[llvm-dev] Updating LLVM Tests for Patch

Wed Sep 20 03:17:16 PDT 2017

Hi,

I am currently working on a more or less intrusive patch (D37896), which 
pulls optimizations on multiplications from some back-ends, e.g., (mul 
x, 2^N + 1) => (add (shl x, N), x) in AArch64, into the DAGCombiner to 
have this optimization generic on all targets.
However, running the LLVM Tests leads to 67 unexpected results.

Am 19.09.2017 um 15:58 schrieb Sanjay Patel:
> For the tests that are changing, you should see if those changes are 
> improvements, regressions, or neutral. This is unfortunately not always 
> obvious for x86 asm, so feel free to just post those diffs in an updated 
> version of the patch at D37896.
> 
> If the test files have auto-generated assertions (look for this string 
> on the first line of the test file: "NOTE: Assertions have been 
> autogenerated by utils/update_llc_test_checks.py"...
> and both of these do as of: https://reviews.llvm.org/rL313631 
> <https://reviews.llvm.org/rL313631> ), then it's easy to observe the 
> diffs by re-running that script after your code patch is applied:
> $ /path/to/update_llc_test_checks.py --llc=/path/to/local/and/new/llc 
> lea-3.ll
> $ svn diff lea-3.ll

As described by Sanjay in the original thread, I updated the llc tests 
but some of the tests were not updated.

For example: CodeGen/X86/lea-3.ll produces the following output:
llvm/utils/update_llc_test_checks.py --llc=/home/dev/local/bin/llc 
CodeGen/X86/lea-3.ll
WARNING: Found conflicting asm under the same prefix: 'CHECK'!
WARNING: Found conflicting asm under the same prefix: 'CHECK'!
WARNING: Found conflicting asm under the same prefix: 'CHECK'!

leaving parts of the test unchanged and the tests still fail.

Other tests like CodeGen/AArch64/aarch64-gep-opt.ll results in:
WARNING: Skipping non-FileChecked RUN line: llc -O3 
-aarch64-enable-gep-opt=true -mattr=-use-aa -print-after=codegenprepare 
< %s >%t 2>&1 && FileCheck --check-prefix=CHECK-NoAA <%t %s
WARNING: Skipping non-FileChecked RUN line: llc -O3 
-aarch64-enable-gep-opt=true -mattr=+use-aa -print-after=codegenprepare 
< %s >%t 2>&1 && FileCheck --check-prefix=CHECK-UseAA <%t %s
WARNING: Skipping non-FileChecked RUN line: llc -O3 
-aarch64-enable-gep-opt=true -print-after=codegenprepare -mcpu=cyclone < 
%s >%t 2>&1 && FileCheck --check-prefix=CHECK-NoAA <%t %s
WARNING: Skipping non-FileChecked RUN line: llc -O3 
-aarch64-enable-gep-opt=true -print-after=codegenprepare 
-mcpu=cortex-a53 < %s >%t 2>&1 && FileCheck --check-prefix=CHECK-UseAA 
<%t %s

And the worst thing I witnessed was with the Hexagon back-end were my 
changes in DAGCombiner trigger an Unreachable:

home/dev/llvm/build/./bin/llc -march=hexagon -mcpu=hexagonv5 
-disable-hsdr < 
/home/dev/llvm/llvm/test/CodeGen/Hexagon/vect/vect-cst-v4i32.ll | 
/home/dev/llvm/build/./bin/FileCheck 
/home/dev/llvm/llvm/test/CodeGen/Hexagon/vect/vect-cst-v4i32.ll
--
Exit Code: 2

Command Output (stderr):
--
ReplaceNodeResults not implemented for this target!
UNREACHABLE executed at 
/home/dev/llvm/llvm/include/llvm/Target/TargetLowering.h:3164!
#0 0x00007f1b2d330cfa llvm::sys::PrintStackTrace(llvm::raw_ostream&) 
(/home/dev/llvm/build/bin/../lib/libLLVMSupport.so.6+0x116cfa)
#1 0x00007f1b2d32ea9e llvm::sys::RunSignalHandlers() 
(/home/dev/llvm/build/bin/../lib/libLLVMSupport.so.6+0x114a9e)
#2 0x00007f1b2d32ec04 SignalHandler(int) 
(/home/dev/llvm/build/bin/../lib/libLLVMSupport.so.6+0x114c04)
#3 0x00007f1b2c3ed7f0 (/lib/x86_64-linux-gnu/libc.so.6+0x357f0)
#4 0x00007f1b2c3ed77f gsignal (/lib/x86_64-linux-gnu/libc.so.6+0x3577f)
#5 0x00007f1b2c3ef37a abort (/lib/x86_64-linux-gnu/libc.so.6+0x3737a)
#6 0x00007f1b2d2b012a 
(/home/dev/llvm/build/bin/../lib/libLLVMSupport.so.6+0x9612a)
#7 0x00007f1b359326ec 
(/home/dev/llvm/build/bin/../lib/libLLVMHexagonCodeGen.so.6+0x1176ec)
#8 0x00007f1b2d6a37a6 
llvm::DAGTypeLegalizer::CustomLowerNode(llvm::SDNode*, llvm::EVT, bool) 
(/home/dev/llvm/build/bin/../lib/libLLVMSelectionDAG.so.6+0x1247a6)
#9 0x00007f1b2d6be0d9 
llvm::DAGTypeLegalizer::SplitVectorResult(llvm::SDNode*, unsigned int) 
(/home/dev/llvm/build/bin/../lib/libLLVMSelectionDAG.so.6+0x13f0d9)
#10 0x00007f1b2d69f156 llvm::DAGTypeLegalizer::run() 
(/home/dev/llvm/build/bin/../lib/libLLVMSelectionDAG.so.6+0x120156)
#11 0x00007f1b2d6a01ff llvm::SelectionDAG::LegalizeTypes() 
(/home/dev/llvm/build/bin/../lib/libLLVMSelectionDAG.so.6+0x1211ff)
#12 0x00007f1b2d785d42 llvm::SelectionDAGISel::CodeGenAndEmitDAG() 
(/home/dev/llvm/build/bin/../lib/libLLVMSelectionDAG.so.6+0x206d42)
#13 0x00007f1b2d790fd8 
llvm::SelectionDAGISel::SelectAllBasicBlocks(llvm::Function const&) 
(/home/dev/llvm/build/bin/../lib/libLLVMSelectionDAG.so.6+0x211fd8)
#14 0x00007f1b2d7930e2 
llvm::SelectionDAGISel::runOnMachineFunction(llvm::MachineFunction&) 
[clone .part.873] 
(/home/dev/llvm/build/bin/../lib/libLLVMSelectionDAG.so.6+0x2140e2)
#15 0x00007f1b35931d6a (anonymous 
namespace)::HexagonDAGToDAGISel::runOnMachineFunction(llvm::MachineFunction&) 
(/home/dev/llvm/build/bin/../lib/libLLVMHexagonCodeGen.so.6+0x116d6a)
#16 0x00007f1b2ef22585 
llvm::MachineFunctionPass::runOnFunction(llvm::Function&) 
(/home/dev/llvm/build/bin/../lib/libLLVMCodeGen.so.6+0x21f585)
#17 0x00007f1b2e922dd3 
llvm::FPPassManager::runOnFunction(llvm::Function&) 
(/home/dev/llvm/build/bin/../lib/libLLVMCore.so.6+0x18ddd3)
#18 0x00007f1b2e922e93 llvm::FPPassManager::runOnModule(llvm::Module&) 
(/home/dev/llvm/build/bin/../lib/libLLVMCore.so.6+0x18de93)
#19 0x00007f1b2e9239e1 llvm::legacy::PassManagerImpl::run(llvm::Module&) 
(/home/dev/llvm/build/bin/../lib/libLLVMCore.so.6+0x18e9e1)
#20 0x000055b29c4ef3e2 compileModule(char**, llvm::LLVMContext&) 
(/home/dev/llvm/build/./bin/llc+0x213e2)
#21 0x000055b29c4e23bc main (/home/dev/llvm/build/./bin/llc+0x143bc)
#22 0x00007f1b2c3d83f1 __libc_start_main 
(/lib/x86_64-linux-gnu/libc.so.6+0x203f1)
#23 0x000055b29c4e256a _start (/home/dev/llvm/build/./bin/llc+0x1456a)
Stack dump:
0.	Program arguments: /home/dev/llvm/build/./bin/llc -march=hexagon 
-mcpu=hexagonv5 -disable-hsdr
1.	Running pass 'Function Pass Manager' on module '<stdin>'.
2.	Running pass 'Hexagon DAG->DAG Pattern Instruction Selection' on 
function '@run'
FileCheck error: '-' is empty.
FileCheck command line:  /home/dev/llvm/build/./bin/FileCheck 
/home/dev/llvm/llvm/test/CodeGen/Hexagon/vect/vect-cst-v4i32.ll

How do I proceed to get the patch running all tests as expected? The 
Tests directly focused on the results of the patch are passing without 
problems.

Cheers,
Michael