corda/src/continuations-x86.S

#ifdef __x86_64__

#define THREAD_CONTINUATION 168
#define THREAD_EXCEPTION 64
#define THREAD_EXCEPTION_STACK_ADJUSTMENT 176
#define THREAD_EXCEPTION_OFFSET 184
#define THREAD_EXCEPTION_HANDLER 192

#define CONTINUATION_NEXT 8
#define CONTINUATION_ADDRESS 32
#define CONTINUATION_RETURN_ADDRESS_OFFSET 40
#define CONTINUATION_FRAME_POINTER_OFFSET 48
#define CONTINUATION_LENGTH 56
#define CONTINUATION_BODY 64

   // call the next continuation, if any
   movq   THREAD_CONTINUATION(%rbx),%rcx
   cmpq   $0,%rcx
   je     LOCAL(vmInvoke_exit)

   // allocate a frame of size (continuation.length * BYTES_PER_WORD)
   // + CALLEE_SAVED_REGISTER_FOOTPRINT
   movq   CONTINUATION_LENGTH(%rcx),%rsi
   shlq   $3,%rsi
   subq   %rsi,%rsp
   subq   $CALLEE_SAVED_REGISTER_FOOTPRINT,%rsp

   // copy the continuation body into the frame
   leaq   CONTINUATION_BODY(%rcx),%rdi
   
   movq   $0,%r9
   jmp    LOCAL(vmInvoke_continuationTest)

LOCAL(vmInvoke_continuationLoop):
   movq   (%rdi,%r9,1),%r8
   movq   %r8,(%rsp,%r9,1)
   addq   $8,%r9
   
LOCAL(vmInvoke_continuationTest):
   cmpq   %rsi,%r9
   jb     LOCAL(vmInvoke_continuationLoop)

   // set the return address to vmInvoke_returnAddress
   movq   CONTINUATION_RETURN_ADDRESS_OFFSET(%rcx),%rdi
   movq   vmInvoke_returnAddress@GOTPCREL(%rip),%r10
   movq   %r10,(%rsp,%rdi,1)

   // save the current base pointer in the frame and update it
   movq   CONTINUATION_FRAME_POINTER_OFFSET(%rcx),%rdi
   movq   %rbp,(%rsp,%rdi,1)
   addq   %rsp,%rdi
   movq   %rdi,%rbp

   // consume the continuation
   movq   CONTINUATION_NEXT(%rcx),%rdi
   movq   %rdi,THREAD_CONTINUATION(%rbx)

   // call the continuation unless we're handling an exception
   movq   THREAD_EXCEPTION(%rbx),%rsi
   cmpq   $0,%rsi
   jne    LOCAL(vmInvoke_handleException)
   jmp    *CONTINUATION_ADDRESS(%rcx)

LOCAL(vmInvoke_handleException):
   // we're handling an exception - call the exception handler instead
   movq   $0,THREAD_EXCEPTION(%rbx)
   movq   THREAD_EXCEPTION_STACK_ADJUSTMENT(%rbx),%rdi
   subq   %rdi,%rsp
   movq   THREAD_EXCEPTION_OFFSET(%rbx),%rdi
   movq   %rsi,(%rsp,%rdi,1)
   
   jmp    *THREAD_EXCEPTION_HANDLER(%rbx)

LOCAL(vmInvoke_exit):

#elif defined __i386__
   
#define THREAD_CONTINUATION 96
#define THREAD_EXCEPTION 36
#define THREAD_EXCEPTION_STACK_ADJUSTMENT 100
#define THREAD_EXCEPTION_OFFSET 104
#define THREAD_EXCEPTION_HANDLER 108

#define CONTINUATION_NEXT 4
#define CONTINUATION_ADDRESS 16
#define CONTINUATION_RETURN_ADDRESS_OFFSET 20
#define CONTINUATION_FRAME_POINTER_OFFSET 24
#define CONTINUATION_LENGTH 28
#define CONTINUATION_BODY 32

   // call the next continuation, if any
   movl   THREAD_CONTINUATION(%ebx),%ecx
   cmpl   $0,%ecx
   je     LOCAL(vmInvoke_exit)

   // allocate a frame of size (continuation.length * BYTES_PER_WORD)
   movl   CONTINUATION_LENGTH(%ecx),%esi
   shll   $2,%esi
   subl   %esi,%esp
   
   // copy the continuation body into the frame
   leal   CONTINUATION_BODY(%ecx),%edi

   push   %eax
   push   %edx
   
   movl   $0,%edx
   jmp    LOCAL(vmInvoke_continuationTest)

LOCAL(vmInvoke_continuationLoop):
   movl   (%edi,%edx,1),%eax
   movl   %eax,8(%esp,%edx,1)
   addl   $4,%edx
   
LOCAL(vmInvoke_continuationTest):
   cmpl   %esi,%edx
   jb     LOCAL(vmInvoke_continuationLoop)

   pop    %edx
   pop    %eax

   // set the return address to vmInvoke_returnAddress
   movl   CONTINUATION_RETURN_ADDRESS_OFFSET(%ecx),%edi
   call   LOCAL(getPC)
   addl   $_GLOBAL_OFFSET_TABLE_,%esi
   movl   vmInvoke_returnAddress@GOT(%esi),%esi
   movl   %esi,(%esp,%edi,1)
   
   // save the current base pointer in the frame and update it
   movl   CONTINUATION_FRAME_POINTER_OFFSET(%ecx),%edi
   movl   %ebp,(%esp,%edi,1)
   addl   %esp,%edi
   movl   %edi,%ebp
   
   // consume the continuation
   movl   CONTINUATION_NEXT(%ecx),%edi
   movl   %edi,THREAD_CONTINUATION(%ebx)

   // call the continuation unless we're handling an exception
   movl   THREAD_EXCEPTION(%ebx),%esi
   cmpl   $0,%esi
   jne    LOCAL(vmInvoke_handleException)

   jmp    *CONTINUATION_ADDRESS(%ecx)

LOCAL(vmInvoke_handleException):
   // we're handling an exception - call the exception handler instead
   movl   $0,THREAD_EXCEPTION(%ebx)
   movl   THREAD_EXCEPTION_STACK_ADJUSTMENT(%ebx),%edi
   subl   %edi,%esp
   movl   THREAD_EXCEPTION_OFFSET(%ebx),%edi
   movl   %esi,(%esp,%edi,1)
   
   jmp    *THREAD_EXCEPTION_HANDLER(%ebx)

LOCAL(vmInvoke_exit):

#else
#  error unsupported architecture
#endif