Enable global address legalization, fixing a todo and allowing the removal

of some code.  This exposes the implicit load from the stubs to the DAG, allowing
them to be optimized by the dag combiner.  It also moves darwin specific stuff
out of the isel into the legalizer, and allows more to be moved to the .td file.

llvm-svn: 24397

3 files changed, 2 insertions, 49 deletions

diff --git a/llvm/lib/Target/PowerPC/PPCISelDAGToDAG.cpp b/llvm/lib/Target/PowerPC/PPCISelDAGToDAG.cpp
index 5baec745c94..549f4539dec 100644
--- a/llvm/lib/Target/PowerPC/PPCISelDAGToDAG.cpp
+++ b/llvm/lib/Target/PowerPC/PPCISelDAGToDAG.cpp
@@ -428,20 +428,7 @@ bool PPCDAGToDAGISel::SelectAddr(SDOperand Addr, SDOperand &Op1,
     }
   }
 
-  // Now check if we're dealing with a global, and whether or not we should emit
-  // an optimized load or store for statics.
-  if (GlobalAddressSDNode *GN = dyn_cast<GlobalAddressSDNode>(Addr)) {
-    GlobalValue *GV = GN->getGlobal();
-    if (!GV->hasWeakLinkage() && !GV->isExternal()) {
-      Op1 = CurDAG->getTargetGlobalAddress(GV, MVT::i32);
-      if (PICEnabled)
-        Op2 = CurDAG->getTargetNode(PPC::ADDIS, MVT::i32, getGlobalBaseReg(),
-                                    Op1);
-      else
-        Op2 = CurDAG->getTargetNode(PPC::LIS, MVT::i32, Op1);
-      return false;
-    }
-  } else if (FrameIndexSDNode *FI = dyn_cast<FrameIndexSDNode>(Addr)) {
+ if (FrameIndexSDNode *FI = dyn_cast<FrameIndexSDNode>(Addr)) {
     Op1 = getI32Imm(0);
     Op2 = CurDAG->getTargetFrameIndex(FI->getIndex(), MVT::i32);
     return false;
@@ -907,22 +894,6 @@ SDOperand PPCDAGToDAGISel::Select(SDOperand Op) {
     }
     return CurDAG->getTargetNode(PPC::LA, MVT::i32, Tmp, CPI);
   }
-#if 1
-  case ISD::GlobalAddress: {
-    GlobalValue *GV = cast<GlobalAddressSDNode>(N)->getGlobal();
-    SDOperand Tmp;
-    SDOperand GA = CurDAG->getTargetGlobalAddress(GV, MVT::i32);
-    if (PICEnabled)
-      Tmp = CurDAG->getTargetNode(PPC::ADDIS, MVT::i32, getGlobalBaseReg(), GA);
-    else
-      Tmp = CurDAG->getTargetNode(PPC::LIS, MVT::i32, GA);
-
-    if (GV->hasWeakLinkage() || GV->isExternal())
-      return CurDAG->getTargetNode(PPC::LWZ, MVT::i32, GA, Tmp);
-    else
-      return CurDAG->getTargetNode(PPC::LA, MVT::i32, Tmp, GA);
-  }
-#endif
   case ISD::FADD: {
     MVT::ValueType Ty = N->getValueType(0);
     if (!NoExcessFPPrecision) {  // Match FMA ops
diff --git a/llvm/lib/Target/PowerPC/PPCISelLowering.cpp b/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
index 3b7a706f52c..216372987f3 100644
--- a/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
+++ b/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
@@ -93,7 +93,7 @@ PPCTargetLowering::PPCTargetLowering(TargetMachine &TM)
   
   // We want to legalize GlobalAddress into the appropriate instructions to
   // materialize the address.
-  //setOperationAction(ISD::GlobalAddress, MVT::i32, Custom);
+  setOperationAction(ISD::GlobalAddress, MVT::i32, Custom);
   
   if (TM.getSubtarget<PPCSubtarget>().is64Bit()) {
     // They also have instructions for converting between i64 and fp.
diff --git a/llvm/lib/Target/PowerPC/README.txt b/llvm/lib/Target/PowerPC/README.txt
index 88582966994..580affb688d 100644
--- a/llvm/lib/Target/PowerPC/README.txt
+++ b/llvm/lib/Target/PowerPC/README.txt
@@ -31,24 +31,6 @@ as one load when using --enable-pic.
 * Support 'update' load/store instructions.  These are cracked on the G5, but
   are still a codesize win.
 
-* Add a custom legalizer for the GlobalAddress node, to move the funky darwin
-  stub stuff from the instruction selector to the legalizer (exposing low-level
-  operations to the dag for optzn.  For example, we want to codegen this:
-
-        int A = 0;
-        void B() { A++; }
-  as:
-        lis r9,ha16(_A)
-        lwz r2,lo16(_A)(r9)
-        addi r2,r2,1
-        stw r2,lo16(_A)(r9)
-  not:
-        lis r2, ha16(_A)
-        lwz r2, lo16(_A)(r2)
-        addi r2, r2, 1
-        lis r3, ha16(_A)
-        stw r2, lo16(_A)(r3)
-
 * should hint to the branch select pass that it doesn't need to print the
   second unconditional branch, so we don't end up with things like:
 	b .LBBl42__2E_expand_function_8_674	; loopentry.24