llvm dev - Apr 2020 - lli cannot execute the bc file for RISCV, Unable to find target for this triple

*llvm-project version:dd8a2013dc1804be1b7d9cffacad2e984300bd22*

*Instructons to build LLVM+clang:*

```
cmake -G Ninja
-DCMAKE_INSTALL_PREFIX=/home/llvm/workspace/llvm/llvm-project/llvm_install
-DCMAKE_BUILD_TYPE="Release"
-DDEFAULT_SYSROOT="/home/llvm/workspace/riscv/riscv-tc-20200220/bin/riscv32-unknown-elf"
-DGCC_INSTALL_PREFIX="/home/llvm/workspace/riscv/riscv-tc-20200220"
-DLLVM_DEFAULT_TARGET_TRIPLE="riscv32-unknown-elf"
-DLLVM_ENABLE_PROJECTS="clang;lld;libc"
-DLLVM_TARGETS_TO_BUILD="RISCV"
../llvm
```

*When compiling the obj file for the RTL simulation platform, everything is
ok. *
*But when I try to run the bc file using lli, I have such an error.*

```
#../llvm/llvm-project/llvm_install/bin/lli main.ll
../llvm/llvm-project/llvm_install/bin/lli: error: error creating EE: Unable
to find target for this triple (no targets are registered)
```

Clang & lli version(Confusion About " *riscv32-unknown-unknown-elf*
" WITH
" *riscv32-unknown-elf* "):
```
$ ../llvm/llvm-project/llvm_install/bin/clang --version
clang version 11.0.0 (https://github.com/llvm/llvm-project.git
dd8a2013dc1804be1b7d9cffacad2e984300bd22)
Target: riscv32-unknown-unknown-elf
Thread model: posix
InstalledDir:
/home/llvm/workspace/test_lli/../llvm/llvm-project/llvm_install/bin

$ ../llvm/llvm-project/llvm_install/bin/lli --version
LLVM (http://llvm.org/):
  LLVM version 11.0.0git
  Optimized build.
  Default target: riscv32-unknown-elf
  Host CPU: skylake
```

  *Instructons to generate main.ll:*

```
../llvm/llvm-project/llvm_install/bin/clang --target=riscv32-unknown-elf
--sysroot=/home/llvm/workspace/riscv/riscv-tc-20200220/bin/riscv32-unknown-elf
--gcc-toolchain=/home/llvm/workspace/riscv/riscv-tc-20200220
-march=rv32imac -mabi=ilp32
-I/home/llvm/workspace/llvm/llvm-project/llvm_install/riscv32-unknown-elf/include
-S -emit-llvm main.c
```

//main.c
```
#include <stdio.h>
int main(){
  int a,b,c;
  a = 5;
  b = 2;
  asm volatile
  (
    "norm   %[z], %[x]\n\t"
    : [z] "=r" (c)
    : [x] "r" (a)
  ) ;
   if ( c != 28 ){
     printf("\nHAAWKING TEST: FAILED\n");
     return -1;
  }
  printf("\nHAAWKING TEST: PASSED\n");
  return 0;
}
```

Since I add some custom instructions to the RISC-V ISA and have not got a
simulator, so I want to check out whether these instructions using lli.
Can anyone figure out why this happens?
-------------- next part --------------
An HTML attachment was scrubbed...
URL:
<http://lists.llvm.org/pipermail/llvm-dev/attachments/20200402/5f8d1d97/attachment.html>

On Thu, Apr 2, 2020 at 2:00 AM Junning Wu via llvm-dev <
llvm-dev at lists.llvm.org> wrote:
> Since I add some custom instructions to the RISC-V ISA and have not got a
> simulator, so I want to check out whether these instructions using lli.
> Can anyone figure out why this happens?
>
LLI will either interpret the LLVM bytecode or "JIT" it to native code
(basically just dynamically do a regular compilation plus code loading), so
I don't think LLI is very well suited for your use case.

In any case, I am currently working on the ELF loader used for the JIT,
which AFAIK is basically the only thing remaining for LLI to work for
RISC-V, *if* you can then execute the native instructions. So you'll need
an emulator anyway. I'm using QEMU, which you can also use for free.

Best,
Luís
-------------- next part --------------
An HTML attachment was scrubbed...
URL:
<http://lists.llvm.org/pipermail/llvm-dev/attachments/20200402/3a07e8e6/attachment.html>

Cool, thanks!
I also got this answer from https://llvm.org/docs/CommandGuide/lli.html,
which says that “*lli* is *not* an emulator. It will not execute IR of
different architectures and it can only interpret (or JIT-compile) for the
host architecture.”
Thanks a lot. I will try QEMU or gem5.


On Thu, Apr 2, 2020 at 6:55 PM Luís Marques <luismarques at lowrisc.org>
wrote:
> On Thu, Apr 2, 2020 at 2:00 AM Junning Wu via llvm-dev <
> llvm-dev at lists.llvm.org> wrote:
>
>> Since I add some custom instructions to the RISC-V ISA and have not got
a
>> simulator, so I want to check out whether these instructions using lli.
>> Can anyone figure out why this happens?
>>
>
> LLI will either interpret the LLVM bytecode or "JIT" it to native
code
> (basically just dynamically do a regular compilation plus code loading), so
> I don't think LLI is very well suited for your use case.
>
> In any case, I am currently working on the ELF loader used for the JIT,
> which AFAIK is basically the only thing remaining for LLI to work for
> RISC-V, *if* you can then execute the native instructions. So you'll
need
> an emulator anyway. I'm using QEMU, which you can also use for free.
>
> Best,
> Luís
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL:
<http://lists.llvm.org/pipermail/llvm-dev/attachments/20200402/e1d3976d/attachment.html>