D2 script (https://github.com/terrastruct/d2) for a three stage compiler diagram (https://en.wikipedia.org/wiki/Compiler#Three-stage_compiler_structure).

three-stage-compiler.d2

title: Three-stage compiler structure {
  shape: text
  near: frontend
  style: {
    font-size: 80
    bold: true
  }
}

direction: right

llvm-ir1: LLVM-IR {
  style: {
    stroke-width: 0
    fill: white
  }
}

llvm-ir2: LLVM-IR {
  style: {
    stroke-width: 0
    fill: white
  }
}

frontend: Frontend {
  clang: Clang {
    style: {
      stroke-width: 3
      stroke: "#000000"
      fill: white
    }
  }

  gollvm: Gollvm {
    style: {
      stroke-width: 3
      stroke: "#000000"
      fill: white
    }
  }

  rustc: {
    style: {
      stroke-width: 3
      stroke: "#000000"
      fill: white
    }
  }

  boltc: {
    style: {
      stroke-width: 3
      stroke: "#000000"
      stroke-dash: 3
      fill: white
    }
  }

  style: {
    stroke-width: 3
    stroke: "#5721ff"
    fill: white
  }
}

middle-end: Middle-end {
  llvm-optimizer: LLVM optimizer {
    style: {
      stroke-width: 3
      stroke: "#000000"
      fill: white
    }
  }

  style: {
    stroke-width: 3
    stroke: "#5721ff"
    fill: white
  }
}

backend: Backend {
  llvm-static-compiler: LLVM static compiler {
    style: {
      stroke-width: 3
      stroke: "#000000"
      fill: white
    }
  }

  style: {
    stroke-width: 3
    stroke: "#5721ff"
    fill: white
  }
}

# Input Languages

c: C {
  style: {
    stroke-width: 0
    fill: white
  }
}

cpp: C++ {
  style: {
    stroke-width: 0
    fill: white
  }
}

go: Go {
  style: {
    stroke-width: 0
    fill: white
  }
}

rust: Rust {
  style: {
    stroke-width: 0
    fill: white
  }
}

bolt: Bolt {
  style: {
    stroke-width: 0
    fill: white
  }
}

# Output
x86: x86 {
  style: {
    stroke-width: 0
    fill: white
  }
}

ARM: {
  style: {
    stroke-width: 0
    fill: white
  }
}

RISC-V: {
  style: {
    stroke-width: 0
    fill: white
  }
}

MIPS: {
  style: {
    stroke-width: 0
    fill: white
  }
}

PowerPC: {
  style: {
    stroke-width: 0
    fill: white
  }
}

other-output: "..." {
  style: {
    stroke-width: 0
    fill: white
  }
}

# Input languages to frontend
c -> frontend.clang
cpp -> frontend.clang
go -> frontend.gollvm
rust -> frontend.rustc
bolt -> frontend.boltc

# Frontend to LLVM
frontend.clang -> llvm-ir1
frontend.gollvm -> llvm-ir1
frontend.rustc -> llvm-ir1
frontend.boltc -> llvm-ir1

# LLVM to Middle-end
llvm-ir1 -> middle-end.llvm-optimizer
llvm-ir2 <- middle-end.llvm-optimizer

# Middle-end to backend
llvm-ir2 -> backend.llvm-static-compiler

# Backend to output
backend.llvm-static-compiler -> x86
backend.llvm-static-compiler -> ARM
backend.llvm-static-compiler -> RISC-V
backend.llvm-static-compiler -> MIPS
backend.llvm-static-compiler -> PowerPC
backend.llvm-static-compiler -> other-output