AryaWu/sqlite

1#include "sqliteInt.h"2#include "unity.h"3#include <stdint.h>4#include <limits.h>5#include <string.h>6 7/* Wrapper for the static function under test (provided in module) */8extern void test_kahanBabuskaNeumaierInit(volatile SumCtx *p, i64 iVal);9 10static const i64 TWO_POW_52 = 4503599627370496LL; /* 2^52 */11static const i64 MOD_16384 = 16384;12 13/* Unity required hooks */14void setUp(void) {15  /* no-op */16}17void tearDown(void) {18  /* no-op */19}20 21/* Helper to run the initializer and check expected results */22static void check_expected(i64 iVal, double expected_rSum, double expected_rErr){23  SumCtx s;24  memset(&s, 0xAA, sizeof(s)); /* poison so function must overwrite */25  test_kahanBabuskaNeumaierInit(&s, iVal);26  TEST_ASSERT_EQUAL_DOUBLE_MESSAGE(expected_rSum, s.rSum, "rSum mismatch");27  TEST_ASSERT_EQUAL_DOUBLE_MESSAGE(expected_rErr, s.rErr, "rErr mismatch");28}29 30/* Helper to compute the expected result per the documented logic */31static void compute_and_check(i64 iVal){32  double expected_rSum, expected_rErr;33  if( iVal <= -TWO_POW_52 || iVal >= +TWO_POW_52 ){34    i64 iSm = iVal % MOD_16384;35    expected_rSum = (double)(iVal - iSm);36    expected_rErr = (double)iSm;37  }else{38    expected_rSum = (double)iVal;39    expected_rErr = 0.0;40  }41  check_expected(iVal, expected_rSum, expected_rErr);42}43 44/* Tests start here */45 46void test_kahanBabuskaNeumaierInit_within_threshold_small_values(void){47  compute_and_check(0);48  compute_and_check(1);49  compute_and_check(-1);50  compute_and_check(TWO_POW_52 - 1);     /* just below +2^52 */51  compute_and_check(-(TWO_POW_52 - 1));  /* just above -2^52 */52}53 54void test_kahanBabuskaNeumaierInit_at_threshold_values(void){55  /* Exactly at +/- 2^52: remainder is 0 because it's a multiple of 16384 */56  compute_and_check(TWO_POW_52);57  compute_and_check(-TWO_POW_52);58}59 60void test_kahanBabuskaNeumaierInit_above_threshold_with_nonzero_remainder_positive(void){61  /* Non-zero remainders trigger split into rSum and rErr */62  i64 v1 = TWO_POW_52 + 1;         /* remainder 1 */63  i64 v2 = TWO_POW_52 + 16385;     /* remainder 1 again (16385 % 16384) */64  i64 v3 = TWO_POW_52 + 12345;     /* general non-zero remainder */65  compute_and_check(v1);66  compute_and_check(v2);67  compute_and_check(v3);68}69 70void test_kahanBabuskaNeumaierInit_below_threshold_with_nonzero_remainder_negative(void){71  /* For negatives, C % retains sign of dividend -> negative remainders */72  i64 v1 = -TWO_POW_52 - 1;        /* remainder -1 */73  i64 v2 = -TWO_POW_52 - 16385;    /* remainder -1 */74  i64 v3 = -TWO_POW_52 - 12345;    /* general negative remainder */75  compute_and_check(v1);76  compute_and_check(v2);77  compute_and_check(v3);78}79 80void test_kahanBabuskaNeumaierInit_large_multiples_of_16384_have_zero_remainder(void){81  /* Values that are multiples of 16384 yield rErr == 0 */82  i64 v1 = TWO_POW_52;                 /* multiple of 16384 */83  i64 v2 = TWO_POW_52 + MOD_16384;     /* still a multiple of 16384 */84  i64 v3 = -TWO_POW_52;                /* negative multiple */85  i64 v4 = -TWO_POW_52 - MOD_16384;    /* negative multiple offset */86  compute_and_check(v1);87  compute_and_check(v2);88  compute_and_check(v3);89  compute_and_check(v4);90}91 92void test_kahanBabuskaNeumaierInit_extreme_64bit_values(void){93  /* Ensure modulo and splitting behave at int64 extremes */94  compute_and_check(LLONG_MAX);95  compute_and_check(LLONG_MIN);96}97 98int main(void){99  UNITY_BEGIN();100  RUN_TEST(test_kahanBabuskaNeumaierInit_within_threshold_small_values);101  RUN_TEST(test_kahanBabuskaNeumaierInit_at_threshold_values);102  RUN_TEST(test_kahanBabuskaNeumaierInit_above_threshold_with_nonzero_remainder_positive);103  RUN_TEST(test_kahanBabuskaNeumaierInit_below_threshold_with_nonzero_remainder_negative);104  RUN_TEST(test_kahanBabuskaNeumaierInit_large_multiples_of_16384_have_zero_remainder);105  RUN_TEST(test_kahanBabuskaNeumaierInit_extreme_64bit_values);106  return UNITY_END();107}