diff options
Diffstat (limited to '05')
| -rw-r--r-- | 05/codegen.b | 20 | ||||
| -rw-r--r-- | 05/main.c | 8 | ||||
| -rw-r--r-- | 05/parse.b | 1 | ||||
| -rw-r--r-- | 05/stdc_common.h | 189 |
4 files changed, 192 insertions, 26 deletions
diff --git a/05/codegen.b b/05/codegen.b index 8e06318..b89ab51 100644 --- a/05/codegen.b +++ b/05/codegen.b @@ -1515,6 +1515,8 @@ function comparison_type argument expr local type1 local type2 + local t1 + local t2 expr += 8 type1 = expr + 4 @@ -1523,17 +1525,19 @@ function comparison_type type2 = expr + 4 type2 = *4type2 - type1 += types - type1 = *1type1 - type2 += types - type2 = *1type2 + t1 = types + type1 + t1 = *1t1 + t2 = types + type2 + t2 = *1t2 ; do float comparisons as double comparisons to make things simpler - if type1 == TYPE_FLOAT goto return_type_double - if type2 == TYPE_FLOAT goto return_type_double + if t1 == TYPE_FLOAT goto return_type_double + if t2 == TYPE_FLOAT goto return_type_double - if type1 == TYPE_POINTER goto return_type_unsigned_long - if type2 == TYPE_POINTER goto return_type_unsigned_long + if t1 == TYPE_POINTER goto return_type_unsigned_long + if t2 == TYPE_POINTER goto return_type_unsigned_long + if t1 == TYPE_ARRAY goto return_type_unsigned_long ; type1 decays to pointer + if t2 == TYPE_ARRAY goto return_type_unsigned_long ; type2 decays to pointer return expr_binary_type_usual_conversions(statement, type1, type2) ; is this comparison expression a comparison between unsigned integers or floats? @@ -3,11 +3,11 @@ #include <string.h> int main(void) { - char s[] = " -0XAh.\n"; + char *s = "1.35984534e135-e12hello"; char *end; - errno = 0; - printf("%ld\n", strtol(s, &end, 0)); - printf("%d:%s",errno,end); + _Float f = _powers_of_10[-307]; + printf("%.15g\n",strtod(s, &end)); + printf("%s\n",end); return 0; } @@ -2775,7 +2775,6 @@ function parse_expression if c == EXPRESSION_LT goto type_int if c == EXPRESSION_GT goto type_int if c == EXPRESSION_COMMA goto type_binary_right - if c == EXPRESSION_EQ goto type_binary_left if c == EXPRESSION_ASSIGN goto type_binary_left if c == EXPRESSION_ASSIGN_ADD goto type_binary_left if c == EXPRESSION_ASSIGN_SUB goto type_binary_left diff --git a/05/stdc_common.h b/05/stdc_common.h index d9e66f1..22c5a42 100644 --- a/05/stdc_common.h +++ b/05/stdc_common.h @@ -1,11 +1,6 @@ #ifndef _STDC_COMMON_H #define _STDC_COMMON_H -#ifdef _STDLIB_DEBUG -int printf(char *); -#endif - - #define signed #define volatile #define register @@ -105,6 +100,24 @@ void _Exit(int status) { return __syscall(60, status, 0, 0, 0, 0, 0); } +int kill(int pid, int sig) { + return __syscall(62, pid, sig, 0, 0, 0, 0); +} + +int getpid(void) { + return __syscall(39, 0, 0, 0, 0, 0, 0); +} + +#define SIGABRT 6 +#define SIGFPE 8 +#define SIGILL 4 +#define SIGINT 2 +#define SIGSEGV 11 +#define SIGTERM 15 +void abort(void) { + kill(getpid(), SIGABRT); +} + typedef long time_t; struct timespec { @@ -126,8 +139,29 @@ int access(const char *pathname, int mode) { return __syscall(21, pathname, mode, 0, 0, 0, 0); } +typedef struct { + int fd; + unsigned char eof; + unsigned char err; +} FILE; int errno; +int printf(char *, ...); +int fprintf(FILE *, char *, ...); // needed now for assert() + +FILE _stdin = {0}, *stdin; +FILE _stdout = {1}, *stdout; +FILE _stderr = {2}, *stderr; + +#ifdef NDEBUG +#define assert(x) ((void)0) +#else +int __assert_failed(const char *file, int line, const char *expr) { + fprintf(stderr, "Assertion failed at %s:%d: %s\n", file, line, expr); + abort(); +} +#define assert(x) (void)((x) || __assert_failed(__FILE__, __LINE__, #x)) +#endif #define EIO 5 #define EDOM 33 @@ -223,7 +257,7 @@ unsigned long strtoul(const char *nptr, char **endptr, int base) { value = newvalue; ++nptr; } - *endptr = nptr; + if (endptr) *endptr = nptr; if (overflow) { errno = ERANGE; return ULONG_MAX; @@ -255,22 +289,151 @@ long strtol(const char *nptr, char **endptr, int base) { } } +long _strtol_clamped(const char *nptr, char **endptr, int base, int min, int max) { + long l = strtol(nptr, endptr, base); + if (l < min) return min; + if (l > max) return max; + return l; +} + +#define _NPOW10 310 +#define _INFINITY 1e1000 +// non-negative floating-point number with more precision than a double +// its value is equal to fraction * 2^exponent typedef struct { - int fd; - unsigned char eof; - unsigned char err; -} FILE; + unsigned long fraction; + int exponent; +} _Float; + +// ensure that f->fraction >= 2^64 / 2 +static void _normalize_float(_Float *f) { + if (!f->fraction) return; + while (f->fraction < 0x8000000000000000) { + f->exponent -= 1; + f->fraction <<= 1; + } +} + +static double _Float_to_double(_Float f) { + unsigned long dbl_fraction; + int dbl_exponent; + unsigned long dbl_value; + if (f.fraction == 0) return 0; + _normalize_float(&f); + f.fraction &= 0x7fffffffffffffff; // remove the "1." in 1.01101110111... to get 63-bit significand + dbl_fraction = (f.fraction + 0x3ff) >> 11; + dbl_exponent = f.exponent + 63; + if (dbl_exponent < -1022) return 0; + if (dbl_exponent > 1023) return _INFINITY; + dbl_exponent += 1023; + dbl_value = (unsigned long)dbl_exponent << 52 | dbl_fraction; + return *(double *)&dbl_value; +} + +static _Float _powers_of_10_dat[2*_NPOW10+1]; +static _Float *_powers_of_10; +static _Float _Float_ZERO = {0, 1}; +static _Float _Float_INFINITY = {0x8000000000000000, 100000}; + + +_Float _int_pow10(int x) { + if (x <= -_NPOW10) return _Float_ZERO; + if (x >= _NPOW10) return _Float_INFINITY; + return _powers_of_10[x]; +} + +double strtod(const char *nptr, char **endptr) { + const char *flt, *dot, *p, *number_end; + double sign = 1; + int exponent = 0; + while (isspace(*nptr)) ++nptr; + + flt = nptr; // start of float + if (*flt == '+') ++flt; + else if (*flt == '-') sign = -1, ++flt; + + if (*flt != '.' && (*flt < '0' || *flt > '9')) { + // this isn't a float + *endptr = nptr; + return 0; + } + + // find the decimal point, if any + dot = flt; + while (*dot >= '0' && *dot <= '9') ++dot; + + nptr = dot + (*dot == '.'); + // skip digits after the dot + while (*nptr >= '0' && *nptr <= '9') ++nptr; + number_end = nptr; + + if (*nptr == 'e') { + ++nptr; + exponent = 1; + if (*nptr == '+') ++nptr; + else if (*nptr == '-') ++nptr, exponent = -1; + exponent *= _strtol_clamped(nptr, &nptr, 10, -10000, 10000); // use _strtol_clamped to prevent problems with -LONG_MIN + } + + // construct the value using the Kahan summation algorithm (https://en.wikipedia.org/wiki/Kahan_summation_algorithm) + double sum = 0; + double c = 0; + for (p = flt; p < number_end; ++p) { + if (*p == '.') continue; + int n = *p - '0'; + assert(n >= 0 && n <= 9); + int pow10 = dot - p; + pow10 -= pow10 > 0; + pow10 += exponent; + _Float f_val = _int_pow10(pow10); + f_val.fraction >>= 4; + f_val.exponent += 4; + f_val.fraction *= n; + double value = _Float_to_double(f_val); + if (value == _INFINITY || sum == _INFINITY) { + sum = _INFINITY; + break; + } + double y = value - c; + double t = sum + y; + c = (t - sum) - y; + sum = t; + } + + if (endptr) *endptr = nptr; + return sum * sign; +} -FILE _stdin = {0}, *stdin; -FILE _stdout = {1}, *stdout; -FILE _stderr = {2}, *stderr; int main(); int _main(int argc, char **argv) { + int i; + _Float p = {1, 0}; + stdin = &_stdin; stdout = &_stdout; stderr = &_stderr; + + // initialize powers of 10 + _powers_of_10 = _powers_of_10_dat + _NPOW10; + for (i = 0; i < _NPOW10; ++i) { + _normalize_float(&p); + _powers_of_10[i] = p; + p.exponent += 4; + p.fraction >>= 4; + p.fraction *= 10; + } + + p.fraction = 1; + p.exponent = 0; + for (i = 0; i > -_NPOW10; --i) { + _normalize_float(&p); + _powers_of_10[i] = p; + p.fraction /= 5; + p.exponent -= 1; + } + return main(argc, argv); } |