softfloat: Move addsub_floats to softfloat-parts.c.inc
In preparation for implementing multiple sizes. Rename to parts_addsub, split out parts_add/sub_normal for future reuse with muladd. Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This commit is contained in:
Richard Henderson
parent
cb3ad0365f
commit
da10a9074a
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@ -0,0 +1,62 @@
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/*
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* Floating point arithmetic implementation
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*
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* The code in this source file is derived from release 2a of the SoftFloat
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* IEC/IEEE Floating-point Arithmetic Package. Those parts of the code (and
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* some later contributions) are provided under that license, as detailed below.
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* It has subsequently been modified by contributors to the QEMU Project,
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* so some portions are provided under:
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* the SoftFloat-2a license
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* the BSD license
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* GPL-v2-or-later
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*
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* Any future contributions to this file after December 1st 2014 will be
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* taken to be licensed under the Softfloat-2a license unless specifically
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* indicated otherwise.
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*/
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static void partsN(add_normal)(FloatPartsN *a, FloatPartsN *b)
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{
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int exp_diff = a->exp - b->exp;
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if (exp_diff > 0) {
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frac_shrjam(b, exp_diff);
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} else if (exp_diff < 0) {
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frac_shrjam(a, -exp_diff);
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a->exp = b->exp;
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}
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if (frac_add(a, a, b)) {
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frac_shrjam(a, 1);
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a->frac_hi |= DECOMPOSED_IMPLICIT_BIT;
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a->exp += 1;
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}
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}
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static bool partsN(sub_normal)(FloatPartsN *a, FloatPartsN *b)
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{
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int exp_diff = a->exp - b->exp;
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int shift;
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if (exp_diff > 0) {
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frac_shrjam(b, exp_diff);
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frac_sub(a, a, b);
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} else if (exp_diff < 0) {
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a->exp = b->exp;
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a->sign ^= 1;
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frac_shrjam(a, -exp_diff);
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frac_sub(a, b, a);
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} else if (frac_sub(a, a, b)) {
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/* Overflow means that A was less than B. */
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frac_neg(a);
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a->sign ^= 1;
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}
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shift = frac_normalize(a);
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if (likely(shift < N)) {
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a->exp -= shift;
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return true;
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}
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a->cls = float_class_zero;
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return false;
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}
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@ -281,3 +281,84 @@ static void partsN(uncanon)(FloatPartsN *p, float_status *s,
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p->exp = exp;
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float_raise(flags, s);
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}
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/*
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* Returns the result of adding or subtracting the values of the
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* floating-point values `a' and `b'. The operation is performed
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* according to the IEC/IEEE Standard for Binary Floating-Point
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* Arithmetic.
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*/
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static FloatPartsN *partsN(addsub)(FloatPartsN *a, FloatPartsN *b,
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float_status *s, bool subtract)
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{
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bool b_sign = b->sign ^ subtract;
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int ab_mask = float_cmask(a->cls) | float_cmask(b->cls);
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if (a->sign != b_sign) {
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/* Subtraction */
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if (likely(ab_mask == float_cmask_normal)) {
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if (parts_sub_normal(a, b)) {
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return a;
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}
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/* Subtract was exact, fall through to set sign. */
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ab_mask = float_cmask_zero;
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}
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if (ab_mask == float_cmask_zero) {
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a->sign = s->float_rounding_mode == float_round_down;
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return a;
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}
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if (unlikely(ab_mask & float_cmask_anynan)) {
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goto p_nan;
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}
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if (ab_mask & float_cmask_inf) {
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if (a->cls != float_class_inf) {
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/* N - Inf */
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goto return_b;
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}
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if (b->cls != float_class_inf) {
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/* Inf - N */
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return a;
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}
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/* Inf - Inf */
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float_raise(float_flag_invalid, s);
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parts_default_nan(a, s);
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return a;
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}
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} else {
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/* Addition */
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if (likely(ab_mask == float_cmask_normal)) {
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parts_add_normal(a, b);
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return a;
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}
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if (ab_mask == float_cmask_zero) {
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return a;
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}
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if (unlikely(ab_mask & float_cmask_anynan)) {
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goto p_nan;
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}
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if (ab_mask & float_cmask_inf) {
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a->cls = float_class_inf;
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return a;
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}
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}
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if (b->cls == float_class_zero) {
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g_assert(a->cls == float_class_normal);
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return a;
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}
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g_assert(a->cls == float_class_zero);
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g_assert(b->cls == float_class_normal);
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return_b:
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b->sign = b_sign;
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return b;
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p_nan:
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return parts_pick_nan(a, b, s);
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}
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253
fpu/softfloat.c
253
fpu/softfloat.c
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@ -749,6 +749,26 @@ static void parts128_uncanon(FloatParts128 *p, float_status *status,
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#define parts_uncanon(A, S, F) \
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PARTS_GENERIC_64_128(uncanon, A)(A, S, F)
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static void parts64_add_normal(FloatParts64 *a, FloatParts64 *b);
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static void parts128_add_normal(FloatParts128 *a, FloatParts128 *b);
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#define parts_add_normal(A, B) \
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PARTS_GENERIC_64_128(add_normal, A)(A, B)
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static bool parts64_sub_normal(FloatParts64 *a, FloatParts64 *b);
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static bool parts128_sub_normal(FloatParts128 *a, FloatParts128 *b);
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#define parts_sub_normal(A, B) \
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PARTS_GENERIC_64_128(sub_normal, A)(A, B)
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static FloatParts64 *parts64_addsub(FloatParts64 *a, FloatParts64 *b,
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float_status *s, bool subtract);
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static FloatParts128 *parts128_addsub(FloatParts128 *a, FloatParts128 *b,
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float_status *s, bool subtract);
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#define parts_addsub(A, B, S, Z) \
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PARTS_GENERIC_64_128(addsub, A)(A, B, S, Z)
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/*
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* Helper functions for softfloat-parts.c.inc, per-size operations.
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*/
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@ -756,6 +776,21 @@ static void parts128_uncanon(FloatParts128 *p, float_status *status,
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#define FRAC_GENERIC_64_128(NAME, P) \
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QEMU_GENERIC(P, (FloatParts128 *, frac128_##NAME), frac64_##NAME)
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static bool frac64_add(FloatParts64 *r, FloatParts64 *a, FloatParts64 *b)
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{
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return uadd64_overflow(a->frac, b->frac, &r->frac);
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}
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static bool frac128_add(FloatParts128 *r, FloatParts128 *a, FloatParts128 *b)
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{
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bool c = 0;
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r->frac_lo = uadd64_carry(a->frac_lo, b->frac_lo, &c);
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r->frac_hi = uadd64_carry(a->frac_hi, b->frac_hi, &c);
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return c;
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}
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#define frac_add(R, A, B) FRAC_GENERIC_64_128(add, R)(R, A, B)
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static bool frac64_addi(FloatParts64 *r, FloatParts64 *a, uint64_t c)
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{
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return uadd64_overflow(a->frac, c, &r->frac);
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@ -824,6 +859,20 @@ static bool frac128_eqz(FloatParts128 *a)
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#define frac_eqz(A) FRAC_GENERIC_64_128(eqz, A)(A)
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static void frac64_neg(FloatParts64 *a)
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{
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a->frac = -a->frac;
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}
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static void frac128_neg(FloatParts128 *a)
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{
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bool c = 0;
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a->frac_lo = usub64_borrow(0, a->frac_lo, &c);
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a->frac_hi = usub64_borrow(0, a->frac_hi, &c);
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}
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#define frac_neg(A) FRAC_GENERIC_64_128(neg, A)(A)
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static int frac64_normalize(FloatParts64 *a)
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{
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if (a->frac) {
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@ -891,18 +940,36 @@ static void frac128_shrjam(FloatParts128 *a, int c)
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#define frac_shrjam(A, C) FRAC_GENERIC_64_128(shrjam, A)(A, C)
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#define partsN(NAME) parts64_##NAME
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#define FloatPartsN FloatParts64
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static bool frac64_sub(FloatParts64 *r, FloatParts64 *a, FloatParts64 *b)
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{
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return usub64_overflow(a->frac, b->frac, &r->frac);
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}
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static bool frac128_sub(FloatParts128 *r, FloatParts128 *a, FloatParts128 *b)
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{
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bool c = 0;
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r->frac_lo = usub64_borrow(a->frac_lo, b->frac_lo, &c);
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r->frac_hi = usub64_borrow(a->frac_hi, b->frac_hi, &c);
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return c;
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}
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#define frac_sub(R, A, B) FRAC_GENERIC_64_128(sub, R)(R, A, B)
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#define partsN(NAME) glue(glue(glue(parts,N),_),NAME)
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#define FloatPartsN glue(FloatParts,N)
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#define N 64
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#include "softfloat-parts-addsub.c.inc"
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#include "softfloat-parts.c.inc"
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#undef partsN
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#undef FloatPartsN
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#define partsN(NAME) parts128_##NAME
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#define FloatPartsN FloatParts128
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#undef N
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#define N 128
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#include "softfloat-parts-addsub.c.inc"
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#include "softfloat-parts.c.inc"
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#undef N
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#undef partsN
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#undef FloatPartsN
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@ -980,165 +1047,73 @@ static float64 float64_round_pack_canonical(FloatParts64 *p,
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}
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/*
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* Returns the result of adding or subtracting the values of the
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* floating-point values `a' and `b'. The operation is performed
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* according to the IEC/IEEE Standard for Binary Floating-Point
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* Arithmetic.
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* Addition and subtraction
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*/
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static FloatParts64 addsub_floats(FloatParts64 a, FloatParts64 b, bool subtract,
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float_status *s)
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static float16 QEMU_FLATTEN
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float16_addsub(float16 a, float16 b, float_status *status, bool subtract)
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{
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bool a_sign = a.sign;
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bool b_sign = b.sign ^ subtract;
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if (a_sign != b_sign) {
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/* Subtraction */
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if (a.cls == float_class_normal && b.cls == float_class_normal) {
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if (a.exp > b.exp || (a.exp == b.exp && a.frac >= b.frac)) {
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shift64RightJamming(b.frac, a.exp - b.exp, &b.frac);
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a.frac = a.frac - b.frac;
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} else {
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shift64RightJamming(a.frac, b.exp - a.exp, &a.frac);
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a.frac = b.frac - a.frac;
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a.exp = b.exp;
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a_sign ^= 1;
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}
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if (a.frac == 0) {
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a.cls = float_class_zero;
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a.sign = s->float_rounding_mode == float_round_down;
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} else {
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int shift = clz64(a.frac);
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a.frac = a.frac << shift;
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a.exp = a.exp - shift;
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a.sign = a_sign;
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}
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return a;
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}
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if (is_nan(a.cls) || is_nan(b.cls)) {
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return *parts_pick_nan(&a, &b, s);
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}
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if (a.cls == float_class_inf) {
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if (b.cls == float_class_inf) {
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float_raise(float_flag_invalid, s);
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parts_default_nan(&a, s);
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}
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return a;
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}
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if (a.cls == float_class_zero && b.cls == float_class_zero) {
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a.sign = s->float_rounding_mode == float_round_down;
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return a;
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}
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if (a.cls == float_class_zero || b.cls == float_class_inf) {
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b.sign = a_sign ^ 1;
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return b;
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}
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if (b.cls == float_class_zero) {
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return a;
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}
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} else {
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/* Addition */
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if (a.cls == float_class_normal && b.cls == float_class_normal) {
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if (a.exp > b.exp) {
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shift64RightJamming(b.frac, a.exp - b.exp, &b.frac);
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} else if (a.exp < b.exp) {
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shift64RightJamming(a.frac, b.exp - a.exp, &a.frac);
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a.exp = b.exp;
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}
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if (uadd64_overflow(a.frac, b.frac, &a.frac)) {
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shift64RightJamming(a.frac, 1, &a.frac);
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a.frac |= DECOMPOSED_IMPLICIT_BIT;
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a.exp += 1;
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}
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return a;
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}
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if (is_nan(a.cls) || is_nan(b.cls)) {
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return *parts_pick_nan(&a, &b, s);
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}
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if (a.cls == float_class_inf || b.cls == float_class_zero) {
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return a;
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}
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if (b.cls == float_class_inf || a.cls == float_class_zero) {
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b.sign = b_sign;
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return b;
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}
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}
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g_assert_not_reached();
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}
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/*
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* Returns the result of adding or subtracting the floating-point
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* values `a' and `b'. The operation is performed according to the
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* IEC/IEEE Standard for Binary Floating-Point Arithmetic.
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*/
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float16 QEMU_FLATTEN float16_add(float16 a, float16 b, float_status *status)
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{
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FloatParts64 pa, pb, pr;
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FloatParts64 pa, pb, *pr;
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float16_unpack_canonical(&pa, a, status);
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float16_unpack_canonical(&pb, b, status);
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pr = addsub_floats(pa, pb, false, status);
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pr = parts_addsub(&pa, &pb, status, subtract);
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return float16_round_pack_canonical(&pr, status);
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return float16_round_pack_canonical(pr, status);
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}
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float16 QEMU_FLATTEN float16_sub(float16 a, float16 b, float_status *status)
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float16 float16_add(float16 a, float16 b, float_status *status)
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{
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FloatParts64 pa, pb, pr;
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return float16_addsub(a, b, status, false);
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}
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float16_unpack_canonical(&pa, a, status);
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float16_unpack_canonical(&pb, b, status);
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pr = addsub_floats(pa, pb, true, status);
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return float16_round_pack_canonical(&pr, status);
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float16 float16_sub(float16 a, float16 b, float_status *status)
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{
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return float16_addsub(a, b, status, true);
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}
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static float32 QEMU_SOFTFLOAT_ATTR
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soft_f32_addsub(float32 a, float32 b, bool subtract, float_status *status)
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soft_f32_addsub(float32 a, float32 b, float_status *status, bool subtract)
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{
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FloatParts64 pa, pb, pr;
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FloatParts64 pa, pb, *pr;
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float32_unpack_canonical(&pa, a, status);
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float32_unpack_canonical(&pb, b, status);
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pr = addsub_floats(pa, pb, subtract, status);
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pr = parts_addsub(&pa, &pb, status, subtract);
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return float32_round_pack_canonical(&pr, status);
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return float32_round_pack_canonical(pr, status);
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}
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static inline float32 soft_f32_add(float32 a, float32 b, float_status *status)
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static float32 soft_f32_add(float32 a, float32 b, float_status *status)
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{
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return soft_f32_addsub(a, b, false, status);
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return soft_f32_addsub(a, b, status, false);
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}
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static inline float32 soft_f32_sub(float32 a, float32 b, float_status *status)
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static float32 soft_f32_sub(float32 a, float32 b, float_status *status)
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{
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return soft_f32_addsub(a, b, true, status);
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return soft_f32_addsub(a, b, status, true);
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}
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static float64 QEMU_SOFTFLOAT_ATTR
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soft_f64_addsub(float64 a, float64 b, bool subtract, float_status *status)
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soft_f64_addsub(float64 a, float64 b, float_status *status, bool subtract)
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{
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FloatParts64 pa, pb, pr;
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FloatParts64 pa, pb, *pr;
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float64_unpack_canonical(&pa, a, status);
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float64_unpack_canonical(&pb, b, status);
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pr = addsub_floats(pa, pb, subtract, status);
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pr = parts_addsub(&pa, &pb, status, subtract);
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return float64_round_pack_canonical(&pr, status);
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return float64_round_pack_canonical(pr, status);
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}
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static inline float64 soft_f64_add(float64 a, float64 b, float_status *status)
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static float64 soft_f64_add(float64 a, float64 b, float_status *status)
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{
|
||||
return soft_f64_addsub(a, b, false, status);
|
||||
return soft_f64_addsub(a, b, status, false);
|
||||
}
|
||||
|
||||
static inline float64 soft_f64_sub(float64 a, float64 b, float_status *status)
|
||||
static float64 soft_f64_sub(float64 a, float64 b, float_status *status)
|
||||
{
|
||||
return soft_f64_addsub(a, b, true, status);
|
||||
return soft_f64_addsub(a, b, status, true);
|
||||
}
|
||||
|
||||
static float hard_f32_add(float a, float b)
|
||||
|
|
@ -1216,30 +1191,26 @@ float64_sub(float64 a, float64 b, float_status *s)
|
|||
return float64_addsub(a, b, s, hard_f64_sub, soft_f64_sub);
|
||||
}
|
||||
|
||||
/*
|
||||
* Returns the result of adding or subtracting the bfloat16
|
||||
* values `a' and `b'.
|
||||
*/
|
||||
bfloat16 QEMU_FLATTEN bfloat16_add(bfloat16 a, bfloat16 b, float_status *status)
|
||||
static bfloat16 QEMU_FLATTEN
|
||||
bfloat16_addsub(bfloat16 a, bfloat16 b, float_status *status, bool subtract)
|
||||
{
|
||||
FloatParts64 pa, pb, pr;
|
||||
FloatParts64 pa, pb, *pr;
|
||||
|
||||
bfloat16_unpack_canonical(&pa, a, status);
|
||||
bfloat16_unpack_canonical(&pb, b, status);
|
||||
pr = addsub_floats(pa, pb, false, status);
|
||||
pr = parts_addsub(&pa, &pb, status, subtract);
|
||||
|
||||
return bfloat16_round_pack_canonical(&pr, status);
|
||||
return bfloat16_round_pack_canonical(pr, status);
|
||||
}
|
||||
|
||||
bfloat16 QEMU_FLATTEN bfloat16_sub(bfloat16 a, bfloat16 b, float_status *status)
|
||||
bfloat16 bfloat16_add(bfloat16 a, bfloat16 b, float_status *status)
|
||||
{
|
||||
FloatParts64 pa, pb, pr;
|
||||
return bfloat16_addsub(a, b, status, false);
|
||||
}
|
||||
|
||||
bfloat16_unpack_canonical(&pa, a, status);
|
||||
bfloat16_unpack_canonical(&pb, b, status);
|
||||
pr = addsub_floats(pa, pb, true, status);
|
||||
|
||||
return bfloat16_round_pack_canonical(&pr, status);
|
||||
bfloat16 bfloat16_sub(bfloat16 a, bfloat16 b, float_status *status)
|
||||
{
|
||||
return bfloat16_addsub(a, b, status, true);
|
||||
}
|
||||
|
||||
/*
|
||||
|
|
|
|||
Loading…
Reference in New Issue