Author: Craig Blackmore Date: 2020-12-18T16:57:05Z New Revision: 698ae90f306248aafbfb5c85cdd9bb81c387bb59
URL: https://github.com/llvm/llvm-project/commit/698ae90f306248aafbfb5c85cdd9bb81c387bb59 DIFF: https://github.com/llvm/llvm-project/commit/698ae90f306248aafbfb5c85cdd9bb81c387bb59.diff LOG: [RegisterScavenging] Fix assert in scavengeRegisterBackwards According to the documentation, if a spill is required to make a register available and AllowSpill is false, then NoRegister should be returned, however, this scenario was actually triggering an assertion failure. This patch moves the assertion after the handling of AllowSpill. Authored by: Lewis Revill Reviewed By: arsenm Differential Revision: https://reviews.llvm.org/D92104 Added: Modified: llvm/lib/CodeGen/RegisterScavenging.cpp Removed: ################################################################################ diff --git a/llvm/lib/CodeGen/RegisterScavenging.cpp b/llvm/lib/CodeGen/RegisterScavenging.cpp index ab9a1d66b835..ab8f4fd9778b 100644 --- a/llvm/lib/CodeGen/RegisterScavenging.cpp +++ b/llvm/lib/CodeGen/RegisterScavenging.cpp @@ -573,9 +573,8 @@ Register RegScavenger::scavengeRegisterBackwards(const TargetRegisterClass &RC, RestoreAfter); MCPhysReg Reg = P.first; MachineBasicBlock::iterator SpillBefore = P.second; - assert(Reg != 0 && "No register left to scavenge!"); // Found an available register? - if (SpillBefore == MBB.end()) { + if (Reg != 0 && SpillBefore == MBB.end()) { LLVM_DEBUG(dbgs() << "Scavenged free register: " << printReg(Reg, TRI) << '\n'); return Reg; @@ -584,6 +583,8 @@ Register RegScavenger::scavengeRegisterBackwards(const TargetRegisterClass &RC, if (!AllowSpill) return 0; + assert(Reg != 0 && "No register left to scavenge!"); + MachineBasicBlock::iterator ReloadAfter = RestoreAfter ? std::next(MBBI) : MBBI; MachineBasicBlock::iterator ReloadBefore = std::next(ReloadAfter); _______________________________________________ llvm-branch-commits mailing list llvm-branch-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
