[llvm-commits] CVS: llvm/lib/Target/PowerPC/PPC32ISelSimple.cpp

[Chris Lattner]

Changes in directory llvm/lib/Target/PowerPC:

PPC32ISelSimple.cpp updated: 1.136 -> 1.137
---
Log message:

Fix CodeGen/Generic/2005-05-09-GlobalInPHI.ll, which was reduced from 254.gap.
This caused the "use before a def" assertion on some programs.

With this patch, 254.gap now passes with the PPC backend.


---
Diffs of the changes:  (+16 -0)

 PPC32ISelSimple.cpp |   16 ++++++++++++++++
 1 files changed, 16 insertions(+)


Index: llvm/lib/Target/PowerPC/PPC32ISelSimple.cpp
diff -u llvm/lib/Target/PowerPC/PPC32ISelSimple.cpp:1.136 llvm/lib/Target/PowerPC/PPC32ISelSimple.cpp:1.137
--- llvm/lib/Target/PowerPC/PPC32ISelSimple.cpp:1.136	Sat Apr  9 14:47:21 2005
+++ llvm/lib/Target/PowerPC/PPC32ISelSimple.cpp	Sat Apr  9 17:05:17 2005
@@ -871,6 +871,16 @@
 void PPC32ISel::SelectPHINodes() {
   const TargetInstrInfo &TII = *TM.getInstrInfo();
   const Function &LF = *F->getFunction();  // The LLVM function...
+
+  MachineBasicBlock::iterator MFLRIt = F->begin()->begin();
+  if (GlobalBaseInitialized) {
+    // If we emitted a MFLR for the global base reg, get an iterator to an
+    // instruction after it.
+    while (MFLRIt->getOpcode() != PPC::MFLR)
+      ++MFLRIt;
+    ++MFLRIt;  // step one MI past it.
+  }
+
   for (Function::const_iterator I = LF.begin(), E = LF.end(); I != E; ++I) {
     const BasicBlock *BB = I;
     MachineBasicBlock &MBB = *MBBMap[I];
@@ -938,6 +948,12 @@
             while (PI != PredMBB->end() && PI->getOpcode() == PPC::PHI)
               ++PI;
 
+            // If this is the entry block, and if the entry block contains a
+            // MFLR instruction, emit this operation after it.  This is needed
+            // because global addresses use it.
+            if (PredMBB == F->begin())
+              PI = MFLRIt;
+
             ValReg = getReg(Val, PredMBB, PI);
           }