[LoongArch] dead loop after nightly-2024-02-12

[heiher]

I tried this code:

rustc -vV
cargo -vV

I expected to see this happen: outputs version info

Instead, this happened: dead loop in main entry function.

Meta

rustc --version --verbose:

a84bb95a1 2024-02-13

b381d3ab2 2024-02-12 good
a84bb95a1 2024-02-13 bad

[heiher]

@rustbot label O-loongarch

[nikic]

That would be due to the LLVM 18 upgrade.

[heiher]

That would be due to the LLVM 18 upgrade.

Yeah. It seems that the CI loongarch64-unknown-linux-gnu ld does not handle R_LARCH_CALL36 (pcaddu18+jirl) relocations correctly.

0000000000000a40 <main>:                           
   a40:   02ffc063    addi.d          $sp, $sp, -16  
   a44:   29c02061    st.d            $ra, $sp, 8    
   a48:   001500a6    move            $a2, $a1       
   a4c:   02800085    addi.w          $a1, $a0, 0    
   a50:   1a000024    pcalau12i       $a0, 1         
   a54:   02e88084    addi.d          $a0, $a0, -1504
   a58:   03800c07    li.w            $a3, 0x3       
>  a5c:   1e000001    pcaddu18i       $ra, 0         # loop
>  a60:   4c000021    jirl            $ra, $ra, 0    
   a64:   28c02061    ld.d            $ra, $sp, 8    
   a68:   02c04063    addi.d          $sp, $sp, 16   
   a6c:   4c000020    ret                            

[heiher]

There is no version of crosstool-ng that supports R_LARCH_CALL36, I'll revert the medium code model until the issue is resolved.

[xry111]

Oooops. Is this communicated with crosstool-ng maintainers?

[xry111]

But maybe crosstool-ng maintainers can't act as well due to the incompatibility between GCC 13.2 and Binutils 2.42 (loongson-community/discussions#41) :(. I'm not sure how to fix such an incompatibility...