Commit e81fcd43 authored Jul 15, 2016 by Peter Zijlstra Committed by Arnaldo Carvalho de Melo Jul 15, 2016

tools: Simplify BITS_PER_LONG define



Do it using (__CHAR_BIT__ * __SIZEOF_LONG__), simpler, works everywhere,
reduces the complexity by ditching CONFIG_64BIT, that was being
synthesized from yet another set of defines, which proved fragile,
breaking the build on linux-next for no obvious reasons.

Committer Note:

Except on:

gcc version 4.1.2 20080704 (Red Hat 4.1.2-55)

Fallback to __WORDSIZE in that case...

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20160715072243.GP30154@twins.programming.kicks-ass.net


Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

parent 32a951b4

tools/include/asm-generic/bitsperlong.h

+2 −21

Original line number	Diff line number	Diff line
		@@ -3,30 +3,11 @@

		#include <uapi/asm-generic/bitsperlong.h>

		/*
		* In the kernel, where this file comes from, we can rely on CONFIG_64BIT,
		* here we have to make amends with what the various compilers provides us
		* to figure out if we're on a 64-bit machine...
		*/
		#ifdef __SIZEOF_LONG__
		# if __SIZEOF_LONG__ == 8
		# define CONFIG_64BIT
		# endif
		#else
		# ifdef __WORDSIZE
		# if __WORDSIZE == 64
		# define CONFIG_64BIT
		# endif
		#define BITS_PER_LONG (__CHAR_BIT__ * __SIZEOF_LONG__)
		#else
		# error Failed to determine BITS_PER_LONG value
		#define BITS_PER_LONG __WORDSIZE
		#endif
		#endif

		#ifdef CONFIG_64BIT
		#define BITS_PER_LONG 64
		#else
		#define BITS_PER_LONG 32
		#endif /* CONFIG_64BIT */

		#if BITS_PER_LONG != __BITS_PER_LONG
		#error Inconsistent word size. Check asm/bitsperlong.h