1 files changed, 15 insertions, 7 deletions
diff --git a/contrib/llvm/lib/Target/AArch64/AArch64ConditionOptimizer.cpp b/contrib/llvm/lib/Target/AArch64/AArch64ConditionOptimizer.cpp
index b9e41c6..fc27bfe 100644
--- a/contrib/llvm/lib/Target/AArch64/AArch64ConditionOptimizer.cpp
+++ b/contrib/llvm/lib/Target/AArch64/AArch64ConditionOptimizer.cpp
@@ -59,6 +59,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "AArch64.h"
+#include "MCTargetDesc/AArch64AddressingModes.h"
 #include "llvm/ADT/DepthFirstIterator.h"
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/Statistic.h"
@@ -153,13 +154,20 @@ MachineInstr *AArch64ConditionOptimizer::findSuitableCompare(
     case AArch64::SUBSXri:
     // cmn is an alias for adds with a dead destination register.
     case AArch64::ADDSWri:
-    case AArch64::ADDSXri:
-      if (MRI->use_empty(I->getOperand(0).getReg()))
-        return I;
-
-      DEBUG(dbgs() << "Destination of cmp is not dead, " << *I << '\n');
-      return nullptr;
-
+    case AArch64::ADDSXri: {
+      unsigned ShiftAmt = AArch64_AM::getShiftValue(I->getOperand(3).getImm());
+      if (!I->getOperand(2).isImm()) {
+        DEBUG(dbgs() << "Immediate of cmp is symbolic, " << *I << '\n');
+        return nullptr;
+      } else if (I->getOperand(2).getImm() << ShiftAmt >= 0xfff) {
+        DEBUG(dbgs() << "Immediate of cmp may be out of range, " << *I << '\n');
+        return nullptr;
+      } else if (!MRI->use_empty(I->getOperand(0).getReg())) {
+        DEBUG(dbgs() << "Destination of cmp is not dead, " << *I << '\n');
+        return nullptr;
+      }
+      return I;
+    }
     // Prevent false positive case like:
     // cmp      w19, #0
     // cinc     w0, w19, gt