https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64855
--- Comment #5 from howarth at bromo dot med.uc.edu --- Confirmed on x86_64-apple-darwin14 that... Index: libffi/testsuite/lib/libffi.exp =================================================================== --- libffi/testsuite/lib/libffi.exp (revision 220263) +++ libffi/testsuite/lib/libffi.exp (working copy) @@ -310,7 +310,7 @@ proc run-many-tests { testcases extra_fl set targetabis { "" } if [string match $compiler_vendor "gnu"] { if { ([istarget "i?86-*-*"] || [istarget "x86_64-*-*"]) - && [is-effective-target ia32] } { + && [is-effective-target ia32] && ![istarget "*-*-darwin*"] } { set targetabis { "" "-DABI_NUM=FFI_STDCALL -DABI_ATTR=__STDCALL__" eliminates all regressions in the libffi test suite. === libffi Summary === # of expected passes 3828 # of unsupported tests 60