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Refactor LLVM JIT (#1613)

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Refactor LLVM JIT for some purposes:
- To simplify the source code of JIT compilation
- To simplify the JIT modes
- To align with LLVM latest changes
- To prepare for the Multi-tier JIT compilation, refer to #1302

The changes mainly include:
- Remove the MCJIT mode, replace it with ORC JIT eager mode
- Remove the LLVM legacy pass manager (only keep the LLVM new pass manager)
- Change the lazy mode's LLVM module/function binding:
  change each function in an individual LLVM module into all functions in a single LLVM module
- Upgraded ORC JIT to ORCv2 JIT to enable lazy compilation

Refer to #1468
This commit is contained in:
Wenyong Huang
2022-10-18 20:17:34 +08:00
committed by GitHub
parent 84b1a6c10e
commit e87a554616
22 changed files with 1058 additions and 1104 deletions
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27
doc/build_wamr.md
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@ -41,7 +41,6 @@ cmake -DWAMR_BUILD_PLATFORM=linux -DWAMR_BUILD_TARGET=ARM
- **WAMR_BUILD_AOT**=1/0, enable AOT or not, default to enable if not set
- **WAMR_BUILD_JIT**=1/0, enable LLVM JIT or not, default to disable if not set
- **WAMR_BUILD_LAZY_JIT**=1/0, whether to use Lazy JIT mode or not when *WAMR_BUILD_JIT* is set, default to enable if not set
- **WAMR_BUILD_FAST_JIT**=1/0, enable Fast JIT or not, default to disable if not set
#### **Configure LIBC**
@ -224,7 +223,7 @@ make
By default in Linux, the `fast interpreter`, `AOT` and `Libc WASI` are enabled, and JIT is disabled.
And the build target is set to X86_64 or X86_32 depending on the platform's bitwidth.
There are total 6 running modes supported: fast interpreter, classi interpreter, AOT, LLVM Lazy JIT, LLVM MC JIT and Fast JIT.
There are total 5 running modes supported: fast interpreter, classi interpreter, AOT, LLVM JIT and Fast JIT.
(1) To run a wasm file with `fast interpreter` mode - build iwasm with default build and then:
```Bash
@ -250,32 +249,34 @@ wamrc -o <AOT file> <WASM file>
iwasm <AOT file>
```
(4) To enable the `LLVM Lazy JIT` mode, firstly we should build LLVM library:
(4) To enable the `LLVM JIT` mode, firstly we should build the LLVM library:
``` Bash
cd product-mini/platforms/linux/
./build_llvm.sh (The llvm source code is cloned under <wamr_root_dir>/core/deps/llvm and auto built)
```
Then pass argument `-DWAMR_BUILD_JIT=1` to cmake to enable LLVM Lazy JIT:
Then pass argument `-DWAMR_BUILD_JIT=1` to cmake to enable LLVM JIT:
``` Bash
mkdir build && cd build
cmake .. -DWAMR_BUILD_JIT=1
make
```
(5) Or disable `LLVM Lazy JIT` and enable `LLVM MC JIT` instead:
```Bash
Note:
By default, the LLVM Orc JIT with Lazy compilation is enabled to speedup the lanuching process and reduce
the JIT compilation time by creating backend threads to compile the WASM functions parallely, and for the
main thread, the functions in the module will not be compiled until they are firstly called and haven't been
compiled by the compilation threads.
If developer wants to disable the Lazy compilation, we can:
``` Bash
mkdir build && cd build
cmake .. -DWAMR_BUILD_JIT=1 -DWAMR_BUILD_LAZY_JIT=0
make
```
In which all the WASM functions will be previously compiled before main thread starts to run the wasm module.
By default, the LLVM Orc Lazy JIT is enabled to speedup the lanuching process and reduce the JIT compilation time
by creating threads to compile the WASM functions parallely, and for the main thread, the functions in the
module will not be compiled until they are firstly called and haven't been compiled by the compilation threads.
To disable it and enable LLVM MC JIT instead, please pass argument `-DWAMR_BUILD_LAZY_JIT=0` to cmake.
(6) To enable the `Fast JIT` mode:
(5) To enable the `Fast JIT` mode:
``` Bash
mkdir build && cd build
cmake .. -DWAMR_BUILD_FAST_JIT=1
@ -588,7 +589,7 @@ In order to use this, you need at least version 4.3.1 of ESP-IDF.
If you don't have it installed, follow the instructions [here](https://docs.espressif.com/projects/esp-idf/en/latest/esp32/get-started/#get-started-get-prerequisites).
ESP-IDF also installs the toolchains needed for compiling WAMR and ESP-IDF.
A small demonstration of how to use WAMR and ESP-IDF can be found under [product_mini](/product-mini/platforms/esp-idf).
The demo builds WAMR for ESP-IDF and runs a small wasm program.
The demo builds WAMR for ESP-IDF and runs a small wasm program.
In order to run it for your specific Espressif chip, edit the [build_and_run.sh](/product-mini/platforms/esp-idf/build_and_run.sh) file and put the correct toolchain file (see #Cross-compilation) and `IDF_TARGET`.
Before compiling it is also necessary to call ESP-IDF's `export.sh` script to bring all compile time relevant information in scope.