r300/compiler: Fix instruction scheduling within IF blocks

Reads of registers that where not written to within the same block were
not being tracked.  So in a situations like this:
0: IF
1: ADD t0, t1, t2
2: MOV t2, t1

Instruction 2 didn't know that instruction 1 read from t2, so
in some cases instruction 2 was being scheduled before instruction 1.

NOTE: This is a candidate for the 7.9 branch.
This commit is contained in:
Tom Stellard
2010-11-13 17:12:58 -08:00
parent e2301b45c2
commit 3e5f9789d6
@@ -126,15 +126,6 @@ static struct reg_value ** get_reg_valuep(struct schedule_state * s,
return &s->Temporary[index].Values[chan];
}
static struct reg_value * get_reg_value(struct schedule_state * s,
rc_register_file file, unsigned int index, unsigned int chan)
{
struct reg_value ** pv = get_reg_valuep(s, file, index, chan);
if (!pv)
return 0;
return *pv;
}
static void add_inst_to_list(struct schedule_instruction ** list, struct schedule_instruction * inst)
{
inst->NextReady = *list;
@@ -591,13 +582,13 @@ static void scan_read(void * data, struct rc_instruction * inst,
rc_register_file file, unsigned int index, unsigned int chan)
{
struct schedule_state * s = data;
struct reg_value * v = get_reg_value(s, file, index, chan);
struct reg_value ** v = get_reg_valuep(s, file, index, chan);
struct reg_value_reader * reader;
if (!v)
return;
if (v->Writer == s->Current) {
if (*v && (*v)->Writer == s->Current) {
/* The instruction reads and writes to a register component.
* In this case, we only want to increment dependencies by one.
*/
@@ -608,16 +599,28 @@ static void scan_read(void * data, struct rc_instruction * inst,
reader = memory_pool_malloc(&s->C->Pool, sizeof(*reader));
reader->Reader = s->Current;
reader->Next = v->Readers;
v->Readers = reader;
v->NumReaders++;
s->Current->NumDependencies++;
if (!*v) {
/* In this situation, the instruction reads from a register
* that hasn't been written to or read from in the current
* block. */
*v = memory_pool_malloc(&s->C->Pool, sizeof(struct reg_value));
memset(*v, 0, sizeof(struct reg_value));
(*v)->Readers = reader;
} else {
reader->Next = (*v)->Readers;
(*v)->Readers = reader;
/* Only update the current instruction's dependencies if the
* register it reads from has been written to in this block. */
if ((*v)->Writer) {
s->Current->NumDependencies++;
}
}
(*v)->NumReaders++;
if (s->Current->NumReadValues >= 12) {
rc_error(s->C, "%s: NumReadValues overflow\n", __FUNCTION__);
} else {
s->Current->ReadValues[s->Current->NumReadValues++] = v;
s->Current->ReadValues[s->Current->NumReadValues++] = *v;
}
}