gcc/libgo/runtime/go-type-complex.c
Ian Lance Taylor 93c521ea9c runtime: fix misc gcc-isms and undefined behavior
This includes the use of __complex and __builtin_ functions where
unprefixed entities would suffice, and the use of a union for
bit-casting between types.

From-SVN: r211036
2014-05-28 23:10:47 +00:00

115 lines
2.5 KiB
C

/* go-type-complex.c -- hash and equality complex functions.
Copyright 2012 The Go Authors. All rights reserved.
Use of this source code is governed by a BSD-style
license that can be found in the LICENSE file. */
#include <complex.h>
#include <math.h>
#include <stdint.h>
#include <string.h>
#include "runtime.h"
#include "go-type.h"
/* Hash function for float types. */
uintptr_t
__go_type_hash_complex (const void *vkey, uintptr_t key_size)
{
if (key_size == 8)
{
const complex float *cfp;
complex float cf;
float cfr;
float cfi;
uint64_t fi;
cfp = (const complex float *) vkey;
cf = *cfp;
cfr = crealf (cf);
cfi = cimagf (cf);
if (isinf (cfr) || isinf (cfi))
return 0;
/* NaN != NaN, so the hash code of a NaN is irrelevant. Make it
random so that not all NaNs wind up in the same place. */
if (isnan (cfr) || isnan (cfi))
return runtime_fastrand1 ();
/* Avoid negative zero. */
if (cfr == 0 && cfi == 0)
return 0;
else if (cfr == 0)
cf = cfi * I;
else if (cfi == 0)
cf = cfr;
memcpy (&fi, &cf, 8);
return (uintptr_t) cfi;
}
else if (key_size == 16)
{
const complex double *cdp;
complex double cd;
double cdr;
double cdi;
uint64_t di[2];
cdp = (const complex double *) vkey;
cd = *cdp;
cdr = creal (cd);
cdi = cimag (cd);
if (isinf (cdr) || isinf (cdi))
return 0;
if (isnan (cdr) || isnan (cdi))
return runtime_fastrand1 ();
/* Avoid negative zero. */
if (cdr == 0 && cdi == 0)
return 0;
else if (cdr == 0)
cd = cdi * I;
else if (cdi == 0)
cd = cdr;
memcpy (&di, &cd, 16);
return di[0] ^ di[1];
}
else
runtime_throw ("__go_type_hash_complex: invalid complex size");
}
/* Equality function for complex types. */
_Bool
__go_type_equal_complex (const void *vk1, const void *vk2, uintptr_t key_size)
{
if (key_size == 8)
{
const complex float *cfp1;
const complex float *cfp2;
cfp1 = (const complex float *) vk1;
cfp2 = (const complex float *) vk2;
return *cfp1 == *cfp2;
}
else if (key_size == 16)
{
const complex double *cdp1;
const complex double *cdp2;
cdp1 = (const complex double *) vk1;
cdp2 = (const complex double *) vk2;
return *cdp1 == *cdp2;
}
else
runtime_throw ("__go_type_equal_complex: invalid complex size");
}