i965/fs: Add support for sub-register byte offsets to the FS back-end IR.

It would be nice if we could have a single 'reg_offset' field
expressed in bytes that would serve the purpose of both, but the
semantics of 'reg_offset' are quite complex currently (it's measured
in units of one, eight or sixteen dwords depending on the register
file and the dispatch width) and changing it to bytes would be a very
intrusive change at this stage.  Add a separate 'subreg_offset' field
for now.

Reviewed-by: Matt Turner <mattst88@gmail.com>
Reviewed-by: Paul Berry <stereotype441@gmail.com>
This commit is contained in:
Francisco Jerez 2013-12-08 04:57:08 +01:00
parent 248606a5f0
commit 4c7206bafd
5 changed files with 46 additions and 21 deletions

View file

@ -432,6 +432,7 @@ fs_reg::equals(const fs_reg &r) const
return (file == r.file &&
reg == r.reg &&
reg_offset == r.reg_offset &&
subreg_offset == r.subreg_offset &&
type == r.type &&
negate == r.negate &&
abs == r.abs &&
@ -1407,7 +1408,9 @@ fs_visitor::assign_curb_setup()
constant_nr % 8);
inst->src[i].file = HW_REG;
inst->src[i].fixed_hw_reg = retype(brw_reg, inst->src[i].type);
inst->src[i].fixed_hw_reg = byte_offset(
retype(brw_reg, inst->src[i].type),
inst->src[i].subreg_offset);
}
}
}
@ -2473,7 +2476,8 @@ fs_visitor::compute_to_mrf()
inst->is_partial_write() ||
inst->dst.file != MRF || inst->src[0].file != GRF ||
inst->dst.type != inst->src[0].type ||
inst->src[0].abs || inst->src[0].negate || inst->src[0].smear != -1)
inst->src[0].abs || inst->src[0].negate ||
inst->src[0].smear != -1 || inst->src[0].subreg_offset)
continue;
/* Work out which hardware MRF registers are written by this
@ -3008,8 +3012,9 @@ fs_visitor::dump_instruction(backend_instruction *be_inst)
switch (inst->dst.file) {
case GRF:
printf("vgrf%d", inst->dst.reg);
if (virtual_grf_sizes[inst->dst.reg] != 1)
printf("+%d", inst->dst.reg_offset);
if (virtual_grf_sizes[inst->dst.reg] != 1 ||
inst->dst.subreg_offset)
printf("+%d.%d", inst->dst.reg_offset, inst->dst.subreg_offset);
break;
case MRF:
printf("m%d", inst->dst.reg);
@ -3061,16 +3066,20 @@ fs_visitor::dump_instruction(backend_instruction *be_inst)
switch (inst->src[i].file) {
case GRF:
printf("vgrf%d", inst->src[i].reg);
if (virtual_grf_sizes[inst->src[i].reg] != 1)
printf("+%d", inst->src[i].reg_offset);
if (virtual_grf_sizes[inst->src[i].reg] != 1 ||
inst->src[i].subreg_offset)
printf("+%d.%d", inst->src[i].reg_offset,
inst->src[i].subreg_offset);
break;
case MRF:
printf("***m%d***", inst->src[i].reg);
break;
case UNIFORM:
printf("u%d", inst->src[i].reg);
if (virtual_grf_sizes[inst->src[i].reg] != 1)
printf(".%d", inst->src[i].reg_offset);
if (virtual_grf_sizes[inst->src[i].reg] != 1 ||
inst->src[i].subreg_offset)
printf("+%d.%d", inst->src[i].reg_offset,
inst->src[i].subreg_offset);
break;
case BAD_FILE:
printf("(null)");

View file

@ -114,9 +114,23 @@ public:
float f;
} imm;
/**
* Offset in bytes from the start of the register. Values up to a
* backend_reg::reg_offset unit are valid.
*/
int subreg_offset;
fs_reg *reladdr;
};
static inline fs_reg
byte_offset(fs_reg reg, unsigned delta)
{
assert(delta == 0 || (reg.file != HW_REG && reg.file != IMM));
reg.subreg_offset += delta;
return reg;
}
static const fs_reg reg_undef;
static const fs_reg reg_null_f(retype(brw_null_reg(), BRW_REGISTER_TYPE_F));
static const fs_reg reg_null_d(retype(brw_null_reg(), BRW_REGISTER_TYPE_D));

View file

@ -284,7 +284,8 @@ fs_visitor::try_copy_propagate(fs_inst *inst, int arg, acp_entry *entry)
if (inst->src[arg].file != entry->dst.file ||
inst->src[arg].reg != entry->dst.reg ||
inst->src[arg].reg_offset != entry->dst.reg_offset) {
inst->src[arg].reg_offset != entry->dst.reg_offset ||
inst->src[arg].subreg_offset != entry->dst.subreg_offset) {
return false;
}
@ -308,6 +309,7 @@ fs_visitor::try_copy_propagate(fs_inst *inst, int arg, acp_entry *entry)
inst->src[arg].reg_offset = entry->src.reg_offset;
if (entry->src.smear != -1)
inst->src[arg].smear = entry->src.smear;
inst->src[arg].subreg_offset = entry->src.subreg_offset;
if (!inst->src[arg].abs) {
inst->src[arg].abs = entry->src.abs;
@ -329,7 +331,8 @@ fs_visitor::try_constant_propagate(fs_inst *inst, acp_entry *entry)
for (int i = 2; i >= 0; i--) {
if (inst->src[i].file != entry->dst.file ||
inst->src[i].reg != entry->dst.reg ||
inst->src[i].reg_offset != entry->dst.reg_offset)
inst->src[i].reg_offset != entry->dst.reg_offset ||
inst->src[i].subreg_offset != entry->dst.subreg_offset)
continue;
/* Don't bother with cases that should have been taken care of by the

View file

@ -1038,6 +1038,7 @@ brw_reg_from_fs_reg(fs_reg *reg)
brw_reg = retype(brw_reg, reg->type);
if (reg->sechalf)
brw_reg = sechalf(brw_reg);
brw_reg = byte_offset(brw_reg, reg->subreg_offset);
break;
case IMM:
switch (reg->type) {

View file

@ -686,11 +686,12 @@ fs_visitor::spill_reg(int spill_reg)
int regs_read = inst->regs_read(this, i);
int subset_spill_offset = (spill_offset +
reg_size * inst->src[i].reg_offset);
fs_reg unspill_dst(GRF, virtual_grf_alloc(regs_read));
inst->src[i].reg = virtual_grf_alloc(regs_read);
inst->src[i].reg = unspill_dst.reg;
inst->src[i].reg_offset = 0;
emit_unspill(inst, inst->src[i], subset_spill_offset, regs_read);
emit_unspill(inst, unspill_dst, subset_spill_offset, regs_read);
}
}
@ -698,24 +699,21 @@ fs_visitor::spill_reg(int spill_reg)
inst->dst.reg == spill_reg) {
int subset_spill_offset = (spill_offset +
reg_size * inst->dst.reg_offset);
inst->dst.reg = virtual_grf_alloc(inst->regs_written);
fs_reg spill_src(GRF, virtual_grf_alloc(inst->regs_written));
inst->dst.reg = spill_src.reg;
inst->dst.reg_offset = 0;
/* If our write is going to affect just part of the
* inst->regs_written(), then we need to unspill the destination
* since we write back out all of the regs_written().
*/
if (inst->predicate || inst->force_uncompressed || inst->force_sechalf) {
emit_unspill(inst, inst->dst, subset_spill_offset,
if (inst->predicate || inst->force_uncompressed ||
inst->force_sechalf || inst->dst.subreg_offset) {
emit_unspill(inst, spill_src, subset_spill_offset,
inst->regs_written);
}
fs_reg spill_src = inst->dst;
spill_src.reg_offset = 0;
spill_src.abs = false;
spill_src.negate = false;
spill_src.smear = -1;
for (int chan = 0; chan < inst->regs_written; chan++) {
fs_inst *spill_inst =
new(mem_ctx) fs_inst(SHADER_OPCODE_GEN4_SCRATCH_WRITE,