diff options
| author | Mikael Pettersson <mikpe@it.uu.se> | 2008-03-11 11:43:31 -0400 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-04-17 11:40:58 -0400 |
| commit | 5d570cbbf25a62e9c077f5b351fb142dbfc67288 (patch) | |
| tree | 8a6958c2cc729741435a3a5d1db697e86cf6436e /include/asm-x86/nops.h | |
| parent | 1415d160c7f7fe8f1026735d5b6cc19aec7a367f (diff) | |
x86: correct/clarify comment in nops.h
<asm-x86/nops.h> describes certain multibyte instructions as
"generic" nops when in fact they aren't nops at all in 64-bit
mode (missing REX.W causing truncation of a register).
Update the comment to state that K8 or P6 style nops should be
used in 64-bit mode. This matches what the alternatives code does.
Signed-off-by: Mikael Pettersson <mikpe@it.uu.se>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'include/asm-x86/nops.h')
| -rw-r--r-- | include/asm-x86/nops.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/include/asm-x86/nops.h b/include/asm-x86/nops.h index b3930ae539b3..ad0bedd10b89 100644 --- a/include/asm-x86/nops.h +++ b/include/asm-x86/nops.h | |||
| @@ -5,6 +5,8 @@ | |||
| 5 | 5 | ||
| 6 | /* generic versions from gas | 6 | /* generic versions from gas |
| 7 | 1: nop | 7 | 1: nop |
| 8 | the following instructions are NOT nops in 64-bit mode, | ||
| 9 | for 64-bit mode use K8 or P6 nops instead | ||
| 8 | 2: movl %esi,%esi | 10 | 2: movl %esi,%esi |
| 9 | 3: leal 0x00(%esi),%esi | 11 | 3: leal 0x00(%esi),%esi |
| 10 | 4: leal 0x00(,%esi,1),%esi | 12 | 4: leal 0x00(,%esi,1),%esi |