Followup to r191252.

Make sure that the code that handles the constant addresses is run for the
GEPs. This just refactors that code and then calls it for the GEPs that are
collected during the iteration.

<rdar://problem/12445434>


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191281 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 127 insertions, 113 deletions

diff --git a/lib/Target/X86/X86FastISel.cpp b/lib/Target/X86/X86FastISel.cpp
index 5afc002b0f..f048038f0b 100644
--- a/lib/Target/X86/X86FastISel.cpp
+++ b/lib/Target/X86/X86FastISel.cpp
@@ -125,6 +125,8 @@ private:
     return static_cast<const X86TargetMachine *>(&TM);
   }
 
+  bool handleConstantAddresses(const Value *V, X86AddressMode &AM);
+
   unsigned TargetMaterializeConstant(const Constant *C);
 
   unsigned TargetMaterializeAlloca(const AllocaInst *C);
@@ -344,9 +346,125 @@ bool X86FastISel::X86FastEmitExtend(ISD::NodeType Opc, EVT DstVT,
   return true;
 }
 
+bool X86FastISel::handleConstantAddresses(const Value *V, X86AddressMode &AM) {
+  // Handle constant address.
+  if (const GlobalValue *GV = dyn_cast<GlobalValue>(V)) {
+    // Can't handle alternate code models yet.
+    if (TM.getCodeModel() != CodeModel::Small)
+      return false;
+
+    // Can't handle TLS yet.
+    if (const GlobalVariable *GVar = dyn_cast<GlobalVariable>(GV))
+      if (GVar->isThreadLocal())
+        return false;
+
+    // Can't handle TLS yet, part 2 (this is slightly crazy, but this is how
+    // it works...).
+    if (const GlobalAlias *GA = dyn_cast<GlobalAlias>(GV))
+      if (const GlobalVariable *GVar =
+            dyn_cast_or_null<GlobalVariable>(GA->resolveAliasedGlobal(false)))
+        if (GVar->isThreadLocal())
+          return false;
+
+    // RIP-relative addresses can't have additional register operands, so if
+    // we've already folded stuff into the addressing mode, just force the
+    // global value into its own register, which we can use as the basereg.
+    if (!Subtarget->isPICStyleRIPRel() ||
+        (AM.Base.Reg == 0 && AM.IndexReg == 0)) {
+      // Okay, we've committed to selecting this global. Set up the address.
+      AM.GV = GV;
+
+      // Allow the subtarget to classify the global.
+      unsigned char GVFlags = Subtarget->ClassifyGlobalReference(GV, TM);
+
+      // If this reference is relative to the pic base, set it now.
+      if (isGlobalRelativeToPICBase(GVFlags)) {
+        // FIXME: How do we know Base.Reg is free??
+        AM.Base.Reg = getInstrInfo()->getGlobalBaseReg(FuncInfo.MF);
+      }
+
+      // Unless the ABI requires an extra load, return a direct reference to
+      // the global.
+      if (!isGlobalStubReference(GVFlags)) {
+        if (Subtarget->isPICStyleRIPRel()) {
+          // Use rip-relative addressing if we can.  Above we verified that the
+          // base and index registers are unused.
+          assert(AM.Base.Reg == 0 && AM.IndexReg == 0);
+          AM.Base.Reg = X86::RIP;
+        }
+        AM.GVOpFlags = GVFlags;
+        return true;
+      }
+
+      // Ok, we need to do a load from a stub.  If we've already loaded from
+      // this stub, reuse the loaded pointer, otherwise emit the load now.
+      DenseMap<const Value*, unsigned>::iterator I = LocalValueMap.find(V);
+      unsigned LoadReg;
+      if (I != LocalValueMap.end() && I->second != 0) {
+        LoadReg = I->second;
+      } else {
+        // Issue load from stub.
+        unsigned Opc = 0;
+        const TargetRegisterClass *RC = NULL;
+        X86AddressMode StubAM;
+        StubAM.Base.Reg = AM.Base.Reg;
+        StubAM.GV = GV;
+        StubAM.GVOpFlags = GVFlags;
+
+        // Prepare for inserting code in the local-value area.
+        SavePoint SaveInsertPt = enterLocalValueArea();
+
+        if (TLI.getPointerTy() == MVT::i64) {
+          Opc = X86::MOV64rm;
+          RC  = &X86::GR64RegClass;
+
+          if (Subtarget->isPICStyleRIPRel())
+            StubAM.Base.Reg = X86::RIP;
+        } else {
+          Opc = X86::MOV32rm;
+          RC  = &X86::GR32RegClass;
+        }
+
+        LoadReg = createResultReg(RC);
+        MachineInstrBuilder LoadMI =
+          BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, TII.get(Opc), LoadReg);
+        addFullAddress(LoadMI, StubAM);
+
+        // Ok, back to normal mode.
+        leaveLocalValueArea(SaveInsertPt);
+
+        // Prevent loading GV stub multiple times in same MBB.
+        LocalValueMap[V] = LoadReg;
+      }
+
+      // Now construct the final address. Note that the Disp, Scale,
+      // and Index values may already be set here.
+      AM.Base.Reg = LoadReg;
+      AM.GV = 0;
+      return true;
+    }
+  }
+
+  // If all else fails, try to materialize the value in a register.
+  if (!AM.GV || !Subtarget->isPICStyleRIPRel()) {
+    if (AM.Base.Reg == 0) {
+      AM.Base.Reg = getRegForValue(V);
+      return AM.Base.Reg != 0;
+    }
+    if (AM.IndexReg == 0) {
+      assert(AM.Scale == 1 && "Scale with no index!");
+      AM.IndexReg = getRegForValue(V);
+      return AM.IndexReg != 0;
+    }
+  }
+
+  return false;
+}
+
 /// X86SelectAddress - Attempt to fill in an address from the given value.
 ///
 bool X86FastISel::X86SelectAddress(const Value *V, X86AddressMode &AM) {
+  SmallVector<const Value *, 32> GEPs;
 redo_gep:
   const User *U = NULL;
   unsigned Opcode = Instruction::UserOp1;
@@ -478,6 +596,7 @@ redo_gep:
     AM.IndexReg = IndexReg;
     AM.Scale = Scale;
     AM.Disp = (uint32_t)Disp;
+    GEPs.push_back(V);
 
     if (const GetElementPtrInst *GEP =
           dyn_cast<GetElementPtrInst>(U->getOperand(0))) {
@@ -492,125 +611,20 @@ redo_gep:
     // If we couldn't merge the gep value into this addr mode, revert back to
     // our address and just match the value instead of completely failing.
     AM = SavedAM;
-    break;
-  unsupported_gep:
-    // Ok, the GEP indices weren't all covered.
-    break;
-  }
-  }
-
-  // Handle constant address.
-  if (const GlobalValue *GV = dyn_cast<GlobalValue>(V)) {
-    // Can't handle alternate code models yet.
-    if (TM.getCodeModel() != CodeModel::Small)
-      return false;
-
-    // Can't handle TLS yet.
-    if (const GlobalVariable *GVar = dyn_cast<GlobalVariable>(GV))
-      if (GVar->isThreadLocal())
-        return false;
-
-    // Can't handle TLS yet, part 2 (this is slightly crazy, but this is how
-    // it works...).
-    if (const GlobalAlias *GA = dyn_cast<GlobalAlias>(GV))
-      if (const GlobalVariable *GVar =
-            dyn_cast_or_null<GlobalVariable>(GA->resolveAliasedGlobal(false)))
-        if (GVar->isThreadLocal())
-          return false;
-
-    // RIP-relative addresses can't have additional register operands, so if
-    // we've already folded stuff into the addressing mode, just force the
-    // global value into its own register, which we can use as the basereg.
-    if (!Subtarget->isPICStyleRIPRel() ||
-        (AM.Base.Reg == 0 && AM.IndexReg == 0)) {
-      // Okay, we've committed to selecting this global. Set up the address.
-      AM.GV = GV;
-
-      // Allow the subtarget to classify the global.
-      unsigned char GVFlags = Subtarget->ClassifyGlobalReference(GV, TM);
 
-      // If this reference is relative to the pic base, set it now.
-      if (isGlobalRelativeToPICBase(GVFlags)) {
-        // FIXME: How do we know Base.Reg is free??
-        AM.Base.Reg = getInstrInfo()->getGlobalBaseReg(FuncInfo.MF);
-      }
-
-      // Unless the ABI requires an extra load, return a direct reference to
-      // the global.
-      if (!isGlobalStubReference(GVFlags)) {
-        if (Subtarget->isPICStyleRIPRel()) {
-          // Use rip-relative addressing if we can.  Above we verified that the
-          // base and index registers are unused.
-          assert(AM.Base.Reg == 0 && AM.IndexReg == 0);
-          AM.Base.Reg = X86::RIP;
-        }
-        AM.GVOpFlags = GVFlags;
+    for (SmallVectorImpl<const Value *>::reverse_iterator
+           I = GEPs.rbegin(), E = GEPs.rend(); I != E; ++I)
+      if (handleConstantAddresses(*I, AM))
         return true;
-      }
-
-      // Ok, we need to do a load from a stub.  If we've already loaded from
-      // this stub, reuse the loaded pointer, otherwise emit the load now.
-      DenseMap<const Value*, unsigned>::iterator I = LocalValueMap.find(V);
-      unsigned LoadReg;
-      if (I != LocalValueMap.end() && I->second != 0) {
-        LoadReg = I->second;
-      } else {
-        // Issue load from stub.
-        unsigned Opc = 0;
-        const TargetRegisterClass *RC = NULL;
-        X86AddressMode StubAM;
-        StubAM.Base.Reg = AM.Base.Reg;
-        StubAM.GV = GV;
-        StubAM.GVOpFlags = GVFlags;
-
-        // Prepare for inserting code in the local-value area.
-        SavePoint SaveInsertPt = enterLocalValueArea();
-
-        if (TLI.getPointerTy() == MVT::i64) {
-          Opc = X86::MOV64rm;
-          RC  = &X86::GR64RegClass;
-
-          if (Subtarget->isPICStyleRIPRel())
-            StubAM.Base.Reg = X86::RIP;
-        } else {
-          Opc = X86::MOV32rm;
-          RC  = &X86::GR32RegClass;
-        }
-
-        LoadReg = createResultReg(RC);
-        MachineInstrBuilder LoadMI =
-          BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, TII.get(Opc), LoadReg);
-        addFullAddress(LoadMI, StubAM);
-
-        // Ok, back to normal mode.
-        leaveLocalValueArea(SaveInsertPt);
-
-        // Prevent loading GV stub multiple times in same MBB.
-        LocalValueMap[V] = LoadReg;
-      }
 
-      // Now construct the final address. Note that the Disp, Scale,
-      // and Index values may already be set here.
-      AM.Base.Reg = LoadReg;
-      AM.GV = 0;
-      return true;
-    }
+    return false;
+  unsupported_gep:
+    // Ok, the GEP indices weren't all covered.
+    break;
   }
-
-  // If all else fails, try to materialize the value in a register.
-  if (!AM.GV || !Subtarget->isPICStyleRIPRel()) {
-    if (AM.Base.Reg == 0) {
-      AM.Base.Reg = getRegForValue(V);
-      return AM.Base.Reg != 0;
-    }
-    if (AM.IndexReg == 0) {
-      assert(AM.Scale == 1 && "Scale with no index!");
-      AM.IndexReg = getRegForValue(V);
-      return AM.IndexReg != 0;
-    }
   }
 
-  return false;
+  return handleConstantAddresses(V, AM);
 }
 
 /// X86SelectCallAddress - Attempt to fill in an address from the given value.