1 files changed, 130 insertions, 0 deletions
diff --git a/subprojects/exess/test/float_test_data.h b/subprojects/exess/test/float_test_data.h
new file mode 100644
index 00000000..eaea65c4
--- /dev/null
+++ b/subprojects/exess/test/float_test_data.h
@@ -0,0 +1,130 @@
+/*
+  Copyright 2019-2021 David Robillard <d@drobilla.net>
+
+  Permission to use, copy, modify, and/or distribute this software for any
+  purpose with or without fee is hereby granted, provided that the above
+  copyright notice and this permission notice appear in all copies.
+
+  THIS SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+
+#include "attributes.h"
+#include "ieee_float.h"
+#include "warnings.h"
+
+#include <assert.h>
+#include <math.h>
+#include <stdint.h>
+#include <string.h>
+
+/// Return the float with representation `rep`
+static inline float
+float_from_rep(const uint32_t rep)
+{
+  float f = 0.0f;
+  memcpy(&f, &rep, sizeof(f));
+  return f;
+}
+
+/// Return the double with representation `rep`
+static inline double
+double_from_rep(const uint64_t rep)
+{
+  double d = 0.0;
+  memcpy(&d, &rep, sizeof(d));
+  return d;
+}
+
+/// Return the distance between two doubles in ULPs
+static EXESS_I_PURE_FUNC uint64_t
+double_ulp_distance(const double a, const double b)
+{
+  assert(a >= 0.0);
+  assert(b >= 0.0);
+
+  const uint64_t ia = double_to_rep(a);
+  const uint64_t ib = double_to_rep(b);
+  if (ia == ib) {
+    return 0;
+  }
+
+  EXESS_DISABLE_CONVERSION_WARNINGS
+  if (isnan(a) || isnan(b) || isinf(a) || isinf(b)) {
+    return UINT64_MAX;
+  }
+  EXESS_RESTORE_WARNINGS
+
+  return ia > ib ? ia - ib : ib - ia;
+}
+
+/// Return the distance between two floats in ULPs
+static EXESS_I_PURE_FUNC uint32_t
+float_ulp_distance(const float a, const float b)
+{
+  assert(a >= 0.0f);
+  assert(b >= 0.0f);
+
+  const uint32_t ia = float_to_rep(a);
+  const uint32_t ib = float_to_rep(b);
+  if (ia == ib) {
+    return 0;
+  }
+
+  EXESS_DISABLE_CONVERSION_WARNINGS
+  if (isnan(a) || isnan(b) || isinf(a) || isinf(b)) {
+    return UINT32_MAX;
+  }
+  EXESS_RESTORE_WARNINGS
+
+  return ia > ib ? ia - ib : ib - ia;
+}
+
+static inline bool
+float_matches(const float a, const float b)
+{
+  EXESS_DISABLE_CONVERSION_WARNINGS
+  const bool a_is_nan      = isnan(a);
+  const bool a_is_negative = signbit(a);
+  const bool b_is_nan      = isnan(b);
+  const bool b_is_negative = signbit(b);
+  EXESS_RESTORE_WARNINGS
+
+  if (a_is_nan && b_is_nan) {
+    return true;
+  }
+
+  if (a_is_nan || b_is_nan || a_is_negative != b_is_negative) {
+    return false;
+  }
+
+  return a_is_negative ? float_ulp_distance(-a, -b) == 0
+                       : float_ulp_distance(a, b) == 0;
+}
+
+static inline bool
+double_matches(const double a, const double b)
+{
+  EXESS_DISABLE_CONVERSION_WARNINGS
+  const bool a_is_nan      = isnan(a);
+  const bool a_is_negative = signbit(a);
+  const bool b_is_nan      = isnan(b);
+  const bool b_is_negative = signbit(b);
+  EXESS_RESTORE_WARNINGS
+
+  if (a_is_nan && b_is_nan) {
+    return true;
+  }
+
+  if (a_is_nan || b_is_nan || a_is_negative != b_is_negative) {
+    return false;
+  }
+
+  return a_is_negative ? double_ulp_distance(-a, -b) == 0
+                       : double_ulp_distance(a, b) == 0;
+}