[llvm] [SPIRV] Start adding support for `int128` (PR #170798)

[Mikael Holmen via llvm-commits]

mikaelholmen wrote:

Hi @AlexVlx 

I noticed that if I build with gcc and -DLLVM_ENABLE_EXPENSIVE_CHECKS=ON many SPIRV lit tests fail with this patch.

E.g. ```build-all-gcc132-expensive/bin/llc -O0 -verify-machineinstrs -mtriple=spirv64-unknown-unknown --spirv-ext=+SPV_ALTERA_arbitrary_precision_integers,+SPV_KHR_bit_instructions test/CodeGen/SPIRV/llvm-intrinsics/bitreverse_small_type.ll -o -``` fails with
```
[...]/gcc/13.2.0/include/c++/13.2.0/bits/stl_algo.h:4892:
In function:
    void std::sort(_RAIter, _RAIter, _Compare) [with _RAIter =
    llvm::StringRef*; _Compare =
    llvm::SPIRVExtensionsParser::parse(llvm::cl::Option&, llvm::StringRef,
    llvm::StringRef, std::
    debug::set<llvm::SPIRV::Extension::Extension>&)::<lambda(auto:4&&,
    auto:5&&)>]

Error: comparison doesn't meet irreflexive requirements, assert(!(a < a)).

Objects involved in the operation:
    instance "functor" @ 0x7ffd92e1a6a0 {
    }
    iterator::value_type "ordered type"  {
    }
PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace and instructions to reproduce the bug.
Stack dump:
0.      Program arguments: build-all-gcc132-expensive/bin/llc -O0 -verify-machineinstrs -mtriple=spirv64-unknown-unknown --spirv-ext=+SPV_ALTERA_arbitrary_precision_integers,+SPV_KHR_bit_instructions test/CodeGen/SPIRV/llvm-intrinsics/bitreverse_small_type.ll -o -
 #0 0x0000000004e8fc6e llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (build-all-gcc132-expensive/bin/llc+0x4e8fc6e)
 #1 0x0000000004e8c5cb llvm::sys::RunSignalHandlers() (build-all-gcc132-expensive/bin/llc+0x4e8c5cb)
 #2 0x0000000004e8c70e SignalHandler(int, siginfo_t*, void*) Signals.cpp:0:0
 #3 0x00007fa6f7f28990 __restore_rt (/lib64/libpthread.so.0+0x12990)
 #4 0x00007fa6f58bf52f raise (/lib64/libc.so.6+0x4e52f)
 #5 0x00007fa6f5892e65 abort (/lib64/libc.so.6+0x21e65)
 #6 0x000000000080410d (build-all-gcc132-expensive/bin/llc+0x80410d)
 #7 0x000000000246ef29 llvm::SPIRVExtensionsParser::parse(llvm::cl::Option&, llvm::StringRef, llvm::StringRef, std::__debug::set<llvm::SPIRV::Extension::Extension, std::less<llvm::SPIRV::Extension::Extension>, std::allocator<llvm::SPIRV::Extension::Extension>>&) crtstuff.c:0:0
 #8 0x00000000024257e5 llvm::cl::opt<std::__debug::set<llvm::SPIRV::Extension::Extension, std::less<llvm::SPIRV::Extension::Extension>, std::allocator<llvm::SPIRV::Extension::Extension>>, false, llvm::SPIRVExtensionsParser>::handleOccurrence(unsigned int, llvm::StringRef, llvm::StringRef) crtstuff.c:0:0
 #9 0x0000000004d4b5c1 llvm::cl::ParseCommandLineOptions(int, char const* const*, llvm::StringRef, llvm::raw_ostream*, llvm::vfs::FileSystem*, char const*, bool) (build-all-gcc132-expensive/bin/llc+0x4d4b5c1)
#10 0x0000000000806968 main (build-all-gcc132-expensive/bin/llc+0x806968)
#11 0x00007fa6f58ab7e5 __libc_start_main (/lib64/libc.so.6+0x3a7e5)
#12 0x00000000009510ee _start (build-all-gcc132-expensive/bin/llc+0x9510ee)
Abort (core dumped)
```
I guess it's this change that cause this
```
 bool SPIRVExtensionsParser::parse(cl::Option &O, StringRef ArgName,
                                   StringRef ArgValue,
                                   std::set<SPIRV::Extension::Extension> &Vals) {
   SmallVector<StringRef, 10> Tokens;
   ArgValue.split(Tokens, ",", -1, false);
-  std::sort(Tokens.begin(), Tokens.end());
+  llvm::sort(Tokens, [](auto &&LHS, auto &&RHS) {
+    // We want to ensure that we handle "all" first, to ensure that any
+    // subsequent disablement actually behaves as expected i.e. given
+    // --spv-ext=all,-foo, we first enable all and then disable foo; this should
+    // be revisited and simplified.
+    if (LHS == "all")
+      return true;
+    if (RHS == "all")
+      return false;
+    return !(RHS < LHS);
+  });
```

https://github.com/llvm/llvm-project/pull/170798