/* calculate required # of delay slots between the instruction that
* assigns a value and the one that consumes
*/
int ir3_delayslots(struct ir3_instruction *assigner,
struct ir3_instruction *consumer, unsigned n)
{
/* worst case is cat1-3 (alu) -> cat4/5 needing 6 cycles, normal
* alu -> alu needs 3 cycles, cat4 -> alu and texture fetch
* handled with sync bits
*/
if (is_meta(assigner))
return 0;
if (writes_addr(assigner))
return 6;
/* handled via sync flags: */
if (is_sfu(assigner) || is_tex(assigner) || is_mem(assigner))
return 0;
/* assigner must be alu: */
if (is_flow(consumer) || is_sfu(consumer) || is_tex(consumer) ||
is_mem(consumer)) {
return 6;
} else if ((consumer->category == 3) &&
(is_mad(consumer->opc) || is_madsh(consumer->opc)) &&
(n == 2)) {
/* special case, 3rd src to cat3 not required on first cycle */
return 1;
} else {
return 3;
}
}
/**
* Handle cp for a given src register. This additionally handles
* the cases of collapsing immedate/const (which replace the src
* register with a non-ssa src) or collapsing mov's from relative
* src (which needs to also fixup the address src reference by the
* instruction).
*/
static void
reg_cp(struct ir3_cp_ctx *ctx, struct ir3_instruction *instr,
struct ir3_register *reg, unsigned n)
{
struct ir3_instruction *src = ssa(reg);
/* don't propagate copies into a PHI, since we don't know if the
* src block executed:
*/
if (instr->opc == OPC_META_PHI)
return;
if (is_eligible_mov(src, true)) {
/* simple case, no immed/const/relativ, only mov's w/ ssa src: */
struct ir3_register *src_reg = src->regs[1];
unsigned new_flags = reg->flags;
combine_flags(&new_flags, src);
if (valid_flags(instr, n, new_flags)) {
if (new_flags & IR3_REG_ARRAY) {
debug_assert(!(reg->flags & IR3_REG_ARRAY));
reg->array = src_reg->array;
}
reg->flags = new_flags;
reg->instr = ssa(src_reg);
}
src = ssa(reg); /* could be null for IR3_REG_ARRAY case */
if (!src)
return;
} else if (is_same_type_mov(src) &&
/* cannot collapse const/immed/etc into meta instrs: */
!is_meta(instr)) {
/* immed/const/etc cases, which require some special handling: */
struct ir3_register *src_reg = src->regs[1];
unsigned new_flags = reg->flags;
combine_flags(&new_flags, src);
if (!valid_flags(instr, n, new_flags)) {
/* See if lowering an immediate to const would help. */
if (valid_flags(instr, n, (new_flags & ~IR3_REG_IMMED) | IR3_REG_CONST)) {
debug_assert(new_flags & IR3_REG_IMMED);
instr->regs[n + 1] = lower_immed(ctx, src_reg, new_flags);
return;
}
/* special case for "normal" mad instructions, we can
* try swapping the first two args if that fits better.
*
* the "plain" MAD's (ie. the ones that don't shift first
* src prior to multiply) can swap their first two srcs if
* src[0] is !CONST and src[1] is CONST:
*/
if ((n == 1) && is_mad(instr->opc) &&
!(instr->regs[0 + 1]->flags & (IR3_REG_CONST | IR3_REG_RELATIV)) &&
valid_flags(instr, 0, new_flags)) {
/* swap src[0] and src[1]: */
struct ir3_register *tmp;
tmp = instr->regs[0 + 1];
instr->regs[0 + 1] = instr->regs[1 + 1];
instr->regs[1 + 1] = tmp;
n = 0;
} else {
return;
}
}
/* Here we handle the special case of mov from
* CONST and/or RELATIV. These need to be handled
* specially, because in the case of move from CONST
* there is no src ir3_instruction so we need to
* replace the ir3_register. And in the case of
* RELATIV we need to handle the address register
* dependency.
*/
if (src_reg->flags & IR3_REG_CONST) {
/* an instruction cannot reference two different
* address registers:
*/
if ((src_reg->flags & IR3_REG_RELATIV) &&
conflicts(instr->address, reg->instr->address))
return;
/* This seems to be a hw bug, or something where the timings
* just somehow don't work out. This restriction may only
* apply if the first src is also CONST.
*/
if ((opc_cat(instr->opc) == 3) && (n == 2) &&
(src_reg->flags & IR3_REG_RELATIV) &&
(src_reg->array.offset == 0))
return;
src_reg = ir3_reg_clone(instr->block->shader, src_reg);
src_reg->flags = new_flags;
instr->regs[n+1] = src_reg;
if (src_reg->flags & IR3_REG_RELATIV)
ir3_instr_set_address(instr, reg->instr->address);
return;
}
if ((src_reg->flags & IR3_REG_RELATIV) &&
!conflicts(instr->address, reg->instr->address)) {
src_reg = ir3_reg_clone(instr->block->shader, src_reg);
src_reg->flags = new_flags;
instr->regs[n+1] = src_reg;
ir3_instr_set_address(instr, reg->instr->address);
return;
}
/* NOTE: seems we can only do immed integers, so don't
* need to care about float. But we do need to handle
* abs/neg *before* checking that the immediate requires
* few enough bits to encode:
*
* TODO: do we need to do something to avoid accidentally
* catching a float immed?
*/
if (src_reg->flags & IR3_REG_IMMED) {
int32_t iim_val = src_reg->iim_val;
debug_assert((opc_cat(instr->opc) == 1) ||
(opc_cat(instr->opc) == 6) ||
ir3_cat2_int(instr->opc));
if (new_flags & IR3_REG_SABS)
iim_val = abs(iim_val);
if (new_flags & IR3_REG_SNEG)
iim_val = -iim_val;
if (new_flags & IR3_REG_BNOT)
iim_val = ~iim_val;
/* other than category 1 (mov) we can only encode up to 10 bits: */
if ((instr->opc == OPC_MOV) ||
!((iim_val & ~0x3ff) && (-iim_val & ~0x3ff))) {
new_flags &= ~(IR3_REG_SABS | IR3_REG_SNEG | IR3_REG_BNOT);
src_reg = ir3_reg_clone(instr->block->shader, src_reg);
src_reg->flags = new_flags;
src_reg->iim_val = iim_val;
instr->regs[n+1] = src_reg;
} else if (valid_flags(instr, n, (new_flags & ~IR3_REG_IMMED) | IR3_REG_CONST)) {
/* See if lowering an immediate to const would help. */
instr->regs[n+1] = lower_immed(ctx, src_reg, new_flags);
}
return;
}
}
}
