arch/mips/math-emu/ieee754dp.h

Source file repositories/reference/linux-study-clean/arch/mips/math-emu/ieee754dp.h

File Facts

System
Linux kernel
Corpus path
arch/mips/math-emu/ieee754dp.h
Extension
.h
Size
1697 bytes
Lines
74
Domain
Architecture Layer
Bucket
arch/mips
Inferred role
Architecture Layer: implementation source
Status
source implementation candidate

Why This File Exists

CPU and platform-specific kernel glue: boot entry, traps, syscall entry, interrupts, page tables, context switch, and low-level barriers.

Dependency Surface

Detected Declarations

Annotated Snippet

#include <linux/compiler.h>

#include "ieee754int.h"

#define assert(expr) ((void)0)

#define DP_EBIAS	1023
#define DP_EMIN		(-1022)
#define DP_EMAX		1023
#define DP_FBITS	52
#define DP_MBITS	52

#define DP_MBIT(x)	((u64)1 << (x))
#define DP_HIDDEN_BIT	DP_MBIT(DP_FBITS)
#define DP_SIGN_BIT	DP_MBIT(63)

#define DPSIGN(dp)	(dp.sign)
#define DPBEXP(dp)	(dp.bexp)
#define DPMANT(dp)	(dp.mant)

static inline int ieee754dp_finite(union ieee754dp x)
{
	return DPBEXP(x) != DP_EMAX + 1 + DP_EBIAS;
}

/* 3bit extended double precision sticky right shift */
#define XDPSRS(v,rs)	\
	((rs > (DP_FBITS+3))?1:((v) >> (rs)) | ((v) << (64-(rs)) != 0))

#define XDPSRSX1() \
	(xe++, (xm = (xm >> 1) | (xm & 1)))

#define XDPSRS1(v)	\
	(((v) >> 1) | ((v) & 1))

/* 32bit * 32bit => 64bit unsigned integer multiplication */
#define DPXMULT(x, y)	((u64)(x) * (u64)y)

/* convert denormal to normalized with extended exponent */
#define DPDNORMx(m,e) \
	while ((m >> DP_FBITS) == 0) { m <<= 1; e--; }
#define DPDNORMX	DPDNORMx(xm, xe)
#define DPDNORMY	DPDNORMx(ym, ye)
#define DPDNORMZ	DPDNORMx(zm, ze)

static inline union ieee754dp builddp(int s, int bx, u64 m)
{
	union ieee754dp r;

	assert((s) == 0 || (s) == 1);
	assert((bx) >= DP_EMIN - 1 + DP_EBIAS
	       && (bx) <= DP_EMAX + 1 + DP_EBIAS);
	assert(((m) >> DP_FBITS) == 0);

	r.sign = s;
	r.bexp = bx;
	r.mant = m;

	return r;
}

extern union ieee754dp __cold ieee754dp_nanxcpt(union ieee754dp);
extern union ieee754dp ieee754dp_format(int, int, u64);

Annotation

Implementation Notes