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

[Quuxplusone]

Bugzilla Link	PR46557
Status	CONFIRMED
Importance	P enhancement
Reported by	Dimitry Andric (dimitry@andric.com)
Reported on	2020-07-02 06:50:13 -0700
Last modified on	2021-11-08 04:58:49 -0800
Version	trunk
Hardware	PC All
CC	htmldeveloper@gmail.com, llvm-bugs@lists.llvm.org, neeilans@live.com, richard-llvm@metafoo.co.uk, spatel+llvm@rotateright.com
Fixed by commit(s)
Attachments
Blocks
Blocked by
See also

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 ('{}')
#0 0x000000000304f378 llvm::sys::PrintStackTrace(llvm::raw_ostream&)
(clang+0x304f378)
#1 0x000000000304d0a8 llvm::sys::RunSignalHandlers() (clang+0x304d0a8)
#2 0x000000000304fadd SignalHandler(int) (clang+0x304fadd)
#3 0x0000000805750a30 handle_signal /usr/src/lib/libthr/thread/thr_sig.c:0:3

[Quuxplusone]

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

[Quuxplusone]

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=<optimized out>, file=<optimized out>,
line=<optimized out>, failedexpr=<optimized out>) 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 https://github.com/llvm/llvm-
project/commit/038edf6029bafe70b1f7165abe2b0e61ddf506b3 ("Don't reject uses of
void-returning consteval functions").