mirrors/emacs
1
Fork 0
mirror of git://git.sv.gnu.org/emacs.git synced 2026-04-27 16:51:06 -07:00
Code Issues Projects Releases Wiki Activity

Mps: working stack scanner for xcppgc

Browse source 
Copied from Perforce
 Change: 147224
 ServerID: perforce.ravenbrook.com
This commit is contained in:
David Jones 2005-03-02 09:56:51 +00:00
parent 013278a0c2
commit d751349d25
1 changed files with 17 additions and 0 deletions
Download patch file Download diff file Expand all files Collapse all files

17
mps/code/ssxcpp.s
View file

@ -107,10 +107,18 @@
# Exported symbols
.globl _StackScan
# Imported symbols
.globl _TraceScanArea
linkageArea = 24 ; size of linkage area to create
paramArea = 12 ; size of param area to create
# .local.size: this size is directly related to what registers we save.
localArea = 76 ; size of local workspace (for 19 registers, r13-r31)
# A throwaway comment in [MORT] p32 "The called routine is responsible
# for allocating its own stack frame, making sure to preserve 16-byte
# alignment on the stack" implies that the stack must always be 16-byte
# aligned. Thus, this sum, frameSize, must be a multiple of 16. 24 +
# 12 + 76 = 112 = 7*16, so much for the abstraction.
frameSize = linkageArea + paramArea + localArea
_StackScan:
@ -122,6 +130,15 @@ _StackScan:
stwu r1, -frameSize(r1)
# r1 + frameSize is SPEP
# setup arguments for call to TraceScanArea, and call it
# First Argument, ScanState, is our first argument, already in r3.
# Arguments are processed out of order because of the dependency on r4
# Third Argument: highest stack address.
mr r5, r4
# Second Argument: lowest stack address.
mr r4, r1
bl _TraceScanArea
lwz r1, 0(r1)
# r1 is SPEP again
lwz r0, 8(r1)