forked from OSchip/llvm-project
76 lines
2.5 KiB
Plaintext
76 lines
2.5 KiB
Plaintext
This is a basic compiler driver for the PIC16 toolchain that shows how to create
|
|
your own llvmc-based drivers. It is based on the examples/Skeleton template.
|
|
|
|
The PIC16 toolchain looks like this:
|
|
|
|
clang-cc (FE) -> llvm-ld (optimizer) -> llc (codegen) -> native-as -> native-ld
|
|
|
|
Following features were requested by Sanjiv:
|
|
|
|
From: Sanjiv Gupta <sanjiv.gupta <at> microchip.com>
|
|
Subject: Re: llvmc for PIC16
|
|
Newsgroups: gmane.comp.compilers.llvm.devel
|
|
Date: 2009-06-05 06:51:14 GMT
|
|
|
|
The salient features that we want to have in the driver are:
|
|
1. llvm-ld will be used as "The Optimizer".
|
|
2. If the user has specified to generate the final executable, then
|
|
llvm-ld should run on all the .bc files generated by clang and create a
|
|
single optimized .bc file for further tools.
|
|
3. -Wo <options> - pass optimizations to the llvm-ld
|
|
4. mcc16 -Wl <options> - pass options to native linker.
|
|
5. mcc16 -Wa <options> - pass options to native assembler.
|
|
|
|
Here are some example command lines and sample command invocations as to
|
|
what should be done.
|
|
|
|
$ mcc16 -S foo.c
|
|
// [clang-cc foo.c] -> foo.bc
|
|
// [llvm-ld foo.bc] -> foo.opt.bc
|
|
// [llc foo.opt.bc] -> foo.s
|
|
|
|
$ mcc16 -S foo.c bar.c
|
|
// [clang-cc foo.c] -> foo.bc
|
|
// [llvm-ld foo.bc] -> foo.opt.bc
|
|
// [llc foo.opt.bc] -> foo.s
|
|
// [clang-cc bar.c] -> bar.bc
|
|
// [llvm-ld bar.bc] -> bar.opt.bc
|
|
// [llc bar.opt.bc] -> bar.s
|
|
|
|
** Use of -g causes llvm-ld to run with -disable-opt
|
|
$ mcc16 -S -g foo.c
|
|
// [clang-cc foo.c] -> foo.bc
|
|
// [llvm-ld -disable-opt foo.bc] -> foo.opt.bc
|
|
// [llc foo.opt.bc] -> foo.s
|
|
|
|
** -I is passed to clang-cc, -pre-RA-sched=list-burr to llc.
|
|
$ mcc16 -S -g -I ../include -pre-RA-sched=list-burr foo.c
|
|
// [clang-cc -I ../include foo.c] -> foo.bc
|
|
// [llvm-ld -disable-opt foo.bc] -> foo.opt.bc
|
|
// [llc -pre-RA-sched=list-burr foo.opt.bc] -> foo.s
|
|
|
|
** -Wo passes options to llvm-ld
|
|
$ mcc16 -Wo=opt1,opt2 -S -I ../include -pre-RA-sched=list-burr foo.c
|
|
// [clang-cc -I ../include foo.c] -> foo.bc
|
|
// [llvm-ld -opt1 -opt2 foo.bc] -> foo.opt.bc
|
|
// [llc -pre-RA-sched=list-burr foo.opt.bc] -> foo.s
|
|
|
|
** -Wa passes options to native as.
|
|
$ mcc16 -c foo.c -Wa=opt1
|
|
// [clang-cc foo.c] -> foo.bc
|
|
// [llvm-ld foo.bc] -> foo.opt.bc
|
|
// [llc foo.opt.bc] -> foo.s
|
|
// [native-as -opt1 foo.s] -> foo.o
|
|
|
|
$ mcc16 -Wo=opt1 -Wl=opt2 -Wa=opt3 foo.c bar.c
|
|
// [clang-cc foo.c] -> foo.bc
|
|
// [clang-cc bar.c] -> bar.bc
|
|
// [llvm-ld -opt1 foo.bc bar.bc] -> a.out.bc
|
|
// [llc a.out.bc] -> a.out.s
|
|
// [native-as -opt3 a.out.s] -> a.out.o
|
|
// [native-ld -opt2 a.out.o] -> a.out
|
|
|
|
Is this achievable by a tablegen based driver ?
|
|
|
|
- Sanjiv
|