Teach instcombine to set the alignment arguments for NEON load/store intrinsics.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@117154 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/InstCombine/InstCombineCalls.cpp b/lib/Transforms/InstCombine/InstCombineCalls.cpp
index ed078ec..d53f329 100644
--- a/lib/Transforms/InstCombine/InstCombineCalls.cpp
+++ b/lib/Transforms/InstCombine/InstCombineCalls.cpp
@@ -702,6 +702,32 @@
     }
     break;
 
+  case Intrinsic::arm_neon_vld1:
+  case Intrinsic::arm_neon_vld2:
+  case Intrinsic::arm_neon_vld3:
+  case Intrinsic::arm_neon_vld4:
+  case Intrinsic::arm_neon_vld2lane:
+  case Intrinsic::arm_neon_vld3lane:
+  case Intrinsic::arm_neon_vld4lane:
+  case Intrinsic::arm_neon_vst1:
+  case Intrinsic::arm_neon_vst2:
+  case Intrinsic::arm_neon_vst3:
+  case Intrinsic::arm_neon_vst4:
+  case Intrinsic::arm_neon_vst2lane:
+  case Intrinsic::arm_neon_vst3lane:
+  case Intrinsic::arm_neon_vst4lane: {
+    unsigned MemAlign = GetOrEnforceKnownAlignment(II->getArgOperand(0));
+    unsigned AlignArg = II->getNumArgOperands() - 1;
+    ConstantInt *IntrAlign = dyn_cast<ConstantInt>(II->getArgOperand(AlignArg));
+    if (IntrAlign && IntrAlign->getZExtValue() < MemAlign) {
+      II->setArgOperand(AlignArg,
+                        ConstantInt::get(Type::getInt32Ty(II->getContext()),
+                                         MemAlign, false));
+      return II;
+    }
+    break;
+  }
+
   case Intrinsic::stackrestore: {
     // If the save is right next to the restore, remove the restore.  This can
     // happen when variable allocas are DCE'd.