[GlobalIsel][X86] Legalize G_BSWAP

[tschuett]

Summary

remark: unable to legalize instruction: %95:_(s16) = G_BSWAP %94:_ (in function: _ZNK4llvm13DataExtractor6getU16EPyPtj) [-Rpass-missed=gisel-legalize]

check plan: ninja check-llvm-codegen-x86

[arsenm]

llvm/test/CodeGen/X86/GlobalISel/legalize-bswap.mir

3

Don't need -O0

9–18

Don't need any of this in any legalize tests

[tschuett]

removed -O0

[tschuett]

Thanks!

llvm/test/CodeGen/X86/GlobalISel/legalize-bswap.mir

9–18

It comes from the checks script.

[arsenm]

llvm/test/CodeGen/X86/GlobalISel/legalize-bswap.mir

9–18

The checks script don't modify the tests themselves. We have really bad MIRPrinter defaults and you don't need any of this header

[bjope]

This seems to have broken lots of tests.
I reverted your patch here: https://github.com/llvm/llvm-project/commit/e016fe817c8e4774c3996314b9519f8d856cc616

See for example this build bot:

https://lab.llvm.org/buildbot/#/builders/16/builds/48152

[bjope]

In D150667#4346179, @bjope wrote:

This seems to have broken lots of tests.
I reverted your patch here: https://github.com/llvm/llvm-project/commit/e016fe817c8e4774c3996314b9519f8d856cc616

See for example this build bot:

https://lab.llvm.org/buildbot/#/builders/16/builds/48152

Solution is probably to use

getActionDefinitionsBuilder(G_BSWAP)

instead of having the initializer list with one element.

[tschuett]

Apple Clang didn't mind. But indeed that was the problem.

[JDevlieghere]

It looks like this is hitting an assert when building compiler-rt: https://green.lab.llvm.org/green/view/LLDB/job/lldb-cmake/55179/console

Assertion failed: (Opcodes.size() >= 2 && "Initializer list must have at least two opcodes"), function getActionDefinitionsBuilder, file /Users/buildslave/jenkins/workspace/lldb-cmake/llvm-project/llvm/lib/CodeGen/GlobalISel/LegalizerInfo.cpp, line 300.

 #0 0x0000000106d9e037 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/Users/buildslave/jenkins/workspace/lldb-cmake/lldb-build/bin/clang-17+0x101d74037)
 #1 0x0000000106d9bf24 llvm::sys::RunSignalHandlers() (/Users/buildslave/jenkins/workspace/lldb-cmake/lldb-build/bin/clang-17+0x101d71f24)
 #2 0x0000000106d9e8f0 SignalHandler(int) (/Users/buildslave/jenkins/workspace/lldb-cmake/lldb-build/bin/clang-17+0x101d748f0)
 #3 0x00007fff203c8d7d (/usr/lib/system/libsystem_platform.dylib+0x7fff20353d7d)
 #4 0x00007fef100b01e8 
 #5 0x00007fff202d8406 (/usr/lib/system/libsystem_c.dylib+0x7fff20263406)
 #6 0x00007fff202d77d8 (/usr/lib/system/libsystem_c.dylib+0x7fff202627d8)
 #7 0x000000010acebb93 llvm::LegalizerInfo::getActionDefinitionsBuilder(std::initializer_list<unsigned int>) (.cold.1) (/Users/buildslave/jenkins/workspace/lldb-cmake/lldb-build/bin/clang-17+0x105cc1b93)
 #8 0x0000000107d29b35 llvm::LegalizerInfo::getActionDefinitionsBuilder(std::initializer_list<unsigned int>) (/Users/buildslave/jenkins/workspace/lldb-cmake/lldb-build/bin/clang-17+0x102cffb35)
 #9 0x0000000105337b52 llvm::X86LegalizerInfo::setLegalizerInfo64bit() (/Users/buildslave/jenkins/workspace/lldb-cmake/lldb-build/bin/clang-17+0x10030db52)
#10 0x00000001053363f5 llvm::X86LegalizerInfo::X86LegalizerInfo(llvm::X86Subtarget const&, llvm::X86TargetMachine const&) (/Users/buildslave/jenkins/workspace/lldb-cmake/lldb-build/bin/clang-17+0x10030c3f5)
#11 0x0000000105381ace llvm::X86Subtarget::X86Subtarget(llvm::Triple const&, llvm::StringRef, llvm::StringRef, llvm::StringRef, llvm::X86TargetMachine const&, llvm::MaybeAlign, unsigned int, unsigned int) (/Users/buildslave/jenkins/workspace/lldb-cmake/lldb-build/bin/clang-17+0x100357ace)
#12 0x0000000105382e50 llvm::X86TargetMachine::getSubtargetImpl(llvm::Function const&) const (/Users/buildslave/jenkins/workspace/lldb-cmake/lldb-build/bin/clang-17+0x100358e50)
#13 0x0000000105382fe6 llvm::X86TargetMachine::getTargetTransformInfo(llvm::Function const&) const (/Users/buildslave/jenkins/workspace/lldb-cmake/lldb-build/bin/clang-17+0x100358fe6)
#14 0x000000010816e2a3 std::__1::__function::__func<llvm::TargetMachine::getTargetIRAnalysis() const::$_3, std::__1::allocator<llvm::TargetMachine::getTargetIRAnalysis() const::$_3>, llvm::TargetTransformInfo (llvm::Function const&)>::operator()(llvm::Function const&) (/Users/buildslave/jenkins/workspace/lldb-cmake/lldb-build/bin/clang-17+0x1031442a3)
#15 0x0000000105ce54e8 llvm::TargetIRAnalysis::run(llvm::Function const&, llvm::AnalysisManager<llvm::Function>&) (/Users/buildslave/jenkins/workspace/lldb-cmake/lldb-build/bin/clang-17+0x100cbb4e8)
#16 0x00000001081059b2 llvm::detail::AnalysisPassModel<llvm::Function, llvm::TargetIRAnalysis, llvm::PreservedAnalyses, llvm::AnalysisManager<llvm::Function>::Invalidator>::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) (/Users/buildslave/jenkins/workspace/lldb-cmake/lldb-build/bin/clang-17+0x1030db9b2)
#17 0x000000010641b806 llvm::AnalysisManager<llvm::Function>::getResultImpl(llvm::AnalysisKey*, llvm::Function&) (/Users/buildslave/jenkins/workspace/lldb-cmake/lldb-build/bin/clang-17+0x1013f1806)
#18 0x0000000106c69ee2 llvm::SimplifyCFGPass::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) (/Users/buildslave/jenkins/workspace/lldb-cmake/lldb-build/bin/clang-17+0x101c3fee2)
#19 0x000000010811b572 llvm::detail::PassModel<llvm::Function, llvm::SimplifyCFGPass, llvm::PreservedAnalyses, llvm::AnalysisManager<llvm::Function>>::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) (/Users/buildslave/jenkins/workspace/lldb-cmake/lldb-build/bin/clang-17+0x1030f1572)
#20 0x00000001064184b9 llvm::PassManager<llvm::Function, llvm::AnalysisManager<llvm::Function>>::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) (/Users/buildslave/jenkins/workspace/lldb-cmake/lldb-build/bin/clang-17+0x1013ee4b9)
#21 0x000000010718ebe2 llvm::detail::PassModel<llvm::Function, llvm::PassManager<llvm::Function, llvm::AnalysisManager<llvm::Function>>, llvm::PreservedAnalyses, llvm::AnalysisManager<llvm::Function>>::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) (/Users/buildslave/jenkins/workspace/lldb-cmake/lldb-build/bin/clang-17+0x102164be2)
#22 0x000000010641d239 llvm::ModuleToFunctionPassAdaptor::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) (/Users/buildslave/jenkins/workspace/lldb-cmake/lldb-build/bin/clang-17+0x1013f3239)
#23 0x0000000107190dc2 llvm::detail::PassModel<llvm::Module, llvm::ModuleToFunctionPassAdaptor, llvm::PreservedAnalyses, llvm::AnalysisManager<llvm::Module>>::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) (/Users/buildslave/jenkins/workspace/lldb-cmake/lldb-build/bin/clang-17+0x102166dc2)
#24 0x0000000106417169 llvm::PassManager<llvm::Module, llvm::AnalysisManager<llvm::Module>>::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) (/Users/buildslave/jenkins/workspace/lldb-cmake/lldb-build/bin/clang-17+0x1013ed169)
#25 0x0000000107188090 (anonymous namespace)::EmitAssemblyHelper::RunOptimizationPipeline(clang::BackendAction, std::__1::unique_ptr<llvm::raw_pwrite_stream, std::__1::default_delete<llvm::raw_pwrite_stream>>&, std::__1::unique_ptr<llvm::ToolOutputFile, std::__1::default_delete<llvm::ToolOutputFile>>&) (/Users/buildslave/jenkins/workspace/lldb-cmake/lldb-build/bin/clang-17+0x10215e090)
#26 0x0000000107181649 clang::EmitBackendOutput(clang::DiagnosticsEngine&, clang::HeaderSearchOptions const&, clang::CodeGenOptions const&, clang::TargetOptions const&, clang::LangOptions const&, llvm::StringRef, llvm::Module*, clang::BackendAction, llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem>, std::__1::unique_ptr<llvm::raw_pwrite_stream, std::__1::default_delete<llvm::raw_pwrite_stream>>) (/Users/buildslave/jenkins/workspace/lldb-cmake/lldb-build/bin/clang-17+0x102157649)
#27 0x00000001075a0fd2 clang::BackendConsumer::HandleTranslationUnit(clang::ASTContext&) (/Users/buildslave/jenkins/workspace/lldb-cmake/lldb-build/bin/clang-17+0x102576fd2)
#28 0x00000001089e8374 clang::ParseAST(clang::Sema&, bool, bool) (/Users/buildslave/jenkins/workspace/lldb-cmake/lldb-build/bin/clang-17+0x1039be374)
#29 0x000000010799d963 clang::FrontendAction::Execute() (/Users/buildslave/jenkins/workspace/lldb-cmake/lldb-build/bin/clang-17+0x102973963)
#30 0x0000000107904159 clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) (/Users/buildslave/jenkins/workspace/lldb-cmake/lldb-build/bin/clang-17+0x1028da159)
#31 0x0000000107a2a860 clang::ExecuteCompilerInvocation(clang::CompilerInstance*) (/Users/buildslave/jenkins/workspace/lldb-cmake/lldb-build/bin/clang-17+0x102a00860)
#32 0x0000000105038b62 cc1_main(llvm::ArrayRef<char const*>, char const*, void*) (/Users/buildslave/jenkins/workspace/lldb-cmake/lldb-build/bin/clang-17+0x10000eb62)
#33 0x0000000105032e05 ExecuteCC1Tool(llvm::SmallVectorImpl<char const*>&, llvm::ToolContext const&) (/Users/buildslave/jenkins/workspace/lldb-cmake/lldb-build/bin/clang-17+0x100008e05)
#34 0x000000010503212d clang_main(int, char**, llvm::ToolContext const&) (/Users/buildslave/jenkins/workspace/lldb-cmake/lldb-build/bin/clang-17+0x10000812d)
#35 0x00000001050447a4 main (/Users/buildslave/jenkins/workspace/lldb-cmake/lldb-build/bin/clang-17+0x10001a7a4)

edit: seems like this already got reverted

[tschuett]

It was reverted. There is an assert in legalFor.

[RKSimon]

@tschuett What's happening with fixing this? It looks easier than the POPCNT/LZCNT cases and still doesn't seem to work :(

[tschuett]

In D150667#4373260, @RKSimon wrote:

@tschuett What's happening with fixing this? It looks easier than the POPCNT/LZCNT cases and still doesn't seem to work :(

I will do that soonish.

llvm/lib/Target/X86/X86LegalizerInfo.cpp

getActionDefinitionsBuilder(
     .clampScalar(1, s8, s8);
 
   // Merge/Unmerge
   LegacyInfo.setAction({G_MERGE_VALUES, s128}, LegacyLegalizeActions::Legal);
   LegacyInfo.setAction({G_UNMERGE_VALUES, 1, s128},
                        LegacyLegalizeActions::Legal);
   LegacyInfo.setAction({G_MERGE_VALUES, 1, s128}, LegacyLegalizeActions::Legal);
   LegacyInfo.setAction({G_UNMERGE_VALUES, s128}, LegacyLegalizeActions::Legal);
+
+  getActionDefinitionsBuilder({G_BSWAP})
+    .legalFor({s32, s64})
+    .widenScalarToNextPow2(1, /*Min=*/32)
+    .clampScalar(0, s32, s64);
+
 }
 
 void X86LegalizerInfo::setLegalizerInfoSSE1() {
   if (!Subtarget.hasSSE1())
     return;
 
   const LLT s32 = LLT::scalar(32);
   const LLT s64 = LLT::scalar(64);

llvm/test/CodeGen/X86/GlobalISel/legalize-bswap.mir

+# NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py UTC_ARGS: --version 2
+# RUN: llc -mtriple=x86_64-linux-gnu -run-pass=legalizer %s -o - | FileCheck %s
+
+# test BSWAP s32 and s64
+
+---
+name:            test_bswap_s96
+alignment:       16
+legalized:       false
+regBankSelected: false
+registers:
+  - { id: 0, class: _, preferred-register: '' }
+  - { id: 1, class: _, preferred-register: '' }
+liveins:
+fixedStack:
+stack:
+constants:
+body:             |
+  bb.1:
+    ; CHECK-LABEL: name: test_bswap_s96
+    ; CHECK: [[DEF:%[0-9]+]]:_(s96) = IMPLICIT_DEF
+    ; CHECK-NEXT: [[ANYEXT:%[0-9]+]]:_(s32) = G_ANYEXT [[DEF]](s96)
+    ; CHECK-NEXT: [[BSWAP:%[0-9]+]]:_(s32) = G_BSWAP [[ANYEXT]]
+    ; CHECK-NEXT: [[C:%[0-9]+]]:_(s8) = G_CONSTANT i8 -64
+    ; CHECK-NEXT: [[LSHR:%[0-9]+]]:_(s32) = G_LSHR [[BSWAP]], [[C]](s8)
+    ; CHECK-NEXT: [[TRUNC:%[0-9]+]]:_(s96) = G_TRUNC [[LSHR]](s32)
+    ; CHECK-NEXT: [[COPY:%[0-9]+]]:_(s96) = COPY [[TRUNC]](s96)
+    ; CHECK-NEXT: RET 0, implicit [[COPY]](s96)
+    %0:_(s96) = IMPLICIT_DEF
+    %1:_(s96) = G_BSWAP %0
+    %2:_(s96) = COPY %1(s96)
+    RET 0, implicit %2
+
+...
+---
+name:            test_bswaps64
+alignment:       16
+legalized:       false
+regBankSelected: false
+registers:
+  - { id: 0, class: _, preferred-register: '' }
+  - { id: 1, class: _, preferred-register: '' }
+liveins:
+fixedStack:
+stack:
+constants:
+body:             |
+  bb.1:
+    ; CHECK-LABEL: name: test_bswaps64
+    ; CHECK: [[DEF:%[0-9]+]]:_(s64) = IMPLICIT_DEF
+    ; CHECK-NEXT: [[BSWAP:%[0-9]+]]:_(s64) = G_BSWAP [[DEF]]
+    ; CHECK-NEXT: [[COPY:%[0-9]+]]:_(s64) = COPY [[BSWAP]](s64)
+    ; CHECK-NEXT: RET 0, implicit [[COPY]](s64)
+    %0:_(s64) = IMPLICIT_DEF
+    %1:_(s64) = G_BSWAP %0
+    %2:_(s64) = COPY %1(s64)
+    RET 0, implicit %2
+
+...
+---
+name:            test_bswap_s32
+alignment:       16
+legalized:       false
+regBankSelected: false
+registers:
+  - { id: 0, class: _, preferred-register: '' }
+  - { id: 1, class: _, preferred-register: '' }
+liveins:
+fixedStack:
+stack:
+constants:
+body:             |
+  bb.1:
+    ; CHECK-LABEL: name: test_bswap_s32
+    ; CHECK: [[DEF:%[0-9]+]]:_(s32) = IMPLICIT_DEF
+    ; CHECK-NEXT: [[BSWAP:%[0-9]+]]:_(s32) = G_BSWAP [[DEF]]
+    ; CHECK-NEXT: [[COPY:%[0-9]+]]:_(s32) = COPY [[BSWAP]](s32)
+    ; CHECK-NEXT: RET 0, implicit [[COPY]](s32)
+    %0:_(s32) = IMPLICIT_DEF
+    %1:_(s32) = G_BSWAP %0
+    %2:_(s32) = COPY %1(s32)
+    RET 0, implicit %2
+
+...
+---
+name:            test_bswap_s16
+alignment:       16
+legalized:       false
+regBankSelected: false
+registers:
+  - { id: 0, class: _, preferred-register: '' }
+  - { id: 1, class: _, preferred-register: '' }
+liveins:
+fixedStack:
+stack:
+constants:
+body:             |
+  bb.1:
+    ; CHECK-LABEL: name: test_bswap_s16
+    ; CHECK: [[DEF:%[0-9]+]]:_(s16) = IMPLICIT_DEF
+    ; CHECK-NEXT: [[ANYEXT:%[0-9]+]]:_(s32) = G_ANYEXT [[DEF]](s16)
+    ; CHECK-NEXT: [[BSWAP:%[0-9]+]]:_(s32) = G_BSWAP [[ANYEXT]]
+    ; CHECK-NEXT: [[C:%[0-9]+]]:_(s8) = G_CONSTANT i8 16
+    ; CHECK-NEXT: [[LSHR:%[0-9]+]]:_(s32) = G_LSHR [[BSWAP]], [[C]](s8)
+    ; CHECK-NEXT: [[TRUNC:%[0-9]+]]:_(s16) = G_TRUNC [[LSHR]](s32)
+    ; CHECK-NEXT: [[COPY:%[0-9]+]]:_(s16) = COPY [[TRUNC]](s16)
+    ; CHECK-NEXT: RET 0, implicit [[COPY]](s16)
+    %0:_(s16) = IMPLICIT_DEF
+    %1:_(s16) = G_BSWAP %0
+    %2:_(s16) = COPY %1(s16)
+    RET 0, implicit %2
+
+...