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add support for concrete floating_point union #112

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73b678c
add support for concrete floating_point union
yuanzhuo-dev Sep 8, 2026
d5ef82a
add unit test for floating union implementation
yuanzhuo-dev Oct 10, 2026
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1 change: 1 addition & 0 deletions headers/gensym/defs.hpp
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Original file line number Diff line number Diff line change
Expand Up @@ -12,6 +12,7 @@ using Id = int;
using Addr = unsigned int;
using IntData = int64_t;
using UIntData = unsigned long long int;
using FloatData = long double;
using Fd = int;
using status_t = unsigned short;

Expand Down
114 changes: 67 additions & 47 deletions headers/gensym/value_ops.hpp
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Expand Up @@ -265,26 +265,51 @@ inline char proj_IntV_char(const PtrVal& v) {
return static_cast<char>(proj_IntV(intV));
}

/* Concrete floating-point values are kept in their native representation;
* `bw` selects which member of the union is the live one.
*/
union FloatV_val {
float f32;
double f64;
long double f80;
FloatV_val(FloatData f, size_t bw) {
switch (bw) {
case 32: f32 = f; break;
case 64: f64 = f; break;
case 80: f80 = f; break;
default: ABORT("Making a float of unsupported bitwidth " << bw);
}
}
};

struct FloatV : Value {
long double f;
FloatV_val f;
size_t bw;
FloatV(long double f, size_t bw=32) : f(f), bw(bw) {
FloatV(FloatData f, size_t bw=32) : f(f, bw), bw(bw) {
hash_combine(hash(), std::string("floatv"));
hash_combine(hash(), f);
hash_combine(hash(), as_ld());
hash_combine(hash(), bw);
}
FloatV(const FloatV& v): FloatV(v.f, v.bw) {}
FloatV(const FloatV& v) : FloatV(v.as_ld(), v.bw) {}
std::string toString() const override {
std::ostringstream ss;
ss << "FloatV(f=" << f << ", bw=" << bw << ")";
ss << "FloatV(f=" << as_ld() << ", bw=" << bw << ")";
return ss.str();
}
virtual bool is_conc() const override { return true; }
virtual size_t get_bw() const override { return bw; }
FloatData as_ld() const {
switch (bw) {
case 32: return f.f32;
case 64: return f.f64;
case 80: return f.f80;
}
ABORT("Reading a float of unsupported bitwidth " << bw);
}

virtual bool compare(const Value* v) const override {
auto that = static_cast<decltype(this)>(v);
if (this->f != that->f) return false;
if (this->as_ld() != that->as_ld()) return false;
return this->bw == that->bw;
}
virtual List<PtrVal> to_bytes() {
Expand All @@ -295,23 +320,19 @@ struct FloatV : Value {
}
};

inline PtrVal make_FloatV(long double f) {
auto ret = make_simple<FloatV>(f);
return hashconsing(ret);
}

inline PtrVal make_FloatV(long double f, size_t bw) {
inline PtrVal make_FloatV(FloatData f, size_t bw=32) {
auto ret = make_simple<FloatV>(f, bw);
return hashconsing(ret);
}

inline PtrVal make_FloatV_fp80(std::array<unsigned char, 10> buf) {
//std::cout << "*(long double*)buf.data(): " << *(long double*) buf.data() << std::endl;
return make_FloatV(*(long double*) buf.data(), 80);
long double f = 0;
std::memcpy(&f, buf.data(), buf.size());
return make_FloatV(f, 80);
}

inline long double proj_FloatV(PtrVal v) {
return v->to_FloatV()->f;
inline FloatData proj_FloatV(const PtrVal& v) {
return v->to_FloatV()->as_ld();
}

inline PtrVal ui_tofp(PtrVal v) {
Expand All @@ -323,13 +344,12 @@ inline PtrVal ui_tofp(PtrVal v) {
inline PtrVal fp_toui(PtrVal v, size_t bw) {
auto fp = v->to_FloatV();
ASSERT(fp != nullptr, "value passed to fp_toui is not a FloatV");
return make_IntV((uint64_t)fp->f, bw);
return make_IntV((uint64_t)fp->as_ld(), bw);
}

inline PtrVal fp_tosi(const PtrVal& v, size_t bw) {
auto fp = v->to_FloatV();
ASSERT(fp != nullptr, "value passed to fp_tosi is not a FloatV");
return make_IntV(fp->f, bw);
ASSERT(v->to_FloatV() != nullptr, "value passed to fp_tosi is not a FloatV");
return make_IntV(proj_FloatV(v), bw);
}

inline PtrVal si_tofp(const PtrVal& v) {
Expand Down Expand Up @@ -892,52 +912,52 @@ inline PtrVal float_op_2(fOP op, const PtrVal& v1, const PtrVal& v2) {
}

if (f1 && f2) {
auto apply = [&](auto x, auto y) -> PtrVal {
switch (op) {
case fOP::op_fadd: return make_FloatV(f1->f + f2->f, MAX(f1->bw, f2->bw));
case fOP::op_fsub: return make_FloatV(f1->f - f2->f, MAX(f1->bw, f2->bw));
case fOP::op_fmul: return make_FloatV(f1->f * f2->f, MAX(f1->bw, f2->bw));
case fOP::op_fdiv: return make_FloatV(f1->f / f2->f, MAX(f1->bw, f2->bw));
case fOP::op_oeq: return make_IntV(f1->f == f2->f, 1);
case fOP::op_ogt: return make_IntV(f1->f > f2->f, 1);
case fOP::op_oge: return make_IntV(f1->f >= f2->f, 1);
case fOP::op_olt: return make_IntV(f1->f < f2->f, 1);
case fOP::op_ole: return make_IntV(f1->f <= f2->f, 1);
case fOP::op_one: return make_IntV(f1->f != f2->f, 1);
case fOP::op_ueq: return make_IntV(f1->f == f2->f, 1);
case fOP::op_ugt: return make_IntV(f1->f > f2->f, 1);
case fOP::op_uge: return make_IntV(f1->f >= f2->f, 1);
case fOP::op_ult: return make_IntV(f1->f < f2->f, 1);
case fOP::op_ule: return make_IntV(f1->f <= f2->f, 1);
case fOP::op_une: return make_IntV(f1->f != f2->f, 1);
case fOP::op_fadd: return make_FloatV(x + y, bw1);
case fOP::op_fsub: return make_FloatV(x - y, bw1);
case fOP::op_fmul: return make_FloatV(x * y, bw1);
case fOP::op_fdiv: return make_FloatV(x / y, bw1);
case fOP::op_oeq: return make_IntV(x == y, 1);
case fOP::op_ogt: return make_IntV(x > y, 1);
case fOP::op_oge: return make_IntV(x >= y, 1);
case fOP::op_olt: return make_IntV(x < y, 1);
case fOP::op_ole: return make_IntV(x <= y, 1);
case fOP::op_one: return make_IntV(x != y, 1);
case fOP::op_ueq: return make_IntV(x == y, 1);
case fOP::op_ugt: return make_IntV(x > y, 1);
case fOP::op_uge: return make_IntV(x >= y, 1);
case fOP::op_ult: return make_IntV(x < y, 1);
case fOP::op_ule: return make_IntV(x <= y, 1);
case fOP::op_une: return make_IntV(x != y, 1);
/* TODO: QNAN <2022-03-10, David Deng> */
case fOP::op_ord: return make_IntV(1);
case fOP::op_uno: return make_IntV(0);
case fOP::const_false: return make_IntV(0, 1);
case fOP::const_true: return make_IntV(1, 1);
}
ABORT("Unknown float_op_2 operation");
ABORT("Unknown float_op_2 operation");};
switch (bw1) {
case 32: return apply(f1->f.f32, f2->f.f32);
case 64: return apply(f1->f.f64, f2->f.f64);
case 80: return apply(f1->f.f80, f2->f.f80);
}
ABORT("Operating on a float of unsupported bitwidth " << bw1);
} else {
ABORT("Non-concrete Float Detected");
}
}
}

/* TODO: implement those two <2022-03-10, David Deng> */

inline PtrVal fp_ext(const PtrVal& v1, int from, int to) {
auto f1 = v1->to_FloatV();
ASSERT((f1 != nullptr), "extending a non-FloatV value");
return make_FloatV(f1->f, to);
return make_FloatV(proj_FloatV(v1), to);
}

inline PtrVal fp_trunc(const PtrVal& v1, int from, int to) {
auto f1 = v1->to_FloatV();
ASSERT((f1 != nullptr), "truncating a non-FloatV value");
/* TODO: support other bw values (e.g. fp80) <2022-03-10, David Deng> */
switch (to) {
case 32: return make_FloatV(float(f1->f), to);
case 64: return make_FloatV(double(f1->f), to);
default: return make_FloatV(f1->f, to);
}
return make_FloatV(proj_FloatV(v1), to);
}

inline std::string ptrval_to_string(const PtrVal& ptr) {
Expand Down
5 changes: 4 additions & 1 deletion headers/test/Makefile
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@@ -1,9 +1,12 @@
FLAGS := -I ../ -I ../../third-party/immer -I ../../third-party/parallel-hashmap -I ../../third-party/stp/build/include/ -L ../../third-party/stp/build/lib/ -lstp -fPIC

targets = fact_lms fact_plain sym_test conc_test stp_test fs_test external_test coverage_test
targets = fact_lms fact_plain sym_test conc_test stp_test fs_test external_test coverage_test float_test

all: $(targets)

float_test: float_test.cpp ../gensym/value_ops.hpp
g++ -std=c++17 float_test.cpp -o float_test $(FLAGS)

coverage_test: coverage_test.cpp ../gensym.hpp
g++ -std=c++17 coverage_test.cpp -o coverage_test $(FLAGS) -pthread

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171 changes: 171 additions & 0 deletions headers/test/float_test.cpp
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@@ -0,0 +1,171 @@
#include <bits/stdc++.h>
#include <sys/resource.h>
#include <parallel_hashmap/phmap.h>

#include <gensym/immeralgo.hpp>
#include <gensym/auxiliary.hpp>
#include <gensym/defs.hpp>
#include <gensym/value_ops.hpp>

namespace {

const long double pi = 3.14159265358979323846L;

template <typename T>
void test_ops(T x, T y, size_t bw) {
const PtrVal lhs = make_FloatV(x, bw), rhs = make_FloatV(y, bw);
assert(lhs->is_conc() && lhs->get_bw() == bw && lhs->get_byte_size() == bw/8);
assert(lhs->to_bytes().size() == bw/8);
assert(proj_FloatV(lhs) == x && proj_FloatV(rhs) == y);
assert(lhs == make_FloatV(x, bw));

assert(proj_FloatV(float_op_2(fOP::op_fadd, lhs, rhs)) == (T)(x + y));
assert(proj_FloatV(float_op_2(fOP::op_fsub, lhs, rhs)) == (T)(x - y));
assert(proj_FloatV(float_op_2(fOP::op_fmul, lhs, rhs)) == (T)(x * y));
assert(proj_FloatV(float_op_2(fOP::op_fdiv, lhs, rhs)) == (T)(x / y));

const std::pair<fOP, bool> cmps[] = {
{ fOP::op_oeq, x == y }, { fOP::op_ogt, x > y }, { fOP::op_oge, x >= y },
{ fOP::op_olt, x < y }, { fOP::op_ole, x <= y }, { fOP::op_one, x != y },
{ fOP::op_ueq, x == y }, { fOP::op_ugt, x > y }, { fOP::op_uge, x >= y },
{ fOP::op_ult, x < y }, { fOP::op_ule, x <= y }, { fOP::op_une, x != y },
{ fOP::op_ord, !std::isnan(x) && !std::isnan(y) },
{ fOP::op_uno, std::isnan(x) || std::isnan(y) },
};
for (auto [op, expected] : cmps) {
const PtrVal c = float_op_2(op, lhs, rhs);
assert(c->get_bw() == (op == fOP::op_ord || op == fOP::op_uno ? default_bw : 1));
assert(proj_IntV(c) == expected);
}
}

void test_f80() {
std::cout << "f80..." << std::endl;
// Round-trip keeps full long double precision, including extremes.
const long double vals[] = { 0.0L, -0.0L, 1.0L, -1.0L, 0.1L, 1.0L/3.0L,
pi, LDBL_EPSILON, LDBL_MAX, -LDBL_MAX, LDBL_TRUE_MIN };
for (long double x : vals) assert(proj_FloatV(make_FloatV(x, 80)) == x);

// Construction from the memory representation.
assert(proj_FloatV(make_FloatV_fp80({0,0,0,0,0,0,0,0x80,0xFF,0x3F})) == 1.0L);
std::array<unsigned char, 10> buf;
std::memcpy(buf.data(), &pi, 10);
assert(proj_FloatV(make_FloatV_fp80(buf)) == pi);
assert(make_FloatV_fp80(buf) == make_FloatV(pi, 80));

test_ops(1.5L, 0.5L, 80);
test_ops(0.1L, 0.2L, 80);
test_ops(1.0L/3.0L, 3.0L, 80);
test_ops(LDBL_TRUE_MIN, LDBL_MAX, 80);

// Float-to-int conversions truncate toward zero.
assert(proj_IntV(fp_toui(make_FloatV(42.9L, 80), 64)) == 42);
assert(proj_IntV(fp_tosi(make_FloatV(-42.9L, 80), 64)) == -42);
assert(proj_FloatV(ui_tofp(make_IntV(5, 64))) == 5.0L);
assert(proj_FloatV(si_tofp(make_IntV(-5, 64))) == -5.0L);
}

void test_f32() {
std::cout << "f32..." << std::endl;
const float vals[] = { 0.0f, -0.0f, 1.0f, 0.1f, 1.0f/3.0f, FLT_EPSILON,
FLT_MAX, -FLT_MAX, FLT_TRUE_MIN };
for (float x : vals) assert(proj_FloatV(make_FloatV(x, 32)) == x);

assert(proj_FloatV(make_FloatV(0.1L, 32)) == 0.1f);
assert(make_FloatV(0.1L, 32) == make_FloatV(0.1f, 32));

test_ops(1.5f, 0.5f, 32);
test_ops(0.1f, 0.2f, 32);
test_ops(1.0f/3.0f, 3.0f, 32);
test_ops(16777216.0f, 1.0f, 32);
test_ops(FLT_TRUE_MIN, FLT_MAX, 32);

// test arithmetic executions in float precision
assert(proj_FloatV(float_op_2(fOP::op_fadd, make_FloatV(1.0L, 32), make_FloatV(1e-8L, 32))) == 1.0f);
assert(proj_IntV(fp_toui(make_FloatV(2.5f, 32), 32)) == 2);
assert(proj_IntV(fp_tosi(make_FloatV(-2.5f, 32), 32)) == -2);
}

void test_f64() {
std::cout << "f64..." << std::endl;
const double vals[] = { 0.0, -0.0, 1.0, 0.1, 1.0/3.0, DBL_EPSILON,
DBL_MAX, -DBL_MAX, DBL_TRUE_MIN };
for (double x : vals) assert(proj_FloatV(make_FloatV(x, 64)) == x);

assert(proj_FloatV(make_FloatV(0.1L, 64)) == 0.1);
assert(proj_FloatV(make_FloatV(0.1L, 64)) != 0.1L);
assert(make_FloatV(0.1L, 64) == make_FloatV(0.1, 64));

test_ops(1.5, 0.5, 64);
test_ops(0.1, 0.2, 64);
test_ops(1.0/3.0, 3.0, 64);
test_ops(DBL_TRUE_MIN, DBL_MAX, 64);

assert(proj_FloatV(float_op_2(fOP::op_fadd, make_FloatV(1.0L, 64), make_FloatV(1e-17L, 64))) == 1.0);
assert(proj_FloatV(float_op_2(fOP::op_fdiv,
make_FloatV(327.8082191780822, 64), make_FloatV(2.9489999999999998, 64)))
== 327.8082191780822 / 2.9489999999999998);

assert(proj_IntV(fp_toui(make_FloatV(2.5, 64), 64)) == 2);
assert(proj_IntV(fp_tosi(make_FloatV(-2.5, 64), 64)) == -2);
}

void test_cross_width() {
std::cout << "cross-width..." << std::endl;
const PtrVal f32pi = make_FloatV((float)pi, 32);
const PtrVal f64pi = make_FloatV((double)pi, 64);
const PtrVal f80pi = make_FloatV(pi, 80);

// fp_ext widens losslessly; fp_trunc rounds to the narrower format.
assert(fp_ext(f32pi, 32, 64)->get_bw() == 64
&& proj_FloatV(fp_ext(f32pi, 32, 64)) == (double)(float)pi);
assert(proj_FloatV(fp_ext(f32pi, 32, 80)) == (float)pi);
assert(proj_FloatV(fp_ext(f64pi, 64, 80)) == (double)pi);
assert(proj_FloatV(fp_trunc(f80pi, 80, 64)) == (double)pi);
assert(proj_FloatV(fp_trunc(f80pi, 80, 32)) == (float)pi);
assert(fp_trunc(f64pi, 64, 32)->get_bw() == 32
&& proj_FloatV(fp_trunc(f64pi, 64, 32)) == (float)pi);
assert(proj_FloatV(fp_trunc(make_FloatV(0.1, 64), 64, 32)) == 0.1f);

assert(make_FloatV(1.5, 64) == make_FloatV(1.5, 64));
assert(make_FloatV(1.5, 64) != make_FloatV(1.5, 32));
assert(*make_FloatV(0.0, 64) == *make_FloatV(-0.0, 64));
}

void test_special_values() {
std::cout << "special values..." << std::endl;
use_hashcons = false;
for (size_t bw : {32, 64, 80}) {
const PtrVal one = make_FloatV(1.0L, bw), zero = make_FloatV(0.0L, bw);
const PtrVal nzero = make_FloatV(-0.0L, bw);
const PtrVal inf = float_op_2(fOP::op_fdiv, one, zero);
const PtrVal neg_inf = float_op_2(fOP::op_fdiv, make_FloatV(-1.0L, bw), zero);
const PtrVal nan = float_op_2(fOP::op_fdiv, zero, zero);
assert(std::isinf(proj_FloatV(inf)));
assert(std::isinf(proj_FloatV(neg_inf)) && std::signbit(proj_FloatV(neg_inf)));
assert(std::isnan(proj_FloatV(nan)));
assert(std::isnan(proj_FloatV(float_op_2(fOP::op_fsub, inf, inf))));
assert(std::isinf(proj_FloatV(float_op_2(fOP::op_fadd, inf, inf))));
assert(proj_IntV(float_op_2(fOP::op_ogt, inf, one)) == 1);
assert(proj_IntV(float_op_2(fOP::op_oeq, nan, nan)) == 0);
assert(proj_IntV(float_op_2(fOP::op_ogt, nan, nan)) == 0);
assert(proj_IntV(float_op_2(fOP::op_one, nan, nan)) == 1);
assert(proj_IntV(float_op_2(fOP::op_oeq, nzero, zero)) == 1);
assert(std::signbit(proj_FloatV(float_op_2(fOP::op_fmul, nzero, one))));
assert(!std::signbit(proj_FloatV(float_op_2(fOP::op_fadd, nzero, zero))));
assert(std::isnan(proj_FloatV(float_op_2(fOP::op_fdiv, nzero, zero))));
}
use_hashcons = true;
}

}

int main() {
test_f80();
test_f32();
test_f64();
test_cross_width();
test_special_values();
std::cout << "All float tests passed." << std::endl;
return 0;
}