arch/mips/math-emu/dp_simple.c

Source file repositories/reference/linux-study-clean/arch/mips/math-emu/dp_simple.c

File Facts

System
Linux kernel
Corpus path
arch/mips/math-emu/dp_simple.c
Extension
.c
Size
909 bytes
Lines
50
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

// SPDX-License-Identifier: GPL-2.0-only
/* IEEE754 floating point arithmetic
 * double precision: common utilities
 */
/*
 * MIPS floating point support
 * Copyright (C) 1994-2000 Algorithmics Ltd.
 */

#include "ieee754dp.h"

union ieee754dp ieee754dp_neg(union ieee754dp x)
{
	union ieee754dp y;

	if (ieee754_csr.abs2008) {
		y = x;
		DPSIGN(y) = !DPSIGN(x);
	} else {
		unsigned int oldrm;

		oldrm = ieee754_csr.rm;
		ieee754_csr.rm = FPU_CSR_RD;
		y = ieee754dp_sub(ieee754dp_zero(0), x);
		ieee754_csr.rm = oldrm;
	}
	return y;
}

union ieee754dp ieee754dp_abs(union ieee754dp x)
{
	union ieee754dp y;

	if (ieee754_csr.abs2008) {
		y = x;
		DPSIGN(y) = 0;
	} else {
		unsigned int oldrm;

		oldrm = ieee754_csr.rm;
		ieee754_csr.rm = FPU_CSR_RD;
		if (DPSIGN(x))
			y = ieee754dp_sub(ieee754dp_zero(0), x);
		else
			y = ieee754dp_add(ieee754dp_zero(0), x);
		ieee754_csr.rm = oldrm;
	}
	return y;
}

Annotation

Implementation Notes