/**
* This function renames registers in an attempt to get the code close to
* SSA form. After this function has completed, most of the register are only
* written to one time, with a few exceptions.
*
* This function assumes all the instructions are still of type
* RC_INSTRUCTION_NORMAL.
*/
void rc_rename_regs(struct radeon_compiler *c, void *user)
{
unsigned int i, used_length;
int new_index;
struct rc_instruction * inst;
struct rc_reader_data reader_data;
unsigned char * used;
/* XXX Remove this once the register allocation works with flow control. */
for(inst = c->Program.Instructions.Next;
inst != &c->Program.Instructions;
inst = inst->Next) {
if (inst->U.I.Opcode == RC_OPCODE_BGNLOOP)
return;
}
used_length = 2 * rc_recompute_ips(c);
used = memory_pool_malloc(&c->Pool, sizeof(unsigned char) * used_length);
memset(used, 0, sizeof(unsigned char) * used_length);
rc_get_used_temporaries(c, used, used_length);
for(inst = c->Program.Instructions.Next;
inst != &c->Program.Instructions;
inst = inst->Next) {
if (inst->U.I.DstReg.File != RC_FILE_TEMPORARY)
continue;
reader_data.ExitOnAbort = 1;
rc_get_readers(c, inst, &reader_data, NULL, NULL, NULL);
if (reader_data.Abort || reader_data.ReaderCount == 0)
continue;
new_index = rc_find_free_temporary_list(c, used, used_length,
RC_MASK_XYZW);
if (new_index < 0) {
rc_error(c, "Ran out of temporary registers\n");
return;
}
reader_data.Writer->U.I.DstReg.Index = new_index;
for(i = 0; i < reader_data.ReaderCount; i++) {
reader_data.Readers[i].U.I.Src->Index = new_index;
}
}
}
unsigned int rc_find_free_temporary(struct radeon_compiler * c)
{
unsigned char used[RC_REGISTER_MAX_INDEX];
int free;
memset(used, 0, sizeof(used));
rc_get_used_temporaries(c, used, RC_REGISTER_MAX_INDEX);
free = rc_find_free_temporary_list(c, used, RC_REGISTER_MAX_INDEX,
RC_MASK_XYZW);
if (free < 0) {
rc_error(c, "Ran out of temporary registers\n");
return 0;
}
return free;
}