X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=tests%2Ftest-truncf2.c;h=a8797eac4c923bd4c6fd785a6842abc7086d3736;hb=c2b08ae26cdc70a3acf7d1bc15bc77c92bbcc97c;hp=dd849ab20b3b484f4133773116e603a1b62d08e4;hpb=f2bbde92e487b8446ff201767c430306450220be;p=gnulib.git diff --git a/tests/test-truncf2.c b/tests/test-truncf2.c index dd849ab20..a8797eac4 100644 --- a/tests/test-truncf2.c +++ b/tests/test-truncf2.c @@ -1,5 +1,5 @@ /* Test of rounding towards zero. - Copyright (C) 2007-2008 Free Software Foundation, Inc. + Copyright (C) 2007-2013 Free Software Foundation, Inc. This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by @@ -16,6 +16,9 @@ /* Written by Bruno Haible , 2007. */ +/* When this test fails on some platform, build it together with the gnulib + module 'fprintf-posix' for optimal debugging output. */ + #include #include @@ -24,21 +27,16 @@ #include #include #include -#include #include "isnanf-nolibm.h" +#include "minus-zero.h" +#include "macros.h" -#define ASSERT(expr) \ - do \ - { \ - if (!(expr)) \ - { \ - fprintf (stderr, "%s:%d: assertion failed\n", __FILE__, __LINE__); \ - fflush (stderr); \ - abort (); \ - } \ - } \ - while (0) +/* MSVC with option -fp:strict refuses to compile constant initializers that + contain floating-point operations. Pacify this compiler. */ +#ifdef _MSC_VER +# pragma fenv_access (off) +#endif /* The reference implementation, taken from lib/trunc.c. */ @@ -47,6 +45,9 @@ #define MANT_DIG FLT_MANT_DIG #define L_(literal) literal##f +/* -0.0. See minus-zero.h. */ +#define MINUS_ZERO minus_zerof + /* 2^(MANT_DIG-1). */ static const DOUBLE TWO_MANT_DIG = /* Assume MANT_DIG <= 5 * 31. @@ -72,29 +73,37 @@ truncf_reference (DOUBLE x) if (z > L_(0.0)) { + /* For 0 < x < 1, return +0.0 even if the current rounding mode is + FE_DOWNWARD. */ + if (z < L_(1.0)) + z = L_(0.0); /* Avoid rounding errors for values near 2^k, where k >= MANT_DIG-1. */ - if (z < TWO_MANT_DIG) - { - /* Round to the next integer (nearest or up or down, doesn't matter). */ - z += TWO_MANT_DIG; - z -= TWO_MANT_DIG; - /* Enforce rounding down. */ - if (z > y) - z -= L_(1.0); - } + else if (z < TWO_MANT_DIG) + { + /* Round to the next integer (nearest or up or down, doesn't matter). */ + z += TWO_MANT_DIG; + z -= TWO_MANT_DIG; + /* Enforce rounding down. */ + if (z > y) + z -= L_(1.0); + } } else if (z < L_(0.0)) { + /* For -1 < x < 0, return -0.0 regardless of the current rounding + mode. */ + if (z > L_(-1.0)) + z = MINUS_ZERO; /* Avoid rounding errors for values near -2^k, where k >= MANT_DIG-1. */ - if (z > - TWO_MANT_DIG) - { - /* Round to the next integer (nearest or up or down, doesn't matter). */ - z -= TWO_MANT_DIG; - z += TWO_MANT_DIG; - /* Enforce rounding up. */ - if (z < y) - z += L_(1.0); - } + else if (z > - TWO_MANT_DIG) + { + /* Round to the next integer (nearest or up or down, doesn't matter). */ + z -= TWO_MANT_DIG; + z += TWO_MANT_DIG; + /* Enforce rounding up. */ + if (z < y) + z += L_(1.0); + } } return z; } @@ -114,11 +123,11 @@ correct_result_p (DOUBLE x, DOUBLE result) return (x >= 0 ? (x < 1 ? result == L_(0.0) : - x - 1 < x ? result <= x && result >= x - 1 && x - result < 1 : - equal (result, x)) + x - 1 < x ? result <= x && result >= x - 1 && x - result < 1 : + equal (result, x)) : (x > -1 ? result == L_(0.0) : - x + 1 > x ? result >= x && result <= x + 1 && result - x < 1 : - equal (result, x))); + x + 1 > x ? result >= x && result <= x + 1 && result - x < 1 : + equal (result, x))); } /* Test the function for a given argument. */ @@ -135,9 +144,11 @@ check (float x) return 0; else { - fprintf (stderr, "truncf %g(%a) = %g(%a) or %g(%a)?\n", - x, x, reference, reference, result, result); - return 1; +#if GNULIB_TEST_FPRINTF_POSIX + fprintf (stderr, "truncf %g(%a) = %g(%a) or %g(%a)?\n", + x, x, reference, reference, result, result); +#endif + return 1; } } } @@ -154,14 +165,14 @@ main () for (highbits = 0; highbits < (1 << NUM_HIGHBITS); highbits++) for (lowbits = 0; lowbits < (1 << NUM_LOWBITS); lowbits++) { - /* Combine highbits and lowbits into a floating-point number, - sign-extending the lowbits to 32-NUM_HIGHBITS bits. */ - union { float f; uint32_t i; } janus; - janus.i = ((uint32_t) highbits << (32 - NUM_HIGHBITS)) - | ((uint32_t) ((int32_t) ((uint32_t) lowbits << (32 - NUM_LOWBITS)) - >> (32 - NUM_LOWBITS - NUM_HIGHBITS)) - >> NUM_HIGHBITS); - error |= check (janus.f); + /* Combine highbits and lowbits into a floating-point number, + sign-extending the lowbits to 32-NUM_HIGHBITS bits. */ + union { float f; uint32_t i; } janus; + janus.i = ((uint32_t) highbits << (32 - NUM_HIGHBITS)) + | ((uint32_t) ((int32_t) ((uint32_t) lowbits << (32 - NUM_LOWBITS)) + >> (32 - NUM_LOWBITS - NUM_HIGHBITS)) + >> NUM_HIGHBITS); + error |= check (janus.f); } return (error ? 1 : 0); }