Codegen error when adding more than 4 variables

[Pavel-Durov]

Not sure if its a duplicate or not.

Description

White working on the SWT multi module control point transition I found this test case that is failing in both HWT and SWT.

Versions

yk version - a797bdf
ykllvm version - ykjit/ykllvm@9cbe89d

Reproduction

This test case fails when adding a fifth variable e to the computation.

Test

// Run-time:
//   env-var: YKD_SERIALISE_COMPILATION=1
//   stderr:
//     ...

#include <assert.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <yk.h>
#include <yk_testing.h>

int main(int argc, char **argv) {
  YkMT *mt = yk_mt_new(NULL);
  yk_mt_hot_threshold_set(mt, 0);
  YkLocation loc = yk_location_new();
  int i = 4;
  NOOPT_VAL(loc);
  NOOPT_VAL(i);
  while (i > 0) {
    int a = i+1;     // Variable 1
    int b = i+a;     // Variable 2
    int c = i+b;     // Variable 3
    int d = i+c;     // Variable 4
    int e = i+d;     // Variable 5 - Adding this triggers the failure
    fprintf(stderr, "a=%d b=%d c=%d d=%d e=%d\n", a, b, c, d, e);
    yk_mt_control_point(mt, &loc);
    i = i - 1;
  }
  yk_location_drop(loc);
  yk_mt_shutdown(mt);
  return (EXIT_SUCCESS);
}

Test output:

test lang_tests::simple5.c ... FAILED

failures:

---- lang_tests::simple5.c status ----
Exited due to signal: 6

---- lang_tests::simple5.c stderr ----

a=5 b=9 c=13 d=17 e=21
a=4 b=7 c=10 d=13 e=16

thread '<unnamed>' panicked at ykrt/src/compile/jitc_yk/codegen/x64/mod.rs:1707:46:
called `Option::unwrap()` on a `None` value
stack backtrace:
   0:     0x7f47221c84b3 - std::backtrace_rs::backtrace::libunwind::trace::ha60d6c8dc3f5f8a4
                               at /rustc/f280acf4c743806abbbbcfe65050ac52ec4bdec0/library/std/src/../../backtrace/src/backtrace/libunwind.rs:117:9
   1:     0x7f47221c84b3 - std::backtrace_rs::backtrace::trace_unsynchronized::habe0365ec6a6308d
                               at /rustc/f280acf4c743806abbbbcfe65050ac52ec4bdec0/library/std/src/../../backtrace/src/backtrace/mod.rs:66:14
   2:     0x7f47221c84b3 - std::sys::backtrace::_print_fmt::hc3ae79cc2516a535
                               at /rustc/f280acf4c743806abbbbcfe65050ac52ec4bdec0/library/std/src/sys/backtrace.rs:66:9
   3:     0x7f47221c84b3 - <std::sys::backtrace::BacktraceLock::print::DisplayBacktrace as core::fmt::Display>::fmt::h8d9b2abef2510cd1
                               at /rustc/f280acf4c743806abbbbcfe65050ac52ec4bdec0/library/std/src/sys/backtrace.rs:39:26
   4:     0x7f47221ed9d3 - core::fmt::rt::Argument::fmt::hd734eb8dccf04fe9
                               at /rustc/f280acf4c743806abbbbcfe65050ac52ec4bdec0/library/core/src/fmt/rt.rs:177:76
   5:     0x7f47221ed9d3 - core::fmt::write::heb9cf6889f45a11e
                               at /rustc/f280acf4c743806abbbbcfe65050ac52ec4bdec0/library/core/src/fmt/mod.rs:1449:21
   6:     0x7f47221c5843 - std::io::Write::write_fmt::h6360a21e44de67e4
                               at /rustc/f280acf4c743806abbbbcfe65050ac52ec4bdec0/library/std/src/io/mod.rs:1890:15
   7:     0x7f47221c8302 - std::sys::backtrace::BacktraceLock::print::h9319588d0d6e4878
                               at /rustc/f280acf4c743806abbbbcfe65050ac52ec4bdec0/library/std/src/sys/backtrace.rs:42:9
   8:     0x7f47221c929a - std::panicking::default_hook::{{closure}}::h4c968bafc99c0b41
                               at /rustc/f280acf4c743806abbbbcfe65050ac52ec4bdec0/library/std/src/panicking.rs:298:22
   9:     0x7f47221c910a - std::panicking::default_hook::hafb4ab1b4e12432b
                               at /rustc/f280acf4c743806abbbbcfe65050ac52ec4bdec0/library/std/src/panicking.rs:325:9
  10:     0x7f47221c9cb2 - std::panicking::rust_panic_with_hook::h5b5ba4a5cbdd9043
                               at /rustc/f280acf4c743806abbbbcfe65050ac52ec4bdec0/library/std/src/panicking.rs:831:13
  11:     0x7f47221c9a06 - std::panicking::begin_panic_handler::{{closure}}::h761c7933b6bd63bc
                               at /rustc/f280acf4c743806abbbbcfe65050ac52ec4bdec0/library/std/src/panicking.rs:697:13
  12:     0x7f47221c89b9 - std::sys::backtrace::__rust_end_short_backtrace::hf28ea39c64a8ec49
                               at /rustc/f280acf4c743806abbbbcfe65050ac52ec4bdec0/library/std/src/sys/backtrace.rs:168:18
  13:     0x7f47221c96cd - rust_begin_unwind
                               at /rustc/f280acf4c743806abbbbcfe65050ac52ec4bdec0/library/std/src/panicking.rs:695:5
  14:     0x7f47221eb530 - core::panicking::panic_fmt::hbb352f67f9fc2f03
                               at /rustc/f280acf4c743806abbbbcfe65050ac52ec4bdec0/library/core/src/panicking.rs:75:14
  15:     0x7f47221eb5bc - core::panicking::panic::h6fc23addbc4b6e02
                               at /rustc/f280acf4c743806abbbbcfe65050ac52ec4bdec0/library/core/src/panicking.rs:145:5
  16:     0x7f47221eb4a9 - core::option::unwrap_failed::h1809b537790d8e9b
                               at /rustc/f280acf4c743806abbbbcfe65050ac52ec4bdec0/library/core/src/option.rs:2015:5
  17:     0x7f4721ef73e1 - core::option::Option<T>::unwrap::h20389401cfd0f26d
                               at /rustc/f280acf4c743806abbbbcfe65050ac52ec4bdec0/library/core/src/option.rs:978:21
  18:     0x7f4721ef73e1 - ykrt::compile::jitc_yk::codegen::x64::Assemble::emit_call::hcc2ef90662c27705
                               at /yk/ykrt/src/compile/jitc_yk/codegen/x64/mod.rs:1707:31
  19:     0x7f4721ef55ce - ykrt::compile::jitc_yk::codegen::x64::Assemble::cg_call::h45210526ae6c3133
                               at /yk/ykrt/src/compile/jitc_yk/codegen/x64/mod.rs:1650:17
  20:     0x7f4721eec4a9 - ykrt::compile::jitc_yk::codegen::x64::Assemble::cg_insts::h8381185b966b8268
                               at /yk/ykrt/src/compile/jitc_yk/codegen/x64/mod.rs:609:42
  21:     0x7f4721ee938a - ykrt::compile::jitc_yk::codegen::x64::Assemble::codegen::h08d08473895f9a27
                               at /yk/ykrt/src/compile/jitc_yk/codegen/x64/mod.rs:408:9
  22:     0x7f4721ee87ae - <ykrt::compile::jitc_yk::codegen::x64::X64CodeGen as ykrt::compile::jitc_yk::codegen::CodeGen>::codegen::h9f02950cbf0643da
                               at /yk/ykrt/src/compile/jitc_yk/codegen/x64/mod.rs:297:9
  23:     0x7f4721fd18f7 - ykrt::compile::jitc_yk::JITCYk<Register>::compile::he19b5748d2e12f7b
                               at /yk/ykrt/src/compile/jitc_yk/mod.rs:173:18
  24:     0x7f4721fd23be - <ykrt::compile::jitc_yk::JITCYk<Register> as ykrt::compile::Compiler>::root_compile::h9f034341cc480048
                               at /yk/ykrt/src/compile/jitc_yk/mod.rs:203:9
  25:     0x7f4721f0e9a9 - ykrt::mt::MT::queue_root_compile_job::{{closure}}::h832814a3394afa45
                               at /yk/ykrt/src/mt.rs:287:19
  26:     0x7f4721e2cfbe - core::ops::function::FnOnce::call_once{{vtable.shim}}::h1c599be0ce88256a
                               at /rustc/f280acf4c743806abbbbcfe65050ac52ec4bdec0/library/core/src/ops/function.rs:250:5
  27:     0x7f4721fb7e68 - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::h3851c4c8b8408317
                               at /rustc/f280acf4c743806abbbbcfe65050ac52ec4bdec0/library/alloc/src/boxed.rs:1972:9
  28:     0x7f4721fd9154 - std::sys::backtrace::__rust_begin_short_backtrace::hfec611756a43de61
                               at /rustc/f280acf4c743806abbbbcfe65050ac52ec4bdec0/library/std/src/sys/backtrace.rs:152:18
  29:     0x7f4721e61243 - std::thread::Builder::spawn_unchecked_::{{closure}}::{{closure}}::h50140d6da4d93985
                               at /rustc/f280acf4c743806abbbbcfe65050ac52ec4bdec0/library/std/src/thread/mod.rs:559:17
  30:     0x7f4721fcfc01 - <core::panic::unwind_safe::AssertUnwindSafe<F> as core::ops::function::FnOnce<()>>::call_once::h7c1446656f0882f0
                               at /rustc/f280acf4c743806abbbbcfe65050ac52ec4bdec0/library/core/src/panic/unwind_safe.rs:272:9
  31:     0x7f4721fd4300 - std::panicking::try::do_call::h8fa39b38a59da830
                               at /rustc/f280acf4c743806abbbbcfe65050ac52ec4bdec0/library/std/src/panicking.rs:587:40
  32:     0x7f4721e618ab - __rust_try
  33:     0x7f4721e60e75 - std::panicking::try::ha476fbd079469ad6
                               at /rustc/f280acf4c743806abbbbcfe65050ac52ec4bdec0/library/std/src/panicking.rs:550:19
  34:     0x7f4721e60e75 - std::panic::catch_unwind::h7bdf85cb89048c64
                               at /rustc/f280acf4c743806abbbbcfe65050ac52ec4bdec0/library/std/src/panic.rs:359:14
  35:     0x7f4721e60e75 - std::thread::Builder::spawn_unchecked_::{{closure}}::he6cb431218615ed5
                               at /rustc/f280acf4c743806abbbbcfe65050ac52ec4bdec0/library/std/src/thread/mod.rs:557:30
  36:     0x7f4721e2d49f - core::ops::function::FnOnce::call_once{{vtable.shim}}::ha965b69f0da3a6df
                               at /rustc/f280acf4c743806abbbbcfe65050ac52ec4bdec0/library/core/src/ops/function.rs:250:5
  37:     0x7f47221cbb5b - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::h882e355ed78c64f7
                               at /rustc/f280acf4c743806abbbbcfe65050ac52ec4bdec0/library/alloc/src/boxed.rs:1972:9
  38:     0x7f47221cbb5b - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::ha4c9de997cf9ce0e
                               at /rustc/f280acf4c743806abbbbcfe65050ac52ec4bdec0/library/alloc/src/boxed.rs:1972:9
  39:     0x7f47221cbb5b - std::sys::pal::unix::thread::Thread::new::thread_start::h208202f9d25af663
                               at /rustc/f280acf4c743806abbbbcfe65050ac52ec4bdec0/library/std/src/sys/pal/unix/thread.rs:106:17
  40:     0x7f4721aa81c4 - start_thread
                               at ./nptl/pthread_create.c:442:8
  41:     0x7f4721b2885c - clone3
                               at ./misc/../sysdeps/unix/sysv/linux/x86_64/clone3.S:81:0
  42:                0x0 - <unknown>

thread '<unnamed>' panicked at ykrt/src/mt.rs:237:39:
called `Result::unwrap()` on an `Err` value: Any { .. }
stack backtrace:
   0:     0x7f47221c84b3 - std::backtrace_rs::backtrace::libunwind::trace::ha60d6c8dc3f5f8a4
                               at /rustc/f280acf4c743806abbbbcfe65050ac52ec4bdec0/library/std/src/../../backtrace/src/backtrace/libunwind.rs:117:9
   1:     0x7f47221c84b3 - std::backtrace_rs::backtrace::trace_unsynchronized::habe0365ec6a6308d
                               at /rustc/f280acf4c743806abbbbcfe65050ac52ec4bdec0/library/std/src/../../backtrace/src/backtrace/mod.rs:66:14
   2:     0x7f47221c84b3 - std::sys::backtrace::_print_fmt::hc3ae79cc2516a535
                               at /rustc/f280acf4c743806abbbbcfe65050ac52ec4bdec0/library/std/src/sys/backtrace.rs:66:9
   3:     0x7f47221c84b3 - <std::sys::backtrace::BacktraceLock::print::DisplayBacktrace as core::fmt::Display>::fmt::h8d9b2abef2510cd1
                               at /rustc/f280acf4c743806abbbbcfe65050ac52ec4bdec0/library/std/src/sys/backtrace.rs:39:26
   4:     0x7f47221ed9d3 - core::fmt::rt::Argument::fmt::hd734eb8dccf04fe9
                               at /rustc/f280acf4c743806abbbbcfe65050ac52ec4bdec0/library/core/src/fmt/rt.rs:177:76
   5:     0x7f47221ed9d3 - core::fmt::write::heb9cf6889f45a11e
                               at /rustc/f280acf4c743806abbbbcfe65050ac52ec4bdec0/library/core/src/fmt/mod.rs:1449:21
   6:     0x7f47221c5843 - std::io::Write::write_fmt::h6360a21e44de67e4
                               at /rustc/f280acf4c743806abbbbcfe65050ac52ec4bdec0/library/std/src/io/mod.rs:1890:15
   7:     0x7f47221c8302 - std::sys::backtrace::BacktraceLock::print::h9319588d0d6e4878
                               at /rustc/f280acf4c743806abbbbcfe65050ac52ec4bdec0/library/std/src/sys/backtrace.rs:42:9
   8:     0x7f47221c929a - std::panicking::default_hook::{{closure}}::h4c968bafc99c0b41
                               at /rustc/f280acf4c743806abbbbcfe65050ac52ec4bdec0/library/std/src/panicking.rs:298:22
   9:     0x7f47221c910a - std::panicking::default_hook::hafb4ab1b4e12432b
                               at /rustc/f280acf4c743806abbbbcfe65050ac52ec4bdec0/library/std/src/panicking.rs:325:9
  10:     0x7f47221c9cb2 - std::panicking::rust_panic_with_hook::h5b5ba4a5cbdd9043
                               at /rustc/f280acf4c743806abbbbcfe65050ac52ec4bdec0/library/std/src/panicking.rs:831:13
  11:     0x7f47221c9a3a - std::panicking::begin_panic_handler::{{closure}}::h761c7933b6bd63bc
                               at /rustc/f280acf4c743806abbbbcfe65050ac52ec4bdec0/library/std/src/panicking.rs:704:13
  12:     0x7f47221c89b9 - std::sys::backtrace::__rust_end_short_backtrace::hf28ea39c64a8ec49
                               at /rustc/f280acf4c743806abbbbcfe65050ac52ec4bdec0/library/std/src/sys/backtrace.rs:168:18
  13:     0x7f47221c96cd - rust_begin_unwind
                               at /rustc/f280acf4c743806abbbbcfe65050ac52ec4bdec0/library/std/src/panicking.rs:695:5
  14:     0x7f47221eb530 - core::panicking::panic_fmt::hbb352f67f9fc2f03
                               at /rustc/f280acf4c743806abbbbcfe65050ac52ec4bdec0/library/core/src/panicking.rs:75:14
  15:     0x7f47221eba56 - core::result::unwrap_failed::h25a540d1f03b8b52
                               at /rustc/f280acf4c743806abbbbcfe65050ac52ec4bdec0/library/core/src/result.rs:1704:5
  16:     0x7f4721edf65d - core::result::Result<T,E>::unwrap::h49b483e44c28a76f
                               at /rustc/f280acf4c743806abbbbcfe65050ac52ec4bdec0/library/core/src/result.rs:1109:23
  17:     0x7f4721edf65d - ykrt::mt::MT::queue_job::heebc2dd2ff016205
                               at /yk/ykrt/src/mt.rs:237:13
  18:     0x7f4721edfc49 - ykrt::mt::MT::queue_root_compile_job::hcedf6918aabff399
                               at /yk/ykrt/src/mt.rs:341:9
  19:     0x7f4721ee1298 - ykrt::mt::MT::control_point::h81101d1808d0812d
                               at /yk/ykrt/src/mt.rs:521:25
  20:     0x7f4721e0e84d - __ykrt_control_point_real
                               at /yk/ykcapi/src/lib.rs:135:9
  21:     0x7f4721e0e291 - __ykrt_control_point
fatal runtime error: failed to initiate panic, error 5


---- lang_tests::simple5.c stdout ----

[ltratt]

I would suggest getting the jit-pre-opt (or jit-post-opt) for this program, having a look, and seeing how we might have an input parameter of type Void.

[ptersilie]

That's not the error @Pavel-Durov is seeing I think. Looking at his yk version it seems to be this:

yk/ykrt/src/compile/jitc_yk/codegen/x64/mod.rs

Line 1707 in a797bdf

let reg = gp_regs.next().unwrap();

. Looks to be running out of registers for the call. Which isn't surprising as this change adds a 7th argument which needs to be passed via the stack, which I believe we haven't implemented yet.

[ltratt]

Ah, right. Sorry, I was looking at master. Yes, we haven't done stack arguments yet, and I'm not busting a gut to implement that right now. I would suggest, for the time being, keeping the number of arguments to 6.