Create constant expression casts instead of constant instructions if possible

[oota-llvm.git] / lib / CodeGen / PrologEpilogInserter.cpp

diff --git a/lib/CodeGen/PrologEpilogInserter.cpp b/lib/CodeGen/PrologEpilogInserter.cpp
index 21107a299c85f5b919855c553c5f6f41ebf3d916..2f7f1f4ef30a8e49a595edf2f7d77333828912e0 100644 (file)
--- a/lib/CodeGen/PrologEpilogInserter.cpp
+++ b/lib/CodeGen/PrologEpilogInserter.cpp
@@ -41,13 +41,13 @@ namespace {
       // Calculate actual frame offsets for all of the abstract stack objects...
       calculateFrameObjectOffsets(Fn);
 
+      // Add prolog and epilog code to the function.
+      insertPrologEpilogCode(Fn);
+
       // Replace all MO_FrameIndex operands with physical register references
       // and actual offsets.
       //
       replaceFrameIndices(Fn);
-
-      // Add prolog and epilog code to the function.
-      insertPrologEpilogCode(Fn);
       return true;
     }
 
@@ -186,23 +186,44 @@ void PEI::calculateFrameObjectOffsets(MachineFunction &Fn) {
   // Loop over all of the stack objects, assigning sequential addresses...
   MachineFrameInfo *FFI = Fn.getFrameInfo();
 
+  unsigned StackAlignment = TFI.getStackAlignment();
+
   // Start at the beginning of the local area...
-  int Offset = -TFI.getOffsetOfLocalArea();
+  int Offset = TFI.getOffsetOfLocalArea();
   for (unsigned i = 0, e = FFI->getObjectIndexEnd(); i != e; ++i) {
     Offset += FFI->getObjectSize(i);         // Allocate Size bytes...
 
     unsigned Align = FFI->getObjectAlignment(i);
+    assert(Align <= StackAlignment && "Cannot align stack object to higher "
+           "alignment boundary than the stack itself!");
     Offset = (Offset+Align-1)/Align*Align;   // Adjust to Alignment boundary...
     
     FFI->setObjectOffset(i, -Offset);        // Set the computed offset
   }
 
   // Align the final stack pointer offset...
-  unsigned StackAlign = TFI.getStackAlignment();
-  Offset = (Offset+StackAlign-1)/StackAlign*StackAlign;
+  Offset = (Offset+StackAlignment-1)/StackAlignment*StackAlignment;
 
   // Set the final value of the stack pointer...
-  FFI->setStackSize(Offset);
+  FFI->setStackSize(Offset-TFI.getOffsetOfLocalArea());
+}
+
+
+/// insertPrologEpilogCode - Scan the function for modified caller saved
+/// registers, insert spill code for these caller saved registers, then add
+/// prolog and epilog code to the function.
+///
+void PEI::insertPrologEpilogCode(MachineFunction &Fn) {
+  // Add prologue to the function...
+  Fn.getTarget().getRegisterInfo()->emitPrologue(Fn);
+
+  // Add epilogue to restore the callee-save registers in each exiting block
+  const TargetInstrInfo &TII = Fn.getTarget().getInstrInfo();
+  for (MachineFunction::iterator I = Fn.begin(), E = Fn.end(); I != E; ++I) {
+    // If last instruction is a return instruction, add an epilogue
+    if (!I->empty() && TII.isReturn(I->back()->getOpcode()))
+      Fn.getTarget().getRegisterInfo()->emitEpilogue(Fn, *I);
+  }
 }
 
 
@@ -226,21 +247,3 @@ void PEI::replaceFrameIndices(MachineFunction &Fn) {
          break;
        }
 }
-
-
-/// insertPrologEpilogCode - Scan the function for modified caller saved
-/// registers, insert spill code for these caller saved registers, then add
-/// prolog and epilog code to the function.
-///
-void PEI::insertPrologEpilogCode(MachineFunction &Fn) {
-  // Add prologue to the function...
-  Fn.getTarget().getRegisterInfo()->emitPrologue(Fn);
-
-  // Add epilogue to restore the callee-save registers in each exiting block
-  const TargetInstrInfo &TII = Fn.getTarget().getInstrInfo();
-  for (MachineFunction::iterator I = Fn.begin(), E = Fn.end(); I != E; ++I) {
-    // If last instruction is a return instruction, add an epilogue
-    if (TII.isReturn(I->back()->getOpcode()))
-      Fn.getTarget().getRegisterInfo()->emitEpilogue(Fn, *I);
-  }
-}