mirror of
https://github.com/neovim/neovim.git
synced 2026-01-30 09:01:07 +10:00
c9c9422af0
Work around a glibc bug where it truncates the argument to fpclassify()
from double to float by implementing fpclassify() ourselves.
Correctness test (Note that the FP_SUBNORMAL test depends on an atof() that
knows how to parse subnormals. Glibc does, not sure about other libcs.):
#include <math.h>
#include <stdint.h>
#include <string.h>
int xfpclassify(double d)
{
uint64_t m;
int e;
memcpy(&m, &d, sizeof(m));
e = 0x7ff & (m >> 52);
m = 0xfffffffffffffULL & m;
switch (e) {
default: return FP_NORMAL;
case 0x000: return m ? FP_SUBNORMAL : FP_ZERO;
case 0x7ff: return m ? FP_NAN : FP_INFINITE;
}
}
#include <assert.h>
#include <stdlib.h>
int main(void)
{
assert(FP_ZERO == xfpclassify(atof("0.0")));
assert(FP_ZERO == xfpclassify(atof("-0.0")));
assert(FP_NORMAL == xfpclassify(atof("1.0")));
assert(FP_NORMAL == xfpclassify(atof("-1.0")));
assert(FP_INFINITE == xfpclassify(atof("inf")));
assert(FP_INFINITE == xfpclassify(atof("-inf")));
assert(FP_NAN == xfpclassify(atof("nan")));
assert(FP_NAN == xfpclassify(atof("-nan")));
assert(FP_SUBNORMAL == xfpclassify(atof("1.8011670033376514e-308")));
return 0;
}
37 lines
735 B
C
37 lines
735 B
C
// This is an open source non-commercial project. Dear PVS-Studio, please check
|
|
// it. PVS-Studio Static Code Analyzer for C, C++ and C#: http://www.viva64.com
|
|
|
|
#include <math.h>
|
|
#include <stdint.h>
|
|
#include <string.h>
|
|
|
|
#include "nvim/math.h"
|
|
|
|
#ifdef INCLUDE_GENERATED_DECLARATIONS
|
|
# include "math.c.generated.h"
|
|
#endif
|
|
|
|
int xfpclassify(double d)
|
|
{
|
|
uint64_t m;
|
|
int e;
|
|
|
|
memcpy(&m, &d, sizeof(m));
|
|
e = 0x7ff & (m >> 52);
|
|
m = 0xfffffffffffffULL & m;
|
|
|
|
switch (e) {
|
|
default: return FP_NORMAL;
|
|
case 0x000: return m ? FP_SUBNORMAL : FP_ZERO;
|
|
case 0x7ff: return m ? FP_NAN : FP_INFINITE;
|
|
}
|
|
}
|
|
int xisinf(double d)
|
|
{
|
|
return FP_INFINITE == xfpclassify(d);
|
|
}
|
|
int xisnan(double d)
|
|
{
|
|
return FP_NAN == xfpclassify(d);
|
|
}
|