li_smallest.cc

void TurboAssembler::li_smallest(Register rd, int64_t j) {
  BlockTrampolinePoolScope block_trampoline_pool(this);
  unsigned trailing = CountTrailingZeros(j);
  unsigned leading = CountLeadingZeros(j);
  unsigned solid = 64 - trailing - leading;
  if (solid <= 12) {
    if (leading >= 44) {
      emit(ORI, rd, zero_reg, j);
    } else if (leading >= 32 && trailing >= 12) {
      emit(LUI, rd, j >> 44);
    } else {
      emit(ORI, rd, zero_reg, j >> trailing);
      emit(SLLI, rd, rd, trailing);
    }
  } else if (solid <= 20) {
    if (leading >= 32) {
      li_smallest(rd, reinterpret_cast<int32_t>(j));
    } else {
      emit(LUI, rd, j >> trailing);
      emit(SLLI, rd, rd, trailing);
    }
  } else if (solid <= 32) {
    if (leading >= 32) {
      li_smallest(rd, reinterpret_cast<int32_t>(j));
    } else {
      li_smallest(rd, reinterpret_cast<int32_t>(j >> trailing));
      emit(SLLI, rd, rd, trailing);
    }
  } else if (solid <= 44) {
    if (leading >= 20) {
      li_smallest(rd, reinterpret_cast<int32_t>(j >> 12 & 0xFFFFFFFF));
      emit(SLLI, rd, rd, 12);
      emit(ORI, rd, rd, j & 0xFFF);
    } else {
      li_smallest(rd,
                  reinterpret_cast<int32_t>(j >> (12 + trailing) & 0xFFFFFFFF));
      emit(SLLI, rd, rd, 12);
      emit(ORI, rd, rd, j >> trailing & 0xFFF);
      emit(SLLI, rd, rd, trailing);
    }
  } else if (solid <= 56) {
    if (leading >= 8) {
      li_smallest(rd, reinterpret_cast<int32_t>(j >> 24 & 0xFFFFFFFF));
      emit(SLLI, rd, rd, 12);
      emit(ORI, rd, rd, j >> 12 & 0xFFF);
      emit(SLLI, rd, rd, 12);
      emit(ORI, rd, rd, j & 0xFFF);
    } else {
      li_smallest(rd,
                  reinterpret_cast<int32_t>(j >> (24 + trailing) & 0xFFFFFFFF));
      emit(SLLI, rd, rd, 12);
      emit(ORI, rd, rd, j >> (12 + trailing) & 0xFFF);
      emit(SLLI, rd, rd, 12);
      emit(ORI, rd, rd, j >> trailing & 0xFFF);
      emit(SLLI, rd, rd, trailing);
    }
  } else {
    li(rd, j);
  }
}

void TurboAssembler::li_smallest(Register rd, int32_t j) {
  BlockTrampolinePoolScope block_trampoline_pool(this);
  bool initialized = false;
  if (j & 0xFFFFF000) {
    emit(LUI, rd, (j & 0xFFFFF000) >> 12);
    initialized = true;
  }
  if (j & 0xFFF) {
    emit(ORI, rd, initialized? rd: zero_reg, j & 0x00000FFF);
  }
}