[llvm] [LLVM][TableGen] Parameterize NumToSkip in DecoderEmitter (PR #135882)

Wed Apr 16 16:31:19 PDT 2025

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `polly-arm-linux` running on `hexagon-build-02` while building `llvm` at step 5 "build".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/90/builds/5529

<details>
<summary>Here is the relevant piece of the build log for the reference</summary>

```
Step 5 (build) failure: 'ninja -j16' (failure)
...
[1787/4327] Building ARMGenInstrInfo.inc...
[1788/4327] Building AArch64GenAsmWriter.inc...
[1789/4327] Building CXX object lib/ExecutionEngine/RuntimeDyld/CMakeFiles/LLVMRuntimeDyld.dir/RuntimeDyldChecker.cpp.o
[1790/4327] Building AArch64GenCallingConv.inc...
[1791/4327] Building ARMGenSubtargetInfo.inc...
[1792/4327] Building AArch64GenAsmWriter1.inc...
[1793/4327] Building AArch64GenExegesis.inc...
[1794/4327] Building CXX object lib/ExecutionEngine/RuntimeDyld/CMakeFiles/LLVMRuntimeDyld.dir/RuntimeDyldMachO.cpp.o
[1795/4327] Building CXX object lib/Target/CMakeFiles/LLVMTarget.dir/TargetLoweringObjectFile.cpp.o
[1796/4327] Building AArch64GenDisassemblerTables.inc...
FAILED: lib/Target/AArch64/AArch64GenDisassemblerTables.inc /local/mnt/workspace/bots/hexagon-build-02/polly-arm-linux/llvm.obj/lib/Target/AArch64/AArch64GenDisassemblerTables.inc 
cd /local/mnt/workspace/bots/hexagon-build-02/polly-arm-linux/llvm.obj && /local/mnt/workspace/bots/hexagon-build-02/polly-arm-linux/llvm.obj/bin/llvm-tblgen -gen-disassembler --num-to-skip-size=3 -I /local/mnt/workspace/bots/hexagon-build-02/polly-arm-linux/llvm.src/llvm/lib/Target/AArch64 -I/local/mnt/workspace/bots/hexagon-build-02/polly-arm-linux/llvm.obj/include -I/local/mnt/workspace/bots/hexagon-build-02/polly-arm-linux/llvm.src/llvm/include -I /local/mnt/workspace/bots/hexagon-build-02/polly-arm-linux/llvm.src/llvm/lib/Target /local/mnt/workspace/bots/hexagon-build-02/polly-arm-linux/llvm.src/llvm/lib/Target/AArch64/AArch64.td --write-if-changed -o lib/Target/AArch64/AArch64GenDisassemblerTables.inc -d lib/Target/AArch64/AArch64GenDisassemblerTables.inc.d
llvm-tblgen: /local/mnt/workspace/bots/hexagon-build-02/polly-arm-linux/llvm.src/llvm/utils/TableGen/DecoderEmitter.cpp:151: void (anonymous namespace)::DecoderTable::patchNumToSkip(size_t, uint32_t): Assertion `DestIdx > FixupIdx + NumToSkipSizeInBytes && "Expecting a forward jump in the decoding table"' failed.
PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace.
Stack dump:
0.	Program arguments: /local/mnt/workspace/bots/hexagon-build-02/polly-arm-linux/llvm.obj/bin/llvm-tblgen -gen-disassembler --num-to-skip-size=3 -I /local/mnt/workspace/bots/hexagon-build-02/polly-arm-linux/llvm.src/llvm/lib/Target/AArch64 -I/local/mnt/workspace/bots/hexagon-build-02/polly-arm-linux/llvm.obj/include -I/local/mnt/workspace/bots/hexagon-build-02/polly-arm-linux/llvm.src/llvm/include -I /local/mnt/workspace/bots/hexagon-build-02/polly-arm-linux/llvm.src/llvm/lib/Target /local/mnt/workspace/bots/hexagon-build-02/polly-arm-linux/llvm.src/llvm/lib/Target/AArch64/AArch64.td --write-if-changed -o lib/Target/AArch64/AArch64GenDisassemblerTables.inc -d lib/Target/AArch64/AArch64GenDisassemblerTables.inc.d
Stack dump without symbol names (ensure you have llvm-symbolizer in your PATH or set the environment var `LLVM_SYMBOLIZER_PATH` to point to it):
0  llvm-tblgen     0x00000000006fa807
1  llvm-tblgen     0x00000000006f862e
2  llvm-tblgen     0x00000000006faeaa
3  libpthread.so.0 0x00007f60c87bb980
4  libc.so.6       0x00007f60c7309e87 gsignal + 199
5  libc.so.6       0x00007f60c730b7f1 abort + 321
6  libc.so.6       0x00007f60c72fb3fa
7  libc.so.6       0x00007f60c72fb472
8  llvm-tblgen     0x000000000059fdbd
9  llvm-tblgen     0x000000000059fb02
10 llvm-tblgen     0x000000000059baa2
11 llvm-tblgen     0x0000000000597cca
12 llvm-tblgen     0x00000000005b8587
13 llvm-tblgen     0x0000000000725a69
14 llvm-tblgen     0x00000000007020ea
15 llvm-tblgen     0x000000000043e1ed
16 libc.so.6       0x00007f60c72ecc87 __libc_start_main + 231
17 llvm-tblgen     0x000000000040801a
Aborted
[1797/4327] Building AArch64GenAsmMatcher.inc...
[1798/4327] Building CXX object lib/Target/CMakeFiles/LLVMTarget.dir/TargetMachineC.cpp.o
[1799/4327] Building AArch64GenMCCodeEmitter.inc...
[1800/4327] Building CXX object lib/ExecutionEngine/RuntimeDyld/CMakeFiles/LLVMRuntimeDyld.dir/RuntimeDyld.cpp.o
[1801/4327] Building AArch64GenFastISel.inc...
[1802/4327] Building CXX object lib/Target/CMakeFiles/LLVMTarget.dir/TargetMachine.cpp.o
[1803/4327] Building AArch64GenDAGISel.inc...
[1804/4327] Building AArch64GenGlobalISel.inc...
[1805/4327] Building CXX object lib/ExecutionEngine/RuntimeDyld/CMakeFiles/LLVMRuntimeDyld.dir/RuntimeDyldELF.cpp.o
[1806/4327] Building CXX object lib/Target/ARM/CMakeFiles/LLVMARMCodeGen.dir/MVEVPTBlockPass.cpp.o
[1807/4327] Building CXX object lib/Target/ARM/CMakeFiles/LLVMARMCodeGen.dir/Thumb1InstrInfo.cpp.o
[1808/4327] Building CXX object lib/Target/ARM/CMakeFiles/LLVMARMCodeGen.dir/ARMLatencyMutations.cpp.o
[1809/4327] Building CXX object lib/Target/ARM/CMakeFiles/LLVMARMCodeGen.dir/MVETPAndVPTOptimisationsPass.cpp.o

```

</details>

https://github.com/llvm/llvm-project/pull/135882