[PATCH] x86_64: Small assembly improvements

Save a byte here and there.  Ultimatively useless, but these things always
catch my eyes when reading the code so just fix them for now.

Also I got at least one patch fixing of them already, which gives a good
excuse.

Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

2 files changed, 13 insertions, 13 deletions

diff --git a/arch/x86_64/kernel/entry.S b/arch/x86_64/kernel/entry.S
index 28817490fdc6..0696e025dce5 100644
--- a/arch/x86_64/kernel/entry.S
+++ b/arch/x86_64/kernel/entry.S
@@ -76,7 +76,7 @@
 
         .macro FAKE_STACK_FRAME child_rip
         /* push in order ss, rsp, eflags, cs, rip */
-        xorq %rax, %rax
+        xorl %eax, %eax
         pushq %rax /* ss */
         CFI_ADJUST_CFA_OFFSET   8
         pushq %rax /* rsp */
@@ -423,7 +423,7 @@ ENTRY(stub_rt_sigreturn)
         testl $3,CS(%rdi)
         je 1f
         swapgs  
-1:      addl $1,%gs:pda_irqcount        # RED-PEN should check preempt count
+1:      incl    %gs:pda_irqcount        # RED-PEN should check preempt count
         movq %gs:pda_irqstackptr,%rax
         cmoveq %rax,%rsp                                                        
         pushq %rdi                      # save old stack        
@@ -436,7 +436,7 @@ ENTRY(common_interrupt)
 ret_from_intr:          
         popq  %rdi
         cli     
-        subl $1,%gs:pda_irqcount
+        decl %gs:pda_irqcount
 #ifdef CONFIG_DEBUG_INFO
         movq RBP(%rdi),%rbp
 #endif
@@ -494,7 +494,7 @@ retint_signal:
         sti
         SAVE_REST
         movq $-1,ORIG_RAX(%rsp)                         
-        xorq %rsi,%rsi          # oldset
+        xorl %esi,%esi          # oldset
         movq %rsp,%rdi          # &pt_regs
         call do_notify_resume
         RESTORE_REST
@@ -752,7 +752,7 @@ child_rip:
         movq %rsi, %rdi
         call *%rax
         # exit
-        xorq %rdi, %rdi
+        xorl %edi, %edi
         call do_exit
 
 /*
diff --git a/arch/x86_64/kernel/head.S b/arch/x86_64/kernel/head.S
index 8d765aa77a26..98ff5eb32b9a 100644
--- a/arch/x86_64/kernel/head.S
+++ b/arch/x86_64/kernel/head.S
@@ -137,14 +137,14 @@ startup_64:
         wrmsr
 
         /* Setup cr0 */
-        xorq    %rax, %rax
-        btsq    $31, %rax                       /* Enable paging */
-        btsq    $0, %rax                        /* Enable protected mode */
-        btsq    $1, %rax                        /* Enable MP */
-        btsq    $4, %rax                        /* Enable ET */
-        btsq    $5, %rax                        /* Enable NE */
-        btsq    $16, %rax                       /* Enable WP */
-        btsq    $18, %rax                       /* Enable AM */
+#define CR0_PM                          1               /* protected mode */
+#define CR0_MP                          (1<<1)
+#define CR0_ET                          (1<<4)
+#define CR0_NE                          (1<<5)
+#define CR0_WP                          (1<<16)
+#define CR0_AM                          (1<<18)
+#define CR0_PAGING                      (1<<31)
+        movl $CR0_PM|CR0_MP|CR0_ET|CR0_NE|CR0_WP|CR0_AM|CR0_PAGING,%eax
         /* Make changes effective */
         movq    %rax, %cr0