ARM FastISel fix load register classes

The register classes when emitting loads weren't quite restricting enough, leading to MI verification failure on the result register.

These are new failures that weren't there the first time I tried enabling ARM FastISel for new targets.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@183624 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/ARM/ARMFastISel.cpp b/lib/Target/ARM/ARMFastISel.cpp
index 62bc782..8d17565 100644
--- a/lib/Target/ARM/ARMFastISel.cpp
+++ b/lib/Target/ARM/ARMFastISel.cpp
@@ -1026,7 +1026,7 @@
           useAM3 = true;
         }
       }
-      RC = &ARM::GPRRegClass;
+      RC = isThumb2 ? &ARM::rGPRRegClass : &ARM::GPRnopcRegClass;
       break;
     case MVT::i16:
       if (Alignment && Alignment < 2 && !Subtarget->allowsUnalignedMem())
@@ -1041,7 +1041,7 @@
         Opc = isZExt ? ARM::LDRH : ARM::LDRSH;
         useAM3 = true;
       }
-      RC = &ARM::GPRRegClass;
+      RC = isThumb2 ? &ARM::rGPRRegClass : &ARM::GPRnopcRegClass;
       break;
     case MVT::i32:
       if (Alignment && Alignment < 4 && !Subtarget->allowsUnalignedMem())
@@ -1055,7 +1055,7 @@
       } else {
         Opc = ARM::LDRi12;
       }
-      RC = &ARM::GPRRegClass;
+      RC = isThumb2 ? &ARM::rGPRRegClass : &ARM::GPRnopcRegClass;
       break;
     case MVT::f32:
       if (!Subtarget->hasVFP2()) return false;
@@ -1064,7 +1064,7 @@
         needVMOV = true;
         VT = MVT::i32;
         Opc = isThumb2 ? ARM::t2LDRi12 : ARM::LDRi12;
-        RC = &ARM::GPRRegClass;
+        RC = isThumb2 ? &ARM::rGPRRegClass : &ARM::GPRnopcRegClass;
       } else {
         Opc = ARM::VLDRS;
         RC = TLI.getRegClassFor(VT);