AArch64: Assert on branch displacement bits

llvm-svn: 277434

1 files changed, 7 insertions, 0 deletions

diff --git a/llvm/lib/Target/AArch64/AArch64InstrInfo.cpp b/llvm/lib/Target/AArch64/AArch64InstrInfo.cpp
index 05bc1cbead2..d3599537a9d 100644
--- a/llvm/lib/Target/AArch64/AArch64InstrInfo.cpp
+++ b/llvm/lib/Target/AArch64/AArch64InstrInfo.cpp
@@ -132,6 +132,13 @@ static unsigned getBranchMaxDisplacementBytes(unsigned Opc) {
 
   unsigned Bits = getBranchDisplacementBits(Opc);
   unsigned MaxOffs = ((1 << (Bits - 1)) - 1) << 2;
+
+  // Verify the displacement bits options have sane values.
+  // XXX: Is there a better place for this?
+  assert(MaxOffs >= 8 &&
+         "max branch displacement must be enough to jump"
+         "over conditional branch expansion");
+
   return MaxOffs;
 }