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chore(printf, test_suite): clean up

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Marco Paland 6 years ago
parent d61d0146e6
commit 87e1c834f7
2 changed files with 89 additions and 76 deletions
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65
printf.c
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@ -65,16 +65,19 @@
#endif
// support for exponential floating point notation (%e/%g)
// default: activated
#ifndef PRINTF_DISABLE_SUPPORT_EXPONENTIAL
#define PRINTF_SUPPORT_EXPONENTIAL
#endif
// define the default floating point precision
// default: 6 digits
#ifndef PRINTF_DEFAULT_FLOAT_PRECISION
#define PRINTF_DEFAULT_FLOAT_PRECISION 6U
#endif
// define the largest float suitable to print with %f
// default: 1e9
#ifndef PRINTF_MAX_FLOAT
#define PRINTF_MAX_FLOAT 1e9
#endif
@ -185,6 +188,7 @@ static unsigned int _atoi(const char** str)
return i;
}
// output the specified string in reverse, taking care of any zero-padding
static size_t _out_rev(out_fct_type out, char* buffer, size_t idx, size_t maxlen, const char* buf, size_t len, unsigned int width, unsigned int flags)
{
@ -198,7 +202,9 @@ static size_t _out_rev(out_fct_type out, char* buffer, size_t idx, size_t maxlen
}
// reverse string
while (len) out(buf[--len], buffer, idx++, maxlen);
while (len) {
out(buf[--len], buffer, idx++, maxlen);
}
// append pad spaces up to given width
if (flags & FLAGS_LEFT) {
@ -210,6 +216,7 @@ static size_t _out_rev(out_fct_type out, char* buffer, size_t idx, size_t maxlen
return idx;
}
// internal itoa format
static size_t _ntoa_format(out_fct_type out, char* buffer, size_t idx, size_t maxlen, char* buf, size_t len, bool negative, unsigned int base, unsigned int prec, unsigned int width, unsigned int flags)
{
@ -321,6 +328,7 @@ static size_t _ntoa_long_long(out_fct_type out, char* buffer, size_t idx, size_t
static size_t _etoa(out_fct_type out, char* buffer, size_t idx, size_t maxlen, double value, unsigned int prec, unsigned int width, unsigned int flags);
#endif
// internal ftoa for fixed decimal floating point
static size_t _ftoa(out_fct_type out, char* buffer, size_t idx, size_t maxlen, double value, unsigned int prec, unsigned int width, unsigned int flags)
{
@ -341,7 +349,7 @@ static size_t _ftoa(out_fct_type out, char* buffer, size_t idx, size_t maxlen, d
// test for very large values
// standard printf behavior is to print EVERY whole number digit -- which could be 100s of characters overflowing your buffers == bad
if ((value > PRINTF_MAX_FLOAT)||(value < -PRINTF_MAX_FLOAT)) {
if ((value > PRINTF_MAX_FLOAT) || (value < -PRINTF_MAX_FLOAT)) {
#if defined(PRINTF_SUPPORT_EXPONENTIAL)
return _etoa(out, buffer, idx, maxlen, value, prec, width, flags);
#else
@ -447,18 +455,21 @@ static size_t _ftoa(out_fct_type out, char* buffer, size_t idx, size_t maxlen, d
return _out_rev(out, buffer, idx, maxlen, buf, len, width, flags);
}
#if defined(PRINTF_SUPPORT_EXPONENTIAL)
// internal ftoa variant for exponential floating-point type
// contributed by Martijn Jasperse <m.jasperse@gmail.com>
// internal ftoa variant for exponential floating-point type, contributed by Martijn Jasperse <m.jasperse@gmail.com>
static size_t _etoa(out_fct_type out, char* buffer, size_t idx, size_t maxlen, double value, unsigned int prec, unsigned int width, unsigned int flags)
{
// check for special values
if ((value != value)||(value > DBL_MAX)||(value < -DBL_MAX))
// check for NaN and special values
if ((value != value) || (value > DBL_MAX) || (value < -DBL_MAX)) {
return _ftoa(out, buffer, idx, maxlen, value, prec, width, flags);
}
// determine the sign
bool negative = value < 0;
if (negative) value = -value;
const bool negative = value < 0;
if (negative) {
value = -value;
}
// default precision
if (!(flags & FLAGS_PRECISION)) {
@ -471,19 +482,19 @@ static size_t _etoa(out_fct_type out, char* buffer, size_t idx, size_t maxlen, d
uint64_t U;
double F;
} conv;
conv.F = value;
int exp2 = (int)((conv.U >> 52) & 0x07FF) - 1023; // effectively log2
conv.U = (conv.U & ((1ULL << 52) - 1)) | (1023ULL << 52); // drop the exponent so conv.F is now in [1,2)
int exp2 = (int)((conv.U >> 52U) & 0x07FFU) - 1023; // effectively log2
conv.U = (conv.U & ((1ULL << 52U) - 1U)) | (1023ULL << 52U); // drop the exponent so conv.F is now in [1,2)
// now approximate log10 from the log2 integer part and an expansion of ln around 1.5
int expval = (int)(0.1760912590558 + exp2*0.301029995663981 + (conv.F - 1.5)*0.289529654602168);
int expval = (int)(0.1760912590558 + exp2 * 0.301029995663981 + (conv.F - 1.5) * 0.289529654602168);
// now we want to compute 10^expval but we want to be sure it won't overflow
exp2 = (int)(expval*3.321928094887362 + 0.5);
double z = expval*2.302585092994046 - exp2*0.6931471805599453;
double z2 = z*z;
conv.U = (uint64_t)(exp2 + 1023) << 52;
// compute exp(z) using continued fractions
// https://en.wikipedia.org/wiki/Exponential_function#Continued_fractions_for_ex
conv.F *= 1 + 2*z/(2 - z + (z2/(6 + (z2/(10 + z2/14)))));
exp2 = (int)(expval * 3.321928094887362 + 0.5);
const double z = expval * 2.302585092994046 - exp2 * 0.6931471805599453;
const double z2 = z * z;
conv.U = (uint64_t)(exp2 + 1023) << 52U;
// compute exp(z) using continued fractions, see https://en.wikipedia.org/wiki/Exponential_function#Continued_fractions_for_ex
conv.F *= 1 + 2 * z / (2 - z + (z2 / (6 + (z2 / (10 + z2 / 14)))));
// correct for rounding errors
if (value < conv.F) {
expval--;
@ -496,21 +507,26 @@ static size_t _etoa(out_fct_type out, char* buffer, size_t idx, size_t maxlen, d
// in "%g" mode, "prec" is the number of *significant figures* not decimals
if (flags & FLAGS_ADAPT_EXP) {
// do we want to fall-back to "%f" mode?
if ((value >= 1e-4)&&(value < 1e6)) {
if ((value >= 1e-4) && (value < 1e6)) {
if ((int)prec > expval) {
prec = (unsigned)((int)prec - expval - 1);
} else {
}
else {
prec = 0;
}
flags |= FLAGS_PRECISION; // make sure _ftoa respects precision
// no characters in exponent
minwidth = 0;
expval = 0;
} else {
}
else {
// we use one sigfig for the whole part
if ((prec > 0)&&(flags & FLAGS_PRECISION)) --prec;
if ((prec > 0) && (flags & FLAGS_PRECISION)) {
--prec;
}
}
}
// will everything fit?
unsigned int fwidth = width;
if (width > minwidth) {
@ -526,7 +542,9 @@ static size_t _etoa(out_fct_type out, char* buffer, size_t idx, size_t maxlen, d
}
// rescale the float value
if (expval) value /= conv.F;
if (expval) {
value /= conv.F;
}
// output the floating part
const size_t start_idx = idx;
@ -545,7 +563,6 @@ static size_t _etoa(out_fct_type out, char* buffer, size_t idx, size_t maxlen, d
}
return idx;
}
#endif // PRINTF_SUPPORT_EXPONENTIAL
#endif // PRINTF_SUPPORT_FLOAT

10
test/test_suite.cpp
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@ -102,6 +102,7 @@ static void vsnprintf_builder_3(char* buffer, ...)
va_end(args);
}
TEST_CASE("vsnprintf", "[]" ) {
char buffer[100];
@ -352,7 +353,6 @@ TEST_CASE("- flag", "[]" ) {
test::sprintf(buffer, "%0-15.3g", -42.);
REQUIRE(!strcmp(buffer, "-42.0 "));
}
@ -876,11 +876,11 @@ TEST_CASE("padding 20.5", "[]" ) {
REQUIRE(!strcmp(buffer, " 00EDCB5433"));
}
TEST_CASE("padding neg numbers", "[]" ) {
char buffer[100];
// space padding
test::sprintf(buffer, "% 1d", -5);
REQUIRE(!strcmp(buffer, "-5"));
@ -894,7 +894,6 @@ TEST_CASE("padding neg numbers", "[]" ) {
REQUIRE(!strcmp(buffer, " -5"));
// zero padding
test::sprintf(buffer, "%01d", -5);
REQUIRE(!strcmp(buffer, "-5"));
@ -908,11 +907,11 @@ TEST_CASE("padding neg numbers", "[]" ) {
REQUIRE(!strcmp(buffer, "-005"));
}
TEST_CASE("float padding neg numbers", "[]" ) {
char buffer[100];
// space padding
test::sprintf(buffer, "% 3.1f", -5.);
REQUIRE(!strcmp(buffer, "-5.0"));
@ -932,7 +931,6 @@ TEST_CASE("float padding neg numbers", "[]" ) {
REQUIRE(!strcmp(buffer, " -5.0e+00"));
// zero padding
test::sprintf(buffer, "%03.1f", -5.);
REQUIRE(!strcmp(buffer, "-5.0"));
@ -946,7 +944,6 @@ TEST_CASE("float padding neg numbers", "[]" ) {
REQUIRE(!strcmp(buffer, "-005.0e+00"));
// zero padding no decimal point
test::sprintf(buffer, "%01.0f", -5.);
REQUIRE(!strcmp(buffer, "-5"));
@ -1291,7 +1288,6 @@ TEST_CASE("types", "[]" ) {
test::sprintf(buffer, "%ji", -2147483647LL);
REQUIRE(!strcmp(buffer, "-2147483647"));
}
}

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