amd64: Fix saving and restoring of FPU state.

diff --git a/sys/platform/pc64/amd64/swtch.s b/sys/platform/pc64/amd64/swtch.s
index f25bdd9..4bf13e7 100644 (file)
--- a/sys/platform/pc64/amd64/swtch.s
+++ b/sys/platform/pc64/amd64/swtch.s
@@ -176,19 +176,18 @@ ENTRY(cpu_heavy_switch)
        movq    %rax,PCB_DR0(%rdx)
 1:
  
-#if JG
 #if NNPX > 0
        /*
         * Save the FP state if we have used the FP.  Note that calling
         * npxsave will NULL out PCPU(npxthread).
         */
-       cmpl    %ebx,PCPU(npxthread)
+       cmpq    %rbx,PCPU(npxthread)
        jne     1f
-       pushl   TD_SAVEFPU(%ebx)
+       movq    %rdi,%r12               /* save %rdi. %r12 is callee-saved */
+       movq    TD_SAVEFPU(%rbx),%rdi
        call    npxsave                 /* do it in a big C function */
-       addl    $4,%esp                 /* EAX, ECX, EDX trashed */
+       movq    %r12,%rdi               /* restore %rdi */
 1:
-#endif
 #endif /* NNPX > 0 */
 
        /*
@@ -504,7 +503,6 @@ ENTRY(savectx)
        movq    %r14,PCB_R14(%rcx)
        movq    %r15,PCB_R15(%rcx)
 
-#if JG
 #if NNPX > 0
        /*
         * If npxthread == NULL, then the npx h/w state is irrelevant and the
@@ -518,31 +516,28 @@ ENTRY(savectx)
         * have to handle h/w bugs for reloading.  We used to lose the
         * parent's npx state for forks by forgetting to reload.
         */
-       movl    PCPU(npxthread),%eax
-       testl   %eax,%eax
-       je      1f
+       movq    PCPU(npxthread),%rax
+       testq   %rax,%rax
+       jz      1f
 
-       pushl   %ecx                    /* target pcb */
-       movl    TD_SAVEFPU(%eax),%eax   /* originating savefpu area */
-       pushl   %eax
+       pushq   %rcx                    /* target pcb */
+       movq    TD_SAVEFPU(%rax),%rax   /* originating savefpu area */
+       pushq   %rax
 
-       pushl   %eax
+       movq    %rax,%rdi
        call    npxsave
-       addl    $4,%esp
 
-       popl    %eax
-       popl    %ecx
+       popq    %rax
+       popq    %rcx
 
-       pushl   $PCB_SAVEFPU_SIZE
-       leal    PCB_SAVEFPU(%ecx),%ecx
-       pushl   %ecx
-       pushl   %eax
+       movq    $PCB_SAVEFPU_SIZE,%rdx
+       leaq    PCB_SAVEFPU(%rcx),%rcx
+       movq    %rcx,%rsi
+       movq    %rax,%rdi
        call    bcopy
-       addl    $12,%esp
 #endif /* NNPX > 0 */
 
 1:
-#endif
        CHECKNZ((%rsp), %r9)
        ret
 
@@ -638,7 +633,6 @@ ENTRY(cpu_lwkt_switch)
        pushq   %r15
        pushfq
 
-#if JG
 #if NNPX > 0
        /*
         * Save the FP state if we have used the FP.  Note that calling
@@ -648,14 +642,14 @@ ENTRY(cpu_lwkt_switch)
         * happen to get preempted or block while doing an optimized
         * bzero/bcopy/memcpy.
         */
-       cmpl    %ebx,PCPU(npxthread)
+       cmpq    %rbx,PCPU(npxthread)
        jne     1f
-       pushl   TD_SAVEFPU(%ebx)
+       movq    %rdi,%r12               /* save %rdi. %r12 is callee-saved */
+       movq    TD_SAVEFPU(%rbx),%rdi
        call    npxsave                 /* do it in a big C function */
-       addl    $4,%esp                 /* EAX, ECX, EDX trashed */
+       movq    %r12,%rdi               /* restore %rdi */
 1:
 #endif /* NNPX > 0 */
-#endif
 
        movq    %rdi,%rax               /* switch to this thread */
        pushq   $cpu_lwkt_restore