------- Comment #4 from vincent at vinc17 dot org 2009-11-26 15:53 ------- (In reply to comment #1) > Aliasing rules are indeed broken because you access a union of anonymous type > through a pointer to a union of type ieee_double_extract.
OK, the real code in MPFR is a "double" accessed through a pointer to a union of type ieee_double_extract, but I suppose this is the same problem. BTW, could my testcase be used to improve GCC's -Wstrict-aliasing=3 (i.e. to have fewer false negatives without introducing more false positives), or is it too difficult / not possible? -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42179