![#include <stdio.h>
int main(int argc, char* argv[]){
puts(“Hello World!”);
return 0;
}
In C
Hello World!
print “Hello World!”
In Python
Hello World!
魔法 我想學魔法!](https://image.slidesharecdn.com/llvmkeynotestatic-160820005906/85/COSCUP-2016-LLVM-6-320.jpg)
COSCUP 2016 - LLVM 由淺入淺
- 3. 楊宗凡 — 浪打 ‣ 成功⼤大學電機系四年級 ‣ sonic.tw.tp (at) gmail.com 戴宏穎 — Hydai ‣ 清華⼤大學資⼯工碩⼀一年級 ‣ z54981220 (at) gmail.com
- 5. Code to Executable $ gcc helloworld.c
- 6. #include <stdio.h> int main(int argc, char* argv[]){ puts(“Hello World!”); return 0; } In C Hello World! print “Hello World!” In Python Hello World! 魔法 我想學魔法!
- 7. The Magic 原始碼 組合語⾔言 機械碼 AssemblerCompiler print “!@#$” mov d, msg$ mov c, 9 call 5 110100…. >./hw 機械碼 110100…. Hello World!
- 9. bdos equ 0005H start: mvi c,9 lxi d,msg$ call bdos ret msg$:db 'Hello, world!$' end start Intel 8080 Assembler MSG: .ASCIIZ "Hello, world!" LDX #0 LDA MSG,X @LP: JSR $FFD2 INX LDA MSG,X BNE @LP RTS MOS 6502 8080 Assemble 6502 Assemble 110110.. 010111.. CP/M Apple Dos
- 10. Perl Python Java C Ruby Javascript 他們都造⾃自⼰己的輪⼦子 對應不同的機器 IA-32 AMD64 IA-64 Arch32 AArch64 Sun Sparc
- 12. Modern Compiler $ export CFLAGS = “-O3”
- 15. Copy Propagation
- 17. Constant Folding
- 22. LLVM Framework $ git clone http://llvm.org/git/llvm.git
- 24. IR LLVM Framework - Front End 原始碼 Backend 組合語⾔言Frontend IRPass IR Pass … Pass IR Pass
- 25. IR LLVM Framework - Optimizer 原始碼 Backend 組合語⾔言Frontend IRPass IR Pass … Pass IR Pass
- 26. IR LLVM Framework - Back End 原始碼 Backend 組合語⾔言Frontend IRPass IR Pass … Pass IR Pass
- 28. Front End $ clang -S -emit-llvm main.c
- 30. Hello, world!
- 32. Whitespace 簡介 • 只有三種 Tokens： • Space 空⽩白(' ') • Tabs 制表符(t) • New lines 換⾏行(n) • 其餘的字元全部都被當成註解
- 33. Front End to IR 程式碼 LLVM IR
- 34. Front End to IR 程式碼 LLVM IRParser LLVM API • Module • IRBuilder • Function • BasicBlock • Instruction
- 35. LLVM IR $ cat main.ll
- 36. LLVM IR • RISC-style (Reduced Instruction Set Computing) • ⼈人類可讀的 • 具備 SSA form (Static Single Assignment) • 無限多的虛擬暫存器 • 任意位元⼤大⼩小 • 不改變⾏行為下 Transform IR ，來做最佳化。
- 37. C to IR
- 39. int a = 1;
- 40. int c = a+b;
- 41. Optimizer • LLVM 使⽤用 opt 做最佳化 • 每⼀一種類的分析跟轉換的 pass 都是 opt 的參數 • opt 會照順序幫你⼀一個⼀一個⾛走過這些 pass • 每個 pass 會⾃自⼰己決定要不要做事
- 42. opt 剛才的 C Code
- 43. Backend $ llc -march=z80 main.ll
- 44. Basic Ideas LLVM IR 組合語⾔言
- 45. Basic Ideas SelectionDAGLLVM IR 組合語⾔言 •Combining •Legalizing •Scheduling •Register Allocation
- 46. What’s a DAG?
- 47. llvm::SelectionDAGISel LLVM IR 組合語⾔言 Original DAG Combined DAG Legalized DAG Target Legalizing DAG Combiner Instruction Selection TableGe n
- 48. llvm::SelectionDAGISel LLVM IR 組合語⾔言 Original DAG Combined DAG Legalized DAG Target Legalizing DAG Combiner Instruction Selection TableGe n
- 53. Register Allocation SSA 虛擬暫存器 CPU暫存器 分配 最佳化 Instruction Scheduling 原先指令順序 CPU 更適合的順續 順序 最佳化
- 54. llvm::SelectionDAGISel LLVM IR 組合語⾔言 Original DAG Combined DAG Legalized DAG Target Legalizing DAG Combiner Instruction Selection TableGe n
- 55. Demo A 40 years portal by LLVM, Linking 1976 and 2016
- 56. Demo A 40 years portal by LLVM, Linking 1976 and 2016 WhiteSpace LLVM IR 組合語⾔言 CP/M LLVM Zilog Z80
- 59. 1. Architecture for Next Generation GCC ftp://gcc.gnu.org/pub/gcc/summit/2003/Architecture%20for%20a%20Next-Generation %20GCC.pdf 2. Life of an Instruction in LLVM http://eli.thegreenplace.net/2012/11/24/life-of-an-instruction-in-llvm 3. A deeper look into the LLVM code generator http://eli.thegreenplace.net/2013/02/25/a-deeper-look-into-the-llvm-code-generator- part-1 4. LLVM TableGen Documentation http://llvm.org/docs/TableGen/index.html 5. LLVM TableGen Introduction http://llvm.org/docs/TableGen/LangIntro.html 6. Independent Code Generator http://llvm.org/docs/CodeGenerator.html 7. The Relationship between selectiondag and selectiondagisel http://stackoverflow.com/questions/26814062/the-relationship-between-selectiondag- and-selectiondagisel 8. How TableGen’s DAGISel Backend Works https://github.com/draperlaboratory/fracture/wiki/How-TableGen's-DAGISel-Backend- Works 9. ZASM - Z80 Assembler http://k1.spdns.de/Develop/Projects/zasm/Documentation/ 10. LLVM Z80 Backend https://github.com/mostlyuseful/llvm-z80/network 11. Whitespace LLVM https://github.com/Subv/Whitespace-LLVM
- 60. Q & A $ man man