hpvm-clang now sends -O flag the first

hpvm/tools/hpvm-clang/main.py.in

@@ -30,7 +30,7 @@ def compile_hpvm_c(
     include: List[PathLike] = None,
     macro: List[str] = None,
     flags: List[str] = None,
-    optim_level: str = "0",  # -O0
+    optim_level: str = "1",  # -O1
     is_cpp: bool = True,  # otherwise is C
     std: str = None,  # language std (-std=c++11)
     link_dirs: List[PathLike] = None,
@@ -98,7 +98,7 @@ def hpvm_c_to_ll(
     extra_includes: List[PathLike] = None,
     macros: List[str] = None,
     flags: List[str] = None,
-    optim_level: str = "0",  # -O0
+    optim_level: str = "1",  # -O1
     is_cpp: bool = True,  # otherwise is C
     std: str = None,  # --std=c++11
 ) -> List[str]:
@@ -110,9 +110,9 @@ def hpvm_c_to_ll(
         flags.append(f"-std={std}")
     clang = "clang++" if is_cpp else "clang"
     return [
-        str(LLVM_BUILD_BIN / clang), *includes_s, *flags, *macros,
-        f"-O{optim_level}", "-emit-llvm", "-S",
-        str(src_file), "-o", str(target_file)
+        str(LLVM_BUILD_BIN / clang), f"-O{optim_level}",
+        *includes_s, *flags, *macros,
+        "-emit-llvm", "-S", str(src_file), "-o", str(target_file)
     ]