[PATCH] x86: uapi: Fix __BITS_PER_LONG for x32

From: Ben Hutchings
Date: Wed Sep 30 2015 - 20:40:55 EST


On x32, gcc predefines __x86_64__ but long is only 32-bit. Use
__ILP32__ to distinguish x32.

Fixes this compiler error in perf:

/ÂPKGBUILDDIRÂ/tools/include/asm-generic/bitops/__ffs.h: In function '__ffs':
/ÂPKGBUILDDIRÂ/tools/include/asm-generic/bitops/__ffs.h:19:8: error: right shift count >= width of type [-Werror=shift-count-overflow]
word >>= 32;
^

This isn't sufficient to build perf for x32, though.

Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
arch/x86/include/uapi/asm/bitsperlong.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/include/uapi/asm/bitsperlong.h b/arch/x86/include/uapi/asm/bitsperlong.h
index b0ae1c4..217909b 100644
--- a/arch/x86/include/uapi/asm/bitsperlong.h
+++ b/arch/x86/include/uapi/asm/bitsperlong.h
@@ -1,7 +1,7 @@
#ifndef __ASM_X86_BITSPERLONG_H
#define __ASM_X86_BITSPERLONG_H

-#ifdef __x86_64__
+#if defined(__x86_64__) && !defined(__ILP32__)
# define __BITS_PER_LONG 64
#else
# define __BITS_PER_LONG 32
--
Ben Hutchings
Knowledge is power. France is bacon.

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