Output labels when disassembling code

[eschnett]

This addresses #6589.

This handles only the LLVM33 non-MCJIT case. Addressing the other cases seems straightforward, but I currently can't test them locally.

[ihnorton]

👍

[nolta]

Is this intentional?

[eschnett]

Thanks for catching this, that's just leftover debug output. Since the actual disassembled output is cached, cout output appears above, making it easy to miss.

[vtjnash]

would this allow us to also start generating better labels for call instructions and variable assignments? or is this just for labels (which is alone very awesome)?

[eschnett]

This is at the moment only for branch labels, where the new code maintains a symbol table.

If Julia already has a symbol table (I guess it does) for call targets, then it should be just a few additional lines to convert those into meaningful names as well. Any pointers?

(What's up with Travis? I always get gfortran errors for the OS X tests, and I don't think it's related to my changes.)

[eschnett]

Call labels are now resolved as well.

[JeffBezanson]

Wow, this is impressive. Can you show some example output?

[eschnett]

Example output with labels. Local (branch) labels use L as prefix, global (call) labels use the respective routine names (thanks, backtrace mechanism!).

julia> code_native(Burgers.u_initial, (Int,))
    .section    __TEXT,__text,regular,pure_instructions
Filename: /Users/eschnett/src/jl/Burgers.jl
Source line: 7
    push    RBP
    mov RBP, RSP
    push    R14
    push    RBX
    sub RSP, 32
    mov RBX, RDI
    mov QWORD PTR [RBP - 48], 4
Source line: 7
    movabs  R14, jl_pgcstack
    mov RAX, QWORD PTR [R14]
    mov QWORD PTR [RBP - 40], RAX
    lea RAX, QWORD PTR [RBP - 48]
    mov QWORD PTR [R14], RAX
    mov QWORD PTR [RBP - 32], 0
    movabs  RAX, 140225061117248
Source line: 8
    mov QWORD PTR [RBP - 24], RAX
    movabs  RAX, jl_new_array
    movabs  RDI, 140225061117248
    mov RSI, RBX
    call    RAX
    test    RBX, RBX
    mov QWORD PTR [RBP - 32], RAX
    jle L240
Source line: 7
    lea RCX, QWORD PTR [RBX - 1]
    vcvtsi2sd   XMM0, XMM0, RCX
    movabs  RCX, 4568076320
    vmovsd  XMM1, QWORD PTR [RCX]
    vdivsd  XMM0, XMM1, XMM0
Source line: 11
    mov RCX, QWORD PTR [RAX + 16]
    xor EDX, EDX
    vxorps  XMM1, XMM1, XMM1
    movabs  RSI, 4568076328
    vmovsd  XMM2, QWORD PTR [RSI]
    movabs  RSI, 4568076336
    vmovsd  XMM3, QWORD PTR [RSI]
    xor ESI, ESI
Source line: 10
L173:   vcvtsi2sd   XMM4, XMM0, RSI
    vmulsd  XMM4, XMM0, XMM4
    vaddsd  XMM4, XMM4, XMM1
    vucomisd    XMM3, XMM4
    vmovaps XMM4, XMM2
    ja  L204
    vxorps  XMM4, XMM4, XMM4
Source line: 11
L204:   cmp RSI, RCX
    jae L256
    mov RDI, QWORD PTR [RAX + 8]
    sub RDI, RDX
    vmovsd  QWORD PTR [RDI], XMM4
    add RDX, -8
    inc RSI
    cmp RBX, RSI
    jne L173
Source line: 13
L240:   mov RCX, QWORD PTR [RBP - 40]
    mov QWORD PTR [R14], RCX
    add RSP, 32
    pop RBX
    pop R14
    pop RBP
    ret
Source line: 11
L256:   movabs  RAX, jl_bounds_exception
    mov RDI, QWORD PTR [RAX]
    movabs  RAX, jl_throw_with_superfluous_argument
    mov ESI, 11
    call    RAX

[eschnett]

It seems the code is missing some symbols. I think this may be related to functions that have not yet been compiled, and where the code presumably is pointing to a wrapper or trampoline. Where is the data structure defined in Julia that holds the mapping between functions and addresses? I found Function and jl_codectx_t in codegen.cpp, but I didn't find any global data structure that holds pointers to these.

[StefanKarpinski]

Nice. This makes the native code dumps actually somewhat decipherable when there are branches.