[LLVMdev] [NVPTX] Backend cannot handle array-of-arrays constant

[Dmitry N. Mikushin]

NVCC successfully handles the same IR, if we try to process the same
.cu file with clang+nvptx and nvcc:

CLANG/NVPTX:
=============

$ cat dayofweek.cu
__attribute__((device)) char yweek[7][4] = { "MON", "TUE", "WED",
"THU", "FRI", "SAT", "SUN" };
$ clang -cc1 -emit-llvm -fcuda-is-device dayofweek.cu -o dayofweek.ll
$ cat dayofweek.ll
; ModuleID = 'dayofweek.cu'
target datalayout =
"e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128"
target triple = "x86_64-unknown-linux-gnu"

@yweek = global [7 x [4 x i8]] [[4 x i8] c"MON\00", [4 x i8]
c"TUE\00", [4 x i8] c"WED\00", [4 x i8] c"THU\00", [4 x i8] c"FRI\00",
[4 x i8] c"SAT\00", [4 x i8] c"SUN\00"], align 16
$ llc -march="nvptx" dayofweek.ll -o -
//
// Generated by LLVM NVPTX Back-End
//

.version 3.0
.target sm_10, texmode_independent
.address_size 32

Unexpected Constant type
UNREACHABLE executed at
/home/marcusmae/rpmbuild/BUILD/llvm/lib/Target/NVPTX/NVPTXAsmPrinter.cpp:1903!

NVCC
=====

$ nvcc -c -keep dayofweek.cu
$ cat dayofweek.ptx

	.global .align 1 .b8 yweek[28] =
{0x4d,0x4f,0x4e,0x0,0x54,0x55,0x45,0x0,0x57,0x45,0x44,0x0,0x54,0x48,0x55,0x0,0x46,0x52,0x49,0x0,0x53,0x41,0x54,0x0,0x53,0x55,0x4e,0x0};

2012/9/3 Dmitry N. Mikushin <maemarcus at gmail.com>:
> Dear all,
>
> Looks like the NVPTX backend cannot handle array-of-arrays contant
> (please see the reporocase below). Is it supposed to work? Any ideas
> how to get it working? Important for our target applications.
>
> Thanks,
> - Dima.
>
> $ cat test.ll
> ; ModuleID = '__kernelgen_main_module'
> target datalayout =
> "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v16:16:16-v32:32:32-v64:64:64-v128:128:128-n16:32:64"
> target triple = "nvptx64-unknown-unknown"
>
> @yweek.1533 = internal global [7 x [3 x i8]] [[3 x i8] c"MON", [3 x
> i8] c"TUE", [3 x i8] c"WED", [3 x i8] c"THU", [3 x i8] c"FRI", [3 x
> i8] c"SAT", [3 x i8] c"SUN"], align 4096
>
> $ llc -march="nvptx" test.ll -o -
> //
> // Generated by LLVM NVPTX Back-End
> //
>
> .version 3.0
> .target sm_10, texmode_independent
> .address_size 32
>
> Unexpected Constant type
> UNREACHABLE executed at
> /home/marcusmae/rpmbuild/BUILD/llvm/lib/Target/NVPTX/NVPTXAsmPrinter.cpp:1903!
> 0  libLLVM-3.2svn.so 0x00007f1bcb71bf0e
> 1  libLLVM-3.2svn.so 0x00007f1bcb71bd0a
> 2  libpthread.so.0   0x00007f1bca33ccb0
> 3  libc.so.6         0x00007f1bc9aa8445 gsignal + 53
> 4  libc.so.6         0x00007f1bc9aabbab abort + 379
> 5  libLLVM-3.2svn.so 0x00007f1bcb7044a3
> 6  libLLVM-3.2svn.so 0x00007f1bcb3e6396
> 7  libLLVM-3.2svn.so 0x00007f1bcb3e6494
> 8  libLLVM-3.2svn.so 0x00007f1bcb3e39fe
> 9  libLLVM-3.2svn.so 0x00007f1bcb3e23e8
> 10 libLLVM-3.2svn.so 0x00007f1bcb1a90a1
> llvm::FPPassManager::doInitialization(llvm::Module&) + 73
> 11 libLLVM-3.2svn.so 0x00007f1bcb1a8fb0
> llvm::FPPassManager::runOnModule(llvm::Module&) + 36
> 12 libLLVM-3.2svn.so 0x00007f1bcb1a9337
> llvm::MPPassManager::runOnModule(llvm::Module&) + 453
> 13 libLLVM-3.2svn.so 0x00007f1bcb1a9869
> llvm::PassManagerImpl::run(llvm::Module&) + 125
> 14 libLLVM-3.2svn.so 0x00007f1bcb1a9a1d
> llvm::PassManager::run(llvm::Module&) + 39
> 15 llc               0x000000000040ed8e main + 3091
> 16 libc.so.6         0x00007f1bc9a9376d __libc_start_main + 237
> 17 llc               0x000000000040dac9
> Stack dump:
> 0.      Program arguments: llc -march=nvptx test.ll -o -
> 1.      Running pass 'Function Pass Manager' on module 'test.ll'.
> Aborted (core dumped)