rat

rat is a simple, handmade, and relatively minimal compiler suite (including a C99 frontend, a simple linker, and a Sea of Nodes backend). Some of the features include but are not limited to:

• ratcc -O1 compiles sqlite3.c about 17x faster than clang -O1)
• ratcc -O1 code runs within 5% of gcc -O1 and 26% of clang -O1.
• rat is small, readable and easy to hack on.

$ make
$ make test
$ make bench

• sccp: sparse conditional constant propagation
• fold: constant folding, algebraic simplification
• simplifycfg: control-flow simplification
• gvn: global value numbering
• memoryopt: load/store forwarding
• inline: function inlining
• strengthreduce: induction-variable strength reduction
• loadcanon: moves loads to their canonical memory state
• slp: scheduling-free SLP vectorization with runtime alias guards
• dfe: dead function elimination

• GCM: global code motion
• x86-lower: instruction selection
• regalloc: bin-packing register allocation
• x86-peephole: copy and spill cleanup
• x86-layout: block layout, loop alignment
• x86-encode: encoding and object emission

• verify: IR invariant checks
• text-emitter: IR dumps as Graphviz
• graph-emitter: IR dumps as text