Implement Thumb2 ldr.

After much back and forth, I decided to deviate from ARM design and split LDR into 4 instructions (r + imm12, r + imm8, r + r << imm12, constantpool). The advantage of this is 1) it follows the latest ARM technical manual, and 2) makes it easier to reduce the width of the instruction later. The down side is this creates more inconsistency between the two sub-targets. We should split ARM LDR instruction in a similar fashion later. I've added a README entry for this.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@74420 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/ARM/ARMConstantIslandPass.cpp b/lib/Target/ARM/ARMConstantIslandPass.cpp
index db723fe..d37e9f2 100644
--- a/lib/Target/ARM/ARMConstantIslandPass.cpp
+++ b/lib/Target/ARM/ARMConstantIslandPass.cpp
@@ -447,21 +447,24 @@
             Bits = 8;
             Scale = 4;  // +-(offset_8*4)
             break;
-          case ARMII::AddrModeT1:
+          case ARMII::AddrModeT1_1:
             Bits = 5;  // +offset_5
             break;
-          case ARMII::AddrModeT2:
+          case ARMII::AddrModeT1_2:
             Bits = 5;
             Scale = 2;  // +(offset_5*2)
             break;
-          case ARMII::AddrModeT4:
+          case ARMII::AddrModeT1_4:
             Bits = 5;
             Scale = 4;  // +(offset_5*4)
             break;
-          case ARMII::AddrModeTs:
+          case ARMII::AddrModeT1_s:
             Bits = 8;
             Scale = 4;  // +(offset_8*4)
             break;
+          case ARMII::AddrModeT2_pc:
+            Bits = 12;  // +-offset_12
+            break;
           }
 
           // Remember that this is a user of a CP entry.