error: scalar-to-vector conversion failed, possible invalid constraint for vector type

[DanAlbert]

similar log:

/var/folders/jw/7vmz4m1970932zln9tb1whxr0000gn/T/tmp.AfBnEXne/caca/dither.c:1268:18: error: scalar-to-vector conversion failed, possible invalid constraint for vector type
    asm volatile("fldl2e\n\t"
                 ^
/var/folders/jw/7vmz4m1970932zln9tb1whxr0000gn/T/tmp.AfBnEXne/caca/dither.c:1277:18: error: scalar-to-vector conversion failed, possible invalid constraint for vector type
    asm volatile("fscale"
                 ^
/var/folders/jw/7vmz4m1970932zln9tb1whxr0000gn/T/tmp.AfBnEXne/caca/dither.c:1277:18: error: scalar-to-vector conversion failed, possible invalid constraint for vector type
Stack dump:
0.	Program arguments: /usr/local/Cellar/android-sdk/6609375/ndk-bundle/toolchains/llvm/prebuilt/darwin-x86_64/bin/clang -cc1 -triple x86_64-unknown-linux-android21 -emit-obj -mnoexecstack -disable-free -disable-llvm-verifier -discard-value-names -main-file-name dither.c -mrelocation-model pic -pic-level 2 -mthread-model posix -masm-verbose -mconstructor-aliases -munwind-tables -fuse-init-array -target-cpu x86-64 -target-feature +sse4.2 -target-feature +popcnt -target-feature +cx16 -dwarf-column-info -debug-info-kind=limited -dwarf-version=4 -debugger-tuning=gdb -target-linker-version 305 -momit-leaf-frame-pointer -coverage-notes-file /var/folders/jw/7vmz4m1970932zln9tb1whxr0000gn/T/tmp.AfBnEXne/1609399549/x86_64/caca/.libs/libcaca_la-dither.gcno -resource-dir /usr/local/Cellar/android-sdk/6609375/ndk-bundle/toolchains/llvm/prebuilt/darwin-x86_64/lib64/clang/9.0.8 -dependency-file .deps/libcaca_la-dither.Tpo -sys-header-deps -MP -MT libcaca_la-dither.lo -D HAVE_CONFIG_H -I . -I /var/folders/jw/7vmz4m1970932zln9tb1whxr0000gn/T/tmp.AfBnEXne/caca -I .. -I /var/folders/jw/7vmz4m1970932zln9tb1whxr0000gn/T/tmp.AfBnEXne -D PLUGINDIR="" -D __LIBCACA__ -I /Users/leleliu008/.ndk-pkg/pkg/imlib2/x86_64/include -I /Users/leleliu008/.ndk-pkg/pkg/libwebp/x86_64/include -I /Users/leleliu008/.ndk-pkg/pkg/libtiff/x86_64/include -I /Users/leleliu008/.ndk-pkg/pkg/libjpeg-turbo/x86_64/include -I /Users/leleliu008/.ndk-pkg/pkg/giflib/x86_64/include -I /Users/leleliu008/.ndk-pkg/pkg/freetype2/x86_64/include -I /Users/leleliu008/.ndk-pkg/pkg/brotli/x86_64/include -I /Users/leleliu008/.ndk-pkg/pkg/bzip2/x86_64/include -I /Users/leleliu008/.ndk-pkg/pkg/libpng/x86_64/include -I /Users/leleliu008/.ndk-pkg/pkg/zlib/x86_64/include -D ftello=ftell -D fseeko=fseek -D X_DISPLAY_MISSING -D PIC -isysroot /usr/local/opt/android-sdk/ndk-bundle/toolchains/llvm/prebuilt/darwin-x86_64/sysroot -internal-isystem /usr/local/opt/android-sdk/ndk-bundle/toolchains/llvm/prebuilt/darwin-x86_64/sysroot/usr/local/include -internal-isystem /usr/local/Cellar/android-sdk/6609375/ndk-bundle/toolchains/llvm/prebuilt/darwin-x86_64/lib64/clang/9.0.8/include -internal-externc-isystem /usr/local/opt/android-sdk/ndk-bundle/toolchains/llvm/prebuilt/darwin-x86_64/sysroot/usr/include/x86_64-linux-android -internal-externc-isystem /usr/local/opt/android-sdk/ndk-bundle/toolchains/llvm/prebuilt/darwin-x86_64/sysroot/include -internal-externc-isystem /usr/local/opt/android-sdk/ndk-bundle/toolchains/llvm/prebuilt/darwin-x86_64/sysroot/usr/include -O2 -Wall -Wpointer-arith -Wcast-align -Wcast-qual -Wstrict-prototypes -Wshadow -Waggregate-return -Wmissing-prototypes -Wnested-externs -Wsign-compare -fdebug-compilation-dir /var/folders/jw/7vmz4m1970932zln9tb1whxr0000gn/T/tmp.AfBnEXne/1609399549/x86_64/caca -ferror-limit 19 -fmessage-length 0 -fobjc-runtime=gcc -fdiagnostics-show-option -vectorize-loops -vectorize-slp -o .libs/libcaca_la-dither.o -x c /var/folders/jw/7vmz4m1970932zln9tb1whxr0000gn/T/tmp.AfBnEXne/caca/dither.c
1.	<eof> parser at end of file
2.	Code generation
3.	Running pass 'Function Pass Manager' on module '/var/folders/jw/7vmz4m1970932zln9tb1whxr0000gn/T/tmp.AfBnEXne/caca/dither.c'.
4.	Running pass 'X86 DAG->DAG Instruction Selection' on function '@caca_set_dither_gamma'
0  clang                    0x00000001015d1f98 void std::__1::__call_once_proxy<std::__1::tuple<void (&)()> >(void*) + 452872
1  clang                    0x00000001015d0fd8 void std::__1::__call_once_proxy<std::__1::tuple<void (&)()> >(void*) + 448840
2  clang                    0x00000001015d25b9 void std::__1::__call_once_proxy<std::__1::tuple<void (&)()> >(void*) + 454441
3  libsystem_platform.dylib 0x00007fff67ee05fd _sigtramp + 29
4  libsystem_platform.dylib 000000000000000000 _sigtramp + 18446603338772511264
5  clang                    0x00000001020603cf llvm::Pass* llvm::callDefaultCtor<llvm::RegBankSelect>() + 782559
6  clang                    0x00000001020813bf llvm::Pass* llvm::callDefaultCtor<llvm::RegBankSelect>() + 917711
7  clang                    0x0000000102086555 llvm::Pass* llvm::callDefaultCtor<llvm::RegBankSelect>() + 938597
8  clang                    0x0000000102153546 llvm::Pass* llvm::callDefaultCtor<llvm::RegBankSelect>() + 1778262
9  clang                    0x000000010215307a llvm::Pass* llvm::callDefaultCtor<llvm::RegBankSelect>() + 1777034
10 clang                    0x0000000102150904 llvm::Pass* llvm::callDefaultCtor<llvm::RegBankSelect>() + 1766932
11 clang                    0x00000001007f9fbd void std::__1::__call_once_proxy<std::__1::tuple<void* (&)(llvm::PassRegistry&), std::__1::reference_wrapper<llvm::PassRegistry>&&> >(void*) + 1175661
12 clang                    0x0000000100d263fd llvm::Pass* llvm::callDefaultCtor<llvm::MachineDominatorTree>() + 92477
13 clang                    0x0000000100ff06e1 llvm::SymbolTableListTraits<llvm::BasicBlock>::toPtr(llvm::ValueSymbolTable&) + 249473
14 clang                    0x0000000100ff09e3 llvm::SymbolTableListTraits<llvm::BasicBlock>::toPtr(llvm::ValueSymbolTable&) + 250243
15 clang                    0x0000000100ff0fd4 llvm::SymbolTableListTraits<llvm::BasicBlock>::toPtr(llvm::ValueSymbolTable&) + 251764
16 clang                    0x00000001017a21cb void llvm::DomTreeBuilder::Calculate<llvm::DominatorTreeBase<llvm::VPBlockBase, false> >(llvm::DominatorTreeBase<llvm::VPBlockBase, false>&) + 559739
17 clang                    0x00000001019e570a void llvm::DomTreeBuilder::Calculate<llvm::DominatorTreeBase<llvm::VPBlockBase, false> >(llvm::DominatorTreeBase<llvm::VPBlockBase, false>&) + 2932666
18 clang                    0x0000000102934763 llvm::RawInstrProfReader<unsigned long long>::getCounter(unsigned long long) const + 72083
19 clang                    0x0000000101ca844a llvm::Registry<clang::PluginASTAction>::begin() + 16218
20 clang                    0x0000000101c46c30 void llvm::DomTreeBuilder::Calculate<llvm::DominatorTreeBase<llvm::VPBlockBase, false> >(llvm::DominatorTreeBase<llvm::VPBlockBase, false>&) + 5428448
21 clang                    0x0000000101d26044 llvm::Registry<clang::PluginASTAction>::begin() + 531284
22 clang                    0x0000000100407259
23 clang                    0x0000000100404fd9
24 libdyld.dylib            0x00007fff67ce7cc9 start + 1
clang: error: unable to execute command: Illegal instruction: 4
clang: error: clang frontend command failed due to signal (use -v to see invocation)
Android (6454773 based on r365631c2) clang version 9.0.8 (https://android.googlesource.com/toolchain/llvm-project 98c855489587874b2a325e7a516b99d838599c6f) (based on LLVM 9.0.8svn)
Target: x86_64-unknown-linux-android21
Thread model: posix
InstalledDir: /usr/local/opt/android-sdk/ndk-bundle/toolchains/llvm/prebuilt/darwin-x86_64/bin
clang: note: diagnostic msg: PLEASE submit a bug report to https://github.com/android-ndk/ndk/issues and include the crash backtrace, preprocessed source, and associated run script.
clang: warning: optimization flag '-fno-strength-reduce' is not supported [-Wignored-optimization-argument]
clang: note: diagnostic msg:
********************

PLEASE ATTACH THE FOLLOWING FILES TO THE BUG REPORT:
Preprocessed source(s) and associated run script(s) are located at:
clang: note: diagnostic msg: /var/folders/jw/7vmz4m1970932zln9tb1whxr0000gn/T/dither-06efae.c
clang: note: diagnostic msg: /var/folders/jw/7vmz4m1970932zln9tb1whxr0000gn/T/dither-06efae.sh
clang: note: diagnostic msg: Crash backtrace is located in
clang: note: diagnostic msg: /Users/leleliu008/Library/Logs/DiagnosticReports/clang_<YYYY-MM-DD-HHMMSS>_<hostname>.crash
clang: note: diagnostic msg: (choose the .crash file that corresponds to your crash)
clang: note: diagnostic msg:

********************

environment =>

NDK version => 21.3.6528147

build machine =>
ProductName:	Mac OS X
ProductVersion:	10.15.7
BuildVersion:	19H15

details are in bug_report_res.zip

to reproduce this issue please run the following commands in your terminal on Unix-ish system:

ndk-pkg update
ndk-pkg install libcaca -v

about ndk-pkg

Originally posted by @leleliu008 in #1377 (comment)

[pirama-arumuga-nainar]

From the crash report in bug_report_res.zip:

Exception Type:        EXC_BAD_INSTRUCTION (SIGILL)
Exception Codes:       0x0000000000000001, 0x0000000000000000
Exception Note:        EXC_CORPSE_NOTIFY

Termination Signal:    Illegal instruction: 4
Termination Reason:    Namespace SIGNAL, Code 0x4
Terminating Process:   exc handler [29779]

Two questions:

1. Does the crash go away when error: scalar-to-vector conversion failed, possible invalid constraint for vector type is fixed? That might suggest that Clang is hitting an llvm_unreachable, which triggers a SIGILL in the MacOS clang.
2. From basic google searches, the "Illegal Instruction: code 4" error can happen on older MacOS versions but you're on MacOs 10.15. Can you share the actual model of your device?

[pirama-arumuga-nainar]

@leleliu008 in case you missed my previous reply. PTAL at my questions.

[leleliu008]

@pirama-arumuga-nainar

1. I didn't try to fix this problem. Beacuse I don't know how to fix.
2. I'm sorry I didn't quite catch what you said Can you share the actual model of your device? what would you like me to do?

[pirama-arumuga-nainar]

Never mind about this being a Mac specific issue. This crashes on Linux as well. Newer Clang versions report failure rather than a crash:

fatal error: error in backend: Cannot select: 0x53fd038: ch = store<(store 2 into %stack.1 + 8, align 8), trunc to i16> 
0x52fe5f8, 0x54585c0, 0x53f5108, undef:i64, /var/folders/jw/7vmz4m1970932zln9tb1whxr0000gn/T/tmp.AfBnEXne/caca/dither.c:
1277 @[ /var/folders/jw/7vmz4m1970932zln9tb1whxr0000gn/T/tmp.AfBnEXne/caca/dither.c:476 ]

Clang tries to make progress even on invalid input (mainly to print additional diagnostics). It then crashes if the initial error causes an inconsistent internal state. IMO, fixing the error: scalar-to-vector conversion failed, possible invalid constraint for vector type should stop the crash.

[leleliu008]

@pirama-arumuga-nainar I got it. Thank you very much!

[pirama-arumuga-nainar]

(If the crash or backend error still happens after fixing the errors, please reopen).