Getting started with LLVM using Swift. Alex Denisov,

Transcription

1 Getting started with LLVM using Swift Alex Denisov,

2 whoami ios Apps Developer Compiler Hobbyist Internet User:

3 Outline What is LLVM Compilation Process Practical Applications LLVM C API QA

4 LLVM

5 Frontend Backend 5

6 Lexer Parser Frontend Code Generation Semantic Analysis Backend 6

7 Lexer Parser Frontend Code Generation Semantic Analysis Optimization Assembler Backend Linker 7

8 Frontend Optimization Assembler Backend Linker 8

9 Frontend Backend ARM x86 MIPS 9

10 Compilation Process

11 int main(){ } return 0; cf fa ed fe f f 5f a f f 5f a b0 5f 5f c0 5f 5f d0 98 0f e0 98 0f f f 5f 75 6e e 64 5f 69 6e 66 6f f 5f a0 0f a0 0f f 5f f d f 5f e8 0f e8 0f a f 5f 4c 49 4e 4b b c d0 d

12 const float factor = 42.f; int calc(float x) { } return factor * x; 12

13 Lexer 13

14 const float factor = 42.f; int calc(float x) { return factor * x; } 14

15 (KW const ) const float factor = 42.f; int calc(float x) { return factor * x; } 15

16 (KW const ) (TYPE float ) const float factor = 42.f; int calc(float x) { return factor * x; } 16

17 (KW const ) (TYPE float ) (ID factor ) (EQ = ) (NUM 42.f ) (SEMI ; ) const float factor = 42.f; int calc(float x) { return factor * x; } 17

18 (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 ) const float factor = 42.f; int calc(float x) { return factor * x; } 18

19 Parser 19

20 return factor * x 20

21 return factor * x (KW return ) (ID factor ) (STAR * ) (ID x ) 21

22 return factor * x (KW return ) (ID factor ) (STAR * ) (ID x ) (KW return ) (STAR * ) (ID factor ) (ID x ) 22

23 return factor * x (KW return ) (ID factor ) (STAR * ) (ID x ) ReturnStmt return BinaryOperator * ReferenceDecl factor 23 ReferenceDecl x

24 AST FunctionDecl calc : int VariableDecl factor : float ParameterDecl x : float ReturnStmt return FloatLiteral 42.f BinaryOperator * ReferenceDecl x 24 ReferenceDecl factor

25 Semantic Analysis 25

26 AST FunctionDecl calc : int VariableDecl factor : float ParameterDecl x : float ReturnStmt return FloatLiteral 42.f BinaryOperator * ReferenceDecl x 26 ReferenceDecl factor

27 AST FunctionDecl calc : int VariableDecl factor : float ParameterDecl x : float ReturnStmt return : int FloatLiteral 42.f : float BinaryOperator * : float ReferenceDecl x : float 27 ReferenceDecl factor : float

28 AST FunctionDecl calc : int VariableDecl factor : float ParameterDecl x : float ReturnStmt return : int FloatLiteral 42.f : float??? BinaryOperator * : float ReferenceDecl x : float 28 ReferenceDecl factor : float

29 AST FunctionDecl calc : int VariableDecl factor : float ParameterDecl x : float ReturnStmt return : int FloatLiteral 42.f : float ImplicitCast ftoi : int BinaryOperator * : float ReferenceDecl x : float 29 ReferenceDecl factor : float

30 Code Generation 30

31 @factor = constant float 42.0 define calc(float %x) { entry: movf %x, %r1 %r2 %r3 = fmul %r1, %r2 movf %r3, %r0 ret } 31

32 Optimization 32

33 @factor = constant float 42.0 define calc(float %x) { entry: movf %x, %r1 %r2 %r3 = fmul %r1, %r2 movf %r3, %r0 ret } 33

34 @factor = constant float 42.0 define calc(float %x) { entry: %r0 = %x ret } 34

35 Assembler 35

36 _calc: push {r7, lr} mov r7, sp mov r1, # orr r1, r1, # bl mulsf3 bl fixsfsi pop {r7, lr} mov pc, lr.section TEXT, 2 _factor:.long float 42 36

37 Linker 37

38 const float factor = 42.f; int calc(float x) { } return factor * x; $ clang -c calc.c -o calc.o 38

39 extern int calc(float); int main() { printf( %d\n, calc(2.f)); return 0; } $ clang -c main.c -o main.o 39

40 $ nm main.o U _calc T _main U _printf 40

41 $ nm main.o U _calc T _main U _printf $ ld -lc calc.o main.o -o main $ nm main f30 T _calc fc8 S _factor f60 T _main U _printf 41

42 Lexer Parser Frontend Code Generation Semantic Analysis Optimization Assembler Backend Linker 42

43 Applications

44 Application #1 UI Development

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47 Application #2 Mocks

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51 Application #3 Mutation Testing

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57 Applications Haml/Slim compiler Swift + Mocks Mutation Testing You name it!

58 LLVM Template

59 $ make setup $ make build $ open LLVMTemplate.xcodeproj

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64 What s next?

65 Design decisions that shaped LLVM Implementing a Language with LLVM Various articles about LLVM Kaleidoscope in Swift LLVM + Swift Xcode Template

66 Thank You! Alex Denisov,