copy mmx values from/to memory with GPRs on x86-32

instead of with mmx registers.  This horribleness is apparently
done by gcc to avoid having to insert emms in places that really 
should have it.  This is the second half of rdar://5741668.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47474 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 25 insertions, 1 deletions

diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp
index 96a58c11ef..a2e0036e38 100644
--- a/lib/Target/X86/X86ISelLowering.cpp
+++ b/lib/Target/X86/X86ISelLowering.cpp
@@ -5897,7 +5897,31 @@ static SDOperand PerformSTORECombine(StoreSDNode *St, SelectionDAG &DAG,
                           St->isVolatile(), St->getAlignment());
     }
     
-    // TODO: 2 32-bit copies.
+    // Otherwise, lower to two 32-bit copies.
+    SDOperand LoAddr = Ld->getBasePtr();
+    SDOperand HiAddr = DAG.getNode(ISD::ADD, MVT::i32, LoAddr,
+                                   DAG.getConstant(MVT::i32, 4));
+    
+    SDOperand LoLd = DAG.getLoad(MVT::i32, Ld->getChain(), LoAddr,
+                                 Ld->getSrcValue(), Ld->getSrcValueOffset(),
+                                 Ld->isVolatile(), Ld->getAlignment());
+    SDOperand HiLd = DAG.getLoad(MVT::i32, Ld->getChain(), HiAddr,
+                                 Ld->getSrcValue(), Ld->getSrcValueOffset()+4,
+                                 Ld->isVolatile(), 
+                                 MinAlign(Ld->getAlignment(), 4));
+    
+    LoAddr = St->getBasePtr();
+    HiAddr = DAG.getNode(ISD::ADD, MVT::i32, LoAddr,
+                         DAG.getConstant(MVT::i32, 4));
+    
+    SDOperand LoSt = DAG.getStore(LoLd.getValue(1), LoLd, LoAddr,
+                        St->getSrcValue(), St->getSrcValueOffset(),
+                        St->isVolatile(), St->getAlignment());
+    SDOperand HiSt = DAG.getStore(HiLd.getValue(1), HiLd, HiAddr,
+                                  St->getSrcValue(), St->getSrcValueOffset()+4,
+                                  St->isVolatile(), 
+                                  MinAlign(St->getAlignment(), 4));
+    return DAG.getNode(ISD::TokenFactor, MVT::Other, LoSt, HiSt);
   }
   return SDOperand();
 }