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Implement the segue optimization for LLVM AOT/JIT (#2230)

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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>
This commit is contained in:
Wenyong Huang
2023-05-26 10:13:33 +08:00
committed by GitHub
parent 27239723a9
commit 76be848ec3
42 changed files with 1864 additions and 123 deletions
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68
wamr-compiler/main.c
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@ -65,6 +65,12 @@ print_help()
printf(" --enable-indirect-mode Enalbe call function through symbol table but not direct call\n");
printf(" --disable-llvm-intrinsics Disable the LLVM built-in intrinsics\n");
printf(" --disable-llvm-lto Disable the LLVM link time optimization\n");
printf(" --enable-segue[=<flags>] Enable using segment register GS as the base address of linear memory,\n");
printf(" only available on linux/linux-sgx x86-64, which may improve performance,\n");
printf(" flags can be: i32.load, i64.load, f32.load, f64.load, v128.load,\n");
printf(" i32.store, i64.store, f32.store, f64.store, v128.store\n");
printf(" Use comma to separate, e.g. --enable-segue=i32.load,i64.store\n");
printf(" and --enable-segue means all flags are added.\n");
printf(" --emit-custom-sections=<section names>\n");
printf(" Emit the specified custom sections to AoT file, using comma to separate\n");
printf(" multiple names, e.g.\n");
@ -84,7 +90,7 @@ print_help()
} while (0)
/**
* Split a strings into an array of strings
* Split a string into an array of strings
* Returns NULL on failure
* Memory must be freed by caller
* Based on: http://stackoverflow.com/a/11198630/471795
@ -126,6 +132,57 @@ split_string(char *str, int *count, const char *delimer)
return res;
}
static uint32
resolve_segue_flags(char *str_flags)
{
uint32 segue_flags = 0;
int32 flag_count, i;
char **flag_list;
flag_list = split_string(str_flags, &flag_count, ",");
if (flag_list) {
for (i = 0; i < flag_count; i++) {
if (!strcmp(flag_list[i], "i32.load")) {
segue_flags |= 1 << 0;
}
else if (!strcmp(flag_list[i], "i64.load")) {
segue_flags |= 1 << 1;
}
else if (!strcmp(flag_list[i], "f32.load")) {
segue_flags |= 1 << 2;
}
else if (!strcmp(flag_list[i], "f64.load")) {
segue_flags |= 1 << 3;
}
else if (!strcmp(flag_list[i], "v128.load")) {
segue_flags |= 1 << 4;
}
else if (!strcmp(flag_list[i], "i32.store")) {
segue_flags |= 1 << 8;
}
else if (!strcmp(flag_list[i], "i64.store")) {
segue_flags |= 1 << 9;
}
else if (!strcmp(flag_list[i], "f32.store")) {
segue_flags |= 1 << 10;
}
else if (!strcmp(flag_list[i], "f64.store")) {
segue_flags |= 1 << 11;
}
else if (!strcmp(flag_list[i], "v128.store")) {
segue_flags |= 1 << 12;
}
else {
/* invalid flag */
segue_flags = (uint32)-1;
break;
}
}
free(flag_list);
}
return segue_flags;
}
int
main(int argc, char *argv[])
{
@ -272,6 +329,15 @@ main(int argc, char *argv[])
else if (!strcmp(argv[0], "--disable-llvm-lto")) {
option.disable_llvm_lto = true;
}
else if (!strcmp(argv[0], "--enable-segue")) {
/* all flags are enabled */
option.segue_flags = 0x1F1F;
}
else if (!strncmp(argv[0], "--enable-segue=", 15)) {
option.segue_flags = resolve_segue_flags(argv[0] + 15);
if (option.segue_flags == (uint32)-1)
PRINT_HELP_AND_EXIT();
}
else if (!strncmp(argv[0], "--emit-custom-sections=", 23)) {
int len = 0;
if (option.custom_sections) {