Now that we propagate constants to the first source of 2src instructions we
see more opportunities of constant folding in the backend.
Shader-db results on KBL:
total instructions in shared programs: 14965607 -> 14855983 (-0.73%)
instructions in affected programs: 3988102 -> 3878478 (-2.75%)
helped: 14292
HURT: 59
total cycles in shared programs: 344324295 -> 340656008 (-1.07%)
cycles in affected programs: 247527740 -> 243859453 (-1.48%)
helped: 14056
HURT: 3314
total loops in shared programs: 4283 -> 4283 (0.00%)
loops in affected programs: 0 -> 0
helped: 0
HURT: 0
total spills in shared programs: 27812 -> 24350 (-12.45%)
spills in affected programs: 24921 -> 21459 (-13.89%)
helped: 345
HURT: 19
total fills in shared programs: 24173 -> 22032 (-8.86%)
fills in affected programs: 21124 -> 18983 (-10.14%)
helped: 355
HURT: 25
LOST: 0
GAINED: 5
---
src/intel/compiler/brw_fs.cpp | 203 ++++++++++++++++++++++++++++++++--
1 file changed, 195 insertions(+), 8 deletions(-)
diff --git a/src/intel/compiler/brw_fs.cpp b/src/intel/compiler/brw_fs.cpp
index 2358acbeb59..b2b60237c82 100644
--- a/src/intel/compiler/brw_fs.cpp
+++ b/src/intel/compiler/brw_fs.cpp
@@ -2583,9 +2583,55 @@ fs_visitor::opt_algebraic()
break;
case BRW_OPCODE_MUL:
- if (inst->src[1].file != IMM)
+ if (inst->src[0].file != IMM && inst->src[1].file != IMM)
continue;
+ /* Constant folding */
+ if (inst->src[0].file == IMM && inst->src[1].file == IMM) {
+ assert(inst->src[0].type == inst->src[1].type);
+ bool local_progress = true;
+ switch (inst->src[0].type) {
+ case BRW_REGISTER_TYPE_HF: {
+ float v1 = _mesa_half_to_float(inst->src[0].ud & 0xffffu);
+ float v2 = _mesa_half_to_float(inst->src[1].ud & 0xffffu);
+ inst->src[0] = brw_imm_w(_mesa_float_to_half(v1 * v2));
+ break;
+ }
+ case BRW_REGISTER_TYPE_W: {
+ int16_t v1 = inst->src[0].ud & 0xffffu;
+ int16_t v2 = inst->src[1].ud & 0xffffu;
+ inst->src[0] = brw_imm_w(v1 * v2);
+ break;
+ }
+ case BRW_REGISTER_TYPE_UW: {
+ uint16_t v1 = inst->src[0].ud & 0xffffu;
+ uint16_t v2 = inst->src[1].ud & 0xffffu;
+ inst->src[0] = brw_imm_uw(v1 * v2);
+ break;
+ }
+ case BRW_REGISTER_TYPE_F:
+ inst->src[0].f *= inst->src[1].f;
+ break;
+ case BRW_REGISTER_TYPE_D:
+ inst->src[0].d *= inst->src[1].d;
+ break;
+ case BRW_REGISTER_TYPE_UD:
+ inst->src[0].ud *= inst->src[1].ud;
+ break;
+ default:
+ local_progress = false;
+ break;
+ };
+
+ if (local_progress) {
+ inst->opcode = BRW_OPCODE_MOV;
+ inst->src[1] = reg_undef;
+ progress = true;
+ break;
+ }
+ }
+
+
/* a * 1.0 = a */
if (inst->src[1].is_one()) {
inst->opcode = BRW_OPCODE_MOV;
@@ -2594,6 +2640,14 @@ fs_visitor::opt_algebraic()
break;
}
+ if (inst->src[0].is_one()) {
+ inst->opcode = BRW_OPCODE_MOV;
+ inst->src[0] = inst->src[1];
+ inst->src[1] = reg_undef;
+ progress = true;
+ break;
+ }
+
/* a * -1.0 = -a */
if (inst->src[1].is_negative_one()) {
inst->opcode = BRW_OPCODE_MOV;
@@ -2603,27 +2657,160 @@ fs_visitor::opt_algebraic()
break;
}
- if (inst->src[0].file == IMM) {
- assert(inst->src[0].type == BRW_REGISTER_TYPE_F);
+ if (inst->src[0].is_negative_one()) {
+ inst->opcode = BRW_OPCODE_MOV;
+ inst->src[0] = inst->src[1];
+ inst->src[0].negate = !inst->src[1].negate;
+ inst->src[1] = reg_undef;
+ progress = true;
+ break;
+ }
+
+ /* a * 0 = 0 (this is not exact for floating point) */
+ if (inst->src[1].is_zero() &&
+ brw_reg_type_is_integer(inst->src[1].type)) {
+ inst->opcode = BRW_OPCODE_MOV;
+ inst->src[0] = inst->src[1];
+ inst->src[1] = reg_undef;
+ progress = true;
+ break;
+ }
+
+ if (inst->src[0].is_zero() &&
+ brw_reg_type_is_integer(inst->src[0].type)) {
inst->opcode = BRW_OPCODE_MOV;
- inst->src[0].f *= inst->src[1].f;
inst->src[1] = reg_undef;
progress = true;
break;
}
break;
case BRW_OPCODE_ADD:
- if (inst->src[1].file != IMM)
+ if (inst->src[0].file != IMM && inst->src[1].file != IMM)
continue;
- if (inst->src[0].file == IMM) {
- assert(inst->src[0].type == BRW_REGISTER_TYPE_F);
+ /* Constant folding */
+ if (inst->src[0].file == IMM && inst->src[1].file == IMM) {
+ assert(inst->src[0].type == inst->src[1].type);
+ bool local_progress = true;
+ switch (inst->src[0].type) {
+ case BRW_REGISTER_TYPE_HF: {
+ float v1 = _mesa_half_to_float(inst->src[0].ud & 0xffffu);
+ float v2 = _mesa_half_to_float(inst->src[1].ud & 0xffffu);
+ inst->src[0] = brw_imm_w(_mesa_float_to_half(v1 + v2));
+ break;
+ }
+ case BRW_REGISTER_TYPE_W: {
+ int16_t v1 = inst->src[0].ud & 0xffffu;
+ int16_t v2 = inst->src[1].ud & 0xffffu;
+ inst->src[0] = brw_imm_w(v1 + v2);
+ break;
+ }
+ case BRW_REGISTER_TYPE_UW: {
+ uint16_t v1 = inst->src[0].ud & 0xffffu;
+ uint16_t v2 = inst->src[1].ud & 0xffffu;
+ inst->src[0] = brw_imm_uw(v1 + v2);
+ break;
+ }
+ case BRW_REGISTER_TYPE_F:
+ inst->src[0].f += inst->src[1].f;
+ break;
+ case BRW_REGISTER_TYPE_D:
+ inst->src[0].d += inst->src[1].d;
+ break;
+ case BRW_REGISTER_TYPE_UD:
+ inst->src[0].ud += inst->src[1].ud;
+ break;
+ default:
+ local_progress = false;
+ break;
+ };
+
+ if (local_progress) {
+ inst->opcode = BRW_OPCODE_MOV;
+ inst->src[1] = reg_undef;
+ progress = true;
+ break;
+ }
+ }
+
+ /* a + 0 = a (this is not exact for floating point) */
+ if (inst->src[1].is_zero() &&
+ brw_reg_type_is_integer(inst->src[1].type)) {
inst->opcode = BRW_OPCODE_MOV;
- inst->src[0].f += inst->src[1].f;
inst->src[1] = reg_undef;
progress = true;
break;
}
+
+ if (inst->src[0].is_zero() &&
+ brw_reg_type_is_integer(inst->src[0].type)) {
+ inst->opcode = BRW_OPCODE_MOV;
+ inst->src[0] = inst->src[1];
+ inst->src[1] = reg_undef;
+ progress = true;
+ break;
+ }
+ break;
+ case BRW_OPCODE_SHL:
+ if (inst->src[0].file == IMM && inst->src[1].file == IMM) {
+ bool local_progress = true;
+ switch (inst->src[0].type) {
+ case BRW_REGISTER_TYPE_D:
+ case BRW_REGISTER_TYPE_UD:
+ inst->src[0].ud <<= inst->src[1].ud;
+ break;
+ case BRW_REGISTER_TYPE_W:
+ case BRW_REGISTER_TYPE_UW: {
+ uint16_t v1 = inst->src[0].ud & 0xffffu;
+ uint16_t v2 = inst->src[1].ud & 0xffffu;
+ inst->src[0] = retype(brw_imm_uw(v1 << v2), inst->src[0].type);
+ break;
+ }
+ default:
+ local_progress = false;
+ break;
+ }
+ if (local_progress) {
+ inst->opcode = BRW_OPCODE_MOV;
+ inst->src[1] = reg_undef;
+ progress = true;
+ break;
+ }
+ }
+ break;
+ case BRW_OPCODE_SHR:
+ if (inst->src[0].file == IMM && inst->src[1].file == IMM) {
+ bool local_progress = true;
+ switch (inst->src[0].type) {
+ case BRW_REGISTER_TYPE_D:
+ inst->src[0].d >>= inst->src[1].ud;
+ break;
+ case BRW_REGISTER_TYPE_UD:
+ inst->src[0].ud >>= inst->src[1].ud;
+ break;
+ case BRW_REGISTER_TYPE_W: {
+ int16_t v1 = inst->src[0].ud & 0xffffu;
+ uint16_t v2 = inst->src[1].ud & 0xffffu;
+ inst->src[0] = brw_imm_w(v1 >> v2);
+ break;
+ }
+ case BRW_REGISTER_TYPE_UW: {
+ uint16_t v1 = inst->src[0].ud & 0xffffu;
+ uint16_t v2 = inst->src[1].ud & 0xffffu;
+ inst->src[0] = brw_imm_uw(v1 >> v2);
+ break;
+ }
+ default:
+ local_progress = false;
+ break;
+ }
+ if (local_progress) {
+ inst->opcode = BRW_OPCODE_MOV;
+ inst->src[1] = reg_undef;
+ progress = true;
+ break;
+ }
+ }
break;
case BRW_OPCODE_OR:
if (inst->src[0].equals(inst->src[1]) ||
--
2.17.1
_______________________________________________
mesa-dev mailing list
mesa-dev@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/mesa-dev
