Issue #7485 has been updated by kosaki (Motohiro KOSAKI).


I guess -march=i486 enable __sync_val_compare_and_swap. 
----------------------------------------
Bug #7485: ruby cannot build on mingw32 due to missing __sync_val_compare_and_swap
https://bugs.ruby-lang.org/issues/7485#change-34264

Author: drbrain (Eric Hodel)
Status: Open
Priority: Normal
Assignee: nobu (Nobuyoshi Nakada)
Category: build
Target version: 2.0.0
ruby -v: trunk


mingw32 GCC has the other atomic builtins but not this one.  The attached patch checks for the GCC builtins used in ruby_atomic.h but not checked for by configure.


-- 
http://bugs.ruby-lang.org/