[pypy-commit] pypy jitframe-on-heap: Update the comments.

[arigo]

Author: Armin Rigo <arigo at tunes.org>
Branch: jitframe-on-heap
Changeset: r61768:69eeabe5c271
Date: 2013-02-25 20:07 +0100
http://bitbucket.org/pypy/pypy/changeset/69eeabe5c271/

Log:	Update the comments.

diff --git a/rpython/jit/backend/x86/regalloc.py b/rpython/jit/backend/x86/regalloc.py
--- a/rpython/jit/backend/x86/regalloc.py
+++ b/rpython/jit/backend/x86/regalloc.py
@@ -720,9 +720,8 @@
         #
         #  - at least the non-callee-saved registers
         #
-        #  - for shadowstack, we assume that any call can collect, and we
+        #  - we assume that any call can collect, and we
         #    save also the callee-saved registers that contain GC pointers
-        #    XXX for asmgcc too for now.
         #
         #  - for CALL_MAY_FORCE or CALL_ASSEMBLER, we have to save all regs
         #    anyway, in case we need to do cpu.force().  The issue is that
@@ -734,6 +733,9 @@
         if not save_all_regs:
             gcrootmap = self.assembler.cpu.gc_ll_descr.gcrootmap
             # we save all the registers for shadowstack and asmgcc for now
+            # --- for asmgcc too: we can't say "register x is a gc ref"
+            # without distinguishing call sites, which we don't do any
+            # more for now.
             if gcrootmap: # and gcrootmap.is_shadow_stack:
                 save_all_regs = 2
         self.rm.before_call(force_store, save_all_regs=save_all_regs)