Compiling C inline powerpc 64-bit architecture assembly code with Clang 14.0.0 compiler, error: Undefined temporary symbol .Ltmp2

[bethebset]

My source code are:
int MyOpen(char * filename,int Attrib)
{//__NR_open
//return syscall(SCN(1024), filename, Attrib, 0777);
int fp;
asm volatile (
"li 0, 1024\n"
"mr 3, %1\n"
"mr 4, %2\n"
"sc\n"
"mr %0, 3\n"
:"=r"(fp)
:"r" (filename),"r" (Attrib)
:"memory"
);
return fp;
}

int main()
{
int fin = MyOpen("/home/test/hello.c",O_RDONLY );
return 0;
}
compile with:
clang -m64 -target powerpc64-linux-gnu test.c -o test
and get ERROR:
error: Undefined temporary symbol .Ltmp2
2 warnings and 1 error generated.

On Ubuntu 22.04
Have a powerpc64 cross-compile environment

I'm a rookie and didn't find a good fit on google to solve the problem, please help me!

[DimitryAndric]

First of all, it looks like you are mixing up x64 inline assembly with a powerpc64 target? That is never going to work.

Secondly, have you tried a newer version of clang? 14.0 is very old now. You can try https://godbolt.org/ to experiment with different versions.

[bethebset]

首先，看起来您正在将 x64 内联汇编与 powerpc64 目标混为一谈？这永远行不通。

其次，您是否尝试过较新版本的 clang？14.0 现在已经很旧了。您可以尝试 https://godbolt.org/ 尝试不同的版本。

Sorry, I accidentally posted the wrong code for x64.int MyOpen(char * filename,int Attrib)
{//__NR_open
//return syscall(SCN(1024), filename, Attrib, 0777);
int fp;
asm volatile (
"li 0, 1024\n"
"mr 3, %1\n"
"mr 4, %2\n"
"sc\n"
"mr %0, 3\n"
:"=r"(fp)
:"r" (filename),"r" (Attrib)
:"memory"
);
return fp;
}

[DimitryAndric]

Yes, this compiles fine with the "powerpc64 clang trunk" setting on Godbolt: https://godbolt.org/z/8aKMdWxEs .

So my next advice would be to try a more recent version of clang. 18.1.5 has been released very recently.

[bethebset]

Yes, this compiles fine with the "powerpc64 clang trunk" setting on Godbolt: https://godbolt.org/z/8aKMdWxEs .

So my next advice would be to try a more recent version of clang. 18.1.5 has been released very recently.

Thanks for the suggestion, I've tried using it for authentication before, I just wanted to see if I could implement it with this release
Because I have a rather large llvm 14.0 based project that I want to extend to the powerpc platform, but don't want to do the upgrades

[chenzheng1030]

I am not sure if there is any new clang 14 releases. From the website https://releases.llvm.org/, looks like when a new "big" release is published, there is no new fix packs for older "big" releases.
I would suggest you upgrade your compiler to get a clean compile.

[bethebset]

Yes, this compiles fine with the "powerpc64 clang trunk" setting on Godbolt: https://godbolt.org/z/8aKMdWxEs .

So my next advice would be to try a more recent version of clang. 18.1.5 has been released very recently.

I tried 18.0, and it's the same. It still gives me an error.

[bethebset]

I am not sure if there is any new clang 14 releases. From the website https://releases.llvm.org/, looks like when a new "big" release is published, there is no new fix packs for older "big" releases. I would suggest you upgrade your compiler to get a clean compile.

Thanks a lot,I tried 18.0, and it's the same. It gives me the same error.

[chenzheng1030]

From https://godbolt.org/z/dPEW7hvnT, seems the case passes with both 18.0 and trunk. Could you please double confirm? Thanks.

[llvmbot]

@llvm/issue-subscribers-backend-powerpc

Author: Qizheng Tian (bethebset)

My source code are: int MyOpen(char * filename,int Attrib) {//__NR_open //return syscall(SCN(1024), filename, Attrib, 0777); int fp; __asm__ __volatile__ ( "li 0, 1024\n" "mr 3, %1\n" "mr 4, %2\n" "sc\n" "mr %0, 3\n" :"=r"(fp) :"r" (filename),"r" (Attrib) :"memory" ); return fp; }

int main()
{
int fin = MyOpen("/home/test/hello.c",O_RDONLY );
return 0;
}
compile with:
clang -m64 -target powerpc64-linux-gnu test.c -o test
and get ERROR:
error: Undefined temporary symbol .Ltmp2
2 warnings and 1 error generated.

On Ubuntu 22.04
Have a powerpc64 cross-compile environment

I'm a rookie and didn't find a good fit on google to solve the problem, please help me!

[bethebset]

From https://godbolt.org/z/dPEW7hvnT, seems the case passes with both 18.0 and trunk. Could you please double confirm? Thanks.

Sorry, I realized that it's not this code that's the problem, it should be this section of my code that's the problem

void* another() {
    char *p1, *p2
    unsigned long Offset;
    unsigned long a = 3;
    
    __asm__ (
        "bl label\n"          
        "label: mflr %0\n"        
        "b pos\n"              
        "pos: lis %1, pos@h\n"    
        "ori %1, %1, pos@l\n"
        : "=r" (p1), "=r" (p2)
        :
        : "memory"
    );
    return (char *)p1 +a;
}

[chenzheng1030]

https://godbolt.org/z/1nWGGEoeE trunk clang still passes your code.

[bethebset]

https://godbolt.org/z/1nWGGEoeE trunk clang still passes your code.

yes, I've also tried this