Getting started with LLVM using Swift

Transcript

1. Alex Denisov, http://lowlevelbits.org Getting started with LLVM using Swift
2. whoami • iOS Apps Developer • Compiler Hobbyist • Internet User: https://twitter.com/1101_debian https://github.com/AlexDenisov http://lowlevelbits.org
3. Outline • What is LLVM • Compilation Process • Practical Applications • LLVM C API • QA
4. LLVM
5. 5 Frontend Backend
6. 6 Lexer Parser Semantic 
 Analysis Code Generation Frontend Backend
7. 7 Lexer Parser Semantic 
 Analysis Code Generation Frontend Optimization Assembler Backend Linker
8. 8 Frontend Optimization Assembler Backend Linker
9. 9 Frontend Backend ARM x86 MIPS •••
10. Compilation Process
11. 0000000 cf fa ed fe 07 00 00 01 03 00 00 80 02 00 00 00 0000010 0f 00 00 00 38 03 00 00 85 00 20 00 00 00 00 00 0000020 19 00 00 00 48 00 00 00 5f 5f 50 41 47 45 5a 45 0000030 52 4f 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0000040 00 00 00 00 01 00 00 00 00 00 00 00 00 00 00 00 0000050 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0000060 00 00 00 00 00 00 00 00 19 00 00 00 38 01 00 00 0000070 5f 5f 54 45 58 54 00 00 00 00 00 00 00 00 00 00 0000080 00 00 00 00 01 00 00 00 00 10 00 00 00 00 00 00 0000090 00 00 00 00 00 00 00 00 00 10 00 00 00 00 00 00 00000a0 07 00 00 00 05 00 00 00 03 00 00 00 00 00 00 00 00000b0 5f 5f 74 65 78 74 00 00 00 00 00 00 00 00 00 00 00000c0 5f 5f 54 45 58 54 00 00 00 00 00 00 00 00 00 00 00000d0 98 0f 00 00 01 00 00 00 08 00 00 00 00 00 00 00 00000e0 98 0f 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00000f0 00 04 00 80 00 00 00 00 00 00 00 00 00 00 00 00 0000100 5f 5f 75 6e 77 69 6e 64 5f 69 6e 66 6f 00 00 00 0000110 5f 5f 54 45 58 54 00 00 00 00 00 00 00 00 00 00 0000120 a0 0f 00 00 01 00 00 00 48 00 00 00 00 00 00 00 0000130 a0 0f 00 00 02 00 00 00 00 00 00 00 00 00 00 00 0000140 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0000150 5f 5f 65 68 5f 66 72 61 6d 65 00 00 00 00 00 00 0000160 5f 5f 54 45 58 54 00 00 00 00 00 00 00 00 00 00 0000170 e8 0f 00 00 01 00 00 00 18 00 00 00 00 00 00 00 0000180 e8 0f 00 00 03 00 00 00 00 00 00 00 00 00 00 00 0000190 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00001a0 19 00 00 00 48 00 00 00 5f 5f 4c 49 4e 4b 45 44 00001b0 49 54 00 00 00 00 00 00 00 10 00 00 01 00 00 00 00001c0 00 10 00 00 00 00 00 00 00 10 00 00 00 00 00 00 00001d0 d8 00 00 00 00 00 00 00 07 00 00 00 01 00 00 00 int main(){ return 0; }
12. 12 const float factor = 42.f; int calc(float x) { return factor * x; }
13. Lexer 13
14. 14 const float factor = 42.f; int calc(float x) { return factor * x; }
15. 15 const float factor = 42.f; int calc(float x) { return factor * x; } (KW ‘const’)
16. 16 const float factor = 42.f; int calc(float x) { return factor * x; } (KW ‘const’) (TYPE ‘float’)
17. 17 const float factor = 42.f; int calc(float x) { return factor * x; } (KW ‘const’) (TYPE ‘float’) (ID ‘factor’) (EQ ‘=‘) (NUM ’42.f’) (SEMI ‘;’)
18. 18 const float factor = 42.f; int calc(float x) { return factor * x; } (KW ‘const’) (TYPE ‘float’) (ID ‘factor’) (EQ ‘=‘) (NUM ’42.f’) (SEMI ‘;’) (TYPE ‘int’) (ID ‘calc’) (L_PAREN ‘(‘) (TYPE ‘float’) (ID ‘x’) (R_PAREN ‘)’) (L_BRACE ‘{‘) (KW ‘return’) (ID ‘factor’) (STAR ‘*’) (ID ‘x’) (SEMI ‘;’) (R_BRACE ‘}’) (EOF ‘’)
19. Parser 19
20. 20 return factor * x
21. 21 (KW ‘return’) (ID ‘factor’) (STAR ‘*’) (ID ‘x’) return factor * x
22. 22 (KW ‘return’) (ID ‘factor’) (STAR ‘*’) (ID ‘x’) (KW ‘return’) (ID ‘factor’) (STAR ‘*’) (ID ‘x’) return factor * x
23. 23 (KW ‘return’) (ID ‘factor’) (STAR ‘*’) (ID ‘x’) return factor * x ReturnStmt return BinaryOperator
 * ReferenceDecl
 x ReferenceDecl
 factor
24. 24 AST VariableDecl
 factor : float FloatLiteral
 42.f FunctionDecl
 calc : int ParameterDecl
 x : float ReturnStmt return BinaryOperator
 * ReferenceDecl
 x ReferenceDecl
 factor
25. Semantic Analysis 25
26. 26 AST VariableDecl
 factor : float FloatLiteral
 42.f FunctionDecl
 calc : int ParameterDecl
 x : float ReturnStmt return BinaryOperator
 * ReferenceDecl
 x ReferenceDecl
 factor
27. 27 AST VariableDecl
 factor : float FloatLiteral
 42.f : float FunctionDecl
 calc : int ParameterDecl
 x : float ReturnStmt return : int BinaryOperator
 * : float ReferenceDecl
 x : float ReferenceDecl
 factor : float
28. 28 AST VariableDecl
 factor : float FloatLiteral
 42.f : float FunctionDecl
 calc : int ParameterDecl
 x : float ReturnStmt return : int BinaryOperator
 * : float ReferenceDecl
 x : float ReferenceDecl
 factor : float ???
29. 29 AST VariableDecl
 factor : float FloatLiteral
 42.f : float FunctionDecl
 calc : int ParameterDecl
 x : float ReturnStmt return : int BinaryOperator
 * : float ReferenceDecl
 x : float ReferenceDecl
 factor : float ImplicitCast
 ftoi : int
30. Code Generation 30
31. 31 @factor = constant float 42.0 define calc(float %x) { entry: movf %x, %r1 movf @factor, %r2 %r3 = fmul %r1, %r2 movf %r3, %r0 ret }
32. Optimization 32
33. 33 @factor = constant float 42.0 define calc(float %x) { entry: movf %x, %r1 movf @factor, %r2 %r3 = fmul %r1, %r2 movf %r3, %r0 ret }
34. 34 @factor = constant float 42.0 define calc(float %x) { entry: %r0 = fmul @factor, %x ret }
35. Assembler 35
36. 36 _calc: push {r7, lr} mov r7, sp mov r1, #36175872 orr r1, r1, #1073741824 bl ___mulsf3 bl ___fixsfsi pop {r7, lr} mov pc, lr .section __TEXT,__const .globl _factor @ @factor .align 2 _factor: .long 1109917696 @ float 42
37. Linker 37
38. 38 $ clang -c calc.c -o calc.o const float factor = 42.f; int calc(float x) { return factor * x; }
39. 39 extern int calc(float); int main() { printf(“%d\n”, calc(2.f)); return 0; } $ clang -c main.c -o main.o
40. 40 $ nm main.o U _calc 0000000000000000 T _main U _printf
41. 41 $ nm main.o U _calc 0000000000000000 T _main U _printf $ ld -lc calc.o main.o -o main $ nm main 0000000000001f30 T _calc 0000000000001fc8 S _factor 0000000000001f60 T _main U _printf
42. 42 Lexer Parser Semantic 
 Analysis Code Generation Frontend Optimization Assembler Backend Linker
43. Applications
44. Application #1 UI Development
47. Application #2 Mocks
51. Application #3 Mutation Testing
57. Applications • Haml/Slim compiler • Swift + Mocks • Mutation Testing • You name it!
58. LLVM Template
59. $ make setup $ make build $ open LLVMTemplate.xcodeproj
64. What’s next?
65. Design decisions that shaped LLVM http://aosabook.org/en/llvm.html Implementing a Language with LLVM http://llvm.org/docs/tutorial/index.html Various articles about LLVM http://lowlevelbits.org/categories/llvm/ LLVM + Swift Xcode Template https://github.com/AlexDenisov/LLVMTemplate Kaleidoscope in Swift https://github.com/AlexDenisov/SwiftKaleidoscope
66. Thank You! Alex Denisov, http://lowlevelbits.org