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edA-qa mort-ora-y

2013-Nov-09 11:47 UTC

[LLVMdev] Error "Cannot emit physreg copy instruction"

I'm getting an error that I don't know how to fix. I've isolated the
input as much as I easily can. I've attached the file that produces the
problem. Just calling "llc err.ll -o err.s" generates the error.

I'm going to try and isolate even further, but as I'm not sure what
I'm
looking for I don't know if I'll be successful. Does anybody know what
this error means?

Cannot emit physreg copy instruction
UNREACHABLE executed at X86InstrInfo.cpp:2899!
0  libLLVM-3.3.so  0x00007f9f68ddf642
llvm::sys::PrintStackTrace(_IO_FILE*) + 34
1  libLLVM-3.3.so  0x00007f9f68dde9a9
2  libpthread.so.0 0x00007f9f67a07cb0
3  libc.so.6       0x00007f9f67156425 gsignal + 53
4  libc.so.6       0x00007f9f67159b8b abort + 379
5  libLLVM-3.3.so  0x00007f9f68dc1e7c
6  libLLVM-3.3.so  0x00007f9f68fd1832
llvm::X86InstrInfo::copyPhysReg(llvm::MachineBasicBlock&,
llvm::MachineBasicBlock::bundle_iterator<llvm::MachineInstr,
llvm::ilist_iterator<llvm::MachineInstr> >, llvm::DebugLoc, unsigned
int, unsigned int, bool) const + 1762
7  libLLVM-3.3.so  0x00007f9f683afab1
8  libLLVM-3.3.so  0x00007f9f6864c417
llvm::FPPassManager::runOnFunction(llvm::Function&) + 487
9  libLLVM-3.3.so  0x00007f9f6864c50b
llvm::FPPassManager::runOnModule(llvm::Module&) + 43
10 libLLVM-3.3.so  0x00007f9f6864beff
llvm::MPPassManager::runOnModule(llvm::Module&) + 559
11 libLLVM-3.3.so  0x00007f9f6864c165
llvm::PassManagerImpl::run(llvm::Module&) + 245
12 llc             0x000000000040d217
13 llc             0x0000000000409a58 main + 360
14 libc.so.6       0x00007f9f6714176d __libc_start_main + 237
15 llc             0x0000000000409ae1
Stack dump:
0.  Program arguments: /opt/llvm/install/bin/llc err.ll -o err.s
1.  Running pass 'Function Pass Manager' on module 'err.ll'.
2.  Running pass 'Post-RA pseudo instruction expansion pass' on function
'@junk___init_module_get_args_3'

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-------------- next part --------------
; ModuleID = 'test'

%0 = type { i64, void (i8*)*, i1 (i8*)*, i8*, i8* }
%junk__range_iter = type { i1 (i8*)* }

@junk__construct_range_iter = global void (i8*)* undef
@junk__get_args = internal global i8* ()* undef

declare i64 @leaf_exception_personality(i64, i32, i64, i8*, i8*)

declare i8* @count_malloc(i64)

declare void @_void_destructor(i8*)

declare void @leaf_rethrow(i8*)

; Function Attrs: uwtable
define internal void @_release_Au32a(i8**) #0 {
entry:
  ret void
}

; Function Attrs: uwtable
define internal void @_release_C0PpRbrc(%0**) #0 {
entry:
  ret void
}

; Function Attrs: uwtable
define internal i8* @junk___init_module_get_args_3() #0 {
entry:
  %_return_path = alloca i8
  store i8 0, i8* %_return_path
  %_exception = alloca { i8*, i64 }
  %_return_val = alloca i8*
  %junk__a = alloca %junk__range_iter
  %cond_result = alloca i1
  %0 = call i8* @count_malloc(i64 16)
  %1 = bitcast i8* %0 to i64*
  store i64 0, i64* %1
  store i8* %0, i8** %_return_val
  br label %defer_error_body_3

func_ret_0:                                       ; preds = %loop_end_6
  %2 = load i8** %_return_val
  ret i8* %2

defer_error_end_1:                                ; preds = %defer_error_block_2
  br label %rethrow_19

defer_error_block_2:                              ; preds = %defer_cont_10,
%defer_error_land_4
  %return_path_3 = load i8* %_return_path
  store i8 0, i8* %_return_path
  call void @_release_Au32a(i8** %_return_val)
  store i8 %return_path_3, i8* %_return_path
  br label %defer_error_end_1

defer_error_body_3:                               ; preds = %entry
  %3 = load void (i8*)** @junk__construct_range_iter
  %4 = bitcast %junk__range_iter* %junk__a to i8*
  invoke void %3(i8* %4)
          to label %post_call_5 unwind label %defer_error_land_4

defer_error_land_4:                               ; preds = %defer_block_11,
%loop_cond_7, %defer_error_body_3
  %5 = landingpad { i8*, i64 } personality i64 (i64, i32, i64, i8*, i8*)*
@leaf_exception_personality
          cleanup
  store { i8*, i64 } %5, { i8*, i64 }* %_exception
  store i8 4, i8* %_return_path
  br label %defer_error_block_2

post_call_5:                                      ; preds = %defer_error_body_3
  br label %loop_cond_7

loop_end_6:                                       ; preds = %defer_end_9
  br label %func_ret_0

loop_cond_7:                                      ; preds = %loop_body_16,
%post_call_5
  %6 = load %junk__range_iter* %junk__a
  %7 = extractvalue %junk__range_iter %6, 0
  %8 = invoke i8* @count_malloc(i64 40)
          to label %post_call_8 unwind label %defer_error_land_4

post_call_8:                                      ; preds = %loop_cond_7
  %9 = bitcast i8* %8 to %0*
  %ref_count_4 = getelementptr inbounds %0* %9, i32 0, i32 0
  store i64 1, i64* %ref_count_4
  %func_ptr_5 = getelementptr inbounds %0* %9, i32 0, i32 2
  store i1 (i8*)* %7, i1 (i8*)** %func_ptr_5
  %10 = bitcast %junk__range_iter* %junk__a to i8*
  %ctx_data_6 = getelementptr inbounds %0* %9, i32 0, i32 3
  store i8* %10, i8** %ctx_data_6
  %dtor_7 = getelementptr inbounds %0* %9, i32 0, i32 1
  store void (i8*)* @_void_destructor, void (i8*)** %dtor_7
  %11 = alloca %0*
  store %0* %9, %0** %11
  br label %defer_body_12

defer_end_9:                                      ; preds = %defer_cont_10,
%defer_cont_10
  %12 = load i1* %cond_result
  br i1 %12, label %loop_body_16, label %loop_end_6

defer_cont_10:                                    ; preds = %post_call_14
  %return_path_14 = load i8* %_return_path
  switch i8 %return_path_14, label %defer_end_9 [
    i8 0, label %defer_end_9
    i8 4, label %defer_error_block_2
  ]

defer_block_11:                                   ; preds = %post_call_15,
%defer_land_13
  %return_path_8 = load i8* %_return_path
  store i8 0, i8* %_return_path
  invoke void @_release_C0PpRbrc(%0** %11)
          to label %post_call_14 unwind label %defer_error_land_4

defer_body_12:                                    ; preds = %post_call_8
  %13 = getelementptr inbounds %0* %9, i32 0, i32 3
  %ctx_gptr_9 = load i8** %13
  %14 = getelementptr inbounds %0* %9, i32 0, i32 2
  %func_ptr_11 = load i1 (i8*)** %14
  %15 = invoke i1 %func_ptr_11(i8* %ctx_gptr_9)
          to label %post_call_15 unwind label %defer_land_13

defer_land_13:                                    ; preds = %defer_body_12
  %16 = landingpad { i8*, i64 } personality i64 (i64, i32, i64, i8*, i8*)*
@leaf_exception_personality
          cleanup
  store { i8*, i64 } %16, { i8*, i64 }* %_exception
  store i8 4, i8* %_return_path
  br label %defer_block_11

post_call_14:                                     ; preds = %defer_block_11
  store i8 %return_path_8, i8* %_return_path
  br label %defer_cont_10

post_call_15:                                     ; preds = %defer_body_12
  store i1 %15, i1* %cond_result
  br label %defer_block_11

loop_body_16:                                     ; preds = %defer_end_9
  br label %loop_cond_7

loop_next_17:                                     ; No predecessors!
  unreachable

loop_break_18:                                    ; No predecessors!
  unreachable

rethrow_19:                                       ; preds = %defer_error_end_1
  %lpad_result_12 = load { i8*, i64 }* %_exception
  %except_13 = extractvalue { i8*, i64 } %lpad_result_12, 0
  call void @leaf_rethrow(i8* %except_13)
  unreachable
}

edA-qa mort-ora-y

2013-Nov-09 12:53 UTC

head link

[LLVMdev] Error "Cannot emit physreg copy instruction"

I've reduced the example down to a minimum. The error is quite
perplexing since the IR appears fine. It is a nonsensical infinite loop
now, but that shouldn't be a problem.

declare i64 @leaf_exception_personality(i64, i32, i64, i8*, i8*)

declare i8* @count_malloc(i64)

define internal i8 @junk___init_module_get_args_3() #0 {
entry:
  %_exception = alloca { i8*, i64 }
  %ignore0 = invoke i8* @count_malloc(i64 10)
          to label %loop_cond_7 unwind label %defer_error_land_4

defer_error_land_4:
  %lpres = landingpad { i8*, i64 } personality i64 (i64, i32, i64, i8*,
i8*)* @leaf_exception_personality
          cleanup
  store { i8*, i64 } %lpres, { i8*, i64 }* %_exception
  ret i8 0

loop_cond_7:
  %ignore1 = invoke i8* @count_malloc(i64 40)
          to label %loop_cond_7 unwind label %defer_error_land_4
}


On 09/11/13 12:47, edA-qa mort-ora-y wrote:> I'm getting an error that I don't know how to fix. I've
isolated the
> input as much as I easily can. I've attached the file that produces the
> problem. Just calling "llc err.ll -o err.s" generates the error.
> 
> I'm going to try and isolate even further, but as I'm not sure what
I'm
> looking for I don't know if I'll be successful. Does anybody know
what
> this error means?
> 
> Cannot emit physreg copy instruction
> UNREACHABLE executed at X86InstrInfo.cpp:2899!
> 0  libLLVM-3.3.so  0x00007f9f68ddf642
> llvm::sys::PrintStackTrace(_IO_FILE*) + 34
> 1  libLLVM-3.3.so  0x00007f9f68dde9a9
> 2  libpthread.so.0 0x00007f9f67a07cb0
> 3  libc.so.6       0x00007f9f67156425 gsignal + 53
> 4  libc.so.6       0x00007f9f67159b8b abort + 379
> 5  libLLVM-3.3.so  0x00007f9f68dc1e7c
> 6  libLLVM-3.3.so  0x00007f9f68fd1832
> llvm::X86InstrInfo::copyPhysReg(llvm::MachineBasicBlock&,
> llvm::MachineBasicBlock::bundle_iterator<llvm::MachineInstr,
> llvm::ilist_iterator<llvm::MachineInstr> >, llvm::DebugLoc,
unsigned
> int, unsigned int, bool) const + 1762
> 7  libLLVM-3.3.so  0x00007f9f683afab1
> 8  libLLVM-3.3.so  0x00007f9f6864c417
> llvm::FPPassManager::runOnFunction(llvm::Function&) + 487
> 9  libLLVM-3.3.so  0x00007f9f6864c50b
> llvm::FPPassManager::runOnModule(llvm::Module&) + 43
> 10 libLLVM-3.3.so  0x00007f9f6864beff
> llvm::MPPassManager::runOnModule(llvm::Module&) + 559
> 11 libLLVM-3.3.so  0x00007f9f6864c165
> llvm::PassManagerImpl::run(llvm::Module&) + 245
> 12 llc             0x000000000040d217
> 13 llc             0x0000000000409a58 main + 360
> 14 libc.so.6       0x00007f9f6714176d __libc_start_main + 237
> 15 llc             0x0000000000409ae1
> Stack dump:
> 0.  Program arguments: /opt/llvm/install/bin/llc err.ll -o err.s
> 1.  Running pass 'Function Pass Manager' on module
'err.ll'.
> 2.  Running pass 'Post-RA pseudo instruction expansion pass' on
function
> '@junk___init_module_get_args_3'
> 
> 
> 
> _______________________________________________
> LLVM Developers mailing list
> LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
> 

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edA-qa mort-ora-y

2013-Nov-09 15:45 UTC

head link

[LLVMdev] Error "Cannot emit physreg copy instruction"

I can make the problem go away, but perhaps there is still an issue in
LLVM. At least a missing assert somewhere. It's strange that only this
very particular structure causes the failure.

If I change the personality routine return value to i32 from i64 then it
works.

On 09/11/13 13:53, edA-qa mort-ora-y wrote:> I've reduced the example down to a minimum. The error is quite
> perplexing since the IR appears fine. It is a nonsensical infinite loop
> now, but that shouldn't be a problem.
> 
> declare i64 @leaf_exception_personality(i64, i32, i64, i8*, i8*)
> 
> declare i8* @count_malloc(i64)
> 
> define internal i8 @junk___init_module_get_args_3() #0 {
> entry:
>   %_exception = alloca { i8*, i64 }
>   %ignore0 = invoke i8* @count_malloc(i64 10)
>           to label %loop_cond_7 unwind label %defer_error_land_4
> 
> defer_error_land_4:
>   %lpres = landingpad { i8*, i64 } personality i64 (i64, i32, i64, i8*,
> i8*)* @leaf_exception_personality
>           cleanup
>   store { i8*, i64 } %lpres, { i8*, i64 }* %_exception
>   ret i8 0
> 
> loop_cond_7:
>   %ignore1 = invoke i8* @count_malloc(i64 40)
>           to label %loop_cond_7 unwind label %defer_error_land_4
> }
> 
> 
> On 09/11/13 12:47, edA-qa mort-ora-y wrote:
>> I'm getting an error that I don't know how to fix. I've
isolated the
>> input as much as I easily can. I've attached the file that produces
the
>> problem. Just calling "llc err.ll -o err.s" generates the
error.
>>
>> I'm going to try and isolate even further, but as I'm not sure
what I'm
>> looking for I don't know if I'll be successful. Does anybody
know what
>> this error means?
>>
>> Cannot emit physreg copy instruction
>> UNREACHABLE executed at X86InstrInfo.cpp:2899!
>> 0  libLLVM-3.3.so  0x00007f9f68ddf642
>> llvm::sys::PrintStackTrace(_IO_FILE*) + 34
>> 1  libLLVM-3.3.so  0x00007f9f68dde9a9
>> 2  libpthread.so.0 0x00007f9f67a07cb0
>> 3  libc.so.6       0x00007f9f67156425 gsignal + 53
>> 4  libc.so.6       0x00007f9f67159b8b abort + 379
>> 5  libLLVM-3.3.so  0x00007f9f68dc1e7c
>> 6  libLLVM-3.3.so  0x00007f9f68fd1832
>> llvm::X86InstrInfo::copyPhysReg(llvm::MachineBasicBlock&,
>> llvm::MachineBasicBlock::bundle_iterator<llvm::MachineInstr,
>> llvm::ilist_iterator<llvm::MachineInstr> >, llvm::DebugLoc,
unsigned
>> int, unsigned int, bool) const + 1762
>> 7  libLLVM-3.3.so  0x00007f9f683afab1
>> 8  libLLVM-3.3.so  0x00007f9f6864c417
>> llvm::FPPassManager::runOnFunction(llvm::Function&) + 487
>> 9  libLLVM-3.3.so  0x00007f9f6864c50b
>> llvm::FPPassManager::runOnModule(llvm::Module&) + 43
>> 10 libLLVM-3.3.so  0x00007f9f6864beff
>> llvm::MPPassManager::runOnModule(llvm::Module&) + 559
>> 11 libLLVM-3.3.so  0x00007f9f6864c165
>> llvm::PassManagerImpl::run(llvm::Module&) + 245
>> 12 llc             0x000000000040d217
>> 13 llc             0x0000000000409a58 main + 360
>> 14 libc.so.6       0x00007f9f6714176d __libc_start_main + 237
>> 15 llc             0x0000000000409ae1
>> Stack dump:
>> 0.  Program arguments: /opt/llvm/install/bin/llc err.ll -o err.s
>> 1.  Running pass 'Function Pass Manager' on module
'err.ll'.
>> 2.  Running pass 'Post-RA pseudo instruction expansion pass' on
function
>> '@junk___init_module_get_args_3'
>>
>>
>>
>> _______________________________________________
>> LLVM Developers mailing list
>> LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
>> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
>>
> 
> 

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Cameron McInally

2013-Nov-09 15:51 UTC

head link

[LLVMdev] Error "Cannot emit physreg copy instruction"

Hey edA-qa mort-ora-y,

On Sat, Nov 9, 2013 at 6:47 AM, edA-qa mort-ora-y <eda-qa at disemia.com>
wrote:> I'm getting an error that I don't know how to fix. I've
isolated the
> input as much as I easily can. I've attached the file that produces the
> problem. Just calling "llc err.ll -o err.s" generates the error.
>
> I'm going to try and isolate even further, but as I'm not sure what
I'm
> looking for I don't know if I'll be successful. Does anybody know
what
> this error means?
>
> Cannot emit physreg copy instruction
> UNREACHABLE executed at X86InstrInfo.cpp:2899!
> 0  libLLVM-3.3.so  0x00007f9f68ddf642
> llvm::sys::PrintStackTrace(_IO_FILE*) + 34
> 1  libLLVM-3.3.so  0x00007f9f68dde9a9
> 2  libpthread.so.0 0x00007f9f67a07cb0
> 3  libc.so.6       0x00007f9f67156425 gsignal + 53
> 4  libc.so.6       0x00007f9f67159b8b abort + 379
> 5  libLLVM-3.3.so  0x00007f9f68dc1e7c
> 6  libLLVM-3.3.so  0x00007f9f68fd1832
> llvm::X86InstrInfo::copyPhysReg(llvm::MachineBasicBlock&,
> llvm::MachineBasicBlock::bundle_iterator<llvm::MachineInstr,
> llvm::ilist_iterator<llvm::MachineInstr> >, llvm::DebugLoc,
unsigned
> int, unsigned int, bool) const + 1762
> 7  libLLVM-3.3.so  0x00007f9f683afab1
> 8  libLLVM-3.3.so  0x00007f9f6864c417
> llvm::FPPassManager::runOnFunction(llvm::Function&) + 487
> 9  libLLVM-3.3.so  0x00007f9f6864c50b
> llvm::FPPassManager::runOnModule(llvm::Module&) + 43
> 10 libLLVM-3.3.so  0x00007f9f6864beff
> llvm::MPPassManager::runOnModule(llvm::Module&) + 559
> 11 libLLVM-3.3.so  0x00007f9f6864c165
> llvm::PassManagerImpl::run(llvm::Module&) + 245
> 12 llc             0x000000000040d217
> 13 llc             0x0000000000409a58 main + 360
> 14 libc.so.6       0x00007f9f6714176d __libc_start_main + 237
> 15 llc             0x0000000000409ae1
> Stack dump:
> 0.  Program arguments: /opt/llvm/install/bin/llc err.ll -o err.s
> 1.  Running pass 'Function Pass Manager' on module
'err.ll'.
> 2.  Running pass 'Post-RA pseudo instruction expansion pass' on
function
> '@junk___init_module_get_args_3'
>
> --
> edA-qa mort-ora-y
I agree that this is an especially hard issue to diagnose, as I have
had issues with it in the recent past. At that time, I was not able to
find a good way to trace the COPY pseudo to a particular statement in
the IR. But, I digress...

The UNREACHABLE you are hitting comes from
X86InstrInfo::copyPhysReg(...) in
llvm/lib/Target/X86/X86InstrInfo.cpp. You're expanding a pseudo COPY
instruction, but the x86 target does not know how to produce a reg-reg
move that matches the problematic COPY instruction.

To find the COPY instruction that is the problem, try compiling with
-debug. You should see a statement, "Cannot copy...", which will give
you the details of the failing instruction.

I have also tried the test cases that you supplied, but was not able
to reproduce the error with ToT. What cpu target are you looking at?

-Cameron

edA-qa mort-ora-y

2013-Nov-09 16:00 UTC

head link

[LLVMdev] Error "Cannot emit physreg copy instruction"

On 09/11/13 16:51, Cameron McInally wrote:> I have also tried the test cases that you supplied, but was not able
> to reproduce the error with ToT. What cpu target are you looking at?
I am targeting Linux x86_64 with LLVM 3.3.

I found the problem was the "store" instruction for the landingpad
result. I don't understand why it was a problem but I have it
"corrected" now (switch i64 to i32 result).


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