Module: Mesa
Branch: master
Commit: 77f269bb56037ddd723882a7ae551ef302881dff
URL:
http://cgit.freedesktop.org/mesa/mesa/commit/?id=77f269bb56037ddd723882a7ae551ef302881dff
Author: Ian Romanick <ian.d.roman...@intel.com>
Date: Wed Jun 13 10:04:55 2018 -0700
i965/fs: Refactor propagation of conditional modifiers from compares to adds
Signed-off-by: Ian Romanick <ian.d.roman...@intel.com>
---
src/intel/compiler/brw_fs_cmod_propagation.cpp | 137 +++++++++++++++----------
1 file changed, 80 insertions(+), 57 deletions(-)
diff --git a/src/intel/compiler/brw_fs_cmod_propagation.cpp
b/src/intel/compiler/brw_fs_cmod_propagation.cpp
index 462e51d504..2587d62a95 100644
--- a/src/intel/compiler/brw_fs_cmod_propagation.cpp
+++ b/src/intel/compiler/brw_fs_cmod_propagation.cpp
@@ -49,6 +49,77 @@
*/
static bool
+cmod_propagate_cmp_to_add(const gen_device_info *devinfo, bblock_t *block,
+ fs_inst *inst)
+{
+ bool read_flag = false;
+
+ foreach_inst_in_block_reverse_starting_from(fs_inst, scan_inst, inst) {
+ /* The extra scope is to prevent compiler errors for gotos crossing a
+ * variable initializer (cond, below).
+ */
+ {
+ bool negate;
+
+ if (scan_inst->opcode != BRW_OPCODE_ADD)
+ goto not_match;
+
+ /* A CMP is basically a subtraction. The result of the
+ * subtraction must be the same as the result of the addition.
+ * This means that one of the operands must be negated. So (a +
+ * b) vs (a == -b) or (a + -b) vs (a == b).
+ */
+ if ((inst->src[0].equals(scan_inst->src[0]) &&
+ inst->src[1].negative_equals(scan_inst->src[1])) ||
+ (inst->src[0].equals(scan_inst->src[1]) &&
+ inst->src[1].negative_equals(scan_inst->src[0]))) {
+ negate = false;
+ } else if ((inst->src[0].negative_equals(scan_inst->src[0]) &&
+ inst->src[1].equals(scan_inst->src[1])) ||
+ (inst->src[0].negative_equals(scan_inst->src[1]) &&
+ inst->src[1].equals(scan_inst->src[0]))) {
+ negate = true;
+ } else {
+ goto not_match;
+ }
+
+ if (scan_inst->is_partial_write() ||
+ scan_inst->exec_size != inst->exec_size)
+ goto not_match;
+
+ /* From the Sky Lake PRM Vol. 7 "Assigning Conditional Mods":
+ *
+ * * Note that the [post condition signal] bits generated at
+ * the output of a compute are before the .sat.
+ *
+ * So we don't have to bail if scan_inst has saturate.
+ */
+ /* Otherwise, try propagating the conditional. */
+ const enum brw_conditional_mod cond =
+ negate ? brw_swap_cmod(inst->conditional_mod)
+ : inst->conditional_mod;
+
+ if (scan_inst->can_do_cmod() &&
+ ((!read_flag && scan_inst->conditional_mod ==
BRW_CONDITIONAL_NONE) ||
+ scan_inst->conditional_mod == cond)) {
+ scan_inst->conditional_mod = cond;
+ inst->remove(block);
+ return true;
+ }
+ break;
+ }
+
+ not_match:
+ if (scan_inst->flags_written())
+ break;
+
+ read_flag = read_flag || scan_inst->flags_read(devinfo);
+ }
+
+ return false;
+}
+
+static bool
opt_cmod_propagation_local(const gen_device_info *devinfo, bblock_t *block)
{
bool progress = false;
@@ -90,64 +161,17 @@ opt_cmod_propagation_local(const gen_device_info *devinfo,
bblock_t *block)
inst->conditional_mod != BRW_CONDITIONAL_NZ)
continue;
+ /* A CMP with a second source of zero can match with anything. A CMP
+ * with a second source that is not zero can only match with an ADD
+ * instruction.
+ */
+ if (inst->opcode == BRW_OPCODE_CMP && !inst->src[1].is_zero()) {
+ progress = cmod_propagate_cmp_to_add(devinfo, block, inst) ||
progress;
+ continue;
+ }
+
bool read_flag = false;
foreach_inst_in_block_reverse_starting_from(fs_inst, scan_inst, inst) {
- /* A CMP with a second source of zero can match with anything. A CMP
- * with a second source that is not zero can only match with an ADD
- * instruction.
- */
- if (inst->opcode == BRW_OPCODE_CMP && !inst->src[1].is_zero()) {
- bool negate;
-
- if (scan_inst->opcode != BRW_OPCODE_ADD)
- goto not_match;
-
- /* A CMP is basically a subtraction. The result of the
- * subtraction must be the same as the result of the addition.
- * This means that one of the operands must be negated. So (a +
- * b) vs (a == -b) or (a + -b) vs (a == b).
- */
- if ((inst->src[0].equals(scan_inst->src[0]) &&
- inst->src[1].negative_equals(scan_inst->src[1])) ||
- (inst->src[0].equals(scan_inst->src[1]) &&
- inst->src[1].negative_equals(scan_inst->src[0]))) {
- negate = false;
- } else if ((inst->src[0].negative_equals(scan_inst->src[0]) &&
- inst->src[1].equals(scan_inst->src[1])) ||
- (inst->src[0].negative_equals(scan_inst->src[1]) &&
- inst->src[1].equals(scan_inst->src[0]))) {
- negate = true;
- } else {
- goto not_match;
- }
-
- if (scan_inst->is_partial_write() ||
- scan_inst->exec_size != inst->exec_size)
- goto not_match;
-
- /* From the Sky Lake PRM Vol. 7 "Assigning Conditional Mods":
- *
- * * Note that the [post condition signal] bits generated at
- * the output of a compute are before the .sat.
- *
- * So we don't have to bail if scan_inst has saturate.
- */
-
- /* Otherwise, try propagating the conditional. */
- const enum brw_conditional_mod cond =
- negate ? brw_swap_cmod(inst->conditional_mod)
- : inst->conditional_mod;
-
- if (scan_inst->can_do_cmod() &&
- ((!read_flag && scan_inst->conditional_mod ==
BRW_CONDITIONAL_NONE) ||
- scan_inst->conditional_mod == cond)) {
- scan_inst->conditional_mod = cond;
- inst->remove(block);
- progress = true;
- }
- break;
- }
-
if (regions_overlap(scan_inst->dst, scan_inst->size_written,
inst->src[0], inst->size_read(0))) {
if (scan_inst->is_partial_write() ||
@@ -242,7 +266,6 @@ opt_cmod_propagation_local(const gen_device_info *devinfo,
bblock_t *block)
break;
}
- not_match:
if (scan_inst->flags_written())
break;
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