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Diffstat (limited to 'libguile/vm-i-system.c')
-rw-r--r--libguile/vm-i-system.c47
1 files changed, 25 insertions, 22 deletions
diff --git a/libguile/vm-i-system.c b/libguile/vm-i-system.c
index ab901e281..244f23ab7 100644
--- a/libguile/vm-i-system.c
+++ b/libguile/vm-i-system.c
@@ -46,14 +46,18 @@ VM_DEFINE_INSTRUCTION (1, halt, "halt", 0, 0, 0)
}
{
- ASSERT (sp == stack_base);
- ASSERT (stack_base == SCM_FRAME_UPPER_ADDRESS (fp) - 1);
+#ifdef VM_ENABLE_STACK_NULLING
+ SCM *old_sp = sp;
+#endif
/* Restore registers */
sp = SCM_FRAME_LOWER_ADDRESS (fp) - 1;
- ip = NULL;
+ /* Setting the ip here doesn't actually affect control flow, as the calling
+ code will restore its own registers, but it does help when walking the
+ stack */
+ ip = SCM_FRAME_RETURN_ADDRESS (fp);
fp = SCM_FRAME_DYNAMIC_LINK (fp);
- NULLSTACK (stack_base - sp);
+ NULLSTACK (old_sp - sp);
}
goto vm_done;
@@ -517,6 +521,8 @@ VM_DEFINE_INSTRUCTION (40, push_rest_list, "push-rest-list", 2, -1, -1)
VM_DEFINE_INSTRUCTION (41, new_frame, "new-frame", 0, 0, 3)
{
+ /* NB: if you change this, see frames.c:vm-frame-num-locals */
+ /* and frames.h, vm-engine.c, etc of course */
PUSH ((SCM)fp); /* dynamic link */
PUSH (0); /* mvra */
PUSH (0); /* ra */
@@ -863,20 +869,19 @@ VM_DEFINE_INSTRUCTION (51, return, "return", 0, 1, 1)
SCM ret;
POP (ret);
- ASSERT (sp == stack_base);
- ASSERT (stack_base == SCM_FRAME_UPPER_ADDRESS (fp) - 1);
+
+#ifdef VM_ENABLE_STACK_NULLING
+ SCM *old_sp = sp;
+#endif
/* Restore registers */
sp = SCM_FRAME_LOWER_ADDRESS (fp);
ip = SCM_FRAME_RETURN_ADDRESS (fp);
fp = SCM_FRAME_DYNAMIC_LINK (fp);
- {
+
#ifdef VM_ENABLE_STACK_NULLING
- int nullcount = stack_base - sp;
+ NULLSTACK (old_sp - sp);
#endif
- stack_base = SCM_FRAME_UPPER_ADDRESS (fp) - 1;
- NULLSTACK (nullcount);
- }
/* Set return value (sp is already pushed) */
*sp = ret;
@@ -898,11 +903,10 @@ VM_DEFINE_INSTRUCTION (52, return_values, "return/values", 1, -1, -1)
EXIT_HOOK ();
RETURN_HOOK ();
- ASSERT (stack_base == SCM_FRAME_UPPER_ADDRESS (fp) - 1);
-
- /* data[1] is the mv return address */
if (nvalues != 1 && SCM_FRAME_MV_RETURN_ADDRESS (fp))
{
+ /* A multiply-valued continuation */
+ SCM *vals = sp - nvalues;
int i;
/* Restore registers */
sp = SCM_FRAME_LOWER_ADDRESS (fp) - 1;
@@ -911,12 +915,11 @@ VM_DEFINE_INSTRUCTION (52, return_values, "return/values", 1, -1, -1)
/* Push return values, and the number of values */
for (i = 0; i < nvalues; i++)
- *++sp = stack_base[1+i];
+ *++sp = vals[i+1];
*++sp = SCM_I_MAKINUM (nvalues);
- /* Finally set new stack_base */
- NULLSTACK (stack_base - sp + nvalues + 1);
- stack_base = SCM_FRAME_UPPER_ADDRESS (fp) - 1;
+ /* Finally null the end of the stack */
+ NULLSTACK (vals + nvalues - sp);
}
else if (nvalues >= 1)
{
@@ -924,17 +927,17 @@ VM_DEFINE_INSTRUCTION (52, return_values, "return/values", 1, -1, -1)
break with guile tradition and try and do something sensible. (Also,
this block handles the single-valued return to an mv
continuation.) */
+ SCM *vals = sp - nvalues;
/* Restore registers */
sp = SCM_FRAME_LOWER_ADDRESS (fp) - 1;
ip = SCM_FRAME_RETURN_ADDRESS (fp);
fp = SCM_FRAME_DYNAMIC_LINK (fp);
/* Push first value */
- *++sp = stack_base[1];
+ *++sp = vals[1];
- /* Finally set new stack_base */
- NULLSTACK (stack_base - sp + nvalues + 1);
- stack_base = SCM_FRAME_UPPER_ADDRESS (fp) - 1;
+ /* Finally null the end of the stack */
+ NULLSTACK (vals + nvalues - sp);
}
else
goto vm_error_no_values;