[llvm] [SimplifyCFG] Cost speculated selects with their real scalar condition (PR #217664)

Sun Sep 27 13:51:56 PDT 2026

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `clang-aarch64-sve-vls-2stage` running on `arm-bbot-clang-aarch64-sve-vls-2stage` while building `llvm` at step 12 "ninja check 2".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/4/builds/13357

<details>
<summary>Here is the relevant piece of the build log for the reference</summary>

```
Step 12 (ninja check 2) failure: stage 2 checked (failure)
******************** TEST 'Clang :: CodeGen/RISCV/rvv-intrinsics-autogenerated/policy/overloaded/vredmaxu.c' FAILED ********************
Exit Code: 1

Command Output (stdout):
--
# RUN: at line 3
/home/buildbot/workspace/clang-aarch64-sve-vls-2stage/stage2/bin/clang -cc1 -internal-isystem /home/buildbot/workspace/clang-aarch64-sve-vls-2stage/stage2/lib/clang/24/include -nostdsysteminc -triple riscv64 -target-feature +v -disable-O0-optnone    -emit-llvm /home/buildbot/workspace/clang-aarch64-sve-vls-2stage/llvm/clang/test/CodeGen/RISCV/rvv-intrinsics-autogenerated/policy/overloaded/vredmaxu.c -o - | /home/buildbot/workspace/clang-aarch64-sve-vls-2stage/stage2/bin/opt -S -passes=mem2reg |    /home/buildbot/workspace/clang-aarch64-sve-vls-2stage/stage2/bin/FileCheck --check-prefix=CHECK-RV64 /home/buildbot/workspace/clang-aarch64-sve-vls-2stage/llvm/clang/test/CodeGen/RISCV/rvv-intrinsics-autogenerated/policy/overloaded/vredmaxu.c
# executed command: /home/buildbot/workspace/clang-aarch64-sve-vls-2stage/stage2/bin/clang -cc1 -internal-isystem /home/buildbot/workspace/clang-aarch64-sve-vls-2stage/stage2/lib/clang/24/include -nostdsysteminc -triple riscv64 -target-feature +v -disable-O0-optnone -emit-llvm /home/buildbot/workspace/clang-aarch64-sve-vls-2stage/llvm/clang/test/CodeGen/RISCV/rvv-intrinsics-autogenerated/policy/overloaded/vredmaxu.c -o -
# .---command stderr------------
# | clang: /home/buildbot/workspace/clang-aarch64-sve-vls-2stage/llvm/clang/lib/Sema/SemaOverload.cpp:14558: void AddOverloadedCallCandidate(Sema &, DeclAccessPair, TemplateArgumentListInfo *, ArrayRef<Expr *>, OverloadCandidateSet &, bool, bool): Assertion `!KnownValid && "unhandled case in overloaded call candidate"' failed.
# | PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace and dumped files.
# | Stack dump:
# | 0.	Program arguments: /home/buildbot/workspace/clang-aarch64-sve-vls-2stage/stage2/bin/clang -cc1 -internal-isystem /home/buildbot/workspace/clang-aarch64-sve-vls-2stage/stage2/lib/clang/24/include -nostdsysteminc -triple riscv64 -target-feature +v -disable-O0-optnone -emit-llvm /home/buildbot/workspace/clang-aarch64-sve-vls-2stage/llvm/clang/test/CodeGen/RISCV/rvv-intrinsics-autogenerated/policy/overloaded/vredmaxu.c -o -
# | 1.	/home/buildbot/workspace/clang-aarch64-sve-vls-2stage/llvm/clang/test/CodeGen/RISCV/rvv-intrinsics-autogenerated/policy/overloaded/vredmaxu.c:116:59: current parser token ')'
# | 2.	/home/buildbot/workspace/clang-aarch64-sve-vls-2stage/llvm/clang/test/CodeGen/RISCV/rvv-intrinsics-autogenerated/policy/overloaded/vredmaxu.c:115:119: parsing function body 'test_vredmaxu_vs_u16m2_u16m1_tu'
# | 3.	/home/buildbot/workspace/clang-aarch64-sve-vls-2stage/llvm/clang/test/CodeGen/RISCV/rvv-intrinsics-autogenerated/policy/overloaded/vredmaxu.c:115:119: in compound statement ('{}')
# |  #0 0x0000b18c78c35fb0 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/home/buildbot/workspace/clang-aarch64-sve-vls-2stage/stage2/bin/clang+0x9425fb0)
# |  #1 0x0000b18c78c33468 llvm::sys::RunSignalHandlers() (/home/buildbot/workspace/clang-aarch64-sve-vls-2stage/stage2/bin/clang+0x9423468)
# |  #2 0x0000b18c78c36a54 SignalHandler(int, siginfo_t*, void*) Signals.cpp:0:0
# |  #3 0x0000b18c78c368a4 SignalHandlerTerminate(int, siginfo_t*, void*) Signals.cpp:0:0
# |  #4 0x0000f95db3142a60 (linux-vdso.so.1+0xa60)
# |  #5 0x0000f95db2c074d8 __pthread_kill_implementation ./nptl/pthread_kill.c:44:76
# |  #6 0x0000f95db2bbcb3c raise ./signal/../sysdeps/posix/raise.c:27:6
# |  #7 0x0000f95db2ba7e00 abort ./stdlib/abort.c:81:7
# |  #8 0x0000f95db2bb5cc0 __assert_fail_base ./assert/assert.c:93:7
# |  #9 0x0000f95db2bb5d30 __assert_perror_fail ./assert/assert-perr.c:31:1
# | #10 0x0000b18c7b66d668 AddOverloadedCallCandidate(clang::Sema&, clang::DeclAccessPair, clang::TemplateArgumentListInfo*, llvm::ArrayRef<clang::Expr*>, clang::OverloadCandidateSet&, bool, bool) SemaOverload.cpp:0:0
# | #11 0x0000b18c7b66d464 clang::Sema::AddOverloadedCallCandidates(clang::UnresolvedLookupExpr*, llvm::ArrayRef<clang::Expr*>, clang::OverloadCandidateSet&, bool) (/home/buildbot/workspace/clang-aarch64-sve-vls-2stage/stage2/bin/clang+0xbe5d464)
# | #12 0x0000b18c7b66d978 clang::Sema::buildOverloadedCallSet(clang::Scope*, clang::Expr*, clang::UnresolvedLookupExpr*, llvm::MutableArrayRef<clang::Expr*>, clang::SourceLocation, clang::OverloadCandidateSet*, clang::ActionResult<clang::Expr*, true>*) (/home/buildbot/workspace/clang-aarch64-sve-vls-2stage/stage2/bin/clang+0xbe5d978)
# | #13 0x0000b18c7b66dd5c clang::Sema::BuildOverloadedCallExpr(clang::Scope*, clang::Expr*, clang::UnresolvedLookupExpr*, clang::SourceLocation, llvm::MutableArrayRef<clang::Expr*>, clang::SourceLocation, clang::Expr*, bool, bool) (/home/buildbot/workspace/clang-aarch64-sve-vls-2stage/stage2/bin/clang+0xbe5dd5c)
# | #14 0x0000b18c7b331578 clang::Sema::BuildCallExpr(clang::Scope*, clang::Expr*, clang::SourceLocation, llvm::MutableArrayRef<clang::Expr*>, clang::SourceLocation, clang::Expr*, bool, bool) (/home/buildbot/workspace/clang-aarch64-sve-vls-2stage/stage2/bin/clang+0xbb21578)
# | #15 0x0000b18c7b347088 clang::Sema::ActOnCallExpr(clang::Scope*, clang::Expr*, clang::SourceLocation, llvm::MutableArrayRef<clang::Expr*>, clang::SourceLocation, clang::Expr*) (/home/buildbot/workspace/clang-aarch64-sve-vls-2stage/stage2/bin/clang+0xbb37088)
# | #16 0x0000b18c7af0fbf0 clang::Parser::ParsePostfixExpressionSuffix(clang::ActionResult<clang::Expr*, true>) (/home/buildbot/workspace/clang-aarch64-sve-vls-2stage/stage2/bin/clang+0xb6ffbf0)
# | #17 0x0000b18c7af119d4 clang::Parser::ParseCastExpression(clang::CastParseKind, bool, bool&, clang::TypoCorrectionTypeBehavior, bool, bool*) (/home/buildbot/workspace/clang-aarch64-sve-vls-2stage/stage2/bin/clang+0xb7019d4)
# | #18 0x0000b18c7af0db48 clang::Parser::ParseAssignmentExpression(clang::TypoCorrectionTypeBehavior) (/home/buildbot/workspace/clang-aarch64-sve-vls-2stage/stage2/bin/clang+0xb6fdb48)
# | #19 0x0000b18c7af0da44 clang::Parser::ParseExpression(clang::TypoCorrectionTypeBehavior) (/home/buildbot/workspace/clang-aarch64-sve-vls-2stage/stage2/bin/clang+0xb6fda44)
# | #20 0x0000b18c7af9fac4 clang::Parser::ParseReturnStatement() (/home/buildbot/workspace/clang-aarch64-sve-vls-2stage/stage2/bin/clang+0xb78fac4)
# | #21 0x0000b18c7af99d58 clang::Parser::ParseStatementOrDeclarationAfterAttributes(llvm::SmallVector<clang::Stmt*, 24u>&, clang::Parser::ParsedStmtContext, clang::SourceLocation*, clang::ParsedAttributes&, clang::ParsedAttributes&, clang::LabelDecl*) (/home/buildbot/workspace/clang-aarch64-sve-vls-2stage/stage2/bin/clang+0xb789d58)
# | #22 0x0000b18c7af985c4 clang::Parser::ParseStatementOrDeclaration(llvm::SmallVector<clang::Stmt*, 24u>&, clang::Parser::ParsedStmtContext, clang::SourceLocation*, clang::LabelDecl*) (/home/buildbot/workspace/clang-aarch64-sve-vls-2stage/stage2/bin/clang+0xb7885c4)
# | #23 0x0000b18c7afa1e1c clang::Parser::ParseCompoundStatementBody(bool) (/home/buildbot/workspace/clang-aarch64-sve-vls-2stage/stage2/bin/clang+0xb791e1c)
# | #24 0x0000b18c7afa3424 clang::Parser::ParseFunctionStatementBody(clang::Decl*, clang::Parser::ParseScope&) (/home/buildbot/workspace/clang-aarch64-sve-vls-2stage/stage2/bin/clang+0xb793424)
# | #25 0x0000b18c7aef0d04 clang::Parser::ParseFunctionDefinition(clang::ParsingDeclarator&, clang::Parser::ParsedTemplateInfo const&, clang::LateParsedAttrList*) (/home/buildbot/workspace/clang-aarch64-sve-vls-2stage/stage2/bin/clang+0xb6e0d04)
# | #26 0x0000b18c7af59d00 clang::Parser::ParseDeclGroup(clang::ParsingDeclSpec&, clang::DeclaratorContext, clang::ParsedAttributes&, clang::Parser::ParsedTemplateInfo&, clang::SourceLocation*, clang::Parser::ForRangeInit*) (/home/buildbot/workspace/clang-aarch64-sve-vls-2stage/stage2/bin/clang+0xb749d00)
# | #27 0x0000b18c7aeefcec clang::Parser::ParseDeclOrFunctionDefInternal(clang::ParsedAttributes&, clang::ParsedAttributes&, clang::ParsingDeclSpec&, clang::AccessSpecifier) (/home/buildbot/workspace/clang-aarch64-sve-vls-2stage/stage2/bin/clang+0xb6dfcec)
# | #28 0x0000b18c7aeef4c8 clang::Parser::ParseDeclarationOrFunctionDefinition(clang::ParsedAttributes&, clang::ParsedAttributes&, clang::ParsingDeclSpec*, clang::AccessSpecifier) (/home/buildbot/workspace/clang-aarch64-sve-vls-2stage/stage2/bin/clang+0xb6df4c8)
# | #29 0x0000b18c7aeee740 clang::Parser::ParseExternalDeclaration(clang::ParsedAttributes&, clang::ParsedAttributes&, clang::ParsingDeclSpec*) (/home/buildbot/workspace/clang-aarch64-sve-vls-2stage/stage2/bin/clang+0xb6de740)
# | #30 0x0000b18c7aeec974 clang::Parser::ParseTopLevelDecl(clang::OpaquePtr<clang::DeclGroupRef>&, clang::Sema::ModuleImportState&) (/home/buildbot/workspace/clang-aarch64-sve-vls-2stage/stage2/bin/clang+0xb6dc974)
# | #31 0x0000b18c7aedfacc clang::ParseAST(clang::Sema&, bool, bool) (/home/buildbot/workspace/clang-aarch64-sve-vls-2stage/stage2/bin/clang+0xb6cfacc)
# | #32 0x0000b18c79a829f0 clang::FrontendAction::Execute() (/home/buildbot/workspace/clang-aarch64-sve-vls-2stage/stage2/bin/clang+0xa2729f0)
# | #33 0x0000b18c79a03b48 clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) (/home/buildbot/workspace/clang-aarch64-sve-vls-2stage/stage2/bin/clang+0xa1f3b48)
...

```

</details>

https://github.com/llvm/llvm-project/pull/217664