lib/lshrdi3.c

Source file repositories/reference/linux-study-clean/lib/lshrdi3.c

File Facts

System
Linux kernel
Corpus path
lib/lshrdi3.c
Extension
.c
Size
559 bytes
Lines
33
Domain
Kernel Services
Bucket
lib
Inferred role
Kernel Services: exported/initcall integration point
Status
integration implementation candidate

Why This File Exists

Shared kernel service surface used by multiple subsystems, including helpers, cryptography, virtualization support, and async I/O infrastructure.

Dependency Surface

Detected Declarations

Annotated Snippet

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * lib/lshrdi3.c
 */

#include <linux/module.h>
#include <linux/libgcc.h>

long long notrace __lshrdi3(long long u, word_type b)
{
	DWunion uu, w;
	word_type bm;

	if (b == 0)
		return u;

	uu.ll = u;
	bm = 32 - b;

	if (bm <= 0) {
		w.s.high = 0;
		w.s.low = (unsigned int) uu.s.high >> -bm;
	} else {
		const unsigned int carries = (unsigned int) uu.s.high << bm;

		w.s.high = (unsigned int) uu.s.high >> b;
		w.s.low = ((unsigned int) uu.s.low >> b) | carries;
	}

	return w.ll;
}
EXPORT_SYMBOL(__lshrdi3);

Annotation

Implementation Notes