1 files changed, 7 insertions, 0 deletions
diff --git a/llvm/lib/Target/AArch64/AArch64InstrInfo.cpp b/llvm/lib/Target/AArch64/AArch64InstrInfo.cpp
index 5a51c81..35b27ea 100644
--- a/llvm/lib/Target/AArch64/AArch64InstrInfo.cpp
+++ b/llvm/lib/Target/AArch64/AArch64InstrInfo.cpp
@@ -1503,6 +1503,13 @@ AArch64InstrInfo::canRemovePTestInstr(MachineInstr *PTest, MachineInstr *Mask,
             getElementSizeForOpcode(PredOpcode))
       return PredOpcode;
 
+    // For PTEST_FIRST(PTRUE_ALL, WHILE), the PTEST_FIRST is redundant since
+    // WHILEcc performs an implicit PTEST with an all active mask, setting
+    // the N flag as the PTEST_FIRST would.
+    if (PTest->getOpcode() == AArch64::PTEST_PP_FIRST &&
+        isPTrueOpcode(MaskOpcode) && Mask->getOperand(1).getImm() == 31)
+      return PredOpcode;
+
     return {};
   }