diff --git a/gen/asm-x86.h b/gen/asm-x86.h
index 8d729fb8..43cfffc0 100644
--- a/gen/asm-x86.h
+++ b/gen/asm-x86.h
@@ -1855,7 +1855,7 @@ namespace AsmParserx8664
                         break;
 
                     default:
-                        assert ( 0 && "asm unsupported arg" );
+                        llvm_unreachable("Unsupported argument in asm.");
                         break;
                 }
             }
@@ -2781,7 +2781,7 @@ namespace AsmParserx8664
                         e = new ComExp ( stmt->loc, e1 );
                         break;
                     default:
-                        assert ( 0 );
+                        llvm_unreachable("Unknown integer operation.");
                 }
                 e = e->semantic ( sc );
                 return e->optimize ( WANTvalue | WANTinterpret );
@@ -3383,7 +3383,7 @@ namespace AsmParserx8664
 #define HOST_WIDE_INT long
     bool getFrameRelativeValue ( LLValue* decl, HOST_WIDE_INT * result )
     {
-        assert ( 0 );
+        llvm_unreachable("getFrameRelativeValue not implemented.");
 // FIXME
 //     // Using this instead of DECL_RTL for struct args seems like a
 //     // good way to get hit by a truck because it may not agree with
diff --git a/gen/toir.cpp b/gen/toir.cpp
index 016f5ad2..387ea862 100644
--- a/gen/toir.cpp
+++ b/gen/toir.cpp
@@ -1123,7 +1123,7 @@ DValue* CallExp::toElem(IRState* p)
                     // *q |= mask;
                     op = llvm::Instruction::Or;
                 } else {
-                    assert(false);
+                    llvm_unreachable("Unrecognized bitop intrinsic.");
                 }
 
                 LLValue *newVal = p->ir->CreateBinOp(op, val, mask, "bitop.new_val");