diff options
| -rw-r--r-- | src/shader_recompiler/ir_opt/ssa_rewrite_pass.cpp | 24 |
1 files changed, 13 insertions, 11 deletions
diff --git a/src/shader_recompiler/ir_opt/ssa_rewrite_pass.cpp b/src/shader_recompiler/ir_opt/ssa_rewrite_pass.cpp index 3bab742e7..a8064a5d0 100644 --- a/src/shader_recompiler/ir_opt/ssa_rewrite_pass.cpp +++ b/src/shader_recompiler/ir_opt/ssa_rewrite_pass.cpp @@ -278,20 +278,22 @@ private: } same = op; } + // Remove the phi node from the block, it will be reinserted + IR::Block::InstructionList& list{block->Instructions()}; + list.erase(IR::Block::InstructionList::s_iterator_to(phi)); + + // Find the first non-phi instruction and use it as an insertion point + IR::Block::iterator reinsert_point{std::ranges::find_if_not(list, IsPhi)}; if (same.IsEmpty()) { // The phi is unreachable or in the start block - // First remove the phi node from the block, it will be reinserted - IR::Block::InstructionList& list{block->Instructions()}; - list.erase(IR::Block::InstructionList::s_iterator_to(phi)); - - // Insert an undef instruction after all phi nodes (to keep phi instructions on top) - const auto first_not_phi{std::ranges::find_if_not(list, IsPhi)}; - same = IR::Value{&*block->PrependNewInst(first_not_phi, undef_opcode)}; - - // Insert the phi node after the undef opcode, this will be replaced with an identity - list.insert(first_not_phi, phi); + // Insert an undefined instruction and make it the phi node replacement + // The "phi" node reinsertion point is specified after this instruction + reinsert_point = block->PrependNewInst(reinsert_point, undef_opcode); + same = IR::Value{&*reinsert_point}; + ++reinsert_point; } - // Reroute all uses of phi to same and remove phi + // Reinsert the phi node and reroute all its uses to the "same" value + list.insert(reinsert_point, phi); phi.ReplaceUsesWith(same); // TODO: Try to recursively remove all phi users, which might have become trivial return same; |