steve
/
factor
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

cpu.x86.bootstrap: simplify leaf-signal-handler 

We can use RET (stack-frame-size - cell) instead of doing stack gymnastics.
db4
Joe Groff 2011-10-29 18:13:22 -07:00
parent 40bc8459db
commit 9f6f36fdec
1 changed files with 3 additions and 13 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

16
basis/cpu/x86/bootstrap.factor
View File

@ -119,19 +119,9 @@ big-endian off
jit-save-context jit-save-context
temp0 vm-reg vm-signal-handler-addr-offset [+] MOV temp0 vm-reg vm-signal-handler-addr-offset [+] MOV
temp0 CALL temp0 CALL
! Stack at this point has a fake stack frame set up to represent the frame-size jit-signal-handler-epilog
! leaf procedure we interrupted. We must tear down that frame in ! Pop the fake leaf frame along with our return address
! addition to our own before resuming. stack-frame-size cell - RET
! Grab our frame's return address and place it just underneath the leaf proc's
! return address, since we can't touch any registers once they've been
! restored. If we got this far there should be no faults here and we
! can get away with corrupting the stack frame.
temp0 stack-reg frame-size bootstrap-cell - [+] MOV
stack-reg frame-size stack-frame-size + 2 bootstrap-cells - [+] temp0 MOV
! Pop enough of the fake frame to leave the resume address at the top of the
! stack when we RET.
frame-size stack-frame-size + bootstrap-cell - jit-signal-handler-epilog
] \ leaf-signal-handler define-sub-primitive ] \ leaf-signal-handler define-sub-primitive
[ [