PERFORCE change 28167 for review

[Peter Wemm]

http://perforce.freebsd.org/chv.cgi?CH=28167

Change 28167 by peter at peter_overcee on 2003/04/04 20:44:55

	drop debug regs

Affected files ...

.. //depot/projects/hammer/sys/x86_64/x86_64/swtch.s#10 edit

Differences ...

==== //depot/projects/hammer/sys/x86_64/x86_64/swtch.s#10 (text+ko) ====

@@ -110,25 +110,6 @@
 	pushfl					/* PSL */
 	popl	PCB_PSL(%edx)
 
-	/* Test if debug registers should be saved. */
-	testl	$PCB_DBREGS,PCB_FLAGS(%edx)
-	jz      1f                              /* no, skip over */
-	movl    %dr7,%eax                       /* yes, do the save */
-	movl    %eax,PCB_DR7(%edx)
-	andl    $0x0000fc00, %eax               /* disable all watchpoints */
-	movl    %eax,%dr7
-	movl    %dr6,%eax
-	movl    %eax,PCB_DR6(%edx)
-	movl    %dr3,%eax
-	movl    %eax,PCB_DR3(%edx)
-	movl    %dr2,%eax
-	movl    %eax,PCB_DR2(%edx)
-	movl    %dr1,%eax
-	movl    %eax,PCB_DR1(%edx)
-	movl    %dr0,%eax
-	movl    %eax,PCB_DR0(%edx)
-1:
-
 	/* have we used fp, and need a save? */
 	cmpl	%ecx,PCPU(FPCURTHREAD)
 	jne	1f
@@ -185,31 +166,6 @@
 cpu_switch_load_gs:
 	movl	PCB_GS(%edx),%gs
 
-	/* Test if debug registers should be restored. */
-	testl	$PCB_DBREGS,PCB_FLAGS(%edx)
-	jz      1f
-
-	/*
-	 * Restore debug registers.  The special code for dr7 is to
-	 * preserve the current values of its reserved bits.
-	 */
-	movl    PCB_DR6(%edx),%eax
-	movl    %eax,%dr6
-	movl    PCB_DR3(%edx),%eax
-	movl    %eax,%dr3
-	movl    PCB_DR2(%edx),%eax
-	movl    %eax,%dr2
-	movl    PCB_DR1(%edx),%eax
-	movl    %eax,%dr1
-	movl    PCB_DR0(%edx),%eax
-	movl    %eax,%dr0
-	movl	%dr7,%eax
-	andl    $0x0000fc00,%eax
-	movl    PCB_DR7(%edx),%ecx
-	andl	$~0x0000fc00,%ecx
-	orl     %ecx,%eax
-	movl    %eax,%dr7
-1:
 	ret
 
 #ifdef INVARIANTS