A possible bug about casting branch condition

[BowenZhang-UST]

Commit

Lattest Main

Location

• ProgramSlicing/ProgramSlicing.cpp
  • Line 419
• DAG/inter_profile.cpp
  • Line 487

Description

The code at ProgramSlicing/ProgramSlicing.cpp Line 419 tries to cast the condition of an conditional branch into Instruction. However, the condition of BranchInst is not always Instruction. When the condition is an Argument, there would be a cast exception.

The code at DAG/inter_profile.cpp Line 487 is similar.

Proposed Fix

Turn the cast into a dynamic cast, and use an if-check to guard it.

    // Only for predicates that are defined in a different basic block
-  auto *pred = cast<Instruction>(br->getCondition());
+ if (auto *pred=dyn_cast<Instruction>(br->getCondition())) {
    if (pred->getParent() == &BB)
      continue; 
+ }

[guilhermeleobas]

Hi @BowenZhang-UST, thanks for the report. As for a more updated implementation, check https://github.com/lac-dcc/wyvern/tree/master/passes

[BowenZhang-UST]

Thank you for reviewing this issue and providing an updated implementation! @guilhermeleobas