[AMDGPU] shader generated by radeonsi crashes LLVM codegen

[Quuxplusone]

Bugzilla Link	PR39214
Status	NEW
Importance	P normal
Reported by	Józef Kucia (joseph.kucia@gmail.com)
Reported on	2018-10-08 01:56:50 -0700
Last modified on	2018-10-08 07:08:21 -0700
Version	6.0
Hardware	PC Linux
CC	llvm-bugs@lists.llvm.org, Matthew.Arsenault@amd.com
Fixed by commit(s)
Attachments	llvm-code.bc (3256 bytes, application/octet-stream)
Blocks
Blocked by
See also

Created attachment 20976
bitcode

The attached LLVM bitcode is prodcued by radeonsi.

LLVM 7.0.0:

--- snip ---
LLVM ERROR: Cannot select: 0x55bf333f40c0: v4i32,ch = load<(dereferenceable
invariant load 16 from %ir.25, addrspace 2)> 0x55bf33367b28, 0x55bf333f9438,
undef:i32
  0x55bf333f9438: i32 = add 0x55bf333f94a0, Constant:i32<272>
    0x55bf333f94a0: i32,ch = CopyFromReg 0x55bf33367b28, Register:i32 %42
      0x55bf333f98b0: i32 = Register %42
    0x55bf333f9710: i32 = Constant<272>
  0x55bf333f4128: i32 = undef
In function: main
--- snip ---

LLVM 6.0.1:

--- snip ---
#0 0x00007fd358284daa llvm::sys::PrintStackTrace(llvm::raw_ostream&)
(/usr/lib64/llvm/6/bin/../lib64/libLLVMSupport.so.6+0x108daa)
#1 0x00007fd358282c96 llvm::sys::RunSignalHandlers()
(/usr/lib64/llvm/6/bin/../lib64/libLLVMSupport.so.6+0x106c96)
#2 0x00007fd358282f1b
(/usr/lib64/llvm/6/bin/../lib64/libLLVMSupport.so.6+0x106f1b)
#3 0x00007fd35717cfe0 (/lib64/libc.so.6+0x35fe0)
#4 0x00007fd359ca34e1
(/usr/lib64/llvm/6/bin/../lib64/libLLVMCodeGen.so.6+0x2fb4e1)
Stack dump:
0.  Program arguments: /usr/lib/llvm/6/bin/llc llvm-code.bc
1.  Running pass 'CallGraph Pass Manager' on module 'llvm-code.bc'.
2.  Running pass 'Simple Register Coalescing' on function '@main'
Segmentation fault
--- snip ---

[Quuxplusone]

Attached llvm-code.bc (3256 bytes, application/octet-stream): bitcode

[Quuxplusone]

How was this bitcode produced? This is using the old address space mapping, which shouldn't work anymore with a recent version

[Quuxplusone]

If I update the constant address space number to 4, this compiles for me on trunk

[Quuxplusone]

It was produced by radeonsi compiled with LLVM 6. You're right it works correctly when radeonsi is compiled with LLVM 7. The bug is present only in LLVM 6. Sorry for wasting your time.