Mesa (master): i965/fs: Add support for specifying register horizontal strides.
Francisco Jerez
currojerez at kemper.freedesktop.org
Wed Feb 12 22:41:26 UTC 2014
Module: Mesa
Branch: master
Commit: 756d37b1d6d09ad7ee3b8835888a49d4256e427b
URL: http://cgit.freedesktop.org/mesa/mesa/commit/?id=756d37b1d6d09ad7ee3b8835888a49d4256e427b
Author: Francisco Jerez <currojerez at riseup.net>
Date: Sun Dec 8 04:57:35 2013 +0100
i965/fs: Add support for specifying register horizontal strides.
v2: Some improvements for copy propagation with non-contiguous
register strides and mismatching types.
v3: Add example of the situation that the copy propagation changes are
intended to avoid. Clarify that 'fs_reg::apply_stride()' is expected
to work with zero strides too.
Reviewed-by: Matt Turner <mattst88 at gmail.com>
Reviewed-by: Paul Berry <stereotype441 at gmail.com>
---
src/mesa/drivers/dri/i965/brw_fs.cpp | 24 +++++++++++--
src/mesa/drivers/dri/i965/brw_fs.h | 5 +++
.../drivers/dri/i965/brw_fs_copy_propagation.cpp | 36 ++++++++++++++++++--
src/mesa/drivers/dri/i965/brw_fs_generator.cpp | 8 +++--
.../drivers/dri/i965/brw_fs_live_variables.cpp | 2 +-
src/mesa/drivers/dri/i965/brw_fs_reg_allocate.cpp | 4 +--
6 files changed, 68 insertions(+), 11 deletions(-)
diff --git a/src/mesa/drivers/dri/i965/brw_fs.cpp b/src/mesa/drivers/dri/i965/brw_fs.cpp
index d82e3ad..b8f7cb4 100644
--- a/src/mesa/drivers/dri/i965/brw_fs.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs.cpp
@@ -381,6 +381,7 @@ fs_reg::init()
{
memset(this, 0, sizeof(*this));
this->smear = -1;
+ stride = 1;
}
/** Generic unset register constructor. */
@@ -440,6 +441,7 @@ fs_reg::equals(const fs_reg &r) const
memcmp(&fixed_hw_reg, &r.fixed_hw_reg,
sizeof(fixed_hw_reg)) == 0 &&
smear == r.smear &&
+ stride == r.stride &&
imm.u == r.imm.u);
}
@@ -451,6 +453,22 @@ fs_reg::retype(uint32_t type)
return result;
}
+fs_reg &
+fs_reg::apply_stride(unsigned stride)
+{
+ assert((this->stride * stride) <= 4 &&
+ (is_power_of_two(stride) || stride == 0) &&
+ file != HW_REG && file != IMM);
+ this->stride *= stride;
+ return *this;
+}
+
+bool
+fs_reg::is_contiguous() const
+{
+ return stride == 1;
+}
+
bool
fs_reg::is_zero() const
{
@@ -708,7 +726,7 @@ fs_inst::is_partial_write()
{
return ((this->predicate && this->opcode != BRW_OPCODE_SEL) ||
this->force_uncompressed ||
- this->force_sechalf);
+ this->force_sechalf || !this->dst.is_contiguous());
}
int
@@ -2317,6 +2335,7 @@ fs_visitor::register_coalesce()
inst->src[0].negate ||
inst->src[0].abs ||
inst->src[0].smear != -1 ||
+ !inst->src[0].is_contiguous() ||
inst->dst.file != GRF ||
inst->dst.type != inst->src[0].type) {
continue;
@@ -2477,7 +2496,8 @@ fs_visitor::compute_to_mrf()
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].subreg_offset)
+ inst->src[0].smear != -1 || !inst->src[0].is_contiguous() ||
+ inst->src[0].subreg_offset)
continue;
/* Work out which hardware MRF registers are written by this
diff --git a/src/mesa/drivers/dri/i965/brw_fs.h b/src/mesa/drivers/dri/i965/brw_fs.h
index 2ec2ee7..84bed9f 100644
--- a/src/mesa/drivers/dri/i965/brw_fs.h
+++ b/src/mesa/drivers/dri/i965/brw_fs.h
@@ -82,7 +82,9 @@ public:
bool is_one() const;
bool is_null() const;
bool is_valid_3src() const;
+ bool is_contiguous() const;
fs_reg retype(uint32_t type);
+ fs_reg &apply_stride(unsigned stride);
/** Register file: GRF, MRF, IMM. */
enum register_file file;
@@ -120,6 +122,9 @@ public:
*/
int subreg_offset;
+ /** Register region horizontal stride */
+ int stride;
+
fs_reg *reladdr;
};
diff --git a/src/mesa/drivers/dri/i965/brw_fs_copy_propagation.cpp b/src/mesa/drivers/dri/i965/brw_fs_copy_propagation.cpp
index 5cf019c..cdb7b80 100644
--- a/src/mesa/drivers/dri/i965/brw_fs_copy_propagation.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs_copy_propagation.cpp
@@ -279,7 +279,9 @@ fs_visitor::try_copy_propagate(fs_inst *inst, int arg, acp_entry *entry)
if (entry->src.file == IMM)
return false;
- if (inst->regs_read(this, arg) > 1)
+ /* Bail if inst is reading more than entry is writing. */
+ if ((inst->regs_read(this, arg) * inst->src[arg].stride *
+ type_sz(inst->src[arg].type)) > type_sz(entry->dst.type))
return false;
if (inst->src[arg].file != entry->dst.file ||
@@ -298,7 +300,32 @@ fs_visitor::try_copy_propagate(fs_inst *inst, int arg, acp_entry *entry)
bool has_source_modifiers = entry->src.abs || entry->src.negate;
if ((has_source_modifiers || entry->src.file == UNIFORM ||
- entry->src.smear != -1) && !can_do_source_mods(inst))
+ entry->src.smear != -1 || !entry->src.is_contiguous()) &&
+ !can_do_source_mods(inst))
+ return false;
+
+ /* Bail if the result of composing both strides would exceed the
+ * hardware limit.
+ */
+ if (entry->src.stride * inst->src[arg].stride > 4)
+ return false;
+
+ /* Bail if the result of composing both strides cannot be expressed
+ * as another stride. This avoids, for example, trying to transform
+ * this:
+ *
+ * MOV (8) rX<1>UD rY<0;1,0>UD
+ * FOO (8) ... rX<8;8,1>UW
+ *
+ * into this:
+ *
+ * FOO (8) ... rY<0;1,0>UW
+ *
+ * Which would have different semantics.
+ */
+ if (entry->src.stride != 1 &&
+ (inst->src[arg].stride *
+ type_sz(inst->src[arg].type)) % type_sz(entry->src.type) != 0)
return false;
if (has_source_modifiers && entry->dst.type != inst->src[arg].type)
@@ -310,6 +337,7 @@ fs_visitor::try_copy_propagate(fs_inst *inst, int arg, acp_entry *entry)
if (entry->src.smear != -1)
inst->src[arg].smear = entry->src.smear;
inst->src[arg].subreg_offset = entry->src.subreg_offset;
+ inst->src[arg].stride *= entry->src.stride;
if (!inst->src[arg].abs) {
inst->src[arg].abs = entry->src.abs;
@@ -332,7 +360,9 @@ fs_visitor::try_constant_propagate(fs_inst *inst, acp_entry *entry)
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].subreg_offset != entry->dst.subreg_offset)
+ inst->src[i].subreg_offset != entry->dst.subreg_offset ||
+ inst->src[i].type != entry->dst.type ||
+ inst->src[i].stride > 1)
continue;
/* Don't bother with cases that should have been taken care of by the
diff --git a/src/mesa/drivers/dri/i965/brw_fs_generator.cpp b/src/mesa/drivers/dri/i965/brw_fs_generator.cpp
index 0d7e8c5..310f993 100644
--- a/src/mesa/drivers/dri/i965/brw_fs_generator.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs_generator.cpp
@@ -1030,11 +1030,13 @@ brw_reg_from_fs_reg(fs_reg *reg)
switch (reg->file) {
case GRF:
case MRF:
- if (reg->smear == -1) {
- brw_reg = brw_vec8_reg(brw_file_from_reg(reg), reg->reg, 0);
+ if (reg->stride == 0 || reg->smear >= 0) {
+ brw_reg = brw_vec1_reg(brw_file_from_reg(reg), reg->reg, reg->smear);
} else {
- brw_reg = brw_vec1_reg(brw_file_from_reg(reg), reg->reg, reg->smear);
+ brw_reg = brw_vec8_reg(brw_file_from_reg(reg), reg->reg, 0);
+ brw_reg = stride(brw_reg, 8 * reg->stride, 8, reg->stride);
}
+
brw_reg = retype(brw_reg, reg->type);
if (reg->sechalf)
brw_reg = sechalf(brw_reg);
diff --git a/src/mesa/drivers/dri/i965/brw_fs_live_variables.cpp b/src/mesa/drivers/dri/i965/brw_fs_live_variables.cpp
index a2d88aa..2aeabad 100644
--- a/src/mesa/drivers/dri/i965/brw_fs_live_variables.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs_live_variables.cpp
@@ -85,7 +85,7 @@ fs_live_variables::setup_one_read(bblock_t *block, fs_inst *inst,
* would get stomped by the first decode as well.
*/
int end_ip = ip;
- if (v->dispatch_width == 16 && (reg.smear != -1 ||
+ if (v->dispatch_width == 16 && (reg.smear != -1 || reg.stride == 0 ||
(v->pixel_x.reg == reg.reg ||
v->pixel_y.reg == reg.reg))) {
end_ip++;
diff --git a/src/mesa/drivers/dri/i965/brw_fs_reg_allocate.cpp b/src/mesa/drivers/dri/i965/brw_fs_reg_allocate.cpp
index fb05aec..fcd66d9 100644
--- a/src/mesa/drivers/dri/i965/brw_fs_reg_allocate.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs_reg_allocate.cpp
@@ -592,7 +592,7 @@ fs_visitor::choose_spill_reg(struct ra_graph *g)
* loading pull constants, so spilling them is unlikely to reduce
* register pressure anyhow.
*/
- if (inst->src[i].smear >= 0) {
+ if (inst->src[i].smear >= 0 || !inst->src[i].is_contiguous()) {
no_spill[inst->src[i].reg] = true;
}
}
@@ -601,7 +601,7 @@ fs_visitor::choose_spill_reg(struct ra_graph *g)
if (inst->dst.file == GRF) {
spill_costs[inst->dst.reg] += inst->regs_written * loop_scale;
- if (inst->dst.smear >= 0) {
+ if (inst->dst.smear >= 0 || !inst->dst.is_contiguous()) {
no_spill[inst->dst.reg] = true;
}
}
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