fb422e6d31
Merge the projects/clang-sparc64 branch back to head. This brings in several updates from the llvm and clang trunks to make the sparc64 backend fully functional. Apart from one patch to sys/sparc64/include/pcpu.h which is still under discussion, this makes it possible to let clang fully build world and kernel for sparc64. Any assistance with testing this on actual sparc64 hardware is greatly appreciated, as there will unavoidably be bugs left. Many thanks go to Roman Divacky for his upstream work on getting the sparc64 backend into shape. MFC r262985: Repair a few minor mismerges from r262261 in the clang-sparc64 project branch. This is also to minimize differences with upstream.
87 lines
2.8 KiB
C
87 lines
2.8 KiB
C
/* ===-- floattixf.c - Implement __floattixf -------------------------------===
|
|
*
|
|
* The LLVM Compiler Infrastructure
|
|
*
|
|
* This file is dual licensed under the MIT and the University of Illinois Open
|
|
* Source Licenses. See LICENSE.TXT for details.
|
|
*
|
|
* ===----------------------------------------------------------------------===
|
|
*
|
|
* This file implements __floattixf for the compiler_rt library.
|
|
*
|
|
* ===----------------------------------------------------------------------===
|
|
*/
|
|
|
|
#include "int_lib.h"
|
|
|
|
#ifdef CRT_HAS_128BIT
|
|
|
|
/* Returns: convert a to a long double, rounding toward even. */
|
|
|
|
/* Assumption: long double is a IEEE 80 bit floating point type padded to 128 bits
|
|
* ti_int is a 128 bit integral type
|
|
*/
|
|
|
|
/* gggg gggg gggg gggg gggg gggg gggg gggg | gggg gggg gggg gggg seee eeee eeee eeee |
|
|
* 1mmm mmmm mmmm mmmm mmmm mmmm mmmm mmmm | mmmm mmmm mmmm mmmm mmmm mmmm mmmm mmmm
|
|
*/
|
|
|
|
si_int __clzti2(ti_int a);
|
|
|
|
long double
|
|
__floattixf(ti_int a)
|
|
{
|
|
if (a == 0)
|
|
return 0.0;
|
|
const unsigned N = sizeof(ti_int) * CHAR_BIT;
|
|
const ti_int s = a >> (N-1);
|
|
a = (a ^ s) - s;
|
|
int sd = N - __clzti2(a); /* number of significant digits */
|
|
int e = sd - 1; /* exponent */
|
|
if (sd > LDBL_MANT_DIG)
|
|
{
|
|
/* start: 0000000000000000000001xxxxxxxxxxxxxxxxxxxxxxPQxxxxxxxxxxxxxxxxxx
|
|
* finish: 000000000000000000000000000000000000001xxxxxxxxxxxxxxxxxxxxxxPQR
|
|
* 12345678901234567890123456
|
|
* 1 = msb 1 bit
|
|
* P = bit LDBL_MANT_DIG-1 bits to the right of 1
|
|
* Q = bit LDBL_MANT_DIG bits to the right of 1
|
|
* R = "or" of all bits to the right of Q
|
|
*/
|
|
switch (sd)
|
|
{
|
|
case LDBL_MANT_DIG + 1:
|
|
a <<= 1;
|
|
break;
|
|
case LDBL_MANT_DIG + 2:
|
|
break;
|
|
default:
|
|
a = ((tu_int)a >> (sd - (LDBL_MANT_DIG+2))) |
|
|
((a & ((tu_int)(-1) >> ((N + LDBL_MANT_DIG+2) - sd))) != 0);
|
|
};
|
|
/* finish: */
|
|
a |= (a & 4) != 0; /* Or P into R */
|
|
++a; /* round - this step may add a significant bit */
|
|
a >>= 2; /* dump Q and R */
|
|
/* a is now rounded to LDBL_MANT_DIG or LDBL_MANT_DIG+1 bits */
|
|
if (a & ((tu_int)1 << LDBL_MANT_DIG))
|
|
{
|
|
a >>= 1;
|
|
++e;
|
|
}
|
|
/* a is now rounded to LDBL_MANT_DIG bits */
|
|
}
|
|
else
|
|
{
|
|
a <<= (LDBL_MANT_DIG - sd);
|
|
/* a is now rounded to LDBL_MANT_DIG bits */
|
|
}
|
|
long_double_bits fb;
|
|
fb.u.high.s.low = ((su_int)s & 0x8000) | /* sign */
|
|
(e + 16383); /* exponent */
|
|
fb.u.low.all = (du_int)a; /* mantissa */
|
|
return fb.f;
|
|
}
|
|
|
|
#endif /* CRT_HAS_128BIT */
|