Adapt API usage to new interfaces where applicable, including LLVM function
usage, obsoleted llvm::Optional type and removal of unavailable headers.
Know issues:
- AOT static PGO isn't enabled
- LLVM JIT may run failed due to llvm_orc_registerEHFrameSectionWrapper
isn't linked into iwasm
Unaligned store v128 value to the AOT function argument of the pointer for
the extra return value may cause segmentation fault.
Fix the issue reported in #2556.
When AOT out of bound linear memory access or stack overflow occurs, the call stack of
AOT functions cannot be unwound currently, so from the exception handler, runtime
cannot jump back into the place that calls the AOT function.
We temporarily skip the current instruction and let AOT code continue to run and return
to caller as soon as possible. And use the zydis library the decode the current instruction
to get its size.
And remove using RtlAddFunctionTable to register the AOT functions since it doesn't work
currently.
AOT relocation to aot_func_internal#n is generated by wamrc --bounds-checks=1.
Resolve the issue by applying the relocation in the compilation stage by wamrc and
don't generate these relocations in the AOT file.
Fixes#2471.
- Fix windows wamrc link error: aot_generate_tempfile_name undefined.
- Clear windows compile warnings.
- And rename folder `samples/bh_atomic` and `samples/mem_allocator` to
`samples/bh-atomic` and `samples/mem-allocator`.
The old method may not work for some cases. This PR iterates over all instructions
in the function, looking for memcpy, memmove and memset instructions, putting
them into a set, and finally expands them into a loop one by one.
And move this LLVM Pass after building the pipe line of pass builder to ensure that
the memcpy/memmove/memset instrinsics are generated before applying the pass.
Fix some build errors when building wamrc with LLVM-13, reported in #2311
Fix some build warnings when building wamrc with LLVM-16:
```
core/iwasm/compilation/aot_llvm_extra2.cpp:26:26: warning:
‘llvm::None’ is deprecated: Use std::nullopt instead. [-Wdeprecated-declarations]
26 | return llvm::None;
```
Fix a maybe-uninitialized compile warning:
```
core/iwasm/compilation/aot_llvm.c:413:9: warning:
‘update_top_block’ may be used uninitialized in this function [-Wmaybe-uninitialized]
413 | LLVMPositionBuilderAtEnd(b, update_top_block);
```
Move the native stack overflow check from the caller to the callee because the
former doesn't work for call_indirect and imported functions.
Make the stack usage estimation more accurate. Instead of making a guess from
the number of wasm locals in the function, use the LLVM's idea of the stack size
of each MachineFunction. The former is inaccurate because a) it doesn't reflect
optimization passes, and b) wasm locals are not the only reason to use stack.
To use the post-compilation stack usage information without requiring 2-pass
compilation or machine-code imm rewriting, introduce a global array to store
stack consumption of each functions:
For JIT, use a custom IRCompiler with an extra pass to fill the array.
For AOT, use `clang -fstack-usage` equivalent because we support external llc.
Re-implement function call stack usage estimation to reflect the real calling
conventions better. (aot_estimate_stack_usage_for_function_call)
Re-implement stack estimation logic (--enable-memory-profiling) based on the new
machinery.
Discussions: #2105.
LLVM PGO (Profile-Guided Optimization) allows the compiler to better optimize code
for how it actually runs. This PR implements the AOT static PGO, and is tested on
Linux x86-64 and x86-32. The basic steps are:
1. Use `wamrc --enable-llvm-pgo -o <aot_file_of_pgo> <wasm_file>`
to generate an instrumented aot file.
2. Compile iwasm with `cmake -DWAMR_BUILD_STATIC_PGO=1` and run
`iwasm --gen-prof-file=<raw_profile_file> <aot_file_of_pgo>`
to generate the raw profile file.
3. Run `llvm-profdata merge -output=<profile_file> <raw_profile_file>`
to merge the raw profile file into the profile file.
4. Run `wamrc --use-prof-file=<profile_file> -o <aot_file> <wasm_file>`
to generate the optimized aot file.
5. Run the optimized aot_file: `iwasm <aot_file>`.
The test scripts are also added for each benchmark, run `test_pgo.sh` under
each benchmark's folder to test the AOT static pgo.
Segue is an optimization technology which uses x86 segment register to store
the WebAssembly linear memory base address, so as to remove most of the cost
of SFI (Software-based Fault Isolation) base addition and free up a general
purpose register, by this way it may:
- Improve the performance of JIT/AOT
- Reduce the footprint of JIT/AOT, the JIT/AOT code generated is smaller
- Reduce the compilation time of JIT/AOT
This PR uses the x86-64 GS segment register to apply the optimization, currently
it supports linux and linux-sgx platforms on x86-64 target. By default it is disabled,
developer can use the option below to enable it for wamrc and iwasm(with LLVM
JIT enabled):
```bash
wamrc --enable-segue=[<flags>] -o output_file wasm_file
iwasm --enable-segue=[<flags>] wasm_file [args...]
```
`flags` can be:
i32.load, i64.load, f32.load, f64.load, v128.load,
i32.store, i64.store, f32.store, f64.store, v128.store
Use comma to separate them, e.g. `--enable-segue=i32.load,i64.store`,
and `--enable-segue` means all flags are added.
Acknowledgement:
Many thanks to Intel Labs, UC San Diego and UT Austin teams for introducing this
technology and the great support and guidance!
Signed-off-by: Wenyong Huang <wenyong.huang@intel.com>
Co-authored-by: Vahldiek-oberwagner, Anjo Lucas <anjo.lucas.vahldiek-oberwagner@intel.com>
- Translate all the opcodes of threads spec proposal for Fast JIT
- Add the atomic flag for Fast JIT load/store IRs to support atomic load/store
- Add new atomic related Fast JIT IRs and translate them in the codegen
- Add suspend_flags check in branch opcodes and before/after call function
- Modify CI to enable Fast JIT multi-threading test
Co-authored-by: TianlongLiang <tianlong.liang@intel.com>
In LLVM AOT/JIT compiler, only need to check the suspend_flags when memory is
a shared memory since the shared memory must be enabled for multi-threading,
so as not to impact the performance in non-multi-threading memory mode. Also
refine the LLVM IRs to check the suspend_flags.
And fix an issue of multi-tier jit for multi-threading, the instance of the child thread
should be removed from the instance list before it is de-instantiated.
- Implement atomic.fence to ensure a proper memory synchronization order
- Destroy exec_env_singleton first in wasm/aot deinstantiation
- Change terminate other threads to wait for other threads in
wasm_exec_env_destroy
- Fix detach thread in thread_manager_start_routine
- Fix duplicated lock cluster->lock in wasm_cluster_cancel_thread
- Add lib-pthread and lib-wasi-threads compilation to Windows CI
Raising "wasi proc exit" exception, spreading it to other threads and then
clearing it in all threads may result in unexpected behavior: the sub thread
may end first, handle the "wasi proc exit" exception and clear exceptions
of other threads, including the main thread. And when main thread's
exception is cleared, it may continue to run and throw "unreachable"
exception. This also leads to some assertion failed.
Ignore exception spreading for "wasi proc exit" and don't clear exception
of other threads to resolve the issue.
And add suspend flag check after atomic wait since the atomic wait may
be notified by other thread when exception occurs.
Implement 2-level Multi-tier JIT engine: tier-up from Fast JIT to LLVM JIT to
get quick cold startup by Fast JIT and better performance by gradually
switching to LLVM JIT when the LLVM JIT functions are compiled by the
backend threads.
Refer to:
https://github.com/bytecodealliance/wasm-micro-runtime/issues/1302
Refine AOT exception check in the caller when returning from callee function,
remove the exception check instructions when hw bound check is enabled to
improve the performance: create guard page to trigger signal handler when
exception occurs.
