diff options
Diffstat (limited to 'gcc/gimple-range-gori.cc')
| -rw-r--r-- | gcc/gimple-range-gori.cc | 21 |
1 files changed, 17 insertions, 4 deletions
diff --git a/gcc/gimple-range-gori.cc b/gcc/gimple-range-gori.cc index abc70cd..4ee0ae3 100644 --- a/gcc/gimple-range-gori.cc +++ b/gcc/gimple-range-gori.cc @@ -1291,13 +1291,26 @@ gori_compute::compute_operand1_and_operand2_range (vrange &r, { Value_Range op_range (TREE_TYPE (name)); - // Calculate a good a range for op2. Since op1 == op2, this will - // have already included whatever the actual range of name is. - if (!compute_operand2_range (op_range, handler, lhs, name, src, rel)) + // If op1 is in the def chain of op2, we'll do the work twice to evalaute + // op1. This can result in an exponential time calculation. + // Instead just evaluate op2, which will eventualy get to op1. + if (in_chain_p (handler.operand1 (), handler.operand2 ())) + return compute_operand2_range (r, handler, lhs, name, src, rel); + + // Likewise if op2 is in the def chain of op1. + if (in_chain_p (handler.operand2 (), handler.operand1 ())) + return compute_operand1_range (r, handler, lhs, name, src, rel); + + // Calculate a good a range through op2. + if (!compute_operand2_range (r, handler, lhs, name, src, rel)) return false; + // If op1 == op2 there is again no need to go further. + if (handler.operand1 () == handler.operand2 ()) + return true; + // Now get the range thru op1. - if (!compute_operand1_range (r, handler, lhs, name, src, rel)) + if (!compute_operand1_range (op_range, handler, lhs, name, src, rel)) return false; // Both operands have to be simultaneously true, so perform an intersection. |