| 61 | } |
| 62 | |
| 63 | opt::DataFlowAnalysis::VisitResult DivergenceAnalysis::VisitBlock(uint32_t id) { |
| 64 | if (!cd_.HasBlock(id)) { |
| 65 | return opt::DataFlowAnalysis::VisitResult::kResultFixed; |
| 66 | } |
| 67 | DivergenceLevel& cur_level = divergence_[id]; |
| 68 | if (cur_level == DivergenceLevel::kDivergent) { |
| 69 | return opt::DataFlowAnalysis::VisitResult::kResultFixed; |
| 70 | } |
| 71 | DivergenceLevel orig = cur_level; |
| 72 | for (const spvtools::opt::ControlDependence& dep : |
| 73 | cd_.GetDependenceSources(id)) { |
| 74 | if (divergence_[dep.source_bb_id()] > cur_level) { |
| 75 | cur_level = divergence_[dep.source_bb_id()]; |
| 76 | divergence_source_[id] = dep.source_bb_id(); |
| 77 | } else if (dep.source_bb_id() != 0) { |
| 78 | uint32_t condition_id = dep.GetConditionID(*context().cfg()); |
| 79 | DivergenceLevel dep_level = divergence_[condition_id]; |
| 80 | // Check if we are along the chain of unconditional branches starting from |
| 81 | // the branch target. |
| 82 | if (follow_unconditional_branches_[dep.branch_target_bb_id()] != |
| 83 | follow_unconditional_branches_[dep.target_bb_id()]) { |
| 84 | // We must have reconverged in order to reach this block. |
| 85 | // Promote partially uniform to divergent. |
| 86 | if (dep_level == DivergenceLevel::kPartiallyUniform) { |
| 87 | dep_level = DivergenceLevel::kDivergent; |
| 88 | } |
| 89 | } |
| 90 | if (dep_level > cur_level) { |
| 91 | cur_level = dep_level; |
| 92 | divergence_source_[id] = condition_id; |
| 93 | divergence_dependence_source_[id] = dep.source_bb_id(); |
| 94 | } |
| 95 | } |
| 96 | } |
| 97 | return cur_level > orig ? VisitResult::kResultChanged |
| 98 | : VisitResult::kResultFixed; |
| 99 | } |
| 100 | |
| 101 | opt::DataFlowAnalysis::VisitResult DivergenceAnalysis::VisitInstruction( |
| 102 | opt::Instruction* inst) { |
nothing calls this directly
no test coverage detected