Make naked functions work on PPC.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@102657 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 11 insertions, 1 deletions

diff --git a/lib/CodeGen/PrologEpilogInserter.cpp b/lib/CodeGen/PrologEpilogInserter.cpp
index 365a84ab52..16bf6ea765 100644
--- a/lib/CodeGen/PrologEpilogInserter.cpp
+++ b/lib/CodeGen/PrologEpilogInserter.cpp
@@ -197,6 +197,10 @@ void PEI::calculateCalleeSavedRegisters(MachineFunction &Fn) {
   if (CSRegs == 0 || CSRegs[0] == 0)
     return;
 
+  // In Naked functions we aren't going to save any registers.
+  if (Fn.getFunction()->hasFnAttr(Attribute::Naked))
+    return;
+
   // Figure out which *callee saved* registers are modified by the current
   // function, thus needing to be saved and restored in the prolog/epilog.
   const TargetRegisterClass * const *CSRegClasses =
diff --git a/lib/Target/PowerPC/PPCRegisterInfo.cpp b/lib/Target/PowerPC/PPCRegisterInfo.cpp
index 8048df21b7..5f1e04eecb 100644
--- a/lib/Target/PowerPC/PPCRegisterInfo.cpp
+++ b/lib/Target/PowerPC/PPCRegisterInfo.cpp
@@ -409,6 +409,9 @@ PPCRegisterInfo::getCalleeSavedRegClasses(const MachineFunction *MF) const {
 //
 static bool needsFP(const MachineFunction &MF) {
   const MachineFrameInfo *MFI = MF.getFrameInfo();
+  // Naked functions have no stack frame pushed, so we don't have a frame pointer.
+  if (MF.getFunction()->hasFnAttr(Attribute::Naked))
+    return false;
   return DisableFramePointerElim(MF) || MFI->hasVarSizedObjects() ||
     (GuaranteedTailCallOpt && MF.getInfo<PPCFunctionInfo>()->hasFastCall());
 }
@@ -794,7 +797,10 @@ PPCRegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II,
   // If we're not using a Frame Pointer that has been set to the value of the
   // SP before having the stack size subtracted from it, then add the stack size
   // to Offset to get the correct offset.
-  Offset += MFI->getStackSize();
+  // Naked functions have stack size 0, although getStackSize may not reflect that
+  // because we didn't call all the pieces that compute it for naked functions.
+  if (!MF.getFunction()->hasFnAttr(Attribute::Naked))
+    Offset += MFI->getStackSize();
 
   // If we can, encode the offset directly into the instruction.  If this is a
   // normal PPC "ri" instruction, any 16-bit value can be safely encoded.  If