[PowerPC] Implement XL compat __fnabs and __fnabss builtins.

[amyk]

Summary

This patch implements the following floating point negative absolute value
builtins that required for compatibility with the XL compiler:

double __fnabs(double);
float __fnabss(float);

These builtins will emit :

• fnabs on PWR6 and below, or if VSX is disabled.
• xsnabsdp on PWR7 and above, if VSX is enabled.

[lei]

LGTM with minor updates before commit.

clang/test/CodeGen/PowerPC/builtins-ppc-xlcompat-fnabs.c

26

Since we emit xsnabsdp for pwr7 and above I don't think it's necessary to have all combination tested on both pwr7 and pwr8.

llvm/test/CodeGen/PowerPC/builtins-ppc-xlcompat-fnabs.ll

25

I think the default pwr level is lower then pwr6 which means it's no vsx by default. Maybe add pwr[7|8] to these test lines to test the -vsx attr?

46

probably don't need both NOVSX and PWR6 checks since they are the same.

[amyk]

Address review comments:

• Remove -no-opaque-pointers and updates CHECKs
• Simplify runs and checks of C and IR test files

[lei]

llvm/test/CodeGen/PowerPC/builtins-ppc-xlcompat-fnabs.ll

47

nit: same as before no need to test all combination for both pwr7 and pwr8. Just a mix of the 2 like in the clang test. What happens if we do pwr6 with +vsx? Is this a possible combination?

[amyk]

llvm/test/CodeGen/PowerPC/builtins-ppc-xlcompat-fnabs.ll

47

Thanks Lei, I'll update those lines. We also discussed outside of this review that adding a P6 and VSX line results in xsnabsdp and it wouldn't hurt to add it here too, so I'll add one line for that, as well.

[amyk]

• Add a P6+VSX run line and remove extra P7/P8 lines for backend test

[nathanchance]

I bisected a crash when compiling the Linux kernel to this change.

A reduced C reproducer:

enum {
  OP_CB_GETATTR = 3,
  OP_CB_RECALL,
  OP_CB_RECALL_ANY = 8,
  OP_CB_RECALL_SLOT = 10,
  OP_CB_NOTIFY_LOCK = 13,
  OP_CB_NOTIFY_DEVICEID,
  OP_CB_OFFLOAD
} static callback_ops_0;
int preprocess_nfs42_op_op_nr, preprocess_nfs42_op_op;
void preprocess_nfs42_op() {
  switch (preprocess_nfs42_op_op_nr)
  case OP_CB_GETATTR:
  case OP_CB_RECALL:
  case OP_CB_RECALL_ANY:
  case OP_CB_RECALL_SLOT:
  case OP_CB_NOTIFY_DEVICEID:
  case OP_CB_NOTIFY_LOCK:
    preprocess_nfs42_op_op = preprocess_nfs42_op_op_nr;
  if (preprocess_nfs42_op_op_nr == OP_CB_OFFLOAD)
    preprocess_nfs42_op_op = callback_ops_0;
}

$ clang --version | head -1
ClangBuiltLinux clang version 15.0.0 (https://github.com/llvm/llvm-project 559b8fc17ef6f5a65ccf9a11fce5f91c0a011b00)

$ clang --target=powerpc64le-linux-gnu -O2 -Wall -Wextra -c -o /dev/null callback_xdr.i

$ clang --version | head -1
ClangBuiltLinux clang version 15.0.0 (https://github.com/llvm/llvm-project c35ca3a1c78f693b749ad11742350b7fc6c5cd89)

$ clang --target=powerpc64le-linux-gnu -O2 -Wall -Wextra -c -o /dev/null callback_xdr.i
Impossible reg-to-reg copy
UNREACHABLE executed at /home/nathan/cbl/src/llvm-project/llvm/lib/Target/PowerPC/PPCInstrInfo.cpp:1861!
PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace, preprocessed source, and associated run script.
Stack dump:
0.      Program arguments: clang --target=powerpc64le-linux-gnu -O2 -Wall -Wextra -c -o /dev/null callback_xdr.i
1.      <eof> parser at end of file
2.      Code generation
3.      Running pass 'Function Pass Manager' on module 'callback_xdr.i'.
4.      Running pass 'Post-RA pseudo instruction expansion pass' on function '@preprocess_nfs42_op'
 #0 0x000055a3bcb4e583 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/home/nathan/tmp/build/llvm-bisect/stage1/bin/clang-15+0x3351583)
 #1 0x000055a3bcb4c50e llvm::sys::RunSignalHandlers() (/home/nathan/tmp/build/llvm-bisect/stage1/bin/clang-15+0x334f50e)
 #2 0x000055a3bcad2923 (anonymous namespace)::CrashRecoveryContextImpl::HandleCrash(int, unsigned long) CrashRecoveryContext.cpp:0:0
 #3 0x000055a3bcad2a9e CrashRecoverySignalHandler(int) CrashRecoveryContext.cpp:0:0
 #4 0x00007f4af3152b00 __restore_rt (/lib64/libc.so.6+0x3eb00)
 #5 0x00007f4af31a2d0c __pthread_kill_implementation (/lib64/libc.so.6+0x8ed0c)
 #6 0x00007f4af3152a56 gsignal (/lib64/libc.so.6+0x3ea56)
 #7 0x00007f4af313c7f4 abort (/lib64/libc.so.6+0x287f4)
 #8 0x000055a3bcad787f (/home/nathan/tmp/build/llvm-bisect/stage1/bin/clang-15+0x32da87f)
 #9 0x000055a3bb83b308 llvm::PPCInstrInfo::copyPhysReg(llvm::MachineBasicBlock&, llvm::MachineInstrBundleIterator<llvm::MachineInstr, false>, llvm::DebugLoc const&, llvm::MCRegister, llvm::MCRegister, bool) const PPCInstrInfo.cpp:0:0
#10 0x000055a3bc1242bb (anonymous namespace)::ExpandPostRA::runOnMachineFunction(llvm::MachineFunction&) ExpandPostRAPseudos.cpp:0:0
#11 0x000055a3bbf62d4d llvm::MachineFunctionPass::runOnFunction(llvm::Function&) (/home/nathan/tmp/build/llvm-bisect/stage1/bin/clang-15+0x2765d4d)
#12 0x000055a3bc3fc107 llvm::FPPassManager::runOnFunction(llvm::Function&) (/home/nathan/tmp/build/llvm-bisect/stage1/bin/clang-15+0x2bff107)
#13 0x000055a3bc403b81 llvm::FPPassManager::runOnModule(llvm::Module&) (/home/nathan/tmp/build/llvm-bisect/stage1/bin/clang-15+0x2c06b81)
#14 0x000055a3bc3fcafc llvm::legacy::PassManagerImpl::run(llvm::Module&) (/home/nathan/tmp/build/llvm-bisect/stage1/bin/clang-15+0x2bffafc)
#15 0x000055a3bd2fd16d clang::EmitBackendOutput(clang::DiagnosticsEngine&, clang::HeaderSearchOptions const&, clang::CodeGenOptions const&, clang::TargetOptions const&, clang::LangOptions const&, llvm::StringRef, llvm::Module*, clang::BackendAction, std::unique_ptr<llvm::raw_pwrite_stream, std::default_delete<llvm::raw_pwrite_stream>>) (/home/nathan/tmp/build/llvm-bisect/stage1/bin/clang-15+0x3b0016d)
#16 0x000055a3bd6a27ee clang::BackendConsumer::HandleTranslationUnit(clang::ASTContext&) CodeGenAction.cpp:0:0
#17 0x000055a3bdf46cb4 clang::ParseAST(clang::Sema&, bool, bool) (/home/nathan/tmp/build/llvm-bisect/stage1/bin/clang-15+0x4749cb4)
#18 0x000055a3bd5f0f50 clang::FrontendAction::Execute() (/home/nathan/tmp/build/llvm-bisect/stage1/bin/clang-15+0x3df3f50)
#19 0x000055a3bd565d1f clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) (/home/nathan/tmp/build/llvm-bisect/stage1/bin/clang-15+0x3d68d1f)
#20 0x000055a3bd69be92 clang::ExecuteCompilerInvocation(clang::CompilerInstance*) (/home/nathan/tmp/build/llvm-bisect/stage1/bin/clang-15+0x3e9ee92)
#21 0x000055a3bb785028 cc1_main(llvm::ArrayRef<char const*>, char const*, void*) (/home/nathan/tmp/build/llvm-bisect/stage1/bin/clang-15+0x1f88028)
#22 0x000055a3bb782f2f ExecuteCC1Tool(llvm::SmallVectorImpl<char const*>&) driver.cpp:0:0
#23 0x000055a3bd3ea372 void llvm::function_ref<void ()>::callback_fn<clang::driver::CC1Command::Execute(llvm::ArrayRef<llvm::Optional<llvm::StringRef>>, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char>>*, bool*) const::$_1>(long) Job.cpp:0:0
#24 0x000055a3bcad2837 llvm::CrashRecoveryContext::RunSafely(llvm::function_ref<void ()>) (/home/nathan/tmp/build/llvm-bisect/stage1/bin/clang-15+0x32d5837)
#25 0x000055a3bd3e9ecf clang::driver::CC1Command::Execute(llvm::ArrayRef<llvm::Optional<llvm::StringRef>>, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char>>*, bool*) const (/home/nathan/tmp/build/llvm-bisect/stage1/bin/clang-15+0x3bececf)
#26 0x000055a3bd3aaa68 clang::driver::Compilation::ExecuteCommand(clang::driver::Command const&, clang::driver::Command const*&) const (/home/nathan/tmp/build/llvm-bisect/stage1/bin/clang-15+0x3bada68)
#27 0x000055a3bd3aad37 clang::driver::Compilation::ExecuteJobs(clang::driver::JobList const&, llvm::SmallVectorImpl<std::pair<int, clang::driver::Command const*>>&) const (/home/nathan/tmp/build/llvm-bisect/stage1/bin/clang-15+0x3badd37)
#28 0x000055a3bd3c5658 clang::driver::Driver::ExecuteCompilation(clang::driver::Compilation&, llvm::SmallVectorImpl<std::pair<int, clang::driver::Command const*>>&) (/home/nathan/tmp/build/llvm-bisect/stage1/bin/clang-15+0x3bc8658)
#29 0x000055a3bb7828a2 main (/home/nathan/tmp/build/llvm-bisect/stage1/bin/clang-15+0x1f858a2)
#30 0x00007f4af313d550 __libc_start_call_main (/lib64/libc.so.6+0x29550)
#31 0x00007f4af313d609 __libc_start_main@GLIBC_2.2.5 (/lib64/libc.so.6+0x29609)
#32 0x000055a3bb77fe85 _start /build/glibc/src/glibc/csu/../sysdeps/x86_64/start.S:117:0
clang-15: error: clang frontend command failed with exit code 134 (use -v to see invocation)
ClangBuiltLinux clang version 15.0.0 (https://github.com/llvm/llvm-project c35ca3a1c78f693b749ad11742350b7fc6c5cd89)
Target: powerpc64le-unknown-linux-gnu
Thread model: posix
InstalledDir: /home/nathan/tmp/build/llvm-bisect/stage1/bin
clang-15: note: diagnostic msg: Error generating preprocessed source(s) - no preprocessable inputs.

[amyk]

In D125506#3528380, @nathanchance wrote:

I bisected a crash when compiling the Linux kernel to this change.

A reduced C reproducer:

enum {
  OP_CB_GETATTR = 3,
  OP_CB_RECALL,
  OP_CB_RECALL_ANY = 8,
  OP_CB_RECALL_SLOT = 10,
  OP_CB_NOTIFY_LOCK = 13,
  OP_CB_NOTIFY_DEVICEID,
  OP_CB_OFFLOAD
} static callback_ops_0;
int preprocess_nfs42_op_op_nr, preprocess_nfs42_op_op;
void preprocess_nfs42_op() {
  switch (preprocess_nfs42_op_op_nr)
  case OP_CB_GETATTR:
  case OP_CB_RECALL:
  case OP_CB_RECALL_ANY:
  case OP_CB_RECALL_SLOT:
  case OP_CB_NOTIFY_DEVICEID:
  case OP_CB_NOTIFY_LOCK:
    preprocess_nfs42_op_op = preprocess_nfs42_op_op_nr;
  if (preprocess_nfs42_op_op_nr == OP_CB_OFFLOAD)
    preprocess_nfs42_op_op = callback_ops_0;
}

$ clang --version | head -1
ClangBuiltLinux clang version 15.0.0 (https://github.com/llvm/llvm-project 559b8fc17ef6f5a65ccf9a11fce5f91c0a011b00)

$ clang --target=powerpc64le-linux-gnu -O2 -Wall -Wextra -c -o /dev/null callback_xdr.i

$ clang --version | head -1
ClangBuiltLinux clang version 15.0.0 (https://github.com/llvm/llvm-project c35ca3a1c78f693b749ad11742350b7fc6c5cd89)

$ clang --target=powerpc64le-linux-gnu -O2 -Wall -Wextra -c -o /dev/null callback_xdr.i
Impossible reg-to-reg copy
UNREACHABLE executed at /home/nathan/cbl/src/llvm-project/llvm/lib/Target/PowerPC/PPCInstrInfo.cpp:1861!
PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace, preprocessed source, and associated run script.
Stack dump:
0.      Program arguments: clang --target=powerpc64le-linux-gnu -O2 -Wall -Wextra -c -o /dev/null callback_xdr.i
1.      <eof> parser at end of file
2.      Code generation
3.      Running pass 'Function Pass Manager' on module 'callback_xdr.i'.
4.      Running pass 'Post-RA pseudo instruction expansion pass' on function '@preprocess_nfs42_op'
 #0 0x000055a3bcb4e583 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/home/nathan/tmp/build/llvm-bisect/stage1/bin/clang-15+0x3351583)
 #1 0x000055a3bcb4c50e llvm::sys::RunSignalHandlers() (/home/nathan/tmp/build/llvm-bisect/stage1/bin/clang-15+0x334f50e)
 #2 0x000055a3bcad2923 (anonymous namespace)::CrashRecoveryContextImpl::HandleCrash(int, unsigned long) CrashRecoveryContext.cpp:0:0
 #3 0x000055a3bcad2a9e CrashRecoverySignalHandler(int) CrashRecoveryContext.cpp:0:0
 #4 0x00007f4af3152b00 __restore_rt (/lib64/libc.so.6+0x3eb00)
 #5 0x00007f4af31a2d0c __pthread_kill_implementation (/lib64/libc.so.6+0x8ed0c)
 #6 0x00007f4af3152a56 gsignal (/lib64/libc.so.6+0x3ea56)
 #7 0x00007f4af313c7f4 abort (/lib64/libc.so.6+0x287f4)
 #8 0x000055a3bcad787f (/home/nathan/tmp/build/llvm-bisect/stage1/bin/clang-15+0x32da87f)
 #9 0x000055a3bb83b308 llvm::PPCInstrInfo::copyPhysReg(llvm::MachineBasicBlock&, llvm::MachineInstrBundleIterator<llvm::MachineInstr, false>, llvm::DebugLoc const&, llvm::MCRegister, llvm::MCRegister, bool) const PPCInstrInfo.cpp:0:0
#10 0x000055a3bc1242bb (anonymous namespace)::ExpandPostRA::runOnMachineFunction(llvm::MachineFunction&) ExpandPostRAPseudos.cpp:0:0
#11 0x000055a3bbf62d4d llvm::MachineFunctionPass::runOnFunction(llvm::Function&) (/home/nathan/tmp/build/llvm-bisect/stage1/bin/clang-15+0x2765d4d)
#12 0x000055a3bc3fc107 llvm::FPPassManager::runOnFunction(llvm::Function&) (/home/nathan/tmp/build/llvm-bisect/stage1/bin/clang-15+0x2bff107)
#13 0x000055a3bc403b81 llvm::FPPassManager::runOnModule(llvm::Module&) (/home/nathan/tmp/build/llvm-bisect/stage1/bin/clang-15+0x2c06b81)
#14 0x000055a3bc3fcafc llvm::legacy::PassManagerImpl::run(llvm::Module&) (/home/nathan/tmp/build/llvm-bisect/stage1/bin/clang-15+0x2bffafc)
#15 0x000055a3bd2fd16d clang::EmitBackendOutput(clang::DiagnosticsEngine&, clang::HeaderSearchOptions const&, clang::CodeGenOptions const&, clang::TargetOptions const&, clang::LangOptions const&, llvm::StringRef, llvm::Module*, clang::BackendAction, std::unique_ptr<llvm::raw_pwrite_stream, std::default_delete<llvm::raw_pwrite_stream>>) (/home/nathan/tmp/build/llvm-bisect/stage1/bin/clang-15+0x3b0016d)
#16 0x000055a3bd6a27ee clang::BackendConsumer::HandleTranslationUnit(clang::ASTContext&) CodeGenAction.cpp:0:0
#17 0x000055a3bdf46cb4 clang::ParseAST(clang::Sema&, bool, bool) (/home/nathan/tmp/build/llvm-bisect/stage1/bin/clang-15+0x4749cb4)
#18 0x000055a3bd5f0f50 clang::FrontendAction::Execute() (/home/nathan/tmp/build/llvm-bisect/stage1/bin/clang-15+0x3df3f50)
#19 0x000055a3bd565d1f clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) (/home/nathan/tmp/build/llvm-bisect/stage1/bin/clang-15+0x3d68d1f)
#20 0x000055a3bd69be92 clang::ExecuteCompilerInvocation(clang::CompilerInstance*) (/home/nathan/tmp/build/llvm-bisect/stage1/bin/clang-15+0x3e9ee92)
#21 0x000055a3bb785028 cc1_main(llvm::ArrayRef<char const*>, char const*, void*) (/home/nathan/tmp/build/llvm-bisect/stage1/bin/clang-15+0x1f88028)
#22 0x000055a3bb782f2f ExecuteCC1Tool(llvm::SmallVectorImpl<char const*>&) driver.cpp:0:0
#23 0x000055a3bd3ea372 void llvm::function_ref<void ()>::callback_fn<clang::driver::CC1Command::Execute(llvm::ArrayRef<llvm::Optional<llvm::StringRef>>, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char>>*, bool*) const::$_1>(long) Job.cpp:0:0
#24 0x000055a3bcad2837 llvm::CrashRecoveryContext::RunSafely(llvm::function_ref<void ()>) (/home/nathan/tmp/build/llvm-bisect/stage1/bin/clang-15+0x32d5837)
#25 0x000055a3bd3e9ecf clang::driver::CC1Command::Execute(llvm::ArrayRef<llvm::Optional<llvm::StringRef>>, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char>>*, bool*) const (/home/nathan/tmp/build/llvm-bisect/stage1/bin/clang-15+0x3bececf)
#26 0x000055a3bd3aaa68 clang::driver::Compilation::ExecuteCommand(clang::driver::Command const&, clang::driver::Command const*&) const (/home/nathan/tmp/build/llvm-bisect/stage1/bin/clang-15+0x3bada68)
#27 0x000055a3bd3aad37 clang::driver::Compilation::ExecuteJobs(clang::driver::JobList const&, llvm::SmallVectorImpl<std::pair<int, clang::driver::Command const*>>&) const (/home/nathan/tmp/build/llvm-bisect/stage1/bin/clang-15+0x3badd37)
#28 0x000055a3bd3c5658 clang::driver::Driver::ExecuteCompilation(clang::driver::Compilation&, llvm::SmallVectorImpl<std::pair<int, clang::driver::Command const*>>&) (/home/nathan/tmp/build/llvm-bisect/stage1/bin/clang-15+0x3bc8658)
#29 0x000055a3bb7828a2 main (/home/nathan/tmp/build/llvm-bisect/stage1/bin/clang-15+0x1f858a2)
#30 0x00007f4af313d550 __libc_start_call_main (/lib64/libc.so.6+0x29550)
#31 0x00007f4af313d609 __libc_start_main@GLIBC_2.2.5 (/lib64/libc.so.6+0x29609)
#32 0x000055a3bb77fe85 _start /build/glibc/src/glibc/csu/../sysdeps/x86_64/start.S:117:0
clang-15: error: clang frontend command failed with exit code 134 (use -v to see invocation)
ClangBuiltLinux clang version 15.0.0 (https://github.com/llvm/llvm-project c35ca3a1c78f693b749ad11742350b7fc6c5cd89)
Target: powerpc64le-unknown-linux-gnu
Thread model: posix
InstalledDir: /home/nathan/tmp/build/llvm-bisect/stage1/bin
clang-15: note: diagnostic msg: Error generating preprocessed source(s) - no preprocessable inputs.

Thanks for reporting this issue, @nathanchance. Sorry for the delayed response. Just wanted to say that I've seen your response now and I will be investigating this.

[amyk]

In D125506#3528380, @nathanchance wrote:

I bisected a crash when compiling the Linux kernel to this change.

A reduced C reproducer:

enum {
  OP_CB_GETATTR = 3,
  OP_CB_RECALL,
  OP_CB_RECALL_ANY = 8,
  OP_CB_RECALL_SLOT = 10,
  OP_CB_NOTIFY_LOCK = 13,
  OP_CB_NOTIFY_DEVICEID,
  OP_CB_OFFLOAD
} static callback_ops_0;
int preprocess_nfs42_op_op_nr, preprocess_nfs42_op_op;
void preprocess_nfs42_op() {
  switch (preprocess_nfs42_op_op_nr)
  case OP_CB_GETATTR:
  case OP_CB_RECALL:
  case OP_CB_RECALL_ANY:
  case OP_CB_RECALL_SLOT:
  case OP_CB_NOTIFY_DEVICEID:
  case OP_CB_NOTIFY_LOCK:
    preprocess_nfs42_op_op = preprocess_nfs42_op_op_nr;
  if (preprocess_nfs42_op_op_nr == OP_CB_OFFLOAD)
    preprocess_nfs42_op_op = callback_ops_0;
}

$ clang --version | head -1
ClangBuiltLinux clang version 15.0.0 (https://github.com/llvm/llvm-project 559b8fc17ef6f5a65ccf9a11fce5f91c0a011b00)

$ clang --target=powerpc64le-linux-gnu -O2 -Wall -Wextra -c -o /dev/null callback_xdr.i

$ clang --version | head -1
ClangBuiltLinux clang version 15.0.0 (https://github.com/llvm/llvm-project c35ca3a1c78f693b749ad11742350b7fc6c5cd89)

$ clang --target=powerpc64le-linux-gnu -O2 -Wall -Wextra -c -o /dev/null callback_xdr.i
Impossible reg-to-reg copy
UNREACHABLE executed at /home/nathan/cbl/src/llvm-project/llvm/lib/Target/PowerPC/PPCInstrInfo.cpp:1861!
PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace, preprocessed source, and associated run script.
Stack dump:
0.      Program arguments: clang --target=powerpc64le-linux-gnu -O2 -Wall -Wextra -c -o /dev/null callback_xdr.i
1.      <eof> parser at end of file
2.      Code generation
3.      Running pass 'Function Pass Manager' on module 'callback_xdr.i'.
4.      Running pass 'Post-RA pseudo instruction expansion pass' on function '@preprocess_nfs42_op'
 #0 0x000055a3bcb4e583 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/home/nathan/tmp/build/llvm-bisect/stage1/bin/clang-15+0x3351583)
 #1 0x000055a3bcb4c50e llvm::sys::RunSignalHandlers() (/home/nathan/tmp/build/llvm-bisect/stage1/bin/clang-15+0x334f50e)
 #2 0x000055a3bcad2923 (anonymous namespace)::CrashRecoveryContextImpl::HandleCrash(int, unsigned long) CrashRecoveryContext.cpp:0:0
 #3 0x000055a3bcad2a9e CrashRecoverySignalHandler(int) CrashRecoveryContext.cpp:0:0
 #4 0x00007f4af3152b00 __restore_rt (/lib64/libc.so.6+0x3eb00)
 #5 0x00007f4af31a2d0c __pthread_kill_implementation (/lib64/libc.so.6+0x8ed0c)
 #6 0x00007f4af3152a56 gsignal (/lib64/libc.so.6+0x3ea56)
 #7 0x00007f4af313c7f4 abort (/lib64/libc.so.6+0x287f4)
 #8 0x000055a3bcad787f (/home/nathan/tmp/build/llvm-bisect/stage1/bin/clang-15+0x32da87f)
 #9 0x000055a3bb83b308 llvm::PPCInstrInfo::copyPhysReg(llvm::MachineBasicBlock&, llvm::MachineInstrBundleIterator<llvm::MachineInstr, false>, llvm::DebugLoc const&, llvm::MCRegister, llvm::MCRegister, bool) const PPCInstrInfo.cpp:0:0
#10 0x000055a3bc1242bb (anonymous namespace)::ExpandPostRA::runOnMachineFunction(llvm::MachineFunction&) ExpandPostRAPseudos.cpp:0:0
#11 0x000055a3bbf62d4d llvm::MachineFunctionPass::runOnFunction(llvm::Function&) (/home/nathan/tmp/build/llvm-bisect/stage1/bin/clang-15+0x2765d4d)
#12 0x000055a3bc3fc107 llvm::FPPassManager::runOnFunction(llvm::Function&) (/home/nathan/tmp/build/llvm-bisect/stage1/bin/clang-15+0x2bff107)
#13 0x000055a3bc403b81 llvm::FPPassManager::runOnModule(llvm::Module&) (/home/nathan/tmp/build/llvm-bisect/stage1/bin/clang-15+0x2c06b81)
#14 0x000055a3bc3fcafc llvm::legacy::PassManagerImpl::run(llvm::Module&) (/home/nathan/tmp/build/llvm-bisect/stage1/bin/clang-15+0x2bffafc)
#15 0x000055a3bd2fd16d clang::EmitBackendOutput(clang::DiagnosticsEngine&, clang::HeaderSearchOptions const&, clang::CodeGenOptions const&, clang::TargetOptions const&, clang::LangOptions const&, llvm::StringRef, llvm::Module*, clang::BackendAction, std::unique_ptr<llvm::raw_pwrite_stream, std::default_delete<llvm::raw_pwrite_stream>>) (/home/nathan/tmp/build/llvm-bisect/stage1/bin/clang-15+0x3b0016d)
#16 0x000055a3bd6a27ee clang::BackendConsumer::HandleTranslationUnit(clang::ASTContext&) CodeGenAction.cpp:0:0
#17 0x000055a3bdf46cb4 clang::ParseAST(clang::Sema&, bool, bool) (/home/nathan/tmp/build/llvm-bisect/stage1/bin/clang-15+0x4749cb4)
#18 0x000055a3bd5f0f50 clang::FrontendAction::Execute() (/home/nathan/tmp/build/llvm-bisect/stage1/bin/clang-15+0x3df3f50)
#19 0x000055a3bd565d1f clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) (/home/nathan/tmp/build/llvm-bisect/stage1/bin/clang-15+0x3d68d1f)
#20 0x000055a3bd69be92 clang::ExecuteCompilerInvocation(clang::CompilerInstance*) (/home/nathan/tmp/build/llvm-bisect/stage1/bin/clang-15+0x3e9ee92)
#21 0x000055a3bb785028 cc1_main(llvm::ArrayRef<char const*>, char const*, void*) (/home/nathan/tmp/build/llvm-bisect/stage1/bin/clang-15+0x1f88028)
#22 0x000055a3bb782f2f ExecuteCC1Tool(llvm::SmallVectorImpl<char const*>&) driver.cpp:0:0
#23 0x000055a3bd3ea372 void llvm::function_ref<void ()>::callback_fn<clang::driver::CC1Command::Execute(llvm::ArrayRef<llvm::Optional<llvm::StringRef>>, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char>>*, bool*) const::$_1>(long) Job.cpp:0:0
#24 0x000055a3bcad2837 llvm::CrashRecoveryContext::RunSafely(llvm::function_ref<void ()>) (/home/nathan/tmp/build/llvm-bisect/stage1/bin/clang-15+0x32d5837)
#25 0x000055a3bd3e9ecf clang::driver::CC1Command::Execute(llvm::ArrayRef<llvm::Optional<llvm::StringRef>>, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char>>*, bool*) const (/home/nathan/tmp/build/llvm-bisect/stage1/bin/clang-15+0x3bececf)
#26 0x000055a3bd3aaa68 clang::driver::Compilation::ExecuteCommand(clang::driver::Command const&, clang::driver::Command const*&) const (/home/nathan/tmp/build/llvm-bisect/stage1/bin/clang-15+0x3bada68)
#27 0x000055a3bd3aad37 clang::driver::Compilation::ExecuteJobs(clang::driver::JobList const&, llvm::SmallVectorImpl<std::pair<int, clang::driver::Command const*>>&) const (/home/nathan/tmp/build/llvm-bisect/stage1/bin/clang-15+0x3badd37)
#28 0x000055a3bd3c5658 clang::driver::Driver::ExecuteCompilation(clang::driver::Compilation&, llvm::SmallVectorImpl<std::pair<int, clang::driver::Command const*>>&) (/home/nathan/tmp/build/llvm-bisect/stage1/bin/clang-15+0x3bc8658)
#29 0x000055a3bb7828a2 main (/home/nathan/tmp/build/llvm-bisect/stage1/bin/clang-15+0x1f858a2)
#30 0x00007f4af313d550 __libc_start_call_main (/lib64/libc.so.6+0x29550)
#31 0x00007f4af313d609 __libc_start_main@GLIBC_2.2.5 (/lib64/libc.so.6+0x29609)
#32 0x000055a3bb77fe85 _start /build/glibc/src/glibc/csu/../sysdeps/x86_64/start.S:117:0
clang-15: error: clang frontend command failed with exit code 134 (use -v to see invocation)
ClangBuiltLinux clang version 15.0.0 (https://github.com/llvm/llvm-project c35ca3a1c78f693b749ad11742350b7fc6c5cd89)
Target: powerpc64le-unknown-linux-gnu
Thread model: posix
InstalledDir: /home/nathan/tmp/build/llvm-bisect/stage1/bin
clang-15: note: diagnostic msg: Error generating preprocessed source(s) - no preprocessable inputs.

Hi @nathanchance, I just wanted to say thanks for providing the reproducer and I wanted to update you that I committed 0bf3c38b0be3f9b45b589b780ed53f2de4d364d4 that should resolve the issue that you reported.

[nathanchance]

@amyk Thank you a lot for the fix! I'll pull it down and verify everything is fixed tonight.

clang/include/clang/Basic/BuiltinsPPC.def

 BUILTIN(__builtin_ppc_addex, "LLiLLiLLiCIi", "")
 // select
 BUILTIN(__builtin_ppc_maxfe, "LdLdLdLd.", "t")
 BUILTIN(__builtin_ppc_maxfl, "dddd.", "t")
 BUILTIN(__builtin_ppc_maxfs, "ffff.", "t")
 BUILTIN(__builtin_ppc_minfe, "LdLdLdLd.", "t")
 BUILTIN(__builtin_ppc_minfl, "dddd.", "t")
 BUILTIN(__builtin_ppc_minfs, "ffff.", "t")
+// Floating Negative Absolute Value
+BUILTIN(__builtin_ppc_fnabs, "dd", "")
+BUILTIN(__builtin_ppc_fnabss, "ff", "")
 
 BUILTIN(__builtin_ppc_get_timebase, "ULLi", "n")
 
 // This is just a placeholder, the types and attributes are wrong.
 BUILTIN(__builtin_altivec_vaddcuw, "V4UiV4UiV4Ui", "")
 
 BUILTIN(__builtin_altivec_vaddsbs, "V16ScV16ScV16Sc", "")
 BUILTIN(__builtin_altivec_vaddubs, "V16UcV16UcV16Uc", "")

clang/lib/Basic/Targets/PPC.cpp

static void defineXLCompatMacros(MacroBuilder &Builder) {
   Builder.defineMacro("__cmplxl", "__builtin_complex");
   Builder.defineMacro("__compare_exp_uo", "__builtin_ppc_compare_exp_uo");
   Builder.defineMacro("__compare_exp_lt", "__builtin_ppc_compare_exp_lt");
   Builder.defineMacro("__compare_exp_gt", "__builtin_ppc_compare_exp_gt");
   Builder.defineMacro("__compare_exp_eq", "__builtin_ppc_compare_exp_eq");
   Builder.defineMacro("__test_data_class", "__builtin_ppc_test_data_class");
   Builder.defineMacro("__swdiv", "__builtin_ppc_swdiv");
   Builder.defineMacro("__swdivs", "__builtin_ppc_swdivs");
+  Builder.defineMacro("__fnabs", "__builtin_ppc_fnabs");
+  Builder.defineMacro("__fnabss", "__builtin_ppc_fnabss");
   Builder.defineMacro("__builtin_maxfe", "__builtin_ppc_maxfe");
   Builder.defineMacro("__builtin_maxfl", "__builtin_ppc_maxfl");
   Builder.defineMacro("__builtin_maxfs", "__builtin_ppc_maxfs");
   Builder.defineMacro("__builtin_minfe", "__builtin_ppc_minfe");
   Builder.defineMacro("__builtin_minfl", "__builtin_ppc_minfl");
   Builder.defineMacro("__builtin_minfs", "__builtin_ppc_minfs");
 }
 

clang/test/CodeGen/PowerPC/builtins-ppc-xlcompat-fnabs.c

+// REQUIRES: powerpc-registered-target
+// RUN: %clang_cc1 -triple powerpc64le-unknown-linux-gnu \
+// RUN:   -emit-llvm %s -target-cpu pwr8 -o - | FileCheck %s
+// RUN: %clang_cc1 -triple powerpc-unknown-aix \
+// RUN:   -emit-llvm %s -target-cpu pwr8 -o - | FileCheck %s
+// RUN: %clang_cc1 -triple powerpc64-unknown-linux-gnu \
+// RUN:   -emit-llvm %s -target-cpu pwr7 -o - | FileCheck %s
+// RUN: %clang_cc1 -triple powerpc64-unknown-aix \
+// RUN:   -emit-llvm %s -target-cpu pwr7 -o - | FileCheck %s
+// RUN: %clang_cc1 -triple powerpc64-unknown-linux-gnu \
+// RUN:   -emit-llvm %s -target-cpu pwr6 -o - | FileCheck %s
+// RUN: %clang_cc1 -triple powerpc64le-unknown-linux-gnu \
+// RUN:   -emit-llvm %s -target-cpu pwr6 -o - | FileCheck %s
+// RUN: %clang_cc1 -triple powerpc64-unknown-aix \
+// RUN:   -emit-llvm %s -target-cpu pwr6 -o - | FileCheck %s
+// RUN: %clang_cc1 -triple powerpc-unknown-aix \
+// RUN:   -emit-llvm %s -target-cpu pwr6 -o - | FileCheck %s
+
+extern float f;
+extern double d;
+
+// CHECK-LABEL: @test_fnabs(
+// CHECK:       [[TMP0:%.*]] = load double, ptr @d
+// CHECK-NEXT:  [[TMP1:%.*]] = call double @llvm.ppc.fnabs(double [[TMP0]])
+// CHECK-NEXT:  ret double [[TMP1]]
+double test_fnabs() {
+  return __fnabs (d);
+}
+
+// CHECK-LABEL: @test_fnabss(
+// CHECK:       [[TMP0:%.*]] = load float, ptr @f
+// CHECK-NEXT:  [[TMP1:%.*]] = call float @llvm.ppc.fnabss(float [[TMP0]])
+// CHECK-NEXT:  ret float [[TMP1]]
+float test_fnabss() {
+  return __fnabss (f);
+}

llvm/include/llvm/IR/IntrinsicsPowerPC.td

def int_ppc_compare_exp_eq : GCCBuiltin<"__builtin_ppc_compare_exp_eq">,
                                          [llvm_double_ty, llvm_double_ty], 
                                          [IntrNoMem]>;
   def int_ppc_test_data_class_d : Intrinsic<[llvm_i32_ty],
                                             [llvm_double_ty, llvm_i32_ty],
                                             [IntrNoMem, ImmArg<ArgIndex<1>>]>;
   def int_ppc_test_data_class_f : Intrinsic<[llvm_i32_ty],
                                             [llvm_float_ty, llvm_i32_ty],
                                             [IntrNoMem, ImmArg<ArgIndex<1>>]>;
+  def int_ppc_fnabs
+      : GCCBuiltin<"__builtin_ppc_fnabs">,
+        Intrinsic <[llvm_double_ty], [llvm_double_ty], [IntrNoMem]>;
+  def int_ppc_fnabss
+      : GCCBuiltin<"__builtin_ppc_fnabss">,
+        Intrinsic <[llvm_float_ty], [llvm_float_ty], [IntrNoMem]>;
 
   def int_ppc_convert_f128_to_ppcf128
       : Intrinsic<[llvm_ppcf128_ty], [llvm_f128_ty], [IntrNoMem]>;
   def int_ppc_convert_ppcf128_to_f128
       : Intrinsic<[llvm_f128_ty], [llvm_ppcf128_ty], [IntrNoMem]>;
 }
 
 //===----------------------------------------------------------------------===//

llvm/lib/Target/PowerPC/P10InstrResources.td

def : InstRW<[P10W_FX_3C, P10W_DISP_ANY, P10FX_Read],
     VEXTSH2D, VEXTSH2Ds,
     VEXTSH2W, VEXTSH2Ws,
     VEXTSW2D, VEXTSW2Ds,
     VNEGD,
     VNEGW,
     WAIT,
     XSABSDP,
     XSABSQP,
-    XSNABSDP,
+    XSNABSDP, XSNABSDPs,
     XSNABSQP,
     XSNEGDP,
     XSNEGQP,
     XSXEXPDP,
     XSXEXPQP,
     XSXSIGDP,
     XVABSDP,
     XVABSSP,

llvm/lib/Target/PowerPC/P9InstrResources.td

def : InstRW<[P9_ALU_2C, IP_EXEC_1C, DISP_1C],
     (instregex "ADD(4|8)(TLS)?(_)?$"),
     (instregex "NEG(8)?(O)?$"),
     (instregex "ADDI(S)?toc(HA|L)(8)?$"),
     (instregex "LA(8)?$"),
     COPY,
     MCRF,
     MCRXRX,
     XSNABSDP,
+    XSNABSDPs,
     XSXEXPDP,
     XSABSDP,
     XSNEGDP,
     XSCPSGNDP,
     MFVSRWZ,
     MFVRWZ,
     EXTSWSLI,
     SRADI_32,

llvm/lib/Target/PowerPC/PPCBack2BackFusion.def

FUSION_OP_SET(ADD4,
     XSIEXPQP,
     XSMAXCDP,
     XSMAXDP,
     XSMAXJDP,
     XSMINCDP,
     XSMINDP,
     XSMINJDP,
     XSNABSDP,
+    XSNABSDPs,
     XSNABSQP,
     XSNEGDP,
     XSNEGQP,
     XSXEXPDP,
     XSXEXPQP,
     XSXSIGDP,
     XVABSDP,
     XVABSSP,
FUSION_OP_SET(ADD4,
     XSIEXPQP,
     XSMAXCDP,
     XSMAXDP,
     XSMAXJDP,
     XSMINCDP,
     XSMINDP,
     XSMINJDP,
     XSNABSDP,
+    XSNABSDPs,
     XSNABSQP,
     XSNEGDP,
     XSNEGQP,
     XSTDIVDP,
     XSTSQRTDP,
     XSTSTDCDP,
     XSTSTDCSP,
     XSXEXPDP,
FUSION_OP_SET(ADD4,
     XXLOR,
     XXLORC,
     XXLORf,
     XXLXOR,
     XXLXORdpz,
     XXLXORspz,
     XXLXORz,
     XXSEL))
 No newline at end of file

llvm/lib/Target/PowerPC/PPCInstrInfo.td

 
 // XL Compat intrinsics.
 def : Pat<(int_ppc_fmsub f64:$A, f64:$B, f64:$C), (FMSUB $A, $B, $C)>;
 def : Pat<(int_ppc_fmsubs f32:$A, f32:$B, f32:$C), (FMSUBS $A, $B, $C)>;
 def : Pat<(int_ppc_fnmadd f64:$A, f64:$B, f64:$C), (FNMADD $A, $B, $C)>;
 def : Pat<(int_ppc_fnmadds f32:$A, f32:$B, f32:$C), (FNMADDS $A, $B, $C)>;
 def : Pat<(int_ppc_fre f64:$A), (FRE $A)>;
 def : Pat<(int_ppc_fres f32:$A), (FRES $A)>;
+def : Pat<(int_ppc_fnabs f64:$A), (FNABSD $A)>;
+def : Pat<(int_ppc_fnabss f32:$A), (FNABSS $A)>;
 
 include "PPCInstrAltivec.td"
 include "PPCInstrSPE.td"
 include "PPCInstr64Bit.td"
 include "PPCInstrVSX.td"
 include "PPCInstrHTM.td"
 
 def crnot : OutPatFrag<(ops node:$in),

llvm/lib/Target/PowerPC/PPCInstrVSX.td

let hasSideEffects = 0 in {
   def XSABSDP : XX2Form<60, 345,
                       (outs vsfrc:$XT), (ins vsfrc:$XB),
                       "xsabsdp $XT, $XB", IIC_VecFP,
                       [(set f64:$XT, (fabs f64:$XB))]>;
   def XSNABSDP : XX2Form<60, 361,
                       (outs vsfrc:$XT), (ins vsfrc:$XB),
                       "xsnabsdp $XT, $XB", IIC_VecFP,
                       [(set f64:$XT, (fneg (fabs f64:$XB)))]>;
+  let isCodeGenOnly = 1 in
+  def XSNABSDPs : XX2Form<60, 361,
+                      (outs vssrc:$XT), (ins vssrc:$XB),
+                      "xsnabsdp $XT, $XB", IIC_VecFP,
+                      [(set f32:$XT, (fneg (fabs f32:$XB)))]>;
   def XSNEGDP : XX2Form<60, 377,
                       (outs vsfrc:$XT), (ins vsfrc:$XB),
                       "xsnegdp $XT, $XB", IIC_VecFP,
                       [(set f64:$XT, (fneg f64:$XB))]>;
   def XSCPSGNDP : XX3Form<60, 176,
                       (outs vsfrc:$XT), (ins vsfrc:$XA, vsfrc:$XB),
                       "xscpsgndp $XT, $XA, $XB", IIC_VecFP,
                       [(set f64:$XT, (fcopysign f64:$XB, f64:$XA))]>;
def : Pat<(v2i64 (PPCvcmp_rec v2i64:$vA, v2i64:$vB, 199)),
           (VCMPGTUB_rec DblwdCmp.MRGEQ, (v2i64 (XXLXORz)))>;
 } // AddedComplexity = 0
 
 // XL Compat builtins.
 def : Pat<(int_ppc_fmsub f64:$A, f64:$B, f64:$C), (XSMSUBMDP $A, $B, $C)>;
 def : Pat<(int_ppc_fnmadd f64:$A, f64:$B, f64:$C), (XSNMADDMDP $A, $B, $C)>;
 def : Pat<(int_ppc_fre f64:$A), (XSREDP $A)>;
 def : Pat<(int_ppc_frsqrte vsfrc:$XB), (XSRSQRTEDP $XB)>;
+def : Pat<(int_ppc_fnabs f64:$A), (XSNABSDP $A)>;
+def : Pat<(int_ppc_fnabss f32:$A), (XSNABSDPs $A)>;
 
 // XXMRG[LH]W is a direct replacement for VMRG[LH]W respectively.
 // Prefer the VSX form for greater register range.
 def:Pat<(vmrglw_unary_shuffle v16i8:$vA, undef),
         (COPY_TO_REGCLASS (XXMRGLW (COPY_TO_REGCLASS $vA, VSRC),
                                    (COPY_TO_REGCLASS $vA, VSRC)), VRRC)>;
 def:Pat<(vmrghw_unary_shuffle v16i8:$vA, undef),
         (COPY_TO_REGCLASS (XXMRGHW (COPY_TO_REGCLASS $vA, VSRC),

llvm/test/CodeGen/PowerPC/builtins-ppc-xlcompat-fnabs.ll

+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
+; RUN: llc -verify-machineinstrs -mtriple=powerpc64le-unknown-linux-gnu \
+; RUN:   -ppc-vsr-nums-as-vr -ppc-asm-full-reg-names -mcpu=pwr8 < %s | \
+; RUN: FileCheck %s --check-prefix=CHECK-DEFAULT
+; RUN: llc -verify-machineinstrs -mtriple=powerpc64-unknown-aix -mcpu=pwr8 \
+; RUN:   -ppc-vsr-nums-as-vr -ppc-asm-full-reg-names < %s | FileCheck %s \
+; RUN:   --check-prefix=CHECK-DEFAULT
+; RUN: llc -verify-machineinstrs -mtriple=powerpc64-unknown-aix -mcpu=pwr7 \
+; RUN:   -ppc-vsr-nums-as-vr -ppc-asm-full-reg-names < %s | FileCheck %s \
+; RUN:   --check-prefix=CHECK-DEFAULT
+; RUN: llc -verify-machineinstrs -mtriple=powerpc-unknown-aix -mcpu=pwr7 \
+; RUN:   -ppc-vsr-nums-as-vr -ppc-asm-full-reg-names < %s | FileCheck %s \
+; RUN:   --check-prefix=CHECK-DEFAULT
+; RUN: llc -verify-machineinstrs -mtriple=powerpc64-unknown-aix -mcpu=pwr6 \
+; RUN:   -ppc-vsr-nums-as-vr -ppc-asm-full-reg-names -mattr=+vsx < %s | \
+; RUN: FileCheck %s --check-prefix=CHECK-DEFAULT
+
+; RUN: llc -verify-machineinstrs -mtriple=powerpc64le-unknown-linux-gnu \
+; RUN:   -ppc-vsr-nums-as-vr -ppc-asm-full-reg-names -mcpu=pwr6 < %s | \
+; RUN: FileCheck %s --check-prefix=CHECK-NOVSX
+; RUN: llc -verify-machineinstrs -mtriple=powerpc64-unknown-aix \
+; RUN:   -ppc-vsr-nums-as-vr -ppc-asm-full-reg-names -mcpu=pwr6 < %s | \
+; RUN: FileCheck %s --check-prefix=CHECK-NOVSX
+; RUN: llc -verify-machineinstrs -mtriple=powerpc64-unknown-linux-gnu \
+; RUN:   -ppc-vsr-nums-as-vr -ppc-asm-full-reg-names -mcpu=pwr8 \
+; RUN:   -mattr=-vsx < %s | FileCheck %s --check-prefix=CHECK-NOVSX
+; RUN: llc -verify-machineinstrs -mtriple=powerpc-unknown-aix \
+; RUN:   -ppc-vsr-nums-as-vr -ppc-asm-full-reg-names -mcpu=pwr8 \
+; RUN:   -mattr=-vsx < %s | FileCheck %s --check-prefix=CHECK-NOVSX
+
+declare double @llvm.ppc.fnabs(double)
+declare float @llvm.ppc.fnabss(float)
+
+define double @test_fnabs2(double %d) {
+; CHECK-DEFAULT-LABEL: test_fnabs2:
+; CHECK-DEFAULT:       # %bb.0: # %entry
+; CHECK-DEFAULT-NEXT:    xsnabsdp f1, f1
+; CHECK-DEFAULT-NEXT:    blr
+;
+; CHECK-NOVSX-LABEL: test_fnabs2:
+; CHECK-NOVSX:       # %bb.0: # %entry
+; CHECK-NOVSX-NEXT:    fnabs f1, f1
+; CHECK-NOVSX-NEXT:    blr
+entry:
+  %0 = tail call double @llvm.ppc.fnabs(double %d)
+  ret double %0
+}
+
+define float @test_fnabss(float %f) {
+; CHECK-DEFAULT-LABEL: test_fnabss:
+; CHECK-DEFAULT:       # %bb.0: # %entry
+; CHECK-DEFAULT-NEXT:    xsnabsdp f1, f1
+; CHECK-DEFAULT-NEXT:    blr
+;
+; CHECK-NOVSX-LABEL: test_fnabss:
+; CHECK-NOVSX:       # %bb.0: # %entry
+; CHECK-NOVSX-NEXT:    fnabs f1, f1
+; CHECK-NOVSX-NEXT:    blr
+entry:
+  %0 = tail call float @llvm.ppc.fnabss(float %f)
+  ret float %0
+}
+