );
- }
- lastBitMask = 1;
- lastBitMask <<= 0x96 - aExp;
- roundBitsMask = lastBitMask - 1;
- z = float32_val(a);
- switch (status->float_rounding_mode) {
- case float_round_nearest_even:
- z += lastBitMask>>1;
- if ((z & roundBitsMask) == 0) {
- z &= ~lastBitMask;
- }
- break;
- case float_round_ties_away:
- z += lastBitMask >> 1;
- break;
- case float_round_to_zero:
- break;
- case float_round_up:
- if (!extractFloat32Sign(make_float32(z))) {
- z += roundBitsMask;
- }
- break;
- case float_round_down:
- if (extractFloat32Sign(make_float32(z))) {
- z += roundBitsMask;
- }
- break;
- default:
- abort();
- }
- z &= ~ roundBitsMask;
- if (z != float32_val(a)) {
- status->float_exception_flags |= float_flag_inexact;
- }
- return make_float32(z);
-
-}
-
-/*----------------------------------------------------------------------------
| Returns the remainder of the single-precision floating-point value `a'
| with respect to the corresponding value `b'. The operation is performed
| according to the IEC/IEEE Standard for Binary Floating-Point Arithmetic.
@@ -4129,99 +4193,6 @@ float128 float64_to_float128(float64 a, float_status *status)
}
-/*----------------------------------------------------------------------------
-| Rounds the double-precision floating-point value `a' to an integer, and
-| returns the result as a double-precision floating-point value. The
-| operation is performed according to the IEC/IEEE Standard for Binary
-| Floating-Point Arithmetic.
-*----------------------------------------------------------------------------*/
-
-float64 float64_round_to_int(float64 a, float_status *status)
-{
- flag aSign;
- int aExp;
- uint64_t lastBitMask, roundBitsMask;
- uint64_t z;
- a = float64_squash_input_denormal(a, status);
-
- aExp = extractFloat64Exp( a );
- if ( 0x433 <= aExp ) {
- if ( ( aExp == 0x7FF ) && extractFloat64Frac( a ) ) {
- return propagateFloat64NaN(a, a, status);
- }
- return a;
- }
- if ( aExp < 0x3FF ) {
- if ( (uint64_t) ( float64_val(a)<<1 ) == 0 ) return a;
- status->float_exception_flags |= float_flag_inexact;
- aSign = extractFloat64Sign( a );
- switch (status->float_rounding_mode) {
- case float_round_nearest_even:
- if ( ( aExp == 0x3FE ) && extractFloat64Frac( a ) ) {
- return packFloat64( aSign, 0x3FF, 0 );
- }
- break;
- case float_round_ties_away:
- if (aExp == 0x3FE) {
- return packFloat64(aSign, 0x3ff, 0);
- }
- break;
- case float_round_down:
- return make_float64(aSign ? LIT64( 0xBFF0000000000000 ) : 0);
- case float_round_up:
- return make_float64(
- aSign ? LIT64( 0x8000000000000000 ) : LIT64( 0x3FF0000000000000 ));
- }
- return packFloat64( aSign, 0, 0 );
- }
- lastBitMask = 1;
- lastBitMask <<= 0x433 - aExp;
- roundBitsMask = lastBitMask - 1;
- z = float64_val(a);
- switch (status->float_rounding_mode) {
- case float_round_nearest_even:
- z += lastBitMask >> 1;
- if ((z & roundBitsMask) == 0) {
- z &= ~lastBitMask;
- }
- break;
- case float_round_ties_away:
- z += lastBitMask >> 1;
- break;
- case float_round_to_zero:
- break;
- case float_round_up:
- if (!extractFloat64Sign(make_float64(z))) {
- z += roundBitsMask;
- }
- break;
- case float_round_down:
- if (extractFloat64Sign(make_float64(z))) {
- z += roundBitsMask;
- }
- break;
- default:
- abort();
- }
- z &= ~ roundBitsMask;
- if (z != float64_val(a)) {
- status->float_exception_flags |= float_flag_inexact;
- }
- return make_float64(z);
-
-}
-
-float64 float64_trunc_to_int(float64 a, float_status *status)
-{
- int oldmode;
- float64 res;
- oldmode = status->float_rounding_mode;
- status->float_rounding_mode = float_round_to_zero;
- res = float64_round_to_int(a, status);
- status->float_rounding_mode = oldmode;
- return res;
-}
-
/*----------------------------------------------------------------------------
| Returns the remainder of the double-precision floating-point value `a'
generated by cgit v1.2.3 (git 2.26.2) at 2024-12-01 06:59:58 +0000