change assert that will never fire to llvm_unreachable

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239497 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Target/X86/X86InstrInfo.cpp b/lib/Target/X86/X86InstrInfo.cpp
index e2762f523812d703f3299bc0c5968dc54d25249d..c1229968e81241a3ba3edb23ce34a5102d42178f 100644 (file)
--- a/lib/Target/X86/X86InstrInfo.cpp
+++ b/lib/Target/X86/X86InstrInfo.cpp
@@ -6424,7 +6424,7 @@ void X86InstrInfo::genAlternativeCodeSequence(
            Pattern == MachineCombinerPattern::MC_REASSOC_XA_YB)
     Prev = MRI.getUniqueVRegDef(Root.getOperand(2).getReg());
   else
-    assert("Unknown pattern for machine combiner");
+    llvm_unreachable("Unknown pattern for machine combiner");
   
   reassociateOps(Root, *Prev, Pattern, InsInstrs, DelInstrs, InstIdxForVirtReg);
   return;