1 files changed, 30 insertions, 12 deletions
diff --git a/llvm/lib/Target/ARM/ARMBaseInstrInfo.cpp b/llvm/lib/Target/ARM/ARMBaseInstrInfo.cpp
index de4ae4f425b..d90d1443448 100644
--- a/llvm/lib/Target/ARM/ARMBaseInstrInfo.cpp
+++ b/llvm/lib/Target/ARM/ARMBaseInstrInfo.cpp
@@ -2685,14 +2685,24 @@ bool ARMBaseInstrInfo::FoldImmediate(MachineInstr *UseMI,
     Commute = UseMI->getOperand(2).getReg() != Reg;
     switch (UseOpc) {
     default: break;
+    case ARM::ADDrr:
     case ARM::SUBrr: {
-      if (Commute)
+      if (UseOpc == ARM::SUBrr && Commute)
+        return false;
+
+      // ADD/SUB are special because they're essentially the same operation, so
+      // we can handle a larger range of immediates.
+      if (ARM_AM::isSOImmTwoPartVal(ImmVal))
+        NewUseOpc = UseOpc == ARM::ADDrr ? ARM::ADDri : ARM::SUBri;
+      else if (ARM_AM::isSOImmTwoPartVal(-ImmVal)) {
+        ImmVal = -ImmVal;
+        NewUseOpc = UseOpc == ARM::ADDrr ? ARM::SUBri : ARM::ADDri;
+      } else
         return false;
-      ImmVal = -ImmVal;
-      NewUseOpc = ARM::SUBri;
-      // Fallthrough
+      SOImmValV1 = (uint32_t)ARM_AM::getSOImmTwoPartFirst(ImmVal);
+      SOImmValV2 = (uint32_t)ARM_AM::getSOImmTwoPartSecond(ImmVal);
+      break;
     }
-    case ARM::ADDrr:
     case ARM::ORRrr:
     case ARM::EORrr: {
       if (!ARM_AM::isSOImmTwoPartVal(ImmVal))
@@ -2701,20 +2711,29 @@ bool ARMBaseInstrInfo::FoldImmediate(MachineInstr *UseMI,
       SOImmValV2 = (uint32_t)ARM_AM::getSOImmTwoPartSecond(ImmVal);
       switch (UseOpc) {
       default: break;
-      case ARM::ADDrr: NewUseOpc = ARM::ADDri; break;
       case ARM::ORRrr: NewUseOpc = ARM::ORRri; break;
       case ARM::EORrr: NewUseOpc = ARM::EORri; break;
       }
       break;
     }
+    case ARM::t2ADDrr:
     case ARM::t2SUBrr: {
-      if (Commute)
+      if (UseOpc == ARM::t2SUBrr && Commute)
+        return false;
+
+      // ADD/SUB are special because they're essentially the same operation, so
+      // we can handle a larger range of immediates.
+      if (ARM_AM::isT2SOImmTwoPartVal(ImmVal))
+        NewUseOpc = UseOpc == ARM::t2ADDrr ? ARM::t2ADDri : ARM::t2SUBri;
+      else if (ARM_AM::isT2SOImmTwoPartVal(-ImmVal)) {
+        ImmVal = -ImmVal;
+        NewUseOpc = UseOpc == ARM::t2ADDrr ? ARM::t2SUBri : ARM::t2ADDri;
+      } else
         return false;
-      ImmVal = -ImmVal;
-      NewUseOpc = ARM::t2SUBri;
-      // Fallthrough
+      SOImmValV1 = (uint32_t)ARM_AM::getT2SOImmTwoPartFirst(ImmVal);
+      SOImmValV2 = (uint32_t)ARM_AM::getT2SOImmTwoPartSecond(ImmVal);
+      break;
     }
-    case ARM::t2ADDrr:
     case ARM::t2ORRrr:
     case ARM::t2EORrr: {
       if (!ARM_AM::isT2SOImmTwoPartVal(ImmVal))
@@ -2723,7 +2742,6 @@ bool ARMBaseInstrInfo::FoldImmediate(MachineInstr *UseMI,
       SOImmValV2 = (uint32_t)ARM_AM::getT2SOImmTwoPartSecond(ImmVal);
       switch (UseOpc) {
       default: break;
-      case ARM::t2ADDrr: NewUseOpc = ARM::t2ADDri; break;
       case ARM::t2ORRrr: NewUseOpc = ARM::t2ORRri; break;
       case ARM::t2EORrr: NewUseOpc = ARM::t2EORri; break;
       }