/* src/vm/jit/i386/asmpart.S - Java-C interface functions for i386
- Copyright (C) 1996-2005, 2006 R. Grafl, A. Krall, C. Kruegel,
+ Copyright (C) 1996-2005, 2006, 2007 R. Grafl, A. Krall, C. Kruegel,
C. Oates, R. Obermaisser, M. Platter, M. Probst, S. Ring,
E. Steiner, C. Thalinger, D. Thuernbeck, P. Tomsich, C. Ullrich,
J. Wenninger, Institut f. Computersprachen - TU Wien
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
02110-1301, USA.
- Contact: cacao@cacaojvm.org
-
- Authors: Andreas Krall
- Reinhard Grafl
- Christian Thalinger
-
- Changes: Joseph Wenninger
- Edwin Steiner
-
- $Id: asmpart.S 4922 2006-05-15 14:39:05Z twisti $
-
*/
#include "config.h"
+#include "md-asm.h"
+
#include "vm/jit/i386/arch.h"
#include "vm/jit/i386/md-abi.h"
-#include "vm/jit/i386/md-asm.h"
-#include "vm/jit/i386/offsets.h"
#include "vm/jit/abi-asm.h"
#include "vm/jit/methodheader.h"
.globl asm_vm_call_method_float
.globl asm_vm_call_method_double
.globl asm_vm_call_method_exception_handler
+ .globl asm_vm_call_method_end
.globl asm_call_jit_compiler
.globl asm_handle_nat_exception
.globl asm_handle_exception
- .globl asm_wrapper_patcher
+ .globl asm_abstractmethoderror
+ .globl asm_patcher_wrapper
+
+#if defined(ENABLE_REPLACEMENT)
.globl asm_replacement_out
.globl asm_replacement_in
+#endif
.globl asm_builtin_f2i
.globl asm_builtin_f2l
.globl asm_builtin_d2i
.globl asm_builtin_d2l
- .globl asm_criticalsections
- .globl asm_getclassvalues_atomic
+ .globl asm_compare_and_swap
+ .globl asm_memory_barrier
.globl asm_get_cycle_count
.long 0 /* isleaf */
.long 0 /* IsSync */
.long 0 /* frame size */
- .long 0 /* method pointer (pointer to name) */
+ .long 0 /* codeinfo pointer */
asm_vm_call_method:
asm_vm_call_method_int:
mov s1,1*4(sp)
mov s2,2*4(sp)
- mov 4*4(bp),itmp1 /* pointer to arg block (4(push)+4(return)+4+4)*/
- mov 3*4(bp),itmp2 /* arg count (4(push)+4(return)+4 */
+ mov sp,s1 /* save stack pointer */
- mov sp,s1 /* save the stackpointer */
+ mov 3*4(bp),t0 /* address of data structure */
+ mov 4*4(bp),itmp1 /* number of stack arguments */
- test itmp2,itmp2 /* maybe we have no args */
- jle calljava_copydone
+ cmp $0,itmp1
+ je L_asm_vm_call_method_stack_copy_done
- mov itmp2,itmp3 /* calculate stack size */
- mov itmp1,%edi /* save pointer to arg block */
+ mov itmp1,itmp2
+ add $1,itmp2 /* keep stack 16-byte aligned */
+ and $0xfffffffe,itmp2
+ shl $3,itmp2 /* calculate stack size */
+ sub itmp2,sp /* create stack frame */
+ mov sp,itmp2 /* temporary stack pointer */
-calljava_calcstacksize:
- mov offvmargtype(itmp1),t0
- test $1,t0 /* two word type? */
- jz calljava_onewordtype
+L_asm_vm_call_method_stack_copy_loop:
+ mov 0(t0),itmp3 /* load argument */
+ mov itmp3,0(itmp2) /* store argument on stack */
+ mov 4(t0),itmp3
+ mov itmp3,4(itmp2)
- sub $4,sp /* add 1 slot to stackframe size */
+ sub $1,itmp1 /* subtract 1 argument */
+ add $8,t0 /* set address of next argument */
+ add $8,itmp2 /* increase SP */
-calljava_onewordtype:
- sub $4,sp /* add 1 slot to stackframe size */
- sub $1,itmp3
- test itmp3,itmp3 /* any args left? */
- jz calljava_setstack
+ cmp $0,itmp1
+ jg L_asm_vm_call_method_stack_copy_loop
- add $sizevmarg,itmp1 /* goto next argument block */
- jmp calljava_calcstacksize
-
-calljava_setstack:
- mov %edi,itmp1 /* restore pointer to arg block */
- and $0xfffffff0,sp /* align stack to 16-byte */
- mov sp,itmp3 /* initialize pointer for copying */
+L_asm_vm_call_method_stack_copy_done:
+ lea (2*4-256)(bp),mptr /* We subtract 256 to force the next */
+ /* move instruction to have a 32-bit */
+ /* offset. */
-calljava_copyloop:
- mov offvmargdata(itmp1),t0 /* get 4-bytes of argument */
- mov t0,(itmp3) /* and store them on the stack */
- add $4,itmp3 /* increase sp to next argument */
- mov offvmargtype(itmp1),t0 /* get the argument type */
- test $1,t0 /* two word type? */
- jz calljava_copynext
-
- mov offvmargdata+4(itmp1),t0 /* get upper 4-bytes of 2 word type */
- mov t0,(itmp3)
- add $4,itmp3 /* increase sp to next argument */
-
-calljava_copynext:
- sub $1,itmp2 /* are there any args left? */
- test itmp2,itmp2
- jle calljava_copydone
-
- add $sizevmarg,itmp1 /* goto next argument block */
- jmp calljava_copyloop
-
-calljava_copydone:
- mov 2*4(bp),itmp1 /* move function pointer to itmp1 */
-
- lea L_asm_call_jit_compiler,itmp3
+ mov (0*4+256)(mptr),itmp3 /* method call as in Java */
call *itmp3 /* call JIT compiler */
L_asm_vm_call_method_return:
push xptr /* pass exception pointer */
call builtin_throw_exception
add $4,sp
+asm_vm_call_method_end:
jmp L_asm_vm_call_method_return
asm_call_jit_compiler:
L_asm_call_jit_compiler: /* required for PIC code */
- sub $((4+2)*4+sizestackframeinfo),sp /* create stack frame */
- mov itmp1,(4+0)*4(sp) /* save method pointer */
-
- mov (4+2)*4+sizestackframeinfo(sp),itmp3 /* get return address */
- mov -1(itmp3),itmp1b /* get function code */
- cmp $0xd1,itmp1b /* called with `call *REG_ITMP2'? */
- jne L_not_static_special
-
- sub $6,itmp3 /* calculate address of immediate */
- jmp L_call_jit_compile
-
-L_not_static_special:
- cmp $0xd0,itmp1b /* called with `call *REG_ITMP1' */
- jne L_not_virtual_interface
-
- sub $6,itmp3 /* calculate address of offset */
- mov (itmp3),itmp3 /* get offset */
- add itmp2,itmp3 /* add base address to get method adr */
- jmp L_call_jit_compile
-
-L_not_virtual_interface:
- xor itmp3,itmp3 /* a call from asm_calljavafunction */
-
-L_call_jit_compile:
- mov itmp3,(4+1)*4(sp) /* save address for method pointer */
-
- mov sp,itmp1 /* create stackframe info */
- add $((4+2)*4),itmp1
- mov itmp1,0*4(sp) /* stackframeinfo pointer */
- movl $0,1*4(sp) /* if pv is NULL, use findmethod */
- mov sp,itmp2
- add $((1+4+2)*4+sizestackframeinfo),itmp2 /* pass java sp */
+ sub $(4*4),sp /* keep stack 16-byte aligned */
+
+ mov itmp1,0*4(sp) /* pass methodinfo pointer */
+ mov mptr,1*4(sp) /* pass method pointer */
+ mov sp,itmp2 /* pass java sp */
+ add $((1+4)*4),itmp2
mov itmp2,2*4(sp)
- mov ((0+4+2)*4+sizestackframeinfo)(sp),itmp3 /* pass java ra */
+ mov 4*4(sp),itmp3 /* pass java ra */
mov itmp3,3*4(sp)
- call stacktrace_create_inline_stackframeinfo
+ call jit_asm_compile
- mov (4+0)*4(sp),itmp1 /* pass method pointer */
- mov itmp1,0*4(sp)
- call jit_compile
- mov v0,(4+0)*4(sp) /* save return value */
-
- mov sp,itmp1 /* remove stackframe info */
- add $((4+2)*4),itmp1
- mov itmp1,0*4(sp) /* stackframeinfo pointer */
- call stacktrace_remove_stackframeinfo
-
- mov (4+0)*4(sp),v0 /* restore return value */
- mov (4+1)*4(sp),itmp3 /* restore address for method pointer */
-
- add $((4+2)*4+sizestackframeinfo),sp /* remove stack frame */
+ add $(4*4),sp /* remove stack frame */
test v0,v0 /* check for exception */
je L_asm_call_jit_compiler_exception
- test itmp3,itmp3 /* was this a JIT call? */
- je L_call_method
-
- mov v0,(itmp3) /* save the new method pointer */
-
-L_call_method:
jmp *v0 /* ...and now call the new method */
L_asm_call_jit_compiler_exception:
-#if defined(ENABLE_THREADS)
- call builtin_asm_get_exceptionptrptr
- mov v0,itmp2 /* v0 == itmp1 */
-#else
- lea _exceptionptr,itmp2
-#endif
- mov (itmp2),xptr /* get the exception pointer */
- movl $0,(itmp2) /* clear the exception pointer */
-
+ call exceptions_get_and_clear_exception
+ /* v0 == xptr */
pop xpc /* get return address */
sub $2,xpc /* faulting address is ra - 2 */
jmp L_asm_handle_exception
asm_handle_exception:
L_asm_handle_exception: /* required for PIC code */
- sub $((ARG_CNT+TMP_CNT)*4),sp /* create maybe-leaf stackframe */
+ sub $((ARG_CNT+TMP_CNT+3)*4),sp /* keep stack 16-byte aligned */
SAVE_ARGUMENT_REGISTERS(0) /* we save arg and temp registers in */
SAVE_TEMPORARY_REGISTERS(ARG_CNT) /* case this is a leaf method */
- mov $((ARG_CNT+TMP_CNT)*4),itmp3/* prepare a3 for handle_exception */
+ mov $((ARG_CNT+TMP_CNT+3)*4),itmp3 /* prepare a3 for handle_exception */
mov $1,t0 /* set maybe-leaf flag */
L_asm_handle_exception_stack_loop:
- sub $(10*4),sp /* create stackframe */
+ sub $(12*4),sp /* keep stack 16-byte aligned */
mov xptr,4*4(sp) /* save exception pointer */
mov xpc,5*4(sp) /* save exception pc */
add sp,itmp3 /* calculate Java sp into a3... */
- add $(10*4),itmp3
+ add $(12*4),itmp3
mov itmp3,7*4(sp) /* ...and save it */
mov t0,8*4(sp) /* save maybe-leaf flag */
mov xpc,0*4(sp) /* pass exception pc */
- call codegen_findmethod
+ call codegen_get_pv_from_pc
mov v0,6*4(sp) /* save data segment pointer */
mov 4*4(sp),itmp3 /* pass exception pointer */
mov v0,xpc /* move handlerpc into xpc */
mov 4*4(sp),xptr /* restore exception pointer */
mov 8*4(sp),t0 /* get maybe-leaf flag */
- add $(10*4),sp /* free stackframe */
+ add $(12*4),sp /* free stackframe */
test t0,t0 /* test for maybe-leaf flag */
jz L_asm_handle_exception_no_leaf
RESTORE_ARGUMENT_REGISTERS(0) /* if this is a leaf method, we have */
RESTORE_TEMPORARY_REGISTERS(ARG_CNT)/* to restore arg and temp registers */
- add $((ARG_CNT+TMP_CNT)*4),sp /* remove maybe-leaf stackframe */
+ add $((ARG_CNT+TMP_CNT+3)*4),sp /* remove maybe-leaf stackframe */
L_asm_handle_exception_no_leaf:
jmp *xpc /* jump to exception handler */
mov 4*4(sp),xptr /* restore exception pointer */
mov 6*4(sp),itmp3 /* restore data segment pointer */
mov 8*4(sp),t0 /* get maybe-leaf flag */
- add $(10*4),sp /* free stackframe */
+ add $(12*4),sp /* free stackframe */
test t0,t0
jz L_asm_handle_exception_no_leaf_stack
- add $((ARG_CNT+TMP_CNT)*4),sp /* remove maybe-leaf stackframe */
+ add $((ARG_CNT+TMP_CNT+3)*4),sp /* remove maybe-leaf stackframe */
xor t0,t0 /* clear the maybe-leaf flag */
L_asm_handle_exception_no_leaf_stack:
cmp $2,itmp1
je int2
- mov -3*4(itmp2),s0
+ mov -3*8(itmp2),s0
int2:
- mov -2*4(itmp2),s1
+ mov -2*8(itmp2),s1
int1:
- mov -1*4(itmp2),s2
+ mov -1*8(itmp2),s2
shl $2,itmp1 /* multiply by 4 bytes */
sub itmp1,itmp2
jmp L_asm_handle_exception_stack_loop
-/* asm_wrapper_patcher *********************************************************
+/* asm_abstractmethoderror *****************************************************
+
+ Creates and throws an AbstractMethodError.
+
+*******************************************************************************/
+
+asm_abstractmethoderror:
+ sub $(3*4),sp /* keep stack 16-byte aligned */
+ mov sp,itmp1 /* pass java sp */
+ add $((1+3)*4),itmp1
+ mov itmp1,0*4(sp)
+ mov 3*4(sp),itmp2 /* pass exception address */
+ sub $2,itmp2
+ mov itmp2,1*4(sp)
+ call exceptions_asm_new_abstractmethoderror
+ /* exception pointer is return value */
+ add $(3*4),sp /* remove stack frame */
+
+ pop xpc /* get exception address */
+ sub $2,xpc /* exception address is ra - 2 */
+ jmp L_asm_handle_exception
+
+
+/* asm_patcher_wrapper *********************************************************
XXX
*******************************************************************************/
-asm_wrapper_patcher:
- sub $((2+4)*4+sizestackframeinfo),sp /* create stack frame */
+asm_patcher_wrapper:
+ sub $((1+4+4)*4),sp /* keep stack 16-byte aligned */
mov itmp1,(0+4)*4(sp) /* save itmp1 and itmp2 */
- mov itmp2,(1+4)*4(sp) /* may be used by some instructions */
-
- mov sp,itmp1 /* create stackframe info */
- add $((2+4)*4),itmp1
- mov itmp1,0*4(sp) /* stackframeinfo pointer */
- movl $0,1*4(sp) /* if pv is NULL, use findmethod */
- mov sp,itmp2
- add $((7+2+4)*4+sizestackframeinfo),itmp2
- mov itmp2,2*4(sp) /* pass Java sp */
- mov ((6+2+4)*4+sizestackframeinfo)(sp),itmp3
- mov itmp3,3*4(sp) /* pass ra to java function */
- call stacktrace_create_inline_stackframeinfo
-
- mov sp,itmp1 /* pass stack pointer */
- add $((1+2+4)*4+sizestackframeinfo),itmp1 /* skip function pointer */
- mov itmp1,0*4(sp)
- mov (0+2+4)*4+sizestackframeinfo(sp),itmp1 /* get function pointer */
- call *itmp1 /* call the patcher function */
- mov v0,1*4(sp) /* save return value */
-
- mov sp,itmp1 /* remove stackframe info */
- add $((2+4)*4),itmp1
- mov itmp1,0*4(sp) /* stackframeinfo pointer */
- call stacktrace_remove_stackframeinfo
+ mov itmp2,(1+4)*4(sp)
- mov 1*4(sp),itmp3 /* restore return value */
- test itmp3,itmp3 /* exception thrown? */
- jz L_asm_wrapper_patcher_exception
+ mov sp,itmp1 /* pass SP of patcher stub */
+ add $((1+4+4)*4),itmp1
+ mov itmp1,0*4(sp)
+ movl $0,1*4(sp) /* pass PV (if NULL, use findmethod) */
+ movl $0,2*4(sp) /* pass RA (it's on the stack) */
+ call patcher_wrapper
+ mov v0,itmp3 /* save return value */
mov (0+4)*4(sp),itmp1 /* restore itmp1 and itmp2 */
- mov (1+4)*4(sp),itmp2 /* may be used by some instructions */
- mov ((5+2+4)*4+sizestackframeinfo)(sp),itmp3
- add $((6+2+4)*4+sizestackframeinfo),sp /* remove stack frame, keep ra */
+ mov (1+4)*4(sp),itmp2
- ret /* call new patched code */
+ test itmp3,itmp3 /* exception thrown? */
+ jne L_asm_patcher_wrapper_exception
-L_asm_wrapper_patcher_exception:
- add $((6+2+4)*4+sizestackframeinfo),sp /* remove stack frame, keep ra */
+ mov (5+1+4+4)*4(sp),itmp3 /* restore itmp3 */
+ add $((6+1+4+4)*4),sp /* remove stack frame, keep RA */
-#if defined(ENABLE_THREADS)
- call builtin_asm_get_exceptionptrptr
- mov v0,itmp2
-#else
- lea _exceptionptr,itmp2
-#endif
- mov (itmp2),xptr /* get the exception pointer */
- movl $0,(itmp2) /* clear the exception pointer */
+ ret /* jump to new patched code */
+L_asm_patcher_wrapper_exception:
+ add $((6+1+4+4)*4),sp /* remove stack frame, keep RA */
+ mov itmp3,xptr /* get exception */
pop xpc /* get and remove return address */
jmp L_asm_handle_exception
+#if defined(ENABLE_REPLACEMENT)
/* asm_replacement_out *********************************************************
sub $(sizeexecutionstate + REPLACEMENT_ROOM),sp
/* save registers in execution state */
- mov %eax,(EAX*8+offes_intregs)(sp)
- mov %ebx,(EBX*8+offes_intregs)(sp)
- mov %ecx,(ECX*8+offes_intregs)(sp)
- mov %edx,(EDX*8+offes_intregs)(sp)
- mov %esi,(ESI*8+offes_intregs)(sp)
- mov %edi,(EDI*8+offes_intregs)(sp)
- mov %ebp,(EBP*8+offes_intregs)(sp)
- movl $0 ,(ESP*8+offes_intregs)(sp) /* not used */
-
-#ifndef NDEBUG
- /* clear high 32bit */
- movl $0,(4+0*8+offes_intregs)(sp)
- movl $0,(4+1*8+offes_intregs)(sp)
- movl $0,(4+2*8+offes_intregs)(sp)
- movl $0,(4+3*8+offes_intregs)(sp)
- movl $0,(4+4*8+offes_intregs)(sp)
- movl $0,(4+5*8+offes_intregs)(sp)
- movl $0,(4+6*8+offes_intregs)(sp)
- movl $0,(4+7*8+offes_intregs)(sp)
-#endif
+ mov %eax,(EAX*4+offes_intregs)(sp)
+ mov %ebx,(EBX*4+offes_intregs)(sp)
+ mov %ecx,(ECX*4+offes_intregs)(sp)
+ mov %edx,(EDX*4+offes_intregs)(sp)
+ mov %esi,(ESI*4+offes_intregs)(sp)
+ mov %edi,(EDI*4+offes_intregs)(sp)
+ mov %ebp,(EBP*4+offes_intregs)(sp)
+ movl $0 ,(ESP*4+offes_intregs)(sp) /* not used */
/* calculate sp of method */
mov sp,itmp1
push sp /* arg1: execution state */
push itmp1 /* arg0: replacement point */
call replace_me /* call C function replace_me */
- call abort /* NEVER REACHED */
+
/* asm_replacement_in **********************************************************
This function never returns!
C prototype:
- void asm_replacement_in(executionstate *es);
+ void asm_replacement_in(executionstate *es, replace_safestack_t *st);
*******************************************************************************/
asm_replacement_in:
- mov 4(sp),%ebp /* executionstate *es */
+ /* get arguments */
+ mov 8(sp),%esi /* replace_safestack_t *st */
+ mov 4(sp),%ebp /* executionstate *es == safe stack */
+
+ /* switch to the safe stack and build a stack frame */
+ mov %ebp,sp
+ sub $(1*4),sp
+
+ /* call replace_build_execution_state(st) */
+ mov %esi,(0*4)(sp)
+ call replace_build_execution_state
/* set new sp */
- mov (offes_sp)(%ebp),%esp
-
- /* store address of new code */
+ mov (offes_sp)(%ebp),sp
+
+ /* push address of new code */
push (offes_pc)(%ebp)
-
- /* copy registers from execution state */
- mov (EAX*8+offes_intregs)(%ebp),%eax
- mov (EBX*8+offes_intregs)(%ebp),%ebx
- mov (ECX*8+offes_intregs)(%ebp),%ecx
- mov (EDX*8+offes_intregs)(%ebp),%edx
- mov (ESI*8+offes_intregs)(%ebp),%esi
- mov (EDI*8+offes_intregs)(%ebp),%edi
- mov (EBP*8+offes_intregs)(%ebp),%ebp
+ /* allocate an executionstate_t on the stack */
+ sub $(sizeexecutionstate),sp
+
+ /* call replace_free_safestack(st,& of allocated executionstate_t) */
+ push sp /* tmpes */
+ push %esi /* st */
+ call replace_free_safestack
+ add $(2*4),sp
- /* jump to new code */
+ /* copy registers from execution state */
+ mov (EAX*4+offes_intregs)(sp),%eax
+ mov (EBX*4+offes_intregs)(sp),%ebx
+ mov (ECX*4+offes_intregs)(sp),%ecx
+ mov (EDX*4+offes_intregs)(sp),%edx
+ mov (ESI*4+offes_intregs)(sp),%esi
+ mov (EDI*4+offes_intregs)(sp),%edi
+ mov (EBP*4+offes_intregs)(sp),%ebp
+
+ /* pop the execution state off the stack */
+ add $(sizeexecutionstate),sp
+
+ /* jump to new code, hold your thumbs! ;) */
ret
+#endif /* defined(ENABLE_REPLACEMENT) */
+
+
/************************ function asm_builtin_x2x *****************************
* *
* Wrapper functions for corner cases *
*******************************************************************************/
asm_builtin_f2i:
- sub $4,%esp
+ sub $(3*4),%esp
fsts (%esp)
call builtin_f2i
- add $4,%esp
+ add $(3*4),%esp
ret
asm_builtin_d2i:
- sub $8,%esp
+ sub $(3*4),%esp
fstl (%esp)
call builtin_d2i
- add $8,%esp
+ add $(3*4),%esp
ret
asm_builtin_f2l:
- sub $4,%esp
+ sub $(3*4),%esp
fsts (%esp)
call builtin_f2l
- add $4,%esp
+ add $(3*4),%esp
ret
asm_builtin_d2l:
- sub $8,%esp
+ sub $(3*4),%esp
fstl (%esp)
call builtin_d2l
- add $8,%esp
+ add $(3*4),%esp
ret
-asm_getclassvalues_atomic:
-_crit_restart2:
- mov 4(%esp),%ecx /* super */
- mov 8(%esp),%edx /* sub */
-_crit_begin2:
- mov offbaseval(%ecx),%eax
- mov offdiffval(%ecx),%ecx
- mov offbaseval(%edx),%edx
-_crit_end2:
- push %ebx
- mov 16(%esp),%ebx /* out */
- mov %eax,offcast_super_baseval(%ebx)
- mov %ecx,offcast_super_diffval(%ebx)
- mov %edx,offcast_sub_baseval(%ebx)
- pop %ebx
- ret
+/* asm_compare_and_swap ********************************************************
- .data
+ Does an atomic compare and swap. Required for the lock
+ implementation.
-asm_criticalsections:
-#if defined(ENABLE_THREADS)
-#if 0
- .long _crit_begin1
- .long _crit_end1
- .long _crit_restart1
-#endif
- .long _crit_begin2
- .long _crit_end2
- .long _crit_restart2
-#endif
- .long 0
+ Atomically do the following: Check if the location still contains
+ `oldval`. If so, replace it by `newval` and return `oldval`.
+ RETURN VALUE:
+ the old value at *p
-/* Disable exec-stacks, required for Gentoo ***********************************/
+ long compare_and_swap(volatile long *p, long oldval, long newval);
-#if defined(__GCC__) && defined(__ELF__)
- .section .note.GNU-stack,"",@progbits
-#endif
+*******************************************************************************/
+
+asm_compare_and_swap:
+ mov 1*4(sp),%ecx /* load p into a register */
+ mov 2*4(sp),%eax /* load oldval into return register */
+ mov 3*4(sp),%edx /* load newval into a register */
+ lock; cmpxchgl %edx,0(%ecx)
+ ret
+
+
+/* asm_memory_barrier **********************************************************
+
+ A memory barrier for the Java Memory Model.
+*******************************************************************************/
+
+asm_memory_barrier:
+ lock; add $0,0(sp)
+ ret
+
/* asm_get_cycle_count *********************************************************
Get the current time-stamp counter from the CPU.
ret
+/* disable exec-stacks ********************************************************/
+
+#if defined(__linux__) && defined(__ELF__)
+ .section .note.GNU-stack,"",%progbits
+#endif
+
+
/*
* These are local overrides for various environment variables in Emacs.
* Please do not remove this and leave it at the end of the file, where