0.9.8.47:

[sbcl.git] / src / runtime / x86-64-assem.S

diff --git a/src/runtime/x86-64-assem.S b/src/runtime/x86-64-assem.S
index b806ce1..02c508a 100644 (file)
--- a/src/runtime/x86-64-assem.S
+++ b/src/runtime/x86-64-assem.S
@@ -60,6 +60,10 @@
        .global GNAME(call_into_c)
        .type   GNAME(call_into_c),@function
 GNAME(call_into_c):
+        /* ABI requires that the direction flag be clear on function
+         * entry and exit. */
+        cld
+        
        push    %rbp            # Save old frame pointer.
        mov     %rsp,%rbp       # Establish new frame.
 
@@ -117,20 +121,26 @@ GNAME(call_into_lisp):
        mov     %rsp,%rbp       # Establish new frame.
 Lstack:
        /* FIXME x86 saves FPU state here */
-       push    %rbx
-       push    %r12
-       push    %r13
-       push    %r14
-       push    %r15
-
+       push    %rbx    # these regs are callee-saved according to C
+       push    %r12    # so must be preserved and restored when 
+       push    %r13    # the lisp function returns
+       push    %r14    #
+       push    %r15    #
 
        mov     %rsp,%rbx       # remember current stack
        push    %rbx            # Save entry stack on (maybe) new stack.
 
-       /* Establish Lisp args. */
-       mov     %rdi,%rax       # lexenv?
-       mov     %rsi,%rbx       # address of arg vec
-       mov     %rdx,%rcx       # num args
+       push    %rdi    # args from C
+       push    %rsi    #
+       push    %rdx    #
+#ifdef LISP_FEATURE_SB_THREAD
+       mov     specials,%rdi
+       call    pthread_getspecific
+       mov     %rax,%r12
+#endif
+       pop     %rcx    # num args
+       pop     %rbx    # arg vector
+       pop     %rax    # function ptr/lexenv
 
        xor     %rdx,%rdx       # clear any descriptor registers 
        xor     %rdi,%rdi       # that we can't be sure we'll 
@@ -173,6 +183,10 @@ Lcall:
        pop     %r12
        pop     %rbx
 
+        /* ABI requires that the direction flag be clear on function
+         * entry and exit. */
+        cld
+        
 /* FIXME Restore the NPX state. */
 
        /* return value is already in rax where lisp expects it */
@@ -328,15 +342,54 @@ GNAME(post_signal_tramp):
        popq %r8
        popq %rdi
        popq %rsi
-       addq $8, %rsp
-       popq %rsp
-       popq %rdx
+        /* skip RBP and RSP */
        popq %rbx
+       popq %rdx
        popq %rcx
        popq %rax
-        popfl
+        popfq
        leave
        ret
        .size GNAME(post_signal_tramp),.-GNAME(post_signal_tramp)
 \f
-       .end
+       .text
+       .align  align_8byte,0x90
+       .global GNAME(fast_bzero)
+       .type   GNAME(fast_bzero),@function
+        
+GNAME(fast_bzero):
+        /* A fast routine for zero-filling blocks of memory that are
+         * guaranteed to start and end at a 4096-byte aligned address.
+         */
+        shr $6, %rsi              /* Amount of 64-byte blocks to copy */
+        jz Lend                   /* If none, stop */
+        mov %rsi, %rcx            /* Save start address */
+        movups %xmm7, -16(%rsp)   /* Save XMM register */
+        xorps  %xmm7, %xmm7       /* Zero the XMM register */
+        jmp Lloop
+        .align 16                 
+Lloop:
+
+        /* Copy the 16 zeroes from xmm7 to memory, 4 times. MOVNTDQ is the
+         * non-caching double-quadword moving variant, i.e. the memory areas
+         * we're touching are not fetched into the L1 cache, since we're just
+         * going to overwrite the memory soon anyway.
+         */
+        movntdq %xmm7, 0(%rdi)
+        movntdq %xmm7, 16(%rdi)
+        movntdq %xmm7, 32(%rdi)
+        movntdq %xmm7, 48(%rdi)
+
+        add $64, %rdi  /* Advance pointer */
+        dec %rsi       /* Decrement 64-byte block count */
+        jnz Lloop
+        mfence         /* Ensure that the writes are globally visible, since
+                        * MOVNTDQ is weakly ordered */
+        movups -16(%rsp), %xmm7 /* Restore the XMM register */
+        prefetcht0 0(%rcx)      /* Prefetch the start of the block into cache,
+                                 * since it's likely to be used immediately. */
+Lend:        
+       ret
+       .size   GNAME(fast_bzero), .-GNAME(fast_bzero)
+
+        .end