[llvm-commits] [llvm] r46398 - in /llvm/trunk: lib/Target/PowerPC/PPCAsmPrinter.cpp lib/Target/X86/X86ATTAsmPrinter.cpp test/CodeGen/X86/2008-01-25-EmptyFunction.ll

[Bill Wendling]

Author: void
Date: Sat Jan 26 03:03:52 2008
New Revision: 46398

URL: http://llvm.org/viewvc/llvm-project?rev=46398&view=rev
Log:
If there's no instructions being emitted on X86 for a function, emit a
nop. Emit the nop directly for PPC.

Added:
    llvm/trunk/test/CodeGen/X86/2008-01-25-EmptyFunction.ll
Modified:
    llvm/trunk/lib/Target/PowerPC/PPCAsmPrinter.cpp
    llvm/trunk/lib/Target/X86/X86ATTAsmPrinter.cpp

Modified: llvm/trunk/lib/Target/PowerPC/PPCAsmPrinter.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/PowerPC/PPCAsmPrinter.cpp?rev=46398&r1=46397&r2=46398&view=diff

==============================================================================
--- llvm/trunk/lib/Target/PowerPC/PPCAsmPrinter.cpp (original)
+++ llvm/trunk/lib/Target/PowerPC/PPCAsmPrinter.cpp Sat Jan 26 03:03:52 2008
@@ -819,12 +819,8 @@
   // 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();

Modified: llvm/trunk/lib/Target/X86/X86ATTAsmPrinter.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86ATTAsmPrinter.cpp?rev=46398&r1=46397&r2=46398&view=diff

==============================================================================
--- llvm/trunk/lib/Target/X86/X86ATTAsmPrinter.cpp (original)
+++ llvm/trunk/lib/Target/X86/X86ATTAsmPrinter.cpp Sat Jan 26 03:03:52 2008
@@ -165,6 +165,16 @@
     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 @@
       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);

Added: llvm/trunk/test/CodeGen/X86/2008-01-25-EmptyFunction.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/2008-01-25-EmptyFunction.ll?rev=46398&view=auto

==============================================================================
--- llvm/trunk/test/CodeGen/X86/2008-01-25-EmptyFunction.ll (added)
+++ llvm/trunk/test/CodeGen/X86/2008-01-25-EmptyFunction.ll Sat Jan 26 03:03:52 2008
@@ -0,0 +1,6 @@
+; RUN: llvm-as < %s | llc -march=x86 | grep nop
+
+define void @bork() noreturn nounwind  {
+entry:
+        unreachable
+}