cvsuser 04/04/22 05:11:04
Modified: imcc reg_alloc.c
Log:
cleanup; add some comments
Revision Changes Path
1.11 +19 -4 parrot/imcc/reg_alloc.c
Index: reg_alloc.c
===================================================================
RCS file: /cvs/public/parrot/imcc/reg_alloc.c,v
retrieving revision 1.10
retrieving revision 1.11
diff -u -w -r1.10 -r1.11
--- reg_alloc.c 22 Apr 2004 11:23:17 -0000 1.10
+++ reg_alloc.c 22 Apr 2004 12:11:04 -0000 1.11
@@ -288,13 +288,18 @@
* regs are sorted now according to their start line of usage
* run through them and allocate all that don't overlap
* in one bunch
+ *
+ * XXX doesn't work yet - currently allocated registers are also
+ * in reglist to find allocatable registers and to check for interference
*/
+
+
#ifdef ALLOCATE_HACK
static void
allocate_non_interfering(Parrot_Interp interpreter, SymReg ** reglist, int n)
{
int i, t;
- int first_color, last_line;
+ int first_color, last_line, bb_index;
SymReg *r;
for (t = 0; t < 4; t++) {
@@ -305,7 +310,8 @@
while (first_color >= 16) {
for (i = 0; i < n; i++) {
r = reglist[i];
- if (r->set != typ || (r->type & VT_REGP) || r->want_regno >= 0)
+ if (r->set != typ || (r->type & VT_REGP) ||
+ r->want_regno >= 0 || r->color >= 0)
continue;
if (r->color == first_color) {
first_color--;
@@ -320,20 +326,29 @@
/*
* no scan reglist for small ranged non-interfering regs of that typ
*/
- last_line = -1;
+ bb_index = last_line = -1;
for (i = 0; i < n; i++) {
r = reglist[i];
- if (r->set != typ || (r->type & VT_REGP) || r->want_regno >= 0)
+ if (r->set != typ || (r->type & VT_REGP) ||
+ r->want_regno >= 0 || r->color >= 0)
continue;
if (r->last_ins->index - r->first_ins->index > 10)
continue;
+ if (r->first_ins->bbindex != r->last_ins->bbindex)
/* found a short ranged reg
*
* if this is used before the previous one ended, they overlap
*/
if (r->first_ins->index <= last_line)
continue;
+ /*
+ * if this is not the same basic block, the might interfer
+ * due to a branch
+ */
+ if (r->first_ins->bbindex != bb_index)
+ continue;
last_line = r->last_ins->index;
+ bb_index = r->last_ins->bbindex;
r->color = first_color;
r->type = VTPASM;
debug(interpreter, DEBUG_IMC, "coloring '%s' %d\n",
