A retargetable compiler for ANSI C

Abstract

A b s t r a c t lcc is a new retargetable compiler for ANSI C. Versions for the VAX, Motorola 68020, SPARC, and MIPS are in production use at Princeton University and at AT&T Bell Laboratories. With a few exceptions, little about lcc is unusual --it integrates several well engineered, existing techniques --but it is smaller and faster than most other C compilers, and it generates code of comparable quality, lcc's target-independent front end performs a few simple, but effective, optimizations that contribute to good code; examples include simulating register declarations and partitioning switch statement cases into dense tables. It also implements target-independent function tracing and expression-level profiling.

Using Multiple Memory Access Instructions for Reducing Code Size

“…The tool chain consists of an ANSI C compiler (based on LCC [7]), a multi-pass optimizer, an ARM Thumb code generator, and a combined register allocator and code motion pass (an implementation of our earlier RACM algorithm [8]). …”

Efficient Partitioning of Fragment Shaders for Multipass Rendering on Programmable Graphics Hardware

“…After partitioning, the compilers order the passes and assign them to textures. To perform instruction selection, both of our back ends use a modified version of lburg 6 . We extended lburg to support operators with arbitrary arity and wrote covering rules to map the shading system's intermediate representation directly to hardware operations.…”

Improving processor efficiency by statically pipelining instructions

“…First, C code is input to the frontend. This consists of the LCC compiler frontend [9] combined with a middleware process that converts LCC's output format into the Register Transfer List (RTL) format used by VPO. This format directly represents machine instructions on the target architecture.…”

“…When generating statically pipelined code, however, the compiler can simply retain a value in one of the internal registers. In Figure 3.19(a), the value of r [9] is read into RS1 three times without the values changing between, so the compiler removes the last two of them.…”