__builtin_assume: Assertion failed: (!areInvalidOperands(C, S1, S2) && "Invalid operands for select"), function init, file llvm/include/llvm/IR/Instructions.h, line 1709.

[DimitryAndric]

Bugzilla Link	46557
Version	trunk
OS	All
CC	@zygoloid,@rotateright

Extended Description

As reported in https://bugs.freebsd.org/247665, clang 10.0 (and the most recent clang 11) asserts while compiling the emulators/rpcs3 port. This happens during parsing of an expression using __builtin_assume:

% cat System-min.cpp
// clang -cc1 -triple x86_64-- -S System-min.cpp
enum {} a;
class b {
public:
  b() { a ? void() : __builtin_assume(0); }
} c;

% clang -cc1 -triple x86_64-- -S System-min.cpp
Assertion failed: (getType() == V->getType() && "All operands to PHI node must be the same type as the PHI node!"), function setIncomingValue, file /home/dim/src/llvm/llvm-project/llvm/include/llvm/IR/Instructions.h, line 2576.
PLEASE submit a bug report to https://bugs.llvm.org/ and include the crash backtrace, preprocessed source, and associated run script.
Stack dump:
0.      Program arguments: clang -cc1 -triple x86_64-- -S System-min.cpp
1.      <eof> parser at end of file
2.      Per-file LLVM IR generation
3.      System-min.cpp:5:3: Generating code for declaration 'b::b'
4.      System-min.cpp:5:7: LLVM IR generation of compound statement ('{}')
#&#8203;0 0x000000000304f378 llvm::sys::PrintStackTrace(llvm::raw_ostream&) (clang+0x304f378)
#&#8203;1 0x000000000304d0a8 llvm::sys::RunSignalHandlers() (clang+0x304d0a8)
#&#8203;2 0x000000000304fadd SignalHandler(int) (clang+0x304fadd)
#&#8203;3 0x0000000805750a30 handle_signal /usr/src/lib/libthr/thread/thr_sig.c:0:3

[rotateright]

This is coming from clang (front-end) codegen; backtrace:
9 clang 0x00000001133734d3 llvm::PHINode::addIncoming(llvm::Value*, llvm::BasicBlock*) (.cold.6) + 35
10 clang 0x000000010fe079bb llvm::PHINode::addIncoming(llvm::Value*, llvm::BasicBlock*) + 315
11 clang 0x00000001106e8a57 (anonymous namespace)::ScalarExprEmitter::VisitAbstractConditionalOperator(clang::AbstractConditionalOperator const*) + 3079
12 clang 0x00000001106d560b clang::CodeGen::CodeGenFunction::EmitScalarExpr(clang::Expr const*, bool) + 107
13 clang 0x000000011068f6c2 clang::CodeGen::CodeGenFunction::EmitAnyExpr(clang::Expr const*, clang::CodeGen::AggValueSlot, bool) + 66
14 clang 0x000000011068f66c clang::CodeGen::CodeGenFunction::EmitIgnoredExpr(clang::Expr const*) + 92
15 clang 0x00000001107d4c56 clang::CodeGen::CodeGenFunction::EmitStmt(clang::Stmt const*, llvm::ArrayRef<clang::Attr const*>) + 294
16 clang 0x00000001107de261 clang::CodeGen::CodeGenFunction::EmitCompoundStmtWithoutScope(clang::CompoundStmt const&, bool, clang::CodeGen::AggValueSlot) + 593
17 clang 0x00000001107dd54a clang::CodeGen::CodeGenFunction::EmitCompoundStmt(clang::CompoundStmt const&, bool, clang::CodeGen::AggValueSlot) + 330
18 clang 0x00000001107d56da clang::CodeGen::CodeGenFunction::EmitSimpleStmt(clang::Stmt const*) + 154
19 clang 0x00000001107d4b82 clang::CodeGen::CodeGenFunction::EmitStmt(clang::Stmt const*, llvm::ArrayRef<clang::Attr const*>) + 82
20 clang 0x00000001106402f2 clang::CodeGen::CodeGenFunction::EmitConstructorBody(clang::CodeGen::FunctionArgList&) + 610
21 clang 0x000000011082e5da clang::CodeGen::CodeGenFunction::GenerateCode(clang::GlobalDecl, llvm::Function*, clang::CodeGen::CGFunctionInfo const&) + 1002

[DimitryAndric]

Note that in the mean time, the assertion changed to:

Assertion failed: (!areInvalidOperands(C, S1, S2) && "Invalid operands for select"), function init, file /home/dim/src/llvm/llvm-project/llvm/include/llvm/IR/Instructions.h, line 1768.

Program received signal SIGABRT, Aborted.
Sent by thr_kill() from pid 66194 and user 1236.
thr_kill () at thr_kill.S:4
4 thr_kill.S: No such file or directory.
(gdb) bt
#​0 thr_kill () at thr_kill.S:4
#​1 0x0000000806309544 in __raise (s=s@entry=6) at /usr/src/lib/libc/gen/raise.c:52
#​2 0x00000008063be6a9 in abort () at /usr/src/lib/libc/stdlib/abort.c:67
#​3 0x00000008062ec461 in __assert (func=, file=, line=, failedexpr=) at /usr/src/lib/libc/gen/assert.c:51
#​4 0x0000000001fdb7a5 in llvm::SelectInst::init(llvm::Value*, llvm::Value*, llvm::Value*) ()
#​5 0x0000000002e4b43d in llvm::IRBuilderBase::CreateSelect(llvm::Value*, llvm::Value*, llvm::Value*, llvm::Twine const&, llvm::Instruction*) ()
#​6 0x0000000003bdecd8 in (anonymous namespace)::ScalarExprEmitter::VisitAbstractConditionalOperator(clang::AbstractConditionalOperator const*) ()
#​7 0x0000000003bcaeeb in clang::CodeGen::CodeGenFunction::EmitScalarExpr(clang::Expr const*, bool) ()
#​8 0x0000000003b1b692 in clang::CodeGen::CodeGenFunction::EmitAnyExpr(clang::Expr const*, clang::CodeGen::AggValueSlot, bool) ()
#​9 0x0000000003b1b639 in clang::CodeGen::CodeGenFunction::EmitIgnoredExpr(clang::Expr const*) ()
#​10 0x0000000003beb9fa in clang::CodeGen::CodeGenFunction::EmitStmt(clang::Stmt const*, llvm::ArrayRef<clang::Attr const*>) ()
#​11 0x0000000003bf6911 in clang::CodeGen::CodeGenFunction::EmitCompoundStmtWithoutScope(clang::CompoundStmt const&, bool, clang::CodeGen::AggValueSlot) ()
#​12 0x0000000003bf5951 in clang::CodeGen::CodeGenFunction::EmitCompoundStmt(clang::CompoundStmt const&, bool, clang::CodeGen::AggValueSlot) ()
#​13 0x0000000003bec16d in clang::CodeGen::CodeGenFunction::EmitSimpleStmt(clang::Stmt const*, llvm::ArrayRef<clang::Attr const*>) ()
#​14 0x0000000003beb91e in clang::CodeGen::CodeGenFunction::EmitStmt(clang::Stmt const*, llvm::ArrayRef<clang::Attr const*>) ()
#​15 0x0000000003c56c05 in clang::CodeGen::CodeGenFunction::EmitConstructorBody(clang::CodeGen::FunctionArgList&) ()
#​16 0x0000000003b0b337 in clang::CodeGen::CodeGenFunction::GenerateCode(clang::GlobalDecl, llvm::Function*, clang::CodeGen::CGFunctionInfo const&) ()
#​17 0x0000000003bb46f0 in clang::CodeGen::CodeGenModule::codegenCXXStructor(clang::GlobalDecl) ()
#​18 0x0000000003dd4a51 in (anonymous namespace)::ItaniumCXXABI::emitCXXStructor(clang::GlobalDecl) ()
#​19 0x0000000003a93fd0 in clang::CodeGen::CodeGenModule::EmitGlobalDefinition(clang::GlobalDecl, llvm::GlobalValue*) ()
#​20 0x0000000003a874c0 in clang::CodeGen::CodeGenModule::EmitDeferred() ()
#​21 0x0000000003a874ec in clang::CodeGen::CodeGenModule::EmitDeferred() ()
#​22 0x0000000003a85dbc in clang::CodeGen::CodeGenModule::Release() ()
#​23 0x0000000004151424 in (anonymous namespace)::CodeGeneratorImpl::HandleTranslationUnit(clang::ASTContext&) ()
#​24 0x000000000414e769 in clang::BackendConsumer::HandleTranslationUnit(clang::ASTContext&) ()
#​25 0x00000000049a8d03 in clang::ParseAST(clang::Sema&, bool, bool) ()
#​26 0x0000000004094563 in clang::FrontendAction::Execute() ()
#​27 0x000000000401ffe9 in clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) ()
#​28 0x00000000041481a1 in clang::ExecuteCompilerInvocation(clang::CompilerInstance*) ()
#​29 0x0000000001bf9b62 in cc1_main(llvm::ArrayRef<char const*>, char const*, void*) ()
#​30 0x0000000001bf7407 in ExecuteCC1Tool(llvm::SmallVectorImpl<char const*>&) ()
#​31 0x0000000001bf719a in main ()

It changed between clang 11 and 12, with commit 038edf6 ("Don't reject uses of void-returning consteval functions").

[arrowd]

Still reproducible with

FreeBSD clang version 14.0.3 (https://github.com/llvm/llvm-project.git llvmorg-14.0.3-0-g1f9140064dfb)

[fhahn]

Also crashes on current main: https://clang.godbolt.org/z/ee7qhrd17

[llvmbot]

@llvm/issue-subscribers-clang-codegen

[xgupta]

Also crashes on current main: https://clang.godbolt.org/z/ee7qhrd17

checked the godbolt link, it is fixed on trunk.