| /* |
| * Copyright © 2014 Broadcom |
| * |
| * Permission is hereby granted, free of charge, to any person obtaining a |
| * copy of this software and associated documentation files (the "Software"), |
| * to deal in the Software without restriction, including without limitation |
| * the rights to use, copy, modify, merge, publish, distribute, sublicense, |
| * and/or sell copies of the Software, and to permit persons to whom the |
| * Software is furnished to do so, subject to the following conditions: |
| * |
| * The above copyright notice and this permission notice (including the next |
| * paragraph) shall be included in all copies or substantial portions of the |
| * Software. |
| * |
| * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL |
| * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING |
| * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS |
| * IN THE SOFTWARE. |
| */ |
| |
| /** |
| * @file v3d_opt_copy_propagation.c |
| * |
| * This implements simple copy propagation for VIR without control flow. |
| * |
| * For each temp, it keeps a qreg of which source it was MOVed from, if it |
| * was. If we see that used later, we can just reuse the source value, since |
| * we know we don't have control flow, and we have SSA for our values so |
| * there's no killing to worry about. |
| */ |
| |
| #include "v3d_compiler.h" |
| |
| static bool |
| is_copy_mov(struct qinst *inst) |
| { |
| if (!inst) |
| return false; |
| |
| if (inst->qpu.type != V3D_QPU_INSTR_TYPE_ALU || |
| (inst->qpu.alu.mul.op != V3D_QPU_M_FMOV && |
| inst->qpu.alu.mul.op != V3D_QPU_M_MOV)) { |
| return false; |
| } |
| |
| if (inst->dst.file != QFILE_TEMP) |
| return false; |
| |
| if (inst->src[0].file != QFILE_TEMP) |
| return false; |
| |
| if (inst->qpu.alu.add.output_pack != V3D_QPU_PACK_NONE || |
| inst->qpu.alu.mul.output_pack != V3D_QPU_PACK_NONE) { |
| return false; |
| } |
| |
| if (inst->qpu.flags.ac != V3D_QPU_COND_NONE || |
| inst->qpu.flags.mc != V3D_QPU_COND_NONE) { |
| return false; |
| } |
| |
| switch (inst->src[0].file) { |
| case QFILE_MAGIC: |
| /* No copy propagating from R3/R4/R5 -- the MOVs from those |
| * are there to register allocate values produced into R3/4/5 |
| * to other regs (though hopefully r3/4/5). |
| */ |
| switch (inst->src[0].index) { |
| case V3D_QPU_WADDR_R3: |
| case V3D_QPU_WADDR_R4: |
| case V3D_QPU_WADDR_R5: |
| return false; |
| default: |
| break; |
| } |
| break; |
| |
| case QFILE_REG: |
| switch (inst->src[0].index) { |
| case 0: |
| case 1: |
| case 2: |
| /* MOVs from rf0/1/2 are only to track the live |
| * intervals for W/centroid W/Z. |
| */ |
| return false; |
| } |
| break; |
| |
| default: |
| break; |
| } |
| |
| return true; |
| } |
| |
| static bool |
| vir_has_unpack(struct qinst *inst, int chan) |
| { |
| assert(chan == 0 || chan == 1); |
| |
| if (vir_is_add(inst)) { |
| if (chan == 0) |
| return inst->qpu.alu.add.a_unpack != V3D_QPU_UNPACK_NONE; |
| else |
| return inst->qpu.alu.add.b_unpack != V3D_QPU_UNPACK_NONE; |
| } else { |
| if (chan == 0) |
| return inst->qpu.alu.mul.a_unpack != V3D_QPU_UNPACK_NONE; |
| else |
| return inst->qpu.alu.mul.b_unpack != V3D_QPU_UNPACK_NONE; |
| } |
| } |
| |
| static bool |
| try_copy_prop(struct v3d_compile *c, struct qinst *inst, struct qinst **movs) |
| { |
| bool debug = false; |
| bool progress = false; |
| |
| for (int i = 0; i < vir_get_nsrc(inst); i++) { |
| if (inst->src[i].file != QFILE_TEMP) |
| continue; |
| |
| /* We have two ways of finding MOVs we can copy propagate |
| * from. One is if it's an SSA def: then we can reuse it from |
| * any block in the program, as long as its source is also an |
| * SSA def. Alternatively, if it's in the "movs" array |
| * tracked within the block, then we know the sources for it |
| * haven't been changed since we saw the instruction within |
| * our block. |
| */ |
| struct qinst *mov = movs[inst->src[i].index]; |
| if (!mov) { |
| if (!is_copy_mov(c->defs[inst->src[i].index])) |
| continue; |
| mov = c->defs[inst->src[i].index]; |
| |
| if (mov->src[0].file == QFILE_TEMP && |
| !c->defs[mov->src[0].index]) |
| continue; |
| } |
| |
| if (vir_has_unpack(mov, 0)) { |
| /* Make sure that the meaning of the unpack |
| * would be the same between the two |
| * instructions. |
| */ |
| if (v3d_qpu_unpacks_f32(&inst->qpu) != |
| v3d_qpu_unpacks_f32(&mov->qpu) || |
| v3d_qpu_unpacks_f16(&inst->qpu) != |
| v3d_qpu_unpacks_f16(&mov->qpu)) { |
| continue; |
| } |
| |
| /* No composing the unpacks. */ |
| if (vir_has_unpack(inst, i)) |
| continue; |
| |
| /* these ops can't represent abs. */ |
| if (mov->qpu.alu.mul.a_unpack == V3D_QPU_UNPACK_ABS) { |
| switch (inst->qpu.alu.add.op) { |
| case V3D_QPU_A_VFPACK: |
| case V3D_QPU_A_FROUND: |
| case V3D_QPU_A_FTRUNC: |
| case V3D_QPU_A_FFLOOR: |
| case V3D_QPU_A_FCEIL: |
| case V3D_QPU_A_FDX: |
| case V3D_QPU_A_FDY: |
| case V3D_QPU_A_FTOIN: |
| case V3D_QPU_A_FTOIZ: |
| case V3D_QPU_A_FTOUZ: |
| case V3D_QPU_A_FTOC: |
| continue; |
| default: |
| break; |
| } |
| } |
| } |
| |
| if (debug) { |
| fprintf(stderr, "Copy propagate: "); |
| vir_dump_inst(c, inst); |
| fprintf(stderr, "\n"); |
| } |
| |
| inst->src[i] = mov->src[0]; |
| if (vir_has_unpack(mov, 0)) { |
| enum v3d_qpu_input_unpack unpack = mov->qpu.alu.mul.a_unpack; |
| |
| vir_set_unpack(inst, i, unpack); |
| } |
| |
| if (debug) { |
| fprintf(stderr, "to: "); |
| vir_dump_inst(c, inst); |
| fprintf(stderr, "\n"); |
| } |
| |
| progress = true; |
| } |
| |
| return progress; |
| } |
| |
| static void |
| apply_kills(struct v3d_compile *c, struct qinst **movs, struct qinst *inst) |
| { |
| if (inst->dst.file != QFILE_TEMP) |
| return; |
| |
| for (int i = 0; i < c->num_temps; i++) { |
| if (movs[i] && |
| (movs[i]->dst.index == inst->dst.index || |
| (movs[i]->src[0].file == QFILE_TEMP && |
| movs[i]->src[0].index == inst->dst.index))) { |
| movs[i] = NULL; |
| } |
| } |
| } |
| |
| bool |
| vir_opt_copy_propagate(struct v3d_compile *c) |
| { |
| bool progress = false; |
| struct qinst **movs; |
| |
| movs = ralloc_array(c, struct qinst *, c->num_temps); |
| if (!movs) |
| return false; |
| |
| vir_for_each_block(block, c) { |
| /* The MOVs array tracks only available movs within the |
| * block. |
| */ |
| memset(movs, 0, sizeof(struct qinst *) * c->num_temps); |
| |
| vir_for_each_inst(inst, block) { |
| progress = try_copy_prop(c, inst, movs) || progress; |
| |
| apply_kills(c, movs, inst); |
| |
| if (is_copy_mov(inst)) |
| movs[inst->dst.index] = inst; |
| } |
| } |
| |
| ralloc_free(movs); |
| |
| return progress; |
| } |
