[Mesa-dev] [PATCH 08/10] i965/fs: Allow immediates in MAD and LRP instructions.
Matt Turner
mattst88 at gmail.com
Wed Feb 4 20:21:25 PST 2015
And then the opt_combine_constants() pass will pull them out into
registers. This will allow us to do some algebraic optimizations on MAD
and LRP.
total instructions in shared programs: 5946656 -> 5931320 (-0.26%)
instructions in affected programs: 778247 -> 762911 (-1.97%)
helped: 3780
HURT: 6
GAINED: 12
LOST: 12
---
.../drivers/dri/i965/brw_fs_combine_constants.cpp | 22 +++++++++++++++++++---
.../drivers/dri/i965/brw_fs_copy_propagation.cpp | 6 ++++++
2 files changed, 25 insertions(+), 3 deletions(-)
diff --git a/src/mesa/drivers/dri/i965/brw_fs_combine_constants.cpp b/src/mesa/drivers/dri/i965/brw_fs_combine_constants.cpp
index ad4a965..e9341b7 100644
--- a/src/mesa/drivers/dri/i965/brw_fs_combine_constants.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs_combine_constants.cpp
@@ -60,6 +60,18 @@ could_coissue(const fs_inst *inst)
}
}
+static bool
+must_promote_imm(const fs_inst *inst)
+{
+ switch (inst->opcode) {
+ case BRW_OPCODE_MAD:
+ case BRW_OPCODE_LRP:
+ return true;
+ default:
+ return false;
+ }
+}
+
struct reg_link {
DECLARE_RALLOC_CXX_OPERATORS(reg_link)
@@ -86,6 +98,7 @@ struct imm {
uint16_t reg;
uint16_t uses_by_coissue;
+ bool must_promote;
bool inserted;
@@ -153,12 +166,13 @@ fs_visitor::opt_combine_constants()
unsigned ip = -1;
/* Make a pass through all instructions and count the number of times each
- * constant is used by coissueable instructions.
+ * constant is used by coissueable instructions or instructions that cannot
+ * take immediate arguments.
*/
foreach_block_and_inst(block, fs_inst, inst, cfg) {
ip++;
- if (!could_coissue(inst))
+ if (!could_coissue(inst) && !must_promote_imm(inst))
continue;
for (int i = 0; i < inst->sources; i++) {
@@ -175,6 +189,7 @@ fs_visitor::opt_combine_constants()
imm->block = intersection;
imm->uses->push_tail(link(const_ctx, &inst->src[i]));
imm->uses_by_coissue += could_coissue(inst);
+ imm->must_promote = imm->must_promote || must_promote_imm(inst);
imm->last_use_ip = ip;
} else {
imm = new_imm(&table, const_ctx);
@@ -184,6 +199,7 @@ fs_visitor::opt_combine_constants()
imm->uses->push_tail(link(const_ctx, &inst->src[i]));
imm->val = val;
imm->uses_by_coissue = could_coissue(inst);
+ imm->must_promote = must_promote_imm(inst);
imm->inserted = false;
imm->first_use_ip = ip;
imm->last_use_ip = ip;
@@ -197,7 +213,7 @@ fs_visitor::opt_combine_constants()
for (int i = 0; i < table.len;) {
struct imm *imm = &table.imm[i];
- if (imm->uses_by_coissue < 4) {
+ if (!imm->must_promote && imm->uses_by_coissue < 4) {
table.imm[i] = table.imm[table.len - 1];
table.len--;
continue;
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 68a266c..1b47851 100644
--- a/src/mesa/drivers/dri/i965/brw_fs_copy_propagation.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs_copy_propagation.cpp
@@ -574,6 +574,12 @@ fs_visitor::try_constant_propagate(fs_inst *inst, acp_entry *entry)
progress = true;
break;
+ case BRW_OPCODE_MAD:
+ case BRW_OPCODE_LRP:
+ inst->src[i] = val;
+ progress = true;
+ break;
+
default:
break;
}
--
2.0.4
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