Author: void
Date: Sat Jan 26 00:51:24 2008
New Revision: 46394
URL: http://llvm.org/viewvc/llvm-project?rev=46394&view=rev
Log:
If there are no machine instructions emitted for a function, then insert
a "nop" instruction so that we don't have the function's label associated
with something that it's not supposed to be associated with.
Modified:
llvm/trunk/lib/Target/PowerPC/PPCAsmPrinter.cpp
llvm/trunk/lib/Transforms/Scalar/SimplifyCFG.cpp
Modified: llvm/trunk/lib/Target/PowerPC/PPCAsmPrinter.cpp
URL:
http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/PowerPC/PPCAsmPrinter.cpp?rev=46394&r1=46393&r2=46394&view=diff
==============================================================================
--- llvm/trunk/lib/Target/PowerPC/PPCAsmPrinter.cpp (original)
+++ llvm/trunk/lib/Target/PowerPC/PPCAsmPrinter.cpp Sat Jan 26 00:51:24 2008
@@ -30,6 +30,7 @@
#include "llvm/CodeGen/MachineModuleInfo.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/CodeGen/MachineInstr.h"
+#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/Support/Mangler.h"
#include "llvm/Support/MathExtras.h"
#include "llvm/Support/CommandLine.h"
@@ -813,6 +814,18 @@
// Emit pre-function debug information.
DW.BeginFunction(&MF);
+ // 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()) {
+ MachineBasicBlock &MBB = MF.front();
+
+ if (MBB.begin() == MBB.end())
+ BuildMI(MBB, MBB.end(), TM.getInstrInfo()->get(PPC::NOP));
+ }
+
// Print out code for the function.
for (MachineFunction::const_iterator I = MF.begin(), E = MF.end();
I != E; ++I) {
@@ -821,8 +834,8 @@
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);
Modified: llvm/trunk/lib/Transforms/Scalar/SimplifyCFG.cpp
URL:
http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/SimplifyCFG.cpp?rev=46394&r1=46393&r2=46394&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/SimplifyCFG.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/SimplifyCFG.cpp Sat Jan 26 00:51:24 2008
@@ -26,7 +26,6 @@
#include "llvm/Transforms/Utils/Local.h"
#include "llvm/Constants.h"
#include "llvm/Instructions.h"
-#include "llvm/Intrinsics.h"
#include "llvm/Module.h"
#include "llvm/ParameterAttributes.h"
#include "llvm/Support/CFG.h"
@@ -155,20 +154,8 @@
bool Changed = MarkAliveBlocks(F.begin(), Reachable);
// If there are unreachable blocks in the CFG...
- if (Reachable.size() == F.size()) {
- if (F.size() == 1) {
- // If the function has only one block with an "unreachable" instruction,
- // then we should create *some* code for it. Issue a "trap" instead.
- BasicBlock &BB = F.front();
-
- if (BB.size() == 1 && dyn_cast<UnreachableInst>(&BB.front()))
- new CallInst(Intrinsic::getDeclaration(F.getParent(),
- Intrinsic::trap),
- "", &BB.front());
- }
-
+ if (Reachable.size() == F.size())
return Changed;
- }
assert(Reachable.size() < F.size());
NumSimpl += F.size()-Reachable.size();
_______________________________________________
llvm-commits mailing list
llvm-commits@cs.uiuc.edu
http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits
