## +24 ## LLVM's Realtime Safety Revolution: Tools for Modern Mission Critical Systems DAVID TREVELYAN & CHRISTOPHER APPLE ## Chris Apple ## David Trevelyan • 10-year veteran of the audio industry safety build:mac unit:mac rtsan build:win unit:mac:arm build:linux unit:win unit:linux ## LLVM 20  WE'RE HERE (is_in_realtime_context(): print_stack_and_die("malloc"); return REAL(malloc)(size); } LLVM Intermediate Representation (IR) ## Real-time context signaling compilation step int dispatch()

Algorithms 973 53.4 Alternate orderings 975 54 Iteration utilities 977 55 C Interface 988 56 LLVM Interface 1000 57 C Standard Library 1001 58 StackTraces 1004 59 SIMD Support 1006 III Standard isbits Union Optimizations ..... 1460 101.13 System Image Building ..... 1461 101.14 Working with LLVM ..... 1463 101.15 printf() and stdio in the Julia runtime ..... 1469 101.16 Bounds checking . good performance, achieved using type inference and just-in-time (JIT) compilation, implemented using LLVM. It is multi-paradigm, combining features of imperative, functional, and object-oriented programming

841 54.4 Alternate orderings 842 55 Iteration utilities 844 56 C Interface 853 57 LLVM Interface 864 58 C Standard Library 865 59 StackTraces 868 60 SIMD Support 870 isbits Union Optimizations ..... 1256 98.13 System Image Building ..... 1257 98.14 Working with LLVM ..... 1259 98.15 printf() and stdio in the Julia runtime ..... 1265 98.16 Bounds checking ... good performance, achieved using type inference and just-in-time (JIT) compilation, implemented using LLVM. It is multi-paradigm, combining features of imperative, functional, and object-oriented programming

Alternate orderings ..... 841 54 Iteration utilities ..... 843 55 C Interface ..... 852 56 LLVM Interface ..... 863 57 C Standard Library ..... 864 58 StackTraces ..... 867 59 SIMD isbits Union Optimizations ..... 1255 97.13 System Image Building ..... 1256 97.14 Working with LLVM ..... 1258 97.15 printf() and stdio in the Julia runtime ..... 1264 97.16 Bounds checking ... good performance, achieved using type inference and just-in-time (JIT) compilation, implemented using LLVM. It is multi-paradigm, combining features of imperative, functional, and object-oriented programming

JULIA_GC_NO_GENERATIONAL ..... 335 JULIA_GC_WAIT_FOR_DEBUGGER ..... 335 ENABLE_JITPROFILING ..... 335 JULIA_LLVM_ARGS ..... 335 JULIA_DEBUG_LOADING ..... 335 7 Embedding Julia ..... 337 37.1 High-Level Embedding Sorting Algorithms ..... 792 63 Iteration utilities ..... 795 64 C Interface ..... 801 65 LLVM Interface ..... 809 66 C Standard Library ..... 811 67 StackTraces ..... 815 68 SIMD Working with LLVM ..... 1163 Overview of Julia to LLVM Interface ..... 1163 Building Julia with a different version of LLVM ..... 1164 Passing options to LLVM ..... 1164 Debugging LLVM transformations

Algorithms 1027 53.4 Alternate orderings 1028 54 Iteration utilities 1031 55 C Interface 1043 56 LLVM Interface 1055 57 C Standard Library 1056 58 StackTraces 1059 59 SIMD Support 1061 III Standard 102.13 System Image Building ..... 1538 102.14 Package Images ..... 1540 102.15 Working with LLVM ..... 1542 102.16 printf() and stdio in the Julia runtime ..... 1548 102.17 Bounds checking . inference and just-in-time (JIT) compilation (and optional ahead-of-time compilation), implemented using LLVM. It is multi-paradigm, combining features of imperative, functional, and object-oriented programming

JULIA_GC_WAIT_FOR_DEBUGGER ..... 333 ENABLE_JITPROFILING ..... 334 ENABLE_GDBLISTENER ..... 334 JULIA_LLVM_ARGS ..... 334 30 Embedding Julia ..... 335 30.1 High-Level Embedding ..... 335 Using Julia-config 864 54.4 Alternate orderings 865 55 Iteration utilities 867 56 C Interface 877 57 LLVM Interface 889 58 C Standard Library 891 59 StackTraces 895 60 SIMD Support 897 Working with LLVM ..... 1300 Overview of Julia to LLVM Interface ..... 1300 Building Julia with a different version of LLVM ..... 1301 Passing options to LLVM ..... 1301 Debugging LLVM transformations

883 54.4 Alternate orderings 884 55 Iteration utilities 886 56 C Interface 896 57 LLVM Interface 907 58 C Standard Library 908 59 StackTraces 911 60 SIMD Support 913 CONTENTS 1306 98.12 isbits Union Optimizations 1309 98.13 System Image Building 1310 98.14 Working with LLVM 1312 98.15 printf() and stdio in the Julia runtime 1318 98.16 Bounds checking 1319 98.17 Proper good performance, achieved using type inference and just-in-time (JIT) compilation, implemented using LLVM. It is multi-paradigm, combining features of imperative, functional, and object-oriented programming

Algorithms 973 53.4 Alternate orderings 975 54 Iteration utilities 977 55 C Interface 988 56 LLVM Interface 1000 57 C Standard Library 1001 58 StackTraces 1004 59 SIMD Support 1006 III Standard good performance, achieved using type inference and just-in-time (JIT) compilation, implemented using LLVM. It is multi-paradigm, combining features of imperative, functional, and object-oriented programming primitive type. This functionality exists to allow Julia to bootstrap the standard primitive types that LLVM supports. Once they are defined, there is very little reason to define more. A primitive type is

Algorithms 973 53.4 Alternate orderings 975 54 Iteration utilities 977 55 C Interface 988 56 LLVM Interface 1000 57 C Standard Library 1001 58 StackTraces 1004 59 SIMD Support 1006 III Standard good performance, achieved using type inference and just-in-time (JIT) compilation, implemented using LLVM. It is multi-paradigm, combining features of imperative, functional, and object-oriented programming primitive type. This functionality exists to allow Julia to bootstrap the standard primitive types that LLVM supports. Once they are defined, there is very little reason to define more. A primitive type is