diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/trans/codegen_c.cpp | 84 |
1 files changed, 82 insertions, 2 deletions
diff --git a/src/trans/codegen_c.cpp b/src/trans/codegen_c.cpp index bf7213b2..56bbdfe2 100644 --- a/src/trans/codegen_c.cpp +++ b/src/trans/codegen_c.cpp @@ -1806,6 +1806,39 @@ namespace { m_of << "\tbool df" << i << " = " << code->drop_flags[i] << ";\n"; } + ::std::vector<unsigned> bb_use_counts( code->blocks.size() ); + for(const auto& blk : code->blocks) + { + TU_MATCHA( (blk.terminator), (te), + (Incomplete, + ), + (Return, + ), + (Diverge, + ), + (Goto, + bb_use_counts[te] ++; + ), + (Panic, + bb_use_counts[te.dst] ++; + ), + (If, + bb_use_counts[te.bb0] ++; + bb_use_counts[te.bb1] ++; + ), + (Switch, + for(const auto& t : te.targets) + bb_use_counts[t] ++; + ), + (SwitchValue, + MIR_TODO(mir_res, "SwitchValue in C codegen"); + ), + (Call, + bb_use_counts[te.ret_block] ++; + ) + ) + } + if( false ) { m_of << "#if 0\n"; @@ -1828,7 +1861,40 @@ namespace { continue ; } + // If the previous block is a goto/function call to this + // block, AND this block only has a single reference, omit the + // label. + #if 1 + if( bb_use_counts.at(i) == 0 ) + { + if( i == 0 ) + { + // First BB, don't print label + } + else + { + // Unused BB (likely part of unsupported panic path) + continue ; + } + } + else if( bb_use_counts.at(i) == 1 ) + { + if( i > 0 && (TU_TEST1(code->blocks[i-1].terminator, Goto, == i) || TU_TEST1(code->blocks[i-1].terminator, Call, .ret_block == i)) ) + { + // Don't print the label, only use is previous block + } + else + { + m_of << "bb" << i << ":\n"; + } + } + else + { + m_of << "bb" << i << ":\n"; + } + #else m_of << "bb" << i << ":\n"; + #endif for(const auto& stmt : code->blocks[i].statements) { @@ -1849,7 +1915,14 @@ namespace { m_of << "\t_Unwind_Resume();\n"; ), (Goto, - m_of << "\tgoto bb" << e << ";\n"; + if( e == i+1 ) + { + // Let it flow on to the next block + } + else + { + m_of << "\tgoto bb" << e << ";\n"; + } ), (Panic, m_of << "\tgoto bb" << e << "; /* panic */\n"; @@ -1896,7 +1969,14 @@ namespace { ), (Call, emit_term_call(mir_res, e, 1); - m_of << "\tgoto bb" << e.ret_block << ";\n"; + if( e.ret_block == i+1 ) + { + // Let it flow on to the next block + } + else + { + m_of << "\tgoto bb" << e.ret_block << ";\n"; + } ) ) m_of << "\t// ^ " << code->blocks[i].terminator << "\n"; |