diff options
Diffstat (limited to 'src/intel')
| -rw-r--r-- | src/intel/compiler/brw_fs_lower_regioning.cpp | 24 |
1 files changed, 23 insertions, 1 deletions
diff --git a/src/intel/compiler/brw_fs_lower_regioning.cpp b/src/intel/compiler/brw_fs_lower_regioning.cpp index cc4163b4c2c..df50993dee6 100644 --- a/src/intel/compiler/brw_fs_lower_regioning.cpp +++ b/src/intel/compiler/brw_fs_lower_regioning.cpp @@ -53,7 +53,21 @@ namespace { unsigned required_dst_byte_stride(const fs_inst *inst) { - if (type_sz(inst->dst.type) < get_exec_type_size(inst) && + if (inst->dst.is_accumulator()) { + /* If the destination is an accumulator, insist that we leave the + * stride alone. We cannot "fix" accumulator destinations by writing + * to a temporary and emitting a MOV into the original destination. + * For multiply instructions (our one use of the accumulator), the + * MUL writes the full 66 bits of the accumulator whereas the MOV we + * would emit only writes 33 bits and leaves the top 33 bits + * undefined. + * + * It's safe to just require the original stride here because the + * lowering pass will detect the mismatch in has_invalid_src_region + * and fix the sources of the multiply instead of the destination. + */ + return inst->dst.stride * type_sz(inst->dst.type); + } else if (type_sz(inst->dst.type) < get_exec_type_size(inst) && !is_byte_raw_mov(inst)) { return get_exec_type_size(inst); } else { @@ -316,6 +330,14 @@ namespace { bool lower_dst_region(fs_visitor *v, bblock_t *block, fs_inst *inst) { + /* We cannot replace the result of an integer multiply which writes the + * accumulator because MUL+MACH pairs act on the accumulator as a 66-bit + * value whereas the MOV will act on only 32 or 33 bits of the + * accumulator. + */ + assert(inst->opcode != BRW_OPCODE_MUL || !inst->dst.is_accumulator() || + brw_reg_type_is_floating_point(inst->dst.type)); + const fs_builder ibld(v, block, inst); const unsigned stride = required_dst_byte_stride(inst) / type_sz(inst->dst.type); |