diff options
| -rw-r--r-- | source/slang/slang-ir-ssa.cpp | 20 |
1 files changed, 19 insertions, 1 deletions
diff --git a/source/slang/slang-ir-ssa.cpp b/source/slang/slang-ir-ssa.cpp index 5f42702ce..08a5ffa67 100644 --- a/source/slang/slang-ir-ssa.cpp +++ b/source/slang/slang-ir-ssa.cpp @@ -456,7 +456,14 @@ IRInst* tryRemoveTrivialPhi( // There were no operands other than the phi itself. // This implies that the value at the use sites should // actually be undefined. - SLANG_UNIMPLEMENTED_X("trivial phi"); + // + // For now we will simply return in this case, without + // removing the phi node. + // + // TODO: Construct a value for `same` that represents an + // undefined value with the same type as `phi`. + // + return phi; } // Removing this phi as trivial may make other phi nodes @@ -498,6 +505,16 @@ IRInst* tryRemoveTrivialPhi( // other phis that might have become trivial. for( auto otherPhi : otherPhis ) { + // It is possible that between when we added a phi + // node to `otherPhis` and here it might have been + // replaced. This could happen if `otherPhis` had + // two entries, `A` and `B`, and the recursive + // `tryRemoveTrivialPhi` on `A` also ended up + // eliminating `B`. + // + if( otherPhi->replacement ) + continue; + tryRemoveTrivialPhi(context, otherPhi); } @@ -524,6 +541,7 @@ IRInst* addPhiOperands( auto predInfo = *context->blockInfos.TryGetValue(predBlock); auto phiOperand = readVar(context, predInfo, var); + SLANG_ASSERT(phiOperand != nullptr); operandValues.add(phiOperand); } |