diff options
Diffstat (limited to 'src/intel/compiler/brw_eu_compact.c')
| -rw-r--r-- | src/intel/compiler/brw_eu_compact.c | 82 |
1 files changed, 80 insertions, 2 deletions
diff --git a/src/intel/compiler/brw_eu_compact.c b/src/intel/compiler/brw_eu_compact.c index a940e214f2e..bf57ddf85c2 100644 --- a/src/intel/compiler/brw_eu_compact.c +++ b/src/intel/compiler/brw_eu_compact.c @@ -956,6 +956,83 @@ is_compactable_immediate(unsigned imm) } /** + * Applies some small changes to instruction types to increase chances of + * compaction. + */ +static brw_inst +precompact(const struct gen_device_info *devinfo, brw_inst inst) +{ + if (brw_inst_src0_reg_file(devinfo, &inst) != BRW_IMMEDIATE_VALUE) + return inst; + + /* The Bspec's section titled "Non-present Operands" claims that if src0 + * is an immediate that src1's type must be the same as that of src0. + * + * The SNB+ DataTypeIndex instruction compaction tables contain mappings + * that do not follow this rule. E.g., from the IVB/HSW table: + * + * DataTypeIndex 18-Bit Mapping Mapped Meaning + * 3 001000001011111101 r:f | i:vf | a:ud | <1> | dir | + * + * And from the SNB table: + * + * DataTypeIndex 18-Bit Mapping Mapped Meaning + * 8 001000000111101100 a:w | i:w | a:ud | <1> | dir | + * + * Neither of these cause warnings from the simulator when used, + * compacted or otherwise. In fact, all compaction mappings that have an + * immediate in src0 use a:ud for src1. + * + * The GM45 instruction compaction tables do not contain mapped meanings + * so it's not clear whether it has the restriction. We'll assume it was + * lifted on SNB. (FINISHME: decode the GM45 tables and check.) + * + * Don't do any of this for 64-bit immediates, since the src1 fields + * overlap with the immediate and setting them would overwrite the + * immediate we set. + */ + if (devinfo->gen >= 6 && + !(devinfo->is_haswell && + brw_inst_opcode(devinfo, &inst) == BRW_OPCODE_DIM) && + !(devinfo->gen >= 8 && + (brw_inst_src0_reg_type(devinfo, &inst) == GEN8_HW_REG_IMM_TYPE_DF || + brw_inst_src0_reg_type(devinfo, &inst) == GEN8_HW_REG_TYPE_UQ || + brw_inst_src0_reg_type(devinfo, &inst) == GEN8_HW_REG_TYPE_Q))) { + brw_inst_set_src1_reg_type(devinfo, &inst, BRW_HW_REG_TYPE_UD); + } + + /* Compacted instructions only have 12-bits (plus 1 for the other 20) + * for immediate values. Presumably the hardware engineers realized + * that the only useful floating-point value that could be represented + * in this format is 0.0, which can also be represented as a VF-typed + * immediate, so they gave us the previously mentioned mapping on IVB+. + * + * Strangely, we do have a mapping for imm:f in src1, so we don't need + * to do this there. + * + * If we see a 0.0:F, change the type to VF so that it can be compacted. + */ + if (brw_inst_imm_ud(devinfo, &inst) == 0x0 && + brw_inst_src0_reg_type(devinfo, &inst) == BRW_HW_REG_TYPE_F && + brw_inst_dst_reg_type(devinfo, &inst) != GEN7_HW_REG_NON_IMM_TYPE_DF) { + brw_inst_set_src0_reg_type(devinfo, &inst, BRW_HW_REG_IMM_TYPE_VF); + } + + /* There are no mappings for dst:d | i:d, so if the immediate is suitable + * set the types to :UD so the instruction can be compacted. + */ + if (is_compactable_immediate(brw_inst_imm_ud(devinfo, &inst)) && + brw_inst_cond_modifier(devinfo, &inst) == BRW_CONDITIONAL_NONE && + brw_inst_src0_reg_type(devinfo, &inst) == BRW_HW_REG_TYPE_D && + brw_inst_dst_reg_type(devinfo, &inst) == BRW_HW_REG_TYPE_D) { + brw_inst_set_src0_reg_type(devinfo, &inst, BRW_HW_REG_TYPE_UD); + brw_inst_set_dst_reg_type(devinfo, &inst, BRW_HW_REG_TYPE_UD); + } + + return inst; +} + +/** * Tries to compact instruction src into dst. * * It doesn't modify dst unless src is compactable, which is relied on by @@ -1427,9 +1504,10 @@ brw_compact_instructions(struct brw_codegen *p, int start_offset, old_ip[offset / sizeof(brw_compact_inst)] = src_offset / sizeof(brw_inst); compacted_counts[src_offset / sizeof(brw_inst)] = compacted_count; - brw_inst saved = *src; + brw_inst inst = precompact(devinfo, *src); + brw_inst saved = inst; - if (brw_try_compact_instruction(devinfo, dst, src)) { + if (brw_try_compact_instruction(devinfo, dst, &inst)) { compacted_count++; if (INTEL_DEBUG) { |