gcc/libgo/runtime/go-type-float.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

87 lines
1.7 KiB
C

/* go-type-float.c -- hash and equality float 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 <math.h>
#include <stdint.h>
#include "runtime.h"
#include "go-type.h"
/* Hash function for float types. */
uintptr_t
__go_type_hash_float (const void *vkey, uintptr_t key_size)
{
if (key_size == 4)
{
const float *fp;
float f;
uint32_t si;
fp = (const float *) vkey;
f = *fp;
if (isinf (f) || f == 0)
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 (f))
return runtime_fastrand1 ();
memcpy (&si, vkey, 4);
return (uintptr_t) si;
}
else if (key_size == 8)
{
const double *dp;
double d;
uint64_t di;
dp = (const double *) vkey;
d = *dp;
if (isinf (d) || d == 0)
return 0;
if (isnan (d))
return runtime_fastrand1 ();
memcpy (&di, vkey, 8);
return (uintptr_t) di;
}
else
runtime_throw ("__go_type_hash_float: invalid float size");
}
/* Equality function for float types. */
_Bool
__go_type_equal_float (const void *vk1, const void *vk2, uintptr_t key_size)
{
if (key_size == 4)
{
const float *fp1;
const float *fp2;
fp1 = (const float *) vk1;
fp2 = (const float *) vk2;
return *fp1 == *fp2;
}
else if (key_size == 8)
{
const double *dp1;
const double *dp2;
dp1 = (const double *) vk1;
dp2 = (const double *) vk2;
return *dp1 == *dp2;
}
else
runtime_throw ("__go_type_equal_float: invalid float size");
}