feat: add optimizer infrastructure and post-lowering structural passes#29
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feat: add optimizer infrastructure and post-lowering structural passes#29
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Add shared optimizer utilities and four post-lowering optimization passes: **Shared utilities** (optimizer/utils.rs): - terminator_successors: Get successor blocks for control flow terminators - build_predecessors: Build predecessor map for dominance analysis - for_each_use/for_each_use_terminator: Iterate over variable uses in instructions - instr_dest: Get destination variable of instructions - set_instr_dest: Redirect instruction output - replace_uses_of: Variable substitution in instructions - count_uses_of: Count how many times a variable is used - is_side_effect_free: Classify instructions **Post-lowering passes** (run after phi node lowering): - empty_blocks: Remove passthrough blocks (only Jump, no instructions) - merge_blocks: Merge single-predecessor blocks with their predecessors - dead_instrs: Remove unused variable definitions - dead_blocks: (refactored) Use shared utils Passes run in multiple iterations to handle cascading opportunities from each pass (e.g., dead_instrs can create empty blocks). The optimize_lowered_ir function coordinates these passes on phi-free IR. Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>
This was referenced Mar 23, 2026
added 2 commits
March 23, 2026 09:45
…r-d/optimizer-infrastructure
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Summary
Adds shared optimizer utilities and four post-lowering optimization passes (running after phi node lowering):
optimizer/utils.rs): Basic IR traversal, variable use tracking, instruction classificationHow it works
Structural passes run in multiple iterations (typically 2) in
optimize_lowered_ir()to handle cascading opportunities:dead_instrsmay remove assignments, leaving some blocks emptyempty_blocksandmerge_blockseliminate now-empty/redundant blocksKey design notes
MemoryFill,MemoryInit,DataDrop) are properly handledTest coverage
All unit tests pass for:
🤖 Generated with Claude Code