Function FoldInvariantSelect

source/opt/const_folding_rules.cpp:1258–1276

}

ConstantFoldingRule FoldInvariantSelect() {
  return [](IRContext*, Instruction* inst,
            const std::vector<const analysis::Constant*>& constants)
             -> const analysis::Constant* {
    assert(inst->opcode() == spv::Op::OpSelect);
    (void)inst;

    if (!constants[1] || !constants[2]) {
      return nullptr;
    }
    if (constants[1] == constants[2]) {
      return constants[1];
    }
    if (constants[1]->IsZero() && constants[2]->IsZero()) {
      return constants[1];
    }
    return nullptr;
  };
}

// Folds an OpDot where all of the inputs are constants to a
// constant.  A new constant is created if necessary.