diff --git a/src/unity.c b/src/unity.c index 0f2d2dea3d2ff19b5dd8232f37ba83d69351b5af..429ff06576e2230f3c6564562dfb2e5f8f20d441 100644 --- a/src/unity.c +++ b/src/unity.c @@ -258,11 +258,14 @@ void UnityPrintMask(const UNITY_UINT mask, const UNITY_UINT number) /*-----------------------------------------------*/ #ifndef UNITY_EXCLUDE_FLOAT_PRINT -/* This function prints a floating-point value in a format similar to - * printf("%.6g"). It can work with either single- or double-precision, - * but for simplicity, it prints only 6 significant digits in either case. - * Printing more than 6 digits accurately is hard (at least in the single- - * precision case) and isn't attempted here. */ +/* + * This function prints a floating-point value in a format similar to + * printf("%.7g"). It can work with either single- or double-precision, + * but for simplicity, it prints only 7 significant digits in either case. + * The 7th digit won't always be totally correct in single-precision + * operation (for that level of accuracy, a more complicated algorithm + * would be needed). + */ void UnityPrintFloat(const UNITY_DOUBLE input_number) { UNITY_DOUBLE number = input_number; @@ -285,22 +288,42 @@ void UnityPrintFloat(const UNITY_DOUBLE input_number) UNITY_INT32 n; char buf[16]; - /* scale up or down by powers of 10 */ - while (number < 100000.0f / 1e6f) { number *= 1e6f; exponent -= 6; } - while (number < 100000.0f) { number *= 10.0f; exponent--; } - while (number > 1000000.0f * 1e6f) { number /= 1e6f; exponent += 6; } - while (number > 1000000.0f) { number /= 10.0f; exponent++; } + /* + * Scale up or down by powers of 10. To minimize rounding error, + * start with a factor/divisor of 10^10, which is the largest + * power of 10 that can be represented exactly. Finally, compute + * (exactly) the remaining power of 10 and perform one more + * multiplication or division. + */ + if(number < 1e6f) + { + UNITY_DOUBLE factor = 1.0f; + + while(number < 1e7f / 1e10f) { number *= 1e10f; exponent -= 10; } + while(number * factor < 1e6f) { factor *= 10.0f; exponent--; } + + number *= factor; + } + else if(number > 1e7f) + { + UNITY_DOUBLE divisor = 1.0f; + + while(number > 1e6f * 1e10f) { number /= 1e10f; exponent += 10; } + while(number / divisor > 1e7f) { divisor *= 10.0f; exponent++; } + + number /= divisor; + } /* round to nearest integer */ n = ((UNITY_INT32)(number + number) + 1) / 2; - if (n > 999999) + if (n > 9999999) { - n = 100000; + n = 1000000; exponent++; } /* determine where to place decimal point */ - decimals = (exponent <= 0 && exponent >= -9) ? -exponent : 5; + decimals = (exponent <= 0 && exponent >= -10) ? -exponent : 6; exponent += decimals; /* truncate trailing zeroes after decimal point */ diff --git a/test/tests/testunity.c b/test/tests/testunity.c index af06647f81c0565dd20b0593b6b2d0586fe5d6db..752c3b289e7bc44c030e8e53e02fc032dc7a2fd4 100644 --- a/test/tests/testunity.c +++ b/test/tests/testunity.c @@ -4466,46 +4466,48 @@ void testFloatPrinting(void) #if defined(UNITY_EXCLUDE_FLOAT_PRINT) || !defined(USING_OUTPUT_SPY) TEST_IGNORE(); #else + /* Some failures are expected due to differences in the last digit + * if UnityPrintFloat uses single-precision calculations. */ TEST_ASSERT_EQUAL_PRINT_FLOATING("0", 0.0f); TEST_ASSERT_EQUAL_PRINT_FLOATING("4.99e-07", 0.000000499f); - TEST_ASSERT_EQUAL_PRINT_FLOATING("5e-07", 0.00000050000005f); - TEST_ASSERT_EQUAL_PRINT_FLOATING("0.100469", 0.100469499f); - TEST_ASSERT_EQUAL_PRINT_FLOATING("1", 0.9999995f); /*Rounding to int place*/ + TEST_ASSERT_EQUAL_PRINT_FLOATING("5e-07", 0.0000005f); + TEST_ASSERT_EQUAL_PRINT_FLOATING("0.1004695", 0.1004695f); + TEST_ASSERT_EQUAL_PRINT_FLOATING("2", 1.9999995f); /*Rounding to int place*/ TEST_ASSERT_EQUAL_PRINT_FLOATING("1", 1.0f); TEST_ASSERT_EQUAL_PRINT_FLOATING("1.25", 1.25f); - TEST_ASSERT_EQUAL_PRINT_FLOATING("7.99999", 7.99999f); /*Not rounding*/ - TEST_ASSERT_EQUAL_PRINT_FLOATING("16.0002", 16.0002f); - TEST_ASSERT_EQUAL_PRINT_FLOATING("16.0004", 16.0004f); - TEST_ASSERT_EQUAL_PRINT_FLOATING("16.0006", 16.0006f); - TEST_ASSERT_EQUAL_PRINT_FLOATING("999999", 999999.0f); /*Last full print integer*/ + TEST_ASSERT_EQUAL_PRINT_FLOATING("7.999999", 7.999999f); /*Not rounding*/ + TEST_ASSERT_EQUAL_PRINT_FLOATING("16.00002", 16.00002f); + TEST_ASSERT_EQUAL_PRINT_FLOATING("16.00004", 16.00004f); + TEST_ASSERT_EQUAL_PRINT_FLOATING("16.00006", 16.00006f); + TEST_ASSERT_EQUAL_PRINT_FLOATING("9999999", 9999999.0f); /*Last full print integer*/ TEST_ASSERT_EQUAL_PRINT_FLOATING("-0", -0.0f); TEST_ASSERT_EQUAL_PRINT_FLOATING("-4.99e-07", -0.000000499f); - TEST_ASSERT_EQUAL_PRINT_FLOATING("-5e-07", -0.00000050000005f); - TEST_ASSERT_EQUAL_PRINT_FLOATING("-0.100469", -0.100469499f); - TEST_ASSERT_EQUAL_PRINT_FLOATING("-1", -0.9999995f); /*Rounding to int place*/ + TEST_ASSERT_EQUAL_PRINT_FLOATING("-5e-07", -0.0000005f); + TEST_ASSERT_EQUAL_PRINT_FLOATING("-0.1004695", -0.1004695f); + TEST_ASSERT_EQUAL_PRINT_FLOATING("-2", -1.9999995f); /*Rounding to int place*/ TEST_ASSERT_EQUAL_PRINT_FLOATING("-1", -1.0f); TEST_ASSERT_EQUAL_PRINT_FLOATING("-1.25", -1.25f); - TEST_ASSERT_EQUAL_PRINT_FLOATING("-7.99999", -7.99999f); /*Not rounding*/ - TEST_ASSERT_EQUAL_PRINT_FLOATING("-16.0002", -16.0002f); - TEST_ASSERT_EQUAL_PRINT_FLOATING("-16.0004", -16.0004f); - TEST_ASSERT_EQUAL_PRINT_FLOATING("-16.0006", -16.0006f); - TEST_ASSERT_EQUAL_PRINT_FLOATING("-999999", -999999.0f); /*Last full print integer*/ - - TEST_ASSERT_EQUAL_PRINT_FLOATING("4.29497e+09", 4294967296.0f); - TEST_ASSERT_EQUAL_PRINT_FLOATING("5e+09", 5000000000.0f); - TEST_ASSERT_EQUAL_PRINT_FLOATING("8e+09", 8.0e+09f); - TEST_ASSERT_EQUAL_PRINT_FLOATING("8.31e+09", 8309999104.0f); - TEST_ASSERT_EQUAL_PRINT_FLOATING("1e+10", 1.0e+10f); - TEST_ASSERT_EQUAL_PRINT_FLOATING("1e+10", 10000000000.0f); + TEST_ASSERT_EQUAL_PRINT_FLOATING("-7.999999", -7.999999f); /*Not rounding*/ + TEST_ASSERT_EQUAL_PRINT_FLOATING("-16.00002", -16.00002f); + TEST_ASSERT_EQUAL_PRINT_FLOATING("-16.00004", -16.00004f); + TEST_ASSERT_EQUAL_PRINT_FLOATING("-16.00006", -16.00006f); + TEST_ASSERT_EQUAL_PRINT_FLOATING("-9999999", -9999999.0f); /*Last full print integer*/ + + TEST_ASSERT_EQUAL_PRINT_FLOATING("4.294967e+09", 4294967296.0f); + TEST_ASSERT_EQUAL_PRINT_FLOATING("5e+09", 5000000000.0f); + TEST_ASSERT_EQUAL_PRINT_FLOATING("8e+09", 8.0e+09f); + TEST_ASSERT_EQUAL_PRINT_FLOATING("8.309999e+09", 8309999104.0f); + TEST_ASSERT_EQUAL_PRINT_FLOATING("1e+10", 1.0e+10f); + TEST_ASSERT_EQUAL_PRINT_FLOATING("1e+10", 10000000000.0f); /* Some compilers have trouble with inexact float constants, a float cast works generally */ - TEST_ASSERT_EQUAL_PRINT_FLOATING("1.00005e+10", (float)1.000054e+10f); - TEST_ASSERT_EQUAL_PRINT_FLOATING("1.1e+38", (float)1.10000005e+38f); - TEST_ASSERT_EQUAL_PRINT_FLOATING("1.6353e+10", 1.63529943e+10f); - TEST_ASSERT_EQUAL_PRINT_FLOATING("3.40282e+38", 3.40282346638e38f); + TEST_ASSERT_EQUAL_PRINT_FLOATING("1.000055e+10", (float)1.000055e+10f); + TEST_ASSERT_EQUAL_PRINT_FLOATING("1.1e+38", (float)1.10000005e+38f); + TEST_ASSERT_EQUAL_PRINT_FLOATING("1.635299e+10", 1.63529943e+10f); + TEST_ASSERT_EQUAL_PRINT_FLOATING("3.402823e+38", 3.40282346638e38f); - TEST_ASSERT_EQUAL_PRINT_FLOATING("-1e+10", -1.0e+10f); - TEST_ASSERT_EQUAL_PRINT_FLOATING("-3.40282e+38", -3.40282346638e38f); + TEST_ASSERT_EQUAL_PRINT_FLOATING("-1e+10", -1.0e+10f); + TEST_ASSERT_EQUAL_PRINT_FLOATING("-3.402823e+38", -3.40282346638e38f); #endif } @@ -4526,27 +4528,43 @@ static void printFloatValue(float f) { char expected[18]; char expected_lower[18]; + char expected_lower2[18]; + char expected_lower3[18]; char expected_higher[18]; + char expected_higher2[18]; + char expected_higher3[18]; startPutcharSpy(); UnityPrintFloat(f); - sprintf(expected, "%.6g", f); + sprintf(expected, "%.7g", f); /* We print all NaN's as "nan", not "-nan" */ if(strcmp(expected, "-nan") == 0) strcpy(expected, "nan"); - /* Allow for rounding differences in last digit */ - double lower = (double)f * 0.9999995; - double higher = (double)f * 1.0000005; - - if (isfinite(lower)) sprintf(expected_lower, "%.6g", lower); else strcpy(expected_lower, expected); - if (isfinite(higher)) sprintf(expected_higher, "%.6g", higher); else strcpy(expected_higher, expected); + /* Allow for relative error of +/-2.5e-7 */ + double lower = (double)f * 0.99999995; + double lower2 = (double)f * 0.99999985; + double lower3 = (double)f * 0.99999975; + double higher = (double)f * 1.00000005; + double higher2 = (double)f * 1.00000015; + double higher3 = (double)f * 1.00000025; + + if(isfinite(lower)) sprintf(expected_lower, "%.7g", lower); else strcpy(expected_lower, expected); + if(isfinite(lower2)) sprintf(expected_lower2, "%.7g", lower2); else strcpy(expected_lower2, expected); + if(isfinite(lower3)) sprintf(expected_lower3, "%.7g", lower3); else strcpy(expected_lower3, expected); + if(isfinite(higher)) sprintf(expected_higher, "%.7g", higher); else strcpy(expected_higher, expected); + if(isfinite(higher2)) sprintf(expected_higher2, "%.7g", higher2); else strcpy(expected_higher2, expected); + if(isfinite(higher3)) sprintf(expected_higher3, "%.7g", higher3); else strcpy(expected_higher3, expected); if (strcmp(expected, getBufferPutcharSpy()) != 0 && strcmp(expected_lower, getBufferPutcharSpy()) != 0 && - strcmp(expected_higher, getBufferPutcharSpy()) != 0) + strcmp(expected_lower2, getBufferPutcharSpy()) != 0 && + strcmp(expected_lower3, getBufferPutcharSpy()) != 0 && + strcmp(expected_higher, getBufferPutcharSpy()) != 0 && + strcmp(expected_higher2, getBufferPutcharSpy()) != 0 && + strcmp(expected_higher3, getBufferPutcharSpy()) != 0) { /* Fail with diagnostic printing */ TEST_ASSERT_EQUAL_PRINT_FLOATING(expected, f); @@ -5252,20 +5270,20 @@ void testDoublePrinting(void) #if defined(UNITY_EXCLUDE_FLOAT_PRINT) || defined(UNITY_EXCLUDE_DOUBLE) || !defined(USING_OUTPUT_SPY) TEST_IGNORE(); #else - TEST_ASSERT_EQUAL_PRINT_FLOATING("0.100469", 0.10046949999999999); - TEST_ASSERT_EQUAL_PRINT_FLOATING("4.29497e+09", 4294967295.999999); - TEST_ASSERT_EQUAL_PRINT_FLOATING("4.29497e+09", 4294967295.9999995); - TEST_ASSERT_EQUAL_PRINT_FLOATING("4.29497e+09", 4294967296.0); - TEST_ASSERT_EQUAL_PRINT_FLOATING("1e+10", 9999999995.0); - TEST_ASSERT_EQUAL_PRINT_FLOATING("9.0072e+15", 9007199254740990.0); - TEST_ASSERT_EQUAL_PRINT_FLOATING("7e+100", 7.0e+100); - TEST_ASSERT_EQUAL_PRINT_FLOATING("3e+200", 3.0e+200); - TEST_ASSERT_EQUAL_PRINT_FLOATING("9.23457e+300", 9.23456789e+300); - - TEST_ASSERT_EQUAL_PRINT_FLOATING("-0.100469", -0.10046949999999999); - TEST_ASSERT_EQUAL_PRINT_FLOATING("-4.29497e+09", -4294967295.999999); - TEST_ASSERT_EQUAL_PRINT_FLOATING("-4.29497e+09", -4294967295.9999995); - TEST_ASSERT_EQUAL_PRINT_FLOATING("-7e+100", -7.0e+100); + TEST_ASSERT_EQUAL_PRINT_FLOATING("0.1004695", 0.10046949999999999); + TEST_ASSERT_EQUAL_PRINT_FLOATING("4.294967e+09", 4294967295.999999); + TEST_ASSERT_EQUAL_PRINT_FLOATING("4.294967e+09", 4294967295.9999995); + TEST_ASSERT_EQUAL_PRINT_FLOATING("4.294967e+09", 4294967296.0); + TEST_ASSERT_EQUAL_PRINT_FLOATING("1e+10", 9999999995.0); + TEST_ASSERT_EQUAL_PRINT_FLOATING("9.007199e+15", 9007199254740990.0); + TEST_ASSERT_EQUAL_PRINT_FLOATING("7e+100", 7.0e+100); + TEST_ASSERT_EQUAL_PRINT_FLOATING("3e+200", 3.0e+200); + TEST_ASSERT_EQUAL_PRINT_FLOATING("9.234568e+300", 9.23456789e+300); + + TEST_ASSERT_EQUAL_PRINT_FLOATING("-0.1004695", -0.10046949999999999); + TEST_ASSERT_EQUAL_PRINT_FLOATING("-4.294967e+09", -4294967295.999999); + TEST_ASSERT_EQUAL_PRINT_FLOATING("-4.294967e+09", -4294967295.9999995); + TEST_ASSERT_EQUAL_PRINT_FLOATING("-7e+100", -7.0e+100); #endif }