Re-enable inline memcpy expansion for Thumb1.

Patch by Moritz Roth!

llvm-svn: 208994

2 files changed, 5 insertions, 6 deletions

diff --git a/llvm/lib/Target/ARM/ARMSelectionDAGInfo.cpp b/llvm/lib/Target/ARM/ARMSelectionDAGInfo.cpp
index cb5812f6d26..7ce988773c7 100644
--- a/llvm/lib/Target/ARM/ARMSelectionDAGInfo.cpp
+++ b/llvm/lib/Target/ARM/ARMSelectionDAGInfo.cpp
@@ -53,9 +53,10 @@ ARMSelectionDAGInfo::EmitTargetCodeForMemcpy(SelectionDAG &DAG, SDLoc dl,
   EVT VT = MVT::i32;
   unsigned VTSize = 4;
   unsigned i = 0;
-  const unsigned MAX_LOADS_IN_LDM = 6;
-  SDValue TFOps[MAX_LOADS_IN_LDM];
-  SDValue Loads[MAX_LOADS_IN_LDM];
+  // Emit a maximum of 4 loads in Thumb1 since we have fewer registers
+  const unsigned MAX_LOADS_IN_LDM = Subtarget->isThumb1Only() ? 4 : 6;
+  SDValue TFOps[6];
+  SDValue Loads[6];
   uint64_t SrcOff = 0, DstOff = 0;
 
   // Emit up to MAX_LOADS_IN_LDM loads, then a TokenFactor barrier, then the
diff --git a/llvm/lib/Target/ARM/ARMSubtarget.h b/llvm/lib/Target/ARM/ARMSubtarget.h
index 77e47193423..fd106f6fc86 100644
--- a/llvm/lib/Target/ARM/ARMSubtarget.h
+++ b/llvm/lib/Target/ARM/ARMSubtarget.h
@@ -239,9 +239,7 @@ protected:
   /// getMaxInlineSizeThreshold - Returns the maximum memset / memcpy size
   /// that still makes it profitable to inline the call.
   unsigned getMaxInlineSizeThreshold() const {
-    // FIXME: For now, we don't lower memcpy's to loads / stores for Thumb1.
-    // Change this once Thumb1 ldmia / stmia support is added.
-    return isThumb1Only() ? 0 : 64;
+    return 64;
   }
   /// ParseSubtargetFeatures - Parses features string setting specified
   /// subtarget options.  Definition of function is auto generated by tblgen.