1 /* $NetBSD: t_round.c,v 1.2 2011/07/04 22:33:29 mrg Exp $ */ 2 3 #include <atf-c.h> 4 #include <math.h> 5 6 /* 7 * This tests for a bug in the initial implementation where 8 * precision was lost in an internal substraction, leading to 9 * rounding into the wrong direction. 10 */ 11 12 /* 0.5 - EPSILON */ 13 #define VAL 0x0.7ffffffffffffcp0 14 #define VALF 0x0.7fffff8p0 15 16 #ifdef __vax__ 17 #define SMALL_NUM 1.0e-38 18 #else 19 #define SMALL_NUM 1.0e-40 20 #endif 21 22 ATF_TC(round_dir); 23 ATF_TC_HEAD(round_dir, tc) 24 { 25 atf_tc_set_md_var(tc, "descr","Check for rounding in wrong direction"); 26 } 27 28 ATF_TC_BODY(round_dir, tc) 29 { 30 double a = VAL, b, c; 31 float af = VALF, bf, cf; 32 33 b = round(a); 34 bf = roundf(af); 35 36 ATF_REQUIRE(fabs(b) < SMALL_NUM); 37 ATF_REQUIRE(fabsf(bf) < SMALL_NUM); 38 39 c = round(-a); 40 cf = roundf(-af); 41 42 ATF_REQUIRE(fabs(c) < SMALL_NUM); 43 ATF_REQUIRE(fabsf(cf) < SMALL_NUM); 44 } 45 46 ATF_TP_ADD_TCS(tp) 47 { 48 49 ATF_TP_ADD_TC(tp, round_dir); 50 51 return atf_no_error(); 52 } 53