summaryrefslogtreecommitdiff
path: root/src
diff options
context:
space:
mode:
authorAlejandro Piñeiro <apinheiro@igalia.com>2015-10-14 20:26:43 +0200
committerAlejandro Piñeiro <apinheiro@igalia.com>2015-10-22 21:58:03 +0200
commita59359ecd22154cc2b3f88bb8c599f21af8a3934 (patch)
treed62b6ae7088a1edeca6ec4df924136c200543dc5 /src
parent8ac3b525c77cb5aae9e61bd984b78f6cbbffdc1c (diff)
i965/vec4: track and use independently each flag channel
vec4_live_variables tracks now each flag channel independently, so vec4_dead_code_eliminate can update the writemask of null registers, based on which component are alive at the moment. This would allow vec4_cmod_propagation to optimize out several movs involving null registers. v2: added support to track each flag channel independently at vec4 live_variables, as v1 assumed that it was already doing it, as pointed by Francisco Jerez v3: general cleaningn after Matt Turner's review Reviewed-by: Matt Turner <mattst88@gmail.com>
Diffstat (limited to 'src')
-rw-r--r--src/mesa/drivers/dri/i965/brw_ir_vec4.h21
-rw-r--r--src/mesa/drivers/dri/i965/brw_vec4_dead_code_eliminate.cpp31
-rw-r--r--src/mesa/drivers/dri/i965/brw_vec4_live_variables.cpp14
3 files changed, 52 insertions, 14 deletions
diff --git a/src/mesa/drivers/dri/i965/brw_ir_vec4.h b/src/mesa/drivers/dri/i965/brw_ir_vec4.h
index 1b57b65db27..74e9733bd44 100644
--- a/src/mesa/drivers/dri/i965/brw_ir_vec4.h
+++ b/src/mesa/drivers/dri/i965/brw_ir_vec4.h
@@ -186,6 +186,27 @@ public:
return predicate || opcode == VS_OPCODE_UNPACK_FLAGS_SIMD4X2;
}
+ bool reads_flag(unsigned c)
+ {
+ if (!reads_flag())
+ return false;
+
+ switch (predicate) {
+ case BRW_PREDICATE_NONE:
+ return false;
+ case BRW_PREDICATE_ALIGN16_REPLICATE_X:
+ return c == 0;
+ case BRW_PREDICATE_ALIGN16_REPLICATE_Y:
+ return c == 1;
+ case BRW_PREDICATE_ALIGN16_REPLICATE_Z:
+ return c == 2;
+ case BRW_PREDICATE_ALIGN16_REPLICATE_W:
+ return c == 3;
+ default:
+ return true;
+ }
+ }
+
bool writes_flag()
{
return (conditional_mod && (opcode != BRW_OPCODE_SEL &&
diff --git a/src/mesa/drivers/dri/i965/brw_vec4_dead_code_eliminate.cpp b/src/mesa/drivers/dri/i965/brw_vec4_dead_code_eliminate.cpp
index 8fc7a365bfc..284e0a8d0a5 100644
--- a/src/mesa/drivers/dri/i965/brw_vec4_dead_code_eliminate.cpp
+++ b/src/mesa/drivers/dri/i965/brw_vec4_dead_code_eliminate.cpp
@@ -78,13 +78,19 @@ vec4_visitor::dead_code_eliminate()
sizeof(BITSET_WORD));
foreach_inst_in_block_reverse(vec4_instruction, inst, block) {
- if (inst->dst.file == GRF && !inst->has_side_effects()) {
+ if ((inst->dst.file == GRF && !inst->has_side_effects()) ||
+ (inst->dst.is_null() && inst->writes_flag())){
bool result_live[4] = { false };
- for (unsigned i = 0; i < inst->regs_written; i++) {
- for (int c = 0; c < 4; c++)
- result_live[c] |= BITSET_TEST(
- live, var_from_reg(alloc, offset(inst->dst, i), c));
+ if (inst->dst.file == GRF) {
+ for (unsigned i = 0; i < inst->regs_written; i++) {
+ for (int c = 0; c < 4; c++)
+ result_live[c] |= BITSET_TEST(
+ live, var_from_reg(alloc, offset(inst->dst, i), c));
+ }
+ } else {
+ for (unsigned c = 0; c < 4; c++)
+ result_live[c] = BITSET_TEST(flag_live, c);
}
/* If the instruction can't do writemasking, then it's all or
@@ -117,7 +123,11 @@ vec4_visitor::dead_code_eliminate()
}
if (inst->dst.is_null() && inst->writes_flag()) {
- if (!BITSET_TEST(flag_live, 0)) {
+ bool combined_live = false;
+ for (unsigned c = 0; c < 4; c++)
+ combined_live |= BITSET_TEST(flag_live, c);
+
+ if (!combined_live) {
inst->opcode = BRW_OPCODE_NOP;
progress = true;
continue;
@@ -136,7 +146,8 @@ vec4_visitor::dead_code_eliminate()
}
if (inst->writes_flag()) {
- BITSET_CLEAR(flag_live, 0);
+ for (unsigned c = 0; c < 4; c++)
+ BITSET_CLEAR(flag_live, c);
}
for (int i = 0; i < 3; i++) {
@@ -150,8 +161,10 @@ vec4_visitor::dead_code_eliminate()
}
}
- if (inst->reads_flag()) {
- BITSET_SET(flag_live, 0);
+ for (unsigned c = 0; c < 4; c++) {
+ if (inst->reads_flag(c)) {
+ BITSET_SET(flag_live, c);
+ }
}
}
}
diff --git a/src/mesa/drivers/dri/i965/brw_vec4_live_variables.cpp b/src/mesa/drivers/dri/i965/brw_vec4_live_variables.cpp
index 678237901f2..aa9a6572eee 100644
--- a/src/mesa/drivers/dri/i965/brw_vec4_live_variables.cpp
+++ b/src/mesa/drivers/dri/i965/brw_vec4_live_variables.cpp
@@ -86,9 +86,10 @@ vec4_live_variables::setup_def_use()
}
}
}
- if (inst->reads_flag()) {
- if (!BITSET_TEST(bd->flag_def, 0)) {
- BITSET_SET(bd->flag_use, 0);
+ for (unsigned c = 0; c < 4; c++) {
+ if (inst->reads_flag(c) &&
+ !BITSET_TEST(bd->flag_def, c)) {
+ BITSET_SET(bd->flag_use, c);
}
}
@@ -110,8 +111,11 @@ vec4_live_variables::setup_def_use()
}
}
if (inst->writes_flag()) {
- if (!BITSET_TEST(bd->flag_use, 0)) {
- BITSET_SET(bd->flag_def, 0);
+ for (unsigned c = 0; c < 4; c++) {
+ if ((inst->dst.writemask & (1 << c)) &&
+ !BITSET_TEST(bd->flag_use, c)) {
+ BITSET_SET(bd->flag_def, c);
+ }
}
}