a.diff

diff --git a/tools/shared.py b/tools/shared.py
index a591325..60a1853 100644
--- a/tools/shared.py
+++ b/tools/shared.py
@@ -1854,49 +1854,50 @@ class Building(object):
   # LLVM optimizations
   # @param opt A list of LLVM optimization parameters
   @staticmethod
   def llvm_opt(filename, opts, out=None):
     inputs = filename
     if not isinstance(inputs, list):
       inputs = [inputs]
     else:
       assert out, 'must provide out if llvm_opt on a list of inputs'
     assert len(opts) > 0, 'should not call opt with nothing to do'
-    opts = opts[:]
-    # TODO: disable inlining when needed
-    # if not Building.can_inline():
-    #   opts.append('-disable-inlining')
-    #opts += ['-debug-pass=Arguments']
-    if not Settings.SIMD:
-      opts += ['-disable-loop-vectorization', '-disable-slp-vectorization', '-vectorize-loops=false', '-vectorize-slp=false']
-      if not Settings.WASM_BACKEND:
-        # This option have been removed in llvm ToT
-        opts += ['-vectorize-slp-aggressive=false']
-    else:
-      opts += ['-bb-vectorize-vector-bits=128']
-
+    opts = opts + Building.get_opt_opts()
     logging.debug('emcc: LLVM opts: ' + ' '.join(opts) + '  [num inputs: ' + str(len(inputs)) + ']')
     target = out or (filename + '.opt.bc')
     proc = Popen([LLVM_OPT] + inputs + opts + ['-o', target], stdout=PIPE)
     output = proc.communicate()[0]
     if proc.returncode != 0 or not os.path.exists(target):
       logging.error('Failed to run llvm optimizations: ' + output)
       for i in inputs:
         if not os.path.exists(i):
           logging.warning('Note: Input file "' + i + '" did not exist.')
         elif not Building.is_bitcode(i):
           logging.warning('Note: Input file "' + i + '" exists but was not an LLVM bitcode file suitable for Emscripten. Perhaps accidentally mixing native built object files with Emscripten?')
       sys.exit(1)
     if not out:
       shutil.move(filename + '.opt.bc', filename)
     return target
 
+  # gets the options we should pass to the llvm-opt optimizer
+  @staticmethod
+  def get_opt_opts():
+    opts = []
+    if not Settings.SIMD:
+      opts += ['-disable-loop-vectorization', '-disable-slp-vectorization', '-vectorize-loops=false', '-vectorize-slp=false']
+      if not Settings.WASM_BACKEND:
+        # This option have been removed in llvm ToT
+        opts += ['-vectorize-slp-aggressive=false']
+    else:
+      opts += ['-bb-vectorize-vector-bits=128']
+    return opts
+
   @staticmethod
   def llvm_opts(filename): # deprecated version, only for test runner. TODO: remove
     if Building.LLVM_OPTS:
       shutil.move(filename + '.o', filename + '.o.pre')
       output = Popen([LLVM_OPT, filename + '.o.pre'] + Building.LLVM_OPT_OPTS + ['-o', filename + '.o'], stdout=PIPE).communicate()[0]
       assert os.path.exists(filename + '.o'), 'Failed to run llvm optimizations: ' + output
 
   @staticmethod
   def llvm_dis(input_filename, output_filename=None):
     # LLVM binary ==> LLVM assembly
diff --git a/tools/system_libs.py b/tools/system_libs.py
index dcca8af..170e895 100755
--- a/tools/system_libs.py
+++ b/tools/system_libs.py
@@ -3,29 +3,30 @@ import os, json, logging, zipfile, glob, shutil
 from . import shared
 from subprocess import Popen, CalledProcessError
 import subprocess, multiprocessing, re
 from tools.shared import check_call
 
 stdout = None
 stderr = None
 
 def call_process(cmd):
   # call clang directly, instead of emcc, when we can (we can't if a special emcc
-  # -s flag is issued)
-  if cmd[0] == shared.PYTHON and cmd[1] in (shared.EMCC, shared.EMXX) and '-s' not in cmd:
+  # -s flag is issued, or js is emitted)
+  if cmd[0] == shared.PYTHON and cmd[1] in (shared.EMCC, shared.EMXX) and \
+     not any([x.endswith('.js') for x in cmd]):
     if cmd[1] == shared.EMCC:
       cmd[1] = shared.CLANG_CC
     else:
       cmd[1] = shared.CLANG_CPP
     cmd = cmd[1:]
     # add compiler opts emcc would have
-    cmd += shared.COMPILER_OPTS + ['-emit-llvm', '-c']
+    cmd += shared.COMPILER_OPTS + ['-emit-llvm', '-c'] + shared.Building.get_opt_opts()
   # call the process
   proc = Popen(cmd, stdout=stdout, stderr=stderr)
   proc.communicate()
   if proc.returncode != 0:
     # Deliberately do not use CalledProcessError, see issue #2944
     raise Exception('Command \'%s\' returned non-zero exit status %s' % (' '.join(cmd), proc.returncode))
 
 CORES = int(os.environ.get('EMCC_CORES') or multiprocessing.cpu_count())
 
 def run_commands(commands):