Mercurial > sdl-ios-xcode
view test/testiconv.c @ 2752:edd2839b36f7
http://sources.redhat.com/ml/newlib/2002/msg00230.html
Stephen L Moshier wrote:
>
> pow(x,y) returns 0 when x is very close to -1.0 and y is very large.
> The following test program prints
>
> pow(1.0000000000000002e+00 4.5035996273704970e+15) = 2.7182818284590455e+00
> pow(-1.0000000000000002e+00 4.5035996273704970e+15) =0.0000000000000000e+00
> pow(9.9999999999999978e-01 4.5035996273704970e+15) = 3.6787944117144222e-01
> pow(-9.9999999999999978e-01 4.5035996273704970e+15) = 0.0000000000000000e+00
>
> which is incorrect for the negative arguments raised to an odd integer
> power.
>
> -----
> double pow (double, double);
>
> int
> main ()
> {
> double x, y, z;
>
> x = 1.0 + pow (2.0, -52.0);
> y = 1.0 + pow (2.0, 52.0);
> z = pow (x, y);
> printf ("pow(%.16e %.16e) = %.16e\n", x, y, z);
> x = -x;
> z = pow (x, y);
> printf ("pow(%.16e %.16e) = %.16e\n", x, y, z);
> x = 1.0 - pow (2.0, -52.0);
> z = pow (x, y);
> printf ("pow(%.16e %.16e) = %.16e\n", x, y, z);
> x = -x;
> z = pow (x, y);
> printf ("pow(%.16e %.16e) = %.16e\n", x, y, z);
> }
> -----
>
> Here is a patch for newlib/libm/math/epow.c:
Patch checked in and duplicated for ef_pow.c. Thanks.
-- Jeff J.
author | Sam Lantinga <slouken@libsdl.org> |
---|---|
date | Mon, 15 Sep 2008 04:31:30 +0000 |
parents | e906da4414a3 |
children |
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line source
#include <stdio.h> #include "SDL.h" static size_t widelen(char *data) { size_t len = 0; Uint32 *p = (Uint32 *) data; while (*p++) { ++len; } return len; } int main(int argc, char *argv[]) { const char *formats[] = { "UTF8", "UTF-8", "UTF16BE", "UTF-16BE", "UTF16LE", "UTF-16LE", "UTF32BE", "UTF-32BE", "UTF32LE", "UTF-32LE", "UCS4", "UCS-4", }; char buffer[BUFSIZ]; char *ucs4; char *test[2]; int i, index = 0; FILE *file; int errors = 0; if (!argv[1]) { argv[1] = "utf8.txt"; } file = fopen(argv[1], "rb"); if (!file) { fprintf(stderr, "Unable to open %s\n", argv[1]); return (1); } while (fgets(buffer, sizeof(buffer), file)) { /* Convert to UCS-4 */ size_t len; ucs4 = SDL_iconv_string("UCS-4", "UTF-8", buffer, SDL_strlen(buffer) + 1); len = (widelen(ucs4) + 1) * 4; for (i = 0; i < SDL_arraysize(formats); ++i) { test[0] = SDL_iconv_string(formats[i], "UCS-4", ucs4, len); test[1] = SDL_iconv_string("UCS-4", formats[i], test[0], len); if (!test[1] || SDL_memcmp(test[1], ucs4, len) != 0) { fprintf(stderr, "FAIL: %s\n", formats[i]); ++errors; } if (test[0]) { SDL_free(test[0]); } if (test[1]) { SDL_free(test[1]); } } test[0] = SDL_iconv_string("UTF-8", "UCS-4", ucs4, len); SDL_free(ucs4); fputs(test[0], stdout); SDL_free(test[0]); } return (errors ? errors + 1 : 0); }