linux-stable-rt/include
Mathieu Desnoyers 3c3b5c3b0b x86: correct register constraints for 64-bit atomic operations
x86_64 add/sub atomic ops does not seems to accept integer values bigger
than 32 bits as immediates. Intel's add/sub documentation specifies they
have to be passed as registers.

The only operations in the x86-64 architecture which accept arbitrary
64-bit immediates is "movq" to any register; similarly, the only
operation which accept arbitrary 64-bit displacement is "movabs" to or
from al/ax/eax/rax.

http://gcc.gnu.org/onlinedocs/gcc-4.3.0/gcc/Machine-Constraints.html

states :

e
    32-bit signed integer constant, or a symbolic reference known to fit
    that range (for immediate operands in sign-extending x86-64
    instructions).
Z
    32-bit unsigned integer constant, or a symbolic reference known to
    fit that range (for immediate operands in zero-extending x86-64
    instructions).

Since add/sub does sign extension, using the "e" constraint seems appropriate.

It applies to 2.6.27-rc, 2.6.26, 2.6.25...

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-18 07:47:30 +02:00
..
acpi
asm-alpha
asm-arm
asm-blackfin
asm-cris
asm-frv
asm-generic Make ioctl.h compatible with userland 2008-08-12 16:07:31 -07:00
asm-m32r
asm-m68k m68k{,nommu}: Wire up new system calls 2008-08-11 10:37:34 -07:00
asm-mips
asm-mn10300
asm-parisc
asm-um
asm-x86 x86: correct register constraints for 64-bit atomic operations 2008-08-18 07:47:30 +02:00
asm-xtensa
crypto crypto: hash - Add missing top-level functions 2008-08-13 20:08:44 +10:00
drm
keys
linux Merge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb-2.6 2008-08-13 20:50:10 -07:00
math-emu
media
mtd
net ipv6: Kill unused ip6_prohibit_entry and ip6_blk_hole_entry declarations. 2008-08-13 02:35:39 -07:00
pcmcia
rdma
rxrpc
scsi
sound
video atmel_lcdfb: add board parameter specify framebuffer memory size 2008-08-12 16:07:29 -07:00
xen
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