Getting LLVM Bitcode from Julia Script

New to Julia
1

I’m new to Julia and I’m trying to get the LLVM IR or bitcode file of a Julia script. Two ways are mentioned in documents:

1- export JULIA_LLVM_ARGS = -print-after-all` dumps IR after each pass.

2- Passing --outout-unopt-bc unopt.bc option to system image build process, which will output the unoptimized IR to the unopt.bc file.

I want the finalized IR and getting IR after each pass is not useful for me. For the second option, as I understand, previous Julia versions accept --output-unopt-bc and --outpu-bc options but version 1.0 does not.

Is there any straightforward way to get the LLVM bitcode file?

2

Put it in a function and use @code_llvm

3

You might want to enable the dump_module option, eg. @code_llvm dump_module=true 1+1, if you want IR that’s compatible with the rest of LLVM tooling.

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4

Is it possible to use the @code_llvm in a script or it works only for the interactive mode of Julia?

I tried it in the interactive mode and it does not print the IR of all functions which are called in the main function.

5

Thanks but still it does not print the whole code’s IR, it only prints that function’s IR in another way.

6

Use the code_llvm function with the io argument set to a IOBuffer.

That’s not true.

julia> code_llvm(+, Tuple{Int, Int})

; Function +
; Location: int.jl:53
define i64 @"julia_+_33814"(i64, i64) {
top:
  %2 = add i64 %1, %0
  ret i64 %2
}

julia> code_llvm(+, Tuple{Int, Int}; dump_module=true)
; ModuleID = '+'
source_filename = "+"
target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128-ni:10:11:12:13"
target triple = "x86_64-unknown-linux-gnu"

%jl_value_t = type opaque

; Function +
; Location: int.jl:53
define i64 @"julia_+_33814"(i64, i64) {
top:
  %2 = add i64 %1, %0
  ret i64 %2
}

define nonnull %jl_value_t addrspace(10)* @"jsys_+_33813"(%jl_value_t addrspace(10)*, %jl_value_t addrspace(10)**, i32) #0 {
top:
  %3 = getelementptr inbounds %jl_value_t addrspace(10)*, %jl_value_t addrspace(10)** %1, i64 1
  %4 = bitcast %jl_value_t addrspace(10)** %3 to i64 addrspace(10)**
  %5 = load i64 addrspace(10)*, i64 addrspace(10)** %4, align 8
  %6 = addrspacecast i64 addrspace(10)* %5 to i64 addrspace(11)*
  %7 = load i64, i64 addrspace(11)* %6, align 8
  %8 = getelementptr inbounds %jl_value_t addrspace(10)*, %jl_value_t addrspace(10)** %1, i64 2
  %9 = bitcast %jl_value_t addrspace(10)** %8 to i64 addrspace(10)**
  %10 = load i64 addrspace(10)*, i64 addrspace(10)** %9, align 8
  %11 = addrspacecast i64 addrspace(10)* %10 to i64 addrspace(11)*
  %12 = load i64, i64 addrspace(11)* %11, align 8
  %13 = call i64 @"julia_+_33814"(i64 %7, i64 %12)
  %14 = call %jl_value_t addrspace(10)* @jl_box_int64(i64 signext %13)
  ret %jl_value_t addrspace(10)* %14
}

declare %jl_value_t addrspace(10)* @jl_box_int64(i64 signext)

attributes #0 = { "thunk" }

!llvm.module.flags = !{!0, !1}
!llvm.dbg.cu = !{!2}

!0 = !{i32 2, !"Dwarf Version", i32 4}
!1 = !{i32 1, !"Debug Info Version", i32 3}
!2 = distinct !DICompileUnit(language: DW_LANG_C89, file: !3, producer: "julia", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !4)
!3 = !DIFile(filename: "int.jl", directory: ".")
!4 = !{}
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