1 files changed, 8 insertions, 1 deletions
diff --git a/test/run-spec-wasm2c.py b/test/run-spec-wasm2c.py
index 8362ce7b..5a246650 100755
--- a/test/run-spec-wasm2c.py
+++ b/test/run-spec-wasm2c.py
@@ -341,10 +341,17 @@ def Compile(cc, c_filename, out_dir, *args):
     if IS_WINDOWS:
         args += ['/nologo', '/MDd', '/c', c_filename, '/Fo' + o_filename]
     else:
-        args += ['-c', c_filename, '-o', o_filename,
+        # See "Compiling the wasm2c output" section of wasm2c/README.md
+        # When compiling with -O2, GCC and clang require '-fno-optimize-sibling-calls'
+        # and '-frounding-math' to maintain conformance with the spec tests
+        # (GCC also requires '-fsignaling-nans')
+        args += ['-c', c_filename, '-o', o_filename, '-O2',
                  '-Wall', '-Werror', '-Wno-unused',
+                 '-Wno-ignored-optimization-argument',
                  '-Wno-tautological-constant-out-of-range-compare',
                  '-Wno-infinite-recursion',
+                 '-fno-optimize-sibling-calls',
+                 '-frounding-math', '-fsignaling-nans',
                  '-std=c99', '-D_DEFAULT_SOURCE']
     # Use RunWithArgsForStdout and discard stdout because cl.exe
     # unconditionally prints the name of input files on stdout