message: [XLA] Permanently disable constant folding for kTuple, since no backends can handle constant literal with tuple shape.
diff: @@ -52,8 +52,10 @@ StatusOr<bool> HloConstantFolding::Run(HloModule* module) {
  computation->root_instruction() != instruction) {
  continue;
  }
  - // Skip Constant, Parameter, and AfterAll operation.
  - // TODO(b/64407269): Enable Tuple once the timeout issue is resolved.
  + // Skip Constant, Parameter, Tuple, AfterAll operation.
  + // Tuple constants are not directly supported by any backends, hence
  + // folding Tuple is not useful and would in fact be expanded back into
  + // kTuple by Algebraic Simplifier.
  // TODO(b/110532604): Enable AfterAll once AfterAll requires at least one
  // operand in which case constant folding will be impossible and this
  // special case is not necessary.
  @@ -63,6 +65,7 @@ StatusOr<bool> HloConstantFolding::Run(HloModule* module) {
  instruction->opcode() == HloOpcode::kAfterAll) {
  continue;
  }
  +
  // Skip instructions with non-constant operands.
  if (!hlo_query::AllOperandsAreConstants(*instruction)) {
  continue;
  