From: Bill Wendling Date: Sat, 26 Jan 2008 09:03:52 +0000 (+0000) Subject: If there's no instructions being emitted on X86 for a function, emit a X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=824a721560f29eedb1427f81182e81cacf7e3ad4;p=oota-llvm.git If there's no instructions being emitted on X86 for a function, emit a nop. Emit the nop directly for PPC. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@46398 91177308-0d34-0410-b5e6-96231b3b80d8 --- diff --git a/lib/Target/PowerPC/PPCAsmPrinter.cpp b/lib/Target/PowerPC/PPCAsmPrinter.cpp index 6a1451d5dcf..6f0e41aec5f 100644 --- a/lib/Target/PowerPC/PPCAsmPrinter.cpp +++ b/lib/Target/PowerPC/PPCAsmPrinter.cpp @@ -819,12 +819,8 @@ bool DarwinAsmPrinter::runOnMachineFunction(MachineFunction &MF) { // be associated with. We emit a noop in this situation. MachineFunction::iterator I = MF.begin(); - if (++I == MF.end()) { - MachineBasicBlock &MBB = MF.front(); - - if (MBB.begin() == MBB.end()) - BuildMI(MBB, MBB.end(), TM.getInstrInfo()->get(PPC::NOP)); - } + if (++I == MF.end() && MF.front().empty()) + O << "\tnop\n"; // Print out code for the function. for (MachineFunction::const_iterator I = MF.begin(), E = MF.end(); diff --git a/lib/Target/X86/X86ATTAsmPrinter.cpp b/lib/Target/X86/X86ATTAsmPrinter.cpp index 8198fbe860e..20f2f003722 100644 --- a/lib/Target/X86/X86ATTAsmPrinter.cpp +++ b/lib/Target/X86/X86ATTAsmPrinter.cpp @@ -165,6 +165,16 @@ bool X86ATTAsmPrinter::runOnMachineFunction(MachineFunction &MF) { DW.BeginFunction(&MF); } + if (Subtarget->isTargetDarwin()) { + // If the function is empty, then we need to emit *something*. Otherwise, + // the function's label might be associated with something that it wasn't + // meant to be associated with. We emit a noop in this situation. + MachineFunction::iterator I = MF.begin(); + + if (++I == MF.end() && MF.front().empty()) + O << "\tnop\n"; + } + // Print out code for the function. for (MachineFunction::const_iterator I = MF.begin(), E = MF.end(); I != E; ++I) { @@ -173,8 +183,8 @@ bool X86ATTAsmPrinter::runOnMachineFunction(MachineFunction &MF) { printBasicBlockLabel(I, true); O << '\n'; } - for (MachineBasicBlock::const_iterator II = I->begin(), E = I->end(); - II != E; ++II) { + for (MachineBasicBlock::const_iterator II = I->begin(), IE = I->end(); + II != IE; ++II) { // Print the assembly for the instruction. O << "\t"; printMachineInstruction(II); diff --git a/test/CodeGen/X86/2008-01-25-EmptyFunction.ll b/test/CodeGen/X86/2008-01-25-EmptyFunction.ll new file mode 100644 index 00000000000..7d738bcc7ee --- /dev/null +++ b/test/CodeGen/X86/2008-01-25-EmptyFunction.ll @@ -0,0 +1,6 @@ +; RUN: llvm-as < %s | llc -march=x86 | grep nop + +define void @bork() noreturn nounwind { +entry: + unreachable +}