| //! Runtime support needed for testing the stdsimd crate. |
| //! |
| //! This basically just disassembles the current executable and then parses the |
| //! output once globally and then provides the `assert` function which makes |
| //! assertions about the disassembly of a function. |
| #![allow(clippy::missing_docs_in_private_items, clippy::print_stdout)] |
| |
| extern crate assert_instr_macro; |
| extern crate backtrace; |
| extern crate cc; |
| #[macro_use] |
| extern crate lazy_static; |
| extern crate rustc_demangle; |
| extern crate simd_test_macro; |
| #[macro_use] |
| extern crate cfg_if; |
| |
| pub use assert_instr_macro::*; |
| pub use simd_test_macro::*; |
| use std::{collections::HashMap, env, str}; |
| |
| // `println!` doesn't work on wasm32 right now, so shadow the compiler's `println!` |
| // macro with our own shim that redirects to `console.log`. |
| #[allow(unused)] |
| #[cfg(target_arch = "wasm32")] |
| #[macro_export] |
| macro_rules! println { |
| ($($args:tt)*) => (wasm::js_console_log(&format!($($args)*))) |
| } |
| |
| cfg_if! { |
| if #[cfg(target_arch = "wasm32")] { |
| extern crate wasm_bindgen; |
| extern crate console_error_panic_hook; |
| pub mod wasm; |
| use wasm::disassemble_myself; |
| } else { |
| mod disassembly; |
| use disassembly::disassemble_myself; |
| } |
| } |
| |
| lazy_static! { |
| static ref DISASSEMBLY: HashMap<String, Vec<Function>> = disassemble_myself(); |
| } |
| |
| struct Function { |
| addr: Option<usize>, |
| instrs: Vec<Instruction>, |
| } |
| |
| struct Instruction { |
| parts: Vec<String>, |
| } |
| |
| fn normalize(symbol: &str) -> String { |
| let symbol = rustc_demangle::demangle(symbol).to_string(); |
| let mut ret = match symbol.rfind("::h") { |
| Some(i) => symbol[..i].to_string(), |
| None => symbol.to_string(), |
| }; |
| // Normalize to no leading underscore to handle platforms that may |
| // inject extra ones in symbol names. |
| while ret.starts_with('_') { |
| ret.remove(0); |
| } |
| ret |
| } |
| |
| /// Main entry point for this crate, called by the `#[assert_instr]` macro. |
| /// |
| /// This asserts that the function at `fnptr` contains the instruction |
| /// `expected` provided. |
| pub fn assert(fnptr: usize, fnname: &str, expected: &str) { |
| let mut fnname = fnname.to_string(); |
| let functions = get_functions(fnptr, &mut fnname); |
| assert_eq!(functions.len(), 1); |
| let function = &functions[0]; |
| |
| let mut instrs = &function.instrs[..]; |
| while instrs.last().map_or(false, |s| s.parts == ["nop"]) { |
| instrs = &instrs[..instrs.len() - 1]; |
| } |
| |
| // Look for `expected` as the first part of any instruction in this |
| // function, returning if we do indeed find it. |
| let mut found = false; |
| for instr in instrs { |
| // Get the first instruction, e.g., tzcntl in tzcntl %rax,%rax. |
| if let Some(part) = instr.parts.get(0) { |
| // Truncate the instruction with the length of the expected |
| // instruction: tzcntl => tzcnt and compares that. |
| if part.starts_with(expected) { |
| found = true; |
| break; |
| } |
| } |
| } |
| |
| // Look for `call` instructions in the disassembly to detect whether |
| // inlining failed: all intrinsics are `#[inline(always)]`, so |
| // calling one intrinsic from another should not generate `call` |
| // instructions. |
| let mut inlining_failed = false; |
| for (i, instr) in instrs.iter().enumerate() { |
| let part = match instr.parts.get(0) { |
| Some(part) => part, |
| None => continue, |
| }; |
| if !part.contains("call") { |
| continue; |
| } |
| |
| // On 32-bit x86 position independent code will call itself and be |
| // immediately followed by a `pop` to learn about the current address. |
| // Let's not take that into account when considering whether a function |
| // failed inlining something. |
| let followed_by_pop = function |
| .instrs |
| .get(i + 1) |
| .and_then(|i| i.parts.get(0)) |
| .map_or(false, |s| s.contains("pop")); |
| if followed_by_pop && cfg!(target_arch = "x86") { |
| continue; |
| } |
| |
| inlining_failed = true; |
| break; |
| } |
| |
| let instruction_limit = std::env::var("STDSIMD_ASSERT_INSTR_LIMIT") |
| .ok() |
| .map_or_else( |
| || match expected { |
| // `cpuid` returns a pretty big aggregate structure, so exempt |
| // it from the slightly more restrictive 22 instructions below. |
| "cpuid" => 30, |
| |
| // Apparently, on Windows, LLVM generates a bunch of |
| // saves/restores of xmm registers around these intstructions, |
| // which exceeds the limit of 20 below. As it seems dictated by |
| // Windows's ABI (I believe?), we probably can't do much |
| // about it. |
| "vzeroall" | "vzeroupper" if cfg!(windows) => 30, |
| |
| // Intrinsics using `cvtpi2ps` are typically "composites" and |
| // in some cases exceed the limit. |
| "cvtpi2ps" => 25, |
| |
| // core_arch/src/acle/simd32 |
| "usad8" => 27, |
| "qadd8" | "qsub8" | "sadd8" | "sel" | "shadd8" | "shsub8" | "usub8" | "ssub8" => 29, |
| |
| // Original limit was 20 instructions, but ARM DSP Intrinsics |
| // are exactly 20 instructions long. So, bump the limit to 22 |
| // instead of adding here a long list of exceptions. |
| _ => 22, |
| }, |
| |v| v.parse().unwrap(), |
| ); |
| let probably_only_one_instruction = instrs.len() < instruction_limit; |
| |
| if found && probably_only_one_instruction && !inlining_failed { |
| return; |
| } |
| |
| // Help debug by printing out the found disassembly, and then panic as we |
| // didn't find the instruction. |
| println!("disassembly for {}: ", fnname,); |
| for (i, instr) in instrs.iter().enumerate() { |
| let mut s = format!("\t{:2}: ", i); |
| for part in &instr.parts { |
| s.push_str(part); |
| s.push_str(" "); |
| } |
| println!("{}", s); |
| } |
| |
| if !found { |
| panic!( |
| "failed to find instruction `{}` in the disassembly", |
| expected |
| ); |
| } else if !probably_only_one_instruction { |
| panic!( |
| "instruction found, but the disassembly contains too many \ |
| instructions: #instructions = {} >= {} (limit)", |
| instrs.len(), |
| instruction_limit |
| ); |
| } else if inlining_failed { |
| panic!( |
| "instruction found, but the disassembly contains `call` \ |
| instructions, which hint that inlining failed" |
| ); |
| } |
| } |
| |
| fn get_functions(fnptr: usize, fnname: &mut String) -> &'static [Function] { |
| // Translate this function pointer to a symbolic name that we'd have found |
| // in the disassembly. |
| let mut sym = None; |
| backtrace::resolve(fnptr as *mut _, |name| { |
| sym = name.name().and_then(|s| s.as_str()).map(normalize); |
| }); |
| |
| if let Some(sym) = &sym { |
| if let Some(s) = DISASSEMBLY.get(sym) { |
| *fnname = sym.to_string(); |
| return s; |
| } |
| } |
| |
| let exact_match = DISASSEMBLY |
| .iter() |
| .find(|(_, list)| list.iter().any(|f| f.addr == Some(fnptr))); |
| if let Some((name, list)) = exact_match { |
| *fnname = name.to_string(); |
| return list; |
| } |
| |
| if let Some(sym) = sym { |
| println!("assumed symbol name: `{}`", sym); |
| } |
| println!("maybe related functions"); |
| for f in DISASSEMBLY.keys().filter(|k| k.contains(&**fnname)) { |
| println!("\t- {}", f); |
| } |
| panic!("failed to find disassembly of {:#x} ({})", fnptr, fnname); |
| } |
| |
| pub fn assert_skip_test_ok(name: &str) { |
| if env::var("STDSIMD_TEST_EVERYTHING").is_err() { |
| return; |
| } |
| panic!("skipped test `{}` when it shouldn't be skipped", name); |
| } |
| |
| // See comment in `assert-instr-macro` crate for why this exists |
| pub static mut _DONT_DEDUP: &'static str = ""; |