diff options
| -rw-r--r-- | src/mesa/program/ir_to_mesa.cpp | 129 |
1 files changed, 129 insertions, 0 deletions
diff --git a/src/mesa/program/ir_to_mesa.cpp b/src/mesa/program/ir_to_mesa.cpp index c601ef6eaaa..0d40b093e4f 100644 --- a/src/mesa/program/ir_to_mesa.cpp +++ b/src/mesa/program/ir_to_mesa.cpp @@ -295,6 +295,8 @@ public: bool process_move_condition(ir_rvalue *ir); + void copy_propagate(void); + void *mem_ctx; }; @@ -2616,6 +2618,131 @@ set_uniform_initializers(struct gl_context *ctx, talloc_free(mem_ctx); } +/* + * On a basic block basis, tracks available PROGRAM_TEMPORARY register + * channels for copy propagation and updates following instructions to + * use the original versions. + * + * The ir_to_mesa_visitor lazily produces code assuming that this pass + * will occur. As an example, a TXP production before this pass: + * + * 0: MOV TEMP[1], INPUT[4].xyyy; + * 1: MOV TEMP[1].w, INPUT[4].wwww; + * 2: TXP TEMP[2], TEMP[1], texture[0], 2D; + * + * and after: + * + * 0: MOV TEMP[1], INPUT[4].xyyy; + * 1: MOV TEMP[1].w, INPUT[4].wwww; + * 2: TXP TEMP[2], INPUT[4].xyyw, texture[0], 2D; + * + * which allows for dead code elimination on TEMP[1]'s writes. + */ +void +ir_to_mesa_visitor::copy_propagate(void) +{ + ir_to_mesa_instruction *acp[this->next_temp * 4]; + + memset(&acp, 0, sizeof(acp)); + + foreach_iter(exec_list_iterator, iter, this->instructions) { + ir_to_mesa_instruction *inst = (ir_to_mesa_instruction *)iter.get(); + + /* First, do any copy propagation possible into the src regs. */ + for (int r = 0; r < 3; r++) { + ir_to_mesa_instruction *first = NULL; + bool good = true; + int acp_base = inst->src_reg[r].index * 4; + + if (inst->src_reg[r].file != PROGRAM_TEMPORARY || + inst->src_reg[r].reladdr) + continue; + + /* See if we can find entries in the ACP consisting of MOVs + * from the same src register for all the swizzled channels + * of this src register reference. + */ + for (int i = 0; i < 4; i++) { + int src_chan = GET_SWZ(inst->src_reg[r].swizzle, i); + ir_to_mesa_instruction *copy_chan = acp[acp_base + src_chan]; + + if (!copy_chan) { + good = false; + break; + } + + if (!first) { + first = copy_chan; + } else { + if (first->src_reg[0].file != copy_chan->src_reg[0].file || + first->src_reg[0].index != copy_chan->src_reg[0].index) { + good = false; + break; + } + } + } + + if (good) { + /* We've now validated that we can copy-propagate to + * replace this src register reference. Do it. + */ + inst->src_reg[r].file = first->src_reg[0].file; + inst->src_reg[r].index = first->src_reg[0].index; + + int swizzle = 0; + for (int i = 0; i < 4; i++) { + int src_chan = GET_SWZ(inst->src_reg[r].swizzle, i); + ir_to_mesa_instruction *copy_inst = acp[acp_base + src_chan]; + swizzle |= (GET_SWZ(copy_inst->src_reg[0].swizzle, src_chan) << + (3 * i)); + } + inst->src_reg[r].swizzle = swizzle; + } + } + + switch (inst->op) { + case OPCODE_BGNLOOP: + case OPCODE_ENDLOOP: + case OPCODE_ELSE: + case OPCODE_ENDIF: + /* End of a basic block, clear the ACP entirely. */ + memset(&acp, 0, sizeof(acp)); + break; + + default: + /* Continuing the block, clear any written channels from + * the ACP. + */ + if (inst->dst_reg.file == PROGRAM_TEMPORARY) { + if (inst->dst_reg.reladdr) { + memset(&acp, 0, sizeof(acp)); + } else { + for (int i = 0; i < 4; i++) { + if (inst->dst_reg.writemask & (1 << i)) { + acp[4 * inst->dst_reg.index + i] = NULL; + } + } + } + } + break; + } + + /* If this is a copy, add it to the ACP. */ + if (inst->op == OPCODE_MOV && + inst->dst_reg.file == PROGRAM_TEMPORARY && + !inst->dst_reg.reladdr && + !inst->saturate && + !inst->src_reg[0].reladdr && + !inst->src_reg[0].negate) { + for (int i = 0; i < 4; i++) { + if (inst->dst_reg.writemask & (1 << i)) { + acp[4 * inst->dst_reg.index + i] = inst; + } + } + } + } +} + /** * Convert a shader's GLSL IR into a Mesa gl_program. @@ -2715,6 +2842,8 @@ get_mesa_program(struct gl_context *ctx, mesa_instruction_annotation = talloc_array(v.mem_ctx, ir_instruction *, num_instructions); + v.copy_propagate(); + /* Convert ir_mesa_instructions into prog_instructions. */ mesa_inst = mesa_instructions; |