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Add FP rounding self test

pull/606/head
Sami Vaarala 8 years ago
parent
35e1e268fd
commit
72645fbe44
1 changed files with 125 additions and 29 deletions
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  1. 154
      src/duk_selftest.c

154
src/duk_selftest.c
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@ -13,7 +13,7 @@
typedef union {
double d;
duk_uint8_t c[8];
duk_uint8_t x[8];
} duk__test_double_union;
/* Self test failed. Expects a local variable 'error_count' to exist. */
@ -36,9 +36,51 @@ typedef union {
typedef union {
duk_uint32_t i;
duk_uint8_t c[8];
duk_uint8_t x[8];
} duk__test_u32_union;
#if defined(DUK_USE_INTEGER_LE)
#define DUK__U32_INIT(u, a, b, c, d) do { \
(u)->x[0] = (d); (u)->x[1] = (c); (u)->x[2] = (b); (u)->x[3] = (a); \
} while (0)
#elif defined(DUK_USE_INTEGER_ME)
#error integer mixed endian not supported now
#elif defined(DUK_USE_INTEGER_BE)
#define DUK__U32_INIT(u, a, b, c, d) do { \
(u)->x[0] = (a); (u)->x[1] = (b); (u)->x[2] = (c); (u)->x[3] = (d); \
} while (0)
#else
#error unknown integer endianness
#endif
#if defined(DUK_USE_DOUBLE_LE)
#define DUK__DOUBLE_INIT(u, a, b, c, d, e, f, g, h) do { \
(u)->x[0] = (h); (u)->x[1] = (g); (u)->x[2] = (f); (u)->x[3] = (e); \
(u)->x[4] = (d); (u)->x[5] = (c); (u)->x[6] = (b); (u)->x[7] = (a); \
} while (0)
#define DUK__DOUBLE_COMPARE(u, a, b, c, d, e, f, g, h) \
((u)->x[0] == (h) && (u)->x[1] == (g) && (u)->x[2] == (f) && (u)->x[3] == (e) && \
(u)->x[4] == (d) && (u)->x[5] == (c) && (u)->x[6] == (b) && (u)->x[7] == (a))
#elif defined(DUK_USE_DOUBLE_ME)
#define DUK__DOUBLE_INIT(u, a, b, c, d, e, f, g, h) do { \
(u)->x[0] = (d); (u)->x[1] = (c); (u)->x[2] = (b); (u)->x[3] = (a); \
(u)->x[4] = (h); (u)->x[5] = (g); (u)->x[6] = (f); (u)->x[7] = (e); \
} while (0)
#define DUK__DOUBLE_COMPARE(u, a, b, c, d, e, f, g, h) \
((u)->x[0] == (d) && (u)->x[1] == (c) && (u)->x[2] == (b) && (u)->x[3] == (a) && \
(u)->x[4] == (h) && (u)->x[5] == (g) && (u)->x[6] == (f) && (u)->x[7] == (e))
#elif defined(DUK_USE_DOUBLE_BE)
#define DUK__DOUBLE_INIT(u, a, b, c, d, e, f, g, h) do { \
(u)->x[0] = (a); (u)->x[1] = (b); (u)->x[2] = (c); (u)->x[3] = (d); \
(u)->x[4] = (e); (u)->x[5] = (f); (u)->x[6] = (g); (u)->x[7] = (h); \
} while (0)
#define DUK__DOUBLE_COMPARE(u, a, b, c, d, e, f, g, h) \
((u)->x[0] == (a) && (u)->x[1] == (b) && (u)->x[2] == (c) && (u)->x[3] == (d) && \
(u)->x[4] == (e) && (u)->x[5] == (f) && (u)->x[6] == (g) && (u)->x[7] == (h))
#else
#error unknown double endianness
#endif
/*
* Various sanity checks for typing
*/
@ -124,28 +166,9 @@ DUK_LOCAL duk_uint_t duk__selftest_byte_order(void) {
* >>> struct.pack('>d', 102030405060).encode('hex')
* '4237c17c6dc40000'
*/
#if defined(DUK_USE_INTEGER_LE)
u1.c[0] = 0xef; u1.c[1] = 0xbe; u1.c[2] = 0xad; u1.c[3] = 0xde;
#elif defined(DUK_USE_INTEGER_ME)
#error integer mixed endian not supported now
#elif defined(DUK_USE_INTEGER_BE)
u1.c[0] = 0xde; u1.c[1] = 0xad; u1.c[2] = 0xbe; u1.c[3] = 0xef;
#else
#error unknown integer endianness
#endif
#if defined(DUK_USE_DOUBLE_LE)
u2.c[0] = 0x00; u2.c[1] = 0x00; u2.c[2] = 0xc4; u2.c[3] = 0x6d;
u2.c[4] = 0x7c; u2.c[5] = 0xc1; u2.c[6] = 0x37; u2.c[7] = 0x42;
#elif defined(DUK_USE_DOUBLE_ME)
u2.c[0] = 0x7c; u2.c[1] = 0xc1; u2.c[2] = 0x37; u2.c[3] = 0x42;
u2.c[4] = 0x00; u2.c[5] = 0x00; u2.c[6] = 0xc4; u2.c[7] = 0x6d;
#elif defined(DUK_USE_DOUBLE_BE)
u2.c[0] = 0x42; u2.c[1] = 0x37; u2.c[2] = 0xc1; u2.c[3] = 0x7c;
u2.c[4] = 0x6d; u2.c[5] = 0xc4; u2.c[6] = 0x00; u2.c[7] = 0x00;
#else
#error unknown double endianness
#endif
DUK__U32_INIT(&u1, 0xde, 0xad, 0xbe, 0xef);
DUK__DOUBLE_INIT(&u2, 0x42, 0x37, 0xc1, 0x7c, 0x6d, 0xc4, 0x00, 0x00);
if (u1.i != (duk_uint32_t) 0xdeadbeefUL) {
DUK__FAILED("duk_uint32_t byte order");
@ -241,20 +264,20 @@ DUK_LOCAL duk_uint_t duk__selftest_double_aliasing(void) {
*/
/* little endian */
a.c[0] = 0x11; a.c[1] = 0x22; a.c[2] = 0x33; a.c[3] = 0x44;
a.c[4] = 0x00; a.c[5] = 0x00; a.c[6] = 0xf1; a.c[7] = 0xff;
a.x[0] = 0x11; a.x[1] = 0x22; a.x[2] = 0x33; a.x[3] = 0x44;
a.x[4] = 0x00; a.x[5] = 0x00; a.x[6] = 0xf1; a.x[7] = 0xff;
b = a;
DUK__DBLUNION_CMP_TRUE(&a, &b);
/* big endian */
a.c[0] = 0xff; a.c[1] = 0xf1; a.c[2] = 0x00; a.c[3] = 0x00;
a.c[4] = 0x44; a.c[5] = 0x33; a.c[6] = 0x22; a.c[7] = 0x11;
a.x[0] = 0xff; a.x[1] = 0xf1; a.x[2] = 0x00; a.x[3] = 0x00;
a.x[4] = 0x44; a.x[5] = 0x33; a.x[6] = 0x22; a.x[7] = 0x11;
b = a;
DUK__DBLUNION_CMP_TRUE(&a, &b);
/* mixed endian */
a.c[0] = 0x00; a.c[1] = 0x00; a.c[2] = 0xf1; a.c[3] = 0xff;
a.c[4] = 0x11; a.c[5] = 0x22; a.c[6] = 0x33; a.c[7] = 0x44;
a.x[0] = 0x00; a.x[1] = 0x00; a.x[2] = 0xf1; a.x[3] = 0xff;
a.x[4] = 0x11; a.x[5] = 0x22; a.x[6] = 0x33; a.x[7] = 0x44;
b = a;
DUK__DBLUNION_CMP_TRUE(&a, &b);
@ -280,6 +303,78 @@ DUK_LOCAL duk_uint_t duk__selftest_double_zero_sign(void) {
return error_count;
}
/*
* Rounding mode: Duktape assumes round-to-nearest, check that this is true.
* If we had C99 fenv.h we could check that fegetround() == FE_TONEAREST,
* but we don't want to rely on that header; and even if we did, it's good
* to ensure the rounding actually works.
*/
DUK_LOCAL duk_uint_t duk__selftest_double_rounding(void) {
duk_uint_t error_count = 0;
duk__test_double_union a, b, c;
#if 0
/* Include <fenv.h> and test manually; these trigger failures: */
fesetround(FE_UPWARD);
fesetround(FE_DOWNWARD);
fesetround(FE_TOWARDZERO);
/* This is the default and passes. */
fesetround(FE_TONEAREST);
#endif
/* Rounding tests check that none of the other modes (round to
* +Inf, round to -Inf, round to zero) can be active:
* http://www.gnu.org/software/libc/manual/html_node/Rounding.html
*/
/* 1.0 + 2^(-53): result is midway between 1.0 and 1.0 + ulp.
* Round to nearest: 1.0
* Round to +Inf: 1.0 + ulp
* Round to -Inf: 1.0
* Round to zero: 1.0
* => Correct result eliminates round to +Inf.
*/
DUK__DOUBLE_INIT(&a, 0xf0, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00);
DUK__DOUBLE_INIT(&b, 0x3c, 0xa0, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00);
DUK_MEMSET((void *) &c, 0, sizeof(c));
c.d = a.d + b.d;
if (!DUK__DOUBLE_COMPARE(&c, 0xf0, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00)) {
DUK_D(DUK_DPRINT("broken result (native endiannesss): %02x %02x %02x %02x %02x %02x %02x %02x",
(unsigned int) c.x[0], (unsigned int) c.x[1],
(unsigned int) c.x[2], (unsigned int) c.x[3],
(unsigned int) c.x[4], (unsigned int) c.x[5],
(unsigned int) c.x[6], (unsigned int) c.x[7]));
DUK__FAILED("invalid result from 1.0 + 0.5ulp");
}
/* (1.0 + ulp) + 2^(-53): result is midway between 1.0 + ulp and 1.0 + 2*ulp.
* Round to nearest: 1.0 + 2*ulp (round to even mantissa)
* Round to +Inf: 1.0 + 2*ulp
* Round to -Inf: 1.0 + ulp
* Round to zero: 1.0 + ulp
* => Correct result eliminates round to -Inf and round to zero.
*/
DUK__DOUBLE_INIT(&a, 0x3f, 0xf0, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01);
DUK__DOUBLE_INIT(&b, 0x3c, 0xa0, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00);
DUK_MEMSET((void *) &c, 0, sizeof(c));
c.d = a.d + b.d;
if (!DUK__DOUBLE_COMPARE(&c, 0x3f, 0xf0, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02)) {
DUK_D(DUK_DPRINT("broken result (native endiannesss): %02x %02x %02x %02x %02x %02x %02x %02x",
(unsigned int) c.x[0], (unsigned int) c.x[1],
(unsigned int) c.x[2], (unsigned int) c.x[3],
(unsigned int) c.x[4], (unsigned int) c.x[5],
(unsigned int) c.x[6], (unsigned int) c.x[7]));
DUK__FAILED("invalid result from (1.0 + ulp) + 0.5ulp");
}
/* Could do negative number testing too, but the tests above should
* differentiate between IEEE 754 rounding modes.
*/
return error_count;
}
/*
* Struct size/alignment if platform requires it
*
@ -467,6 +562,7 @@ DUK_INTERNAL duk_uint_t duk_selftest_run_tests(duk_alloc_function alloc_func,
error_count += duk__selftest_double_union_size();
error_count += duk__selftest_double_aliasing();
error_count += duk__selftest_double_zero_sign();
error_count += duk__selftest_double_rounding();
error_count += duk__selftest_struct_align();
error_count += duk__selftest_64bit_arithmetic();
error_count += duk__selftest_cast_double_to_small_uint();

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