Commit f25aefce authored by Eric Anholt's avatar Eric Anholt

i965: Support instruction compaction between control flow.

Reviewed-by: Paul Berry's avatarPaul Berry <stereotype441@gmail.com>
parent 077d01b6
......@@ -299,6 +299,18 @@ brw_try_compact_instruction(struct brw_compile *p,
{
struct brw_compact_instruction temp;
if (src->header.opcode == BRW_OPCODE_IF ||
src->header.opcode == BRW_OPCODE_ELSE ||
src->header.opcode == BRW_OPCODE_ENDIF ||
src->header.opcode == BRW_OPCODE_HALT ||
src->header.opcode == BRW_OPCODE_DO ||
src->header.opcode == BRW_OPCODE_WHILE) {
/* FINISHME: The fixup code below, and brw_set_uip_jip and friends, needs
* to be able to handle compacted flow control instructions..
*/
return false;
}
/* FINISHME: immediates */
if (src->bits1.da1.src0_reg_file == BRW_IMMEDIATE_VALUE ||
src->bits1.da1.src1_reg_file == BRW_IMMEDIATE_VALUE)
......@@ -434,12 +446,45 @@ void brw_debug_compact_uncompact(struct intel_context *intel,
}
}
static int
compacted_between(int old_ip, int old_target_ip, int *compacted_counts)
{
int this_compacted_count = compacted_counts[old_ip];
int target_compacted_count = compacted_counts[old_target_ip];
return target_compacted_count - this_compacted_count;
}
static void
update_uip_jip(struct brw_instruction *insn, int this_old_ip,
int *compacted_counts)
{
int target_old_ip;
target_old_ip = this_old_ip + insn->bits3.break_cont.jip;
insn->bits3.break_cont.jip -= compacted_between(this_old_ip,
target_old_ip,
compacted_counts);
target_old_ip = this_old_ip + insn->bits3.break_cont.uip;
insn->bits3.break_cont.uip -= compacted_between(this_old_ip,
target_old_ip,
compacted_counts);
}
void
brw_compact_instructions(struct brw_compile *p)
{
struct brw_context *brw = p->brw;
struct intel_context *intel = &brw->intel;
void *store = p->store;
/* For an instruction at byte offset 8*i before compaction, this is the number
* of compacted instructions that preceded it.
*/
int compacted_counts[p->next_insn_offset / 8];
/* For an instruction at byte offset 8*i after compaction, this is the
* 8-byte offset it was at before compaction.
*/
int old_ip[p->next_insn_offset / 8];
assert(gen6_control_index_table[ARRAY_SIZE(gen6_control_index_table) - 1] != 0);
assert(gen6_datatype_table[ARRAY_SIZE(gen6_datatype_table) - 1] != 0);
......@@ -449,40 +494,22 @@ brw_compact_instructions(struct brw_compile *p)
if (intel->gen != 6)
return;
/* FINISHME: If we are going to compress instructions between flow control,
* we have to do fixups to flow control offsets to represent the new
* distances, since flow control uses (virtual address distance)/2, not a
* logical instruction count. We can at least compress up until an IF
* instruction, but there's no instruction indicating the start of a
* do/while loop.
*/
bool continue_compressing = true;
for (int i = 0; i < p->nr_insn; i++) {
if (p->store[i].header.opcode == BRW_OPCODE_WHILE)
return;
}
int src_offset;
int offset = 0;
int compacted_count = 0;
for (src_offset = 0; src_offset < p->nr_insn * 16;) {
struct brw_instruction *src = store + src_offset;
void *dst = store + offset;
switch (src->header.opcode) {
case BRW_OPCODE_IF:
case BRW_OPCODE_HALT:
case BRW_OPCODE_JMPI:
continue_compressing = false;
break;
}
old_ip[offset / 8] = src_offset / 8;
compacted_counts[src_offset / 8] = compacted_count;
struct brw_instruction saved = *src;
if (continue_compressing &&
!src->header.cmpt_control &&
if (!src->header.cmpt_control &&
brw_try_compact_instruction(p, dst, src)) {
compacted_count++;
/* debug */
if (INTEL_DEBUG) {
struct brw_instruction uncompacted;
brw_uncompact_instruction(intel, &uncompacted, dst);
......@@ -508,10 +535,11 @@ brw_compact_instructions(struct brw_compile *p)
align->dw0.opcode = BRW_OPCODE_NOP;
align->dw0.cmpt_ctrl = 1;
offset += 8;
old_ip[offset / 8] = src_offset / 8;
dst = store + offset;
}
/* If we didn't compact this instruction, we need to move it down into
/* If we didn't compact this intruction, we need to move it down into
* place.
*/
if (offset != src_offset) {
......@@ -522,20 +550,56 @@ brw_compact_instructions(struct brw_compile *p)
}
}
/* Fix up control flow offsets. */
p->next_insn_offset = offset;
for (offset = 0; offset < p->next_insn_offset;) {
struct brw_instruction *insn = store + offset;
int this_old_ip = old_ip[offset / 8];
int this_compacted_count = compacted_counts[this_old_ip];
int target_old_ip, target_compacted_count;
switch (insn->header.opcode) {
case BRW_OPCODE_BREAK:
case BRW_OPCODE_CONTINUE:
case BRW_OPCODE_HALT:
update_uip_jip(insn, this_old_ip, compacted_counts);
break;
case BRW_OPCODE_IF:
case BRW_OPCODE_ELSE:
case BRW_OPCODE_ENDIF:
case BRW_OPCODE_WHILE:
if (intel->gen == 6) {
target_old_ip = this_old_ip + insn->bits1.branch_gen6.jump_count;
target_compacted_count = compacted_counts[target_old_ip];
insn->bits1.branch_gen6.jump_count -= (target_compacted_count -
this_compacted_count);
} else {
update_uip_jip(insn, this_old_ip, compacted_counts);
}
break;
}
if (insn->header.cmpt_control) {
offset += 8;
} else {
offset += 16;
}
}
/* p->nr_insn is counting the number of uncompacted instructions still, so
* divide. We do want to be sure there's a valid instruction in any
* alignment padding, so that the next compression pass (for the FS 8/16
* compile passes) parses correctly.
*/
if (offset & 8) {
if (p->next_insn_offset & 8) {
struct brw_compact_instruction *align = store + offset;
memset(align, 0, sizeof(*align));
align->dw0.opcode = BRW_OPCODE_NOP;
align->dw0.cmpt_ctrl = 1;
offset += 8;
p->next_insn_offset += 8;
}
p->next_insn_offset = offset;
p->nr_insn = offset / 16;
p->nr_insn = p->next_insn_offset / 16;
if (0) {
fprintf(stdout, "dumping compacted program\n");
......
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