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Diffstat (limited to 'lib/libpthread/stdlib/strtod.c')
| -rw-r--r-- | lib/libpthread/stdlib/strtod.c | 178 |
1 files changed, 178 insertions, 0 deletions
diff --git a/lib/libpthread/stdlib/strtod.c b/lib/libpthread/stdlib/strtod.c new file mode 100644 index 00000000000..173ca1e4bdf --- /dev/null +++ b/lib/libpthread/stdlib/strtod.c @@ -0,0 +1,178 @@ +/* +** An alternative implemtation of "strtod()" that is both +** simplier, and thread-safe. +*/ +#include <pthread.h> +#include <ctype.h> +#include <math.h> + +#ifdef TEST +# define strtod NewStrtod +#include <stdio.h> +#endif + +static double scaler10[] = { + 1.0, 1e10, 1e20, 1e30, 1e40, 1e50, 1e60, 1e70, 1e80, 1e90 +}; +static double scaler1[] = { + 1.0, 10.0, 1e2, 1e3, 1e4, 1e5, 1e6, 1e7, 1e8, 1e9 +}; +static double pastpoint[] = { + 1e-1, 1e-2, 1e-3, 1e-4, 1e-5, 1e-6, 1e-7, 1e-8, 1e-9, + 1e-10, 1e-11, 1e-12, 1e-13, 1e-14, 1e-15, 1e-16, 1e-17, 1e-18, 1e-19, + 1e-20, 1e-21, 1e-22, 1e-23, 1e-24, 1e-25, 1e-26, 1e-27, 1e-28, 1e-29, + 1e-30, 1e-31, 1e-32, 1e-33, 1e-34, 1e-35, 1e-36, 1e-37, 1e-38, 1e-39, + 1e-40, 1e-41, 1e-42, 1e-43, 1e-44, 1e-45, 1e-46, 1e-47, 1e-48, 1e-49, + 1e-50, 1e-51, 1e-52, 1e-53, 1e-54, 1e-55, 1e-56, 1e-57, 1e-58, 1e-59, +}; + +#ifndef DBL_MAX +#define DBL_MAX 1.7976931348623157e+308 +#endif + +double strtod(const char *zNum, char **pzEnd){ + double rResult = 0.0; + int isNegative = 0; + + while( isspace(*zNum) ){ + zNum++; + } + if( *zNum=='-' ){ + zNum++; + isNegative = 1; + }else if( *zNum=='+' ){ + zNum++; + } + while( isdigit(*zNum) ){ + rResult = rResult*10.0 + (*zNum - '0'); + zNum++; + } + if( *zNum=='.' ){ + int n = 0; + zNum++; + while( isdigit(*zNum) ){ + if( n<sizeof(pastpoint)/sizeof(pastpoint[0]) ){ + rResult += pastpoint[n] * (*zNum - '0'); + n++; + } + zNum++; + } + } + if( *zNum=='e' || *zNum=='E' ){ + int expVal = 0; + int isNegExp = 0; + const char *zExpStart = zNum; + zNum++; + if( *zNum=='-' ){ + isNegExp = 1; + zNum++; + }else if( *zNum=='+' ){ + zNum++; + } + if( !isdigit(*zNum) ){ + zNum = zExpStart; + }else{ + double scaler = 1.0; + while( isdigit(*zNum) ){ + expVal = expVal*10 + *zNum - '0'; + zNum++; + } + if( expVal >= 1000 ){ + if( isNegExp ){ + rResult = 0.0; + }else{ + rResult = DBL_MAX; + } + goto done; + } + while( expVal >= 100 ){ + scaler *= 1.0e100; + expVal -= 100; + } + scaler *= scaler10[expVal/10]*scaler1[expVal%10]; + if( isNegExp ){ + scaler = 1.0/scaler; + } + rResult *= scaler; + } + + } + +done: + if( pzEnd ){ + *pzEnd = (char *)zNum; + } + if( isNegative && rResult!=0.0 ){ + rResult = -rResult; + } + return rResult; +} + +double atof(const char *nptr) +{ + return (strtod(nptr, 0)); +} + +#ifdef TEST +#undef strtod + +double strtod(const char*,char**); +double NewStrtod(const char*,char**); + +int main(int argc, char **argv){ + int nTest = 0; + int nFail = 0; + int nBigFail = 0; + char zBuf[1000]; + + while( fgets(zBuf,sizeof(zBuf),stdin) ){ + double old, new; + char *zTailOld, *zTailNew; + int i; + + for(i=0; zBuf[i] && zBuf[i]!='\n'; i++){} + zBuf[i] = 0; + +#if TEST==1 + printf("Input line: [%s]\n",zBuf); + old = strtod(zBuf,&zTailOld); + printf("value=%g\n",old); + printf("Old: 0x%08x%08x tail=[%s]\n", + ((int*)&old)[1], ((int*)&old)[0], zTailOld); + new = NewStrtod(zBuf,&zTailNew); + printf("value=%g\n",new); + printf("New: 0x%08x%08x tail=[%s]\n\n", + ((int*)&new)[1], ((int*)&new)[0], zTailNew); +#else + old = strtod(zBuf,&zTailOld); + new = NewStrtod(zBuf,&zTailNew); + nTest++; + if( strcmp(zTailOld,zTailNew) + || ((int*)&old)[0]!=((int*)&new)[0] + || ((int*)&old)[1]!=((int*)&new)[1] + ){ + int olda, oldb, newa, newb; + + nFail++; + olda = ((int*)&old)[1]; + oldb = ((int*)&old)[0]; + newa = ((int*)&new)[1]; + newb = ((int*)&new)[0]; + + if( olda!=newa || abs(oldb-newb)>2 ){ + nBigFail++; + printf("******* Big failure \n"); + } + printf("Input = [%s]\n",zBuf); + printf("old: val=%g 0x%08x%08x tail=[%s]\n", + old, olda, oldb, zTailOld); + printf("new: val=%g 0x%08x%08x tail=[%s]\n\n", + new, newa, newb, zTailNew); + } +#endif + } + + printf("Out of %d tests, %d failures and %d big failurs\n", + nTest,nFail, nBigFail); +} +#endif |