Segfaults in tests on upcoming 1.12

[KristofferC]

https://s3.amazonaws.com/julialang-reports/nanosoldier/pkgeval/by_hash/7825364_vs_d63aded/LightBSON.primary.log

[41] signal 11 (128): Segmentation fault
in expression starting at /home/pkgeval/.julia/packages/LightBSON/wxK99/test/reader_tests.jl:1
unsafe_load at ./pointer.jl:153 [inlined]
unsafe_load at ./pointer.jl:153 [inlined]
load_bits_ at /home/pkgeval/.julia/packages/LightBSON/wxK99/src/reader.jl:185 [inlined]
read_field_ at /home/pkgeval/.julia/packages/LightBSON/wxK99/src/reader.jl:202 [inlined]
getindex at /home/pkgeval/.julia/packages/LightBSON/wxK99/src/reader.jl:535 [inlined]
read_field_ at /home/pkgeval/.julia/packages/LightBSON/wxK99/src/reader.jl:469
getindex at /home/pkgeval/.julia/packages/LightBSON/wxK99/src/reader.jl:535

I haven't looked into it anything, just reporting.

[ancapdev]

Thanks for the heads up, I'll look into this. Is 1.12 stable enough that this is unlikely to be a compiler issue?

[vtjnash]

No, this is probably a compiler issue. I don't know exactly the reason, but it is copying the dest alignment to the source for the unsafe_load, which is incorrect codegen similar to JuliaLang/julia#57722, though does not seem to be fixed by that yet

L546:                                             ; preds = %L543                                                                                                                                                                                                                                                                       
; ││ @ /home/vtjnash/.julia/packages/LightBSON/wxK99/src/reader.jl:202 within `read_field_`                                                                         
    %833 = call token (...) @llvm.julia.gc_preserve_begin(ptr addrspace(10) %8), !dbg !658                                                                                                                                                                                                                                              
; ││┌ @ /home/vtjnash/.julia/packages/LightBSON/wxK99/src/reader.jl:37 within `pointer` @ abstractarray.jl:1255                                                     
; │││┌ @ pointer.jl:65 within `cconvert`                                                                                                                            
      %834 = addrspacecast ptr addrspace(10) %8 to ptr addrspace(11), !dbg !659                                                                                                                                                                                                                                                         
      %835 = getelementptr inbounds { ptr, ptr addrspace(10) }, ptr addrspace(11) %834, i32 0, i32 0, !dbg !659                                                                                                                                                                                                                         
      %836 = load ptr, ptr addrspace(11) %835, align 8, !dbg !659, !tbaa !64, !alias.scope !67, !noalias !68                                                                                                                                                                                                                            
      %837 = getelementptr inbounds { ptr, ptr addrspace(10) }, ptr addrspace(11) %834, i32 0, i32 1, !dbg !659                                                                                                                                                                                                                         
      %838 = load ptr addrspace(10), ptr addrspace(11) %837, align 8, !dbg !659, !tbaa !64, !alias.scope !67, !noalias !68, !dereferenceable_or_null !69, !align !70                                                                                                                                                                    
      %839 = insertvalue { ptr, ptr addrspace(10) } zeroinitializer, ptr %836, 0, !dbg !659                                                                                                                                                                                                                                             
      %.ref506 = insertvalue { ptr, ptr addrspace(10) } %839, ptr addrspace(10) %838, 1, !dbg !659                                                                                                                                                                                                                                      
; │││└                                                                                                                                                                                                                                                                                                                                  
; │││┌ @ pointer.jl:90 within `unsafe_convert` @ pointer.jl:79                                                                                                                                                                                                                                                                          
      %.ref506.ptr_or_offset = extractvalue { ptr, ptr addrspace(10) } %.ref506, 0, !dbg !662                                                                                                                                                                                                                                           
; │││└                                                                                                                                                                                                                                                                                                                                  
; │││ @ /home/vtjnash/.julia/packages/LightBSON/wxK99/src/reader.jl:37 within `pointer`                                                                                                                                                                                                                                                 
; │││┌ @ Base_compiler.jl:55 within `getproperty`                                                                                                                                                                                                                                                                                       
      %840 = getelementptr inbounds i8, ptr addrspace(11) %"reader::BSONReader", i32 8, !dbg !664                                                                                                                                                                                                                                       
; │││└                                                                                                                                                                                                                                                                                                                                  
; │││┌ @ pointer.jl:316 within `+`                                                                                                                                                                                                                                                                                                      
; ││││┌ @ int.jl:554 within `rem`                                                                                                                                                                                                                                                                                                       
       %bitcast507 = load i64, ptr addrspace(11) %840, align 8, !dbg !665, !tbaa !36, !invariant.load !0, !alias.scope !46, !noalias !47                                                                                                                                                                                                
; ││││└                                                                                                                                                                                                                                                                                                                                 
      %841 = getelementptr i8, ptr %.ref506.ptr_or_offset, i64 %bitcast507, !dbg !666                                                                                                                                                                                                                                                   
; ││└└                                                                                                                                                                                                                                                                                                                                  
; ││┌ @ /home/vtjnash/.julia/packages/LightBSON/wxK99/src/reader.jl:185 within `load_bits_`                                                                                                                                                                                                                                             
; │││┌ @ pointer.jl:153 within `unsafe_load` @ pointer.jl:153                                                                                                                                                                                                                                                                           
      %842 = getelementptr inbounds [1 x i128], ptr %841, i64 0, !dbg !667                                                                                                                                                                                                                                                              
      call void @llvm.memcpy.p0.p0.i64(ptr align 16 %pointerref508, ptr align 16 %842, i64 16, i1 false), !dbg !667, !tbaa !93, !alias.scope !404, !noalias !103    
; ││└└                                                                                                                                                              
    call void @llvm.julia.gc_preserve_end(token %833), !dbg !658                                                                                                    
    br label %L562, !dbg !658