Clamping of llvm llc to -O1 and -O2
We currently clamp the optimization level of llvm llc (3.9 and 4.0) within [1,2].
The reason is that with -O0, the naive register allocator can topple over with
Error while trying to spill R1 from class GPR: Cannot scavenge register
without an emergency spill slot!and with -O3 the llvm::SelectionDAGISel::LowerArguments may break, when compiling
rts/HeapStackCheck.cmm with the stage1 ghc.
0 llc 0x0000000102ae63e8 llvm::sys::PrintStackTrace(llvm::raw_ostream&) + 40
1 llc 0x0000000102ae69a6 SignalHandler(int) + 358
2 libsystem_platform.dylib 0x00007fffc23f4b3a _sigtramp + 26
3 libsystem_c.dylib 0x00007fffc226498b __vfprintf + 17876
4 llc 0x00000001029d5123 llvm::SelectionDAGISel::LowerArguments(llvm::Function const&) + 5699
5 llc 0x0000000102a21a35 llvm::SelectionDAGISel::SelectAllBasicBlocks(llvm::Function const&) + 3381
6 llc 0x0000000102a202b1 llvm::SelectionDAGISel::runOnMachineFunction(llvm::MachineFunction&) + 1457
7 llc 0x0000000101bdc474 (anonymous namespace)::ARMDAGToDAGISel::runOnMachineFunction(llvm::MachineFunction&) + 20
8 llc 0x00000001025573a6 llvm::MachineFunctionPass::runOnFunction(llvm::Function&) + 134
9 llc 0x000000010274fb12 llvm::FPPassManager::runOnFunction(llvm::Function&) + 498
10 llc 0x000000010274fd23 llvm::FPPassManager::runOnModule(llvm::Module&) + 67
11 llc 0x00000001027501b8 llvm::legacy::PassManagerImpl::run(llvm::Module&) + 920
12 llc 0x000000010195f075 compileModule(char**, llvm::LLVMContext&) + 12133
13 llc 0x000000010195bf0b main + 491
14 libdyld.dylib 0x00007fffc21e5235 start + 1
Stack dump:
0. Program arguments: llc -O3 -mtriple=arm-unknown-linux-gnueabihf -enable-tbaa /var/folders/fv/xqjrpfj516n5xq_m_ljpsjx00000gn/T/ghc33674_0/ghc_6.bc -o /var/folders/fv/xqjrpfj516n5xq_m_ljpsjx00000gn/T/ghc33674_0/ghc_7.lm_s
1. Running pass 'Function Pass Manager' on module '/var/folders/fv/xqjrpfj516n5xq_m_ljpsjx00000gn/T/ghc33674_0/ghc_6.bc'.
2. Running pass 'ARM Instruction Selection' on function '@"stg_gc_f1$def"'opt and llc should respect -opt_lo and -opt_lc, such that -opt_lc=-O3 can be used to validate the behaviour.
Trac metadata
| Trac field | Value |
|---|---|
| Version | 8.3 |
| Type | Bug |
| TypeOfFailure | OtherFailure |
| Priority | normal |
| Resolution | Unresolved |
| Component | Compiler (LLVM) |
| Test case | |
| Differential revisions | |
| BlockedBy | |
| Related | |
| Blocking | |
| CC | bgamari |
| Operating system | |
| Architecture |