diff --git a/llvm/lib/Target/RISCV/RISCVPushPopOptimizer.cpp b/llvm/lib/Target/RISCV/RISCVPushPopOptimizer.cpp index a93e750eadc6f..f885adca669fe 100644 --- a/llvm/lib/Target/RISCV/RISCVPushPopOptimizer.cpp +++ b/llvm/lib/Target/RISCV/RISCVPushPopOptimizer.cpp @@ -132,7 +132,8 @@ bool RISCVPushPopOpt::runOnMachineFunction(MachineFunction &Fn) { for (auto &MBB : Fn) { MachineBasicBlock::iterator MBBI = containsPop(MBB); MachineBasicBlock::iterator NextI = next_nodbg(MBBI, MBB.end()); - if (MBBI != MBB.end() && NextI->getOpcode() == RISCV::PseudoRET) + if (MBBI != MBB.end() && NextI != MBB.end() && + NextI->getOpcode() == RISCV::PseudoRET) Modified |= usePopRet(MBBI, NextI, adjustRetVal(MBBI)); } return Modified; diff --git a/llvm/test/CodeGen/RISCV/push-pop-opt-crash.ll b/llvm/test/CodeGen/RISCV/push-pop-opt-crash.ll new file mode 100644 index 0000000000000..ca6895dc51fa8 --- /dev/null +++ b/llvm/test/CodeGen/RISCV/push-pop-opt-crash.ll @@ -0,0 +1,52 @@ +; RUN: llc -mattr=+zcmp -verify-machineinstrs \ +; RUN: -mtriple=riscv32 -target-abi ilp32 < %s \ +; RUN: | FileCheck %s -check-prefixes=RV32IZCMP +; RUN: llc -mattr=+zcmp -verify-machineinstrs \ +; RUN: -mtriple=riscv64 -target-abi ilp64 < %s \ +; RUN: | FileCheck %s -check-prefixes=RV64IZCMP + +; This source code exposed a crash in the RISC-V Zcmp Push/Pop optimization +; pass. The root cause was: Not doing a bounds check before using a returned +; iterator. + +declare dso_local void @f1() local_unnamed_addr +declare dso_local void @f2() local_unnamed_addr +define dso_local void @f0() local_unnamed_addr { +; RV32IZCMP-LABEL: f0: +; RV32IZCMP: .cfi_startproc +; RV32IZCMP-NEXT: # %bb.0: # %entry +; RV32IZCMP-NEXT: bnez zero, .LBB0_2 +; RV32IZCMP-NEXT: # %bb.1: # %if.T +; RV32IZCMP-NEXT: cm.push {ra}, -16 +; RV32IZCMP-NEXT: .cfi_def_cfa_offset 16 +; RV32IZCMP-NEXT: .cfi_offset ra, -4 +; RV32IZCMP-NEXT: call f1 +; RV32IZCMP-NEXT: cm.pop {ra}, 16 +; RV32IZCMP-NEXT: .LBB0_2: # %if.F +; RV32IZCMP-NEXT: tail f2 +; RV32IZCMP-NEXT: .Lfunc_end0: + +; RV64IZCMP-LABEL: f0: +; RV64IZCMP: .cfi_startproc +; RV64IZCMP-NEXT: # %bb.0: # %entry +; RV64IZCMP-NEXT: bnez zero, .LBB0_2 +; RV64IZCMP-NEXT: # %bb.1: # %if.T +; RV64IZCMP-NEXT: cm.push {ra}, -16 +; RV64IZCMP-NEXT: .cfi_def_cfa_offset 16 +; RV64IZCMP-NEXT: .cfi_offset ra, -8 +; RV64IZCMP-NEXT: call f1 +; RV64IZCMP-NEXT: cm.pop {ra}, 16 +; RV64IZCMP-NEXT: .LBB0_2: # %if.F +; RV64IZCMP-NEXT: tail f2 +; RV64IZCMP-NEXT: .Lfunc_end0: +entry: + br i1 poison, label %if.T, label %if.F + +if.T: + tail call void @f1() + br label %if.F + +if.F: + tail call void @f2() + ret void +}