Found when attempting to compile powerpc64-linux glibc using current mainline gcc, the attached cut-down testcase results in
tcboff.i: In function 'dummy': tcboff.i:24: warning: asm operand 0 probably doesn't match constraints tcboff.i:24: error: impossible constraint in 'asm' -- Summary: tree optimizer doesn't meet asm constraints Product: gcc Version: 4.0.0 Status: UNCONFIRMED Severity: normal Priority: P2 Component: tree-optimization AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: amodra at bigpond dot net dot au CC: gcc-bugs at gcc dot gnu dot org GCC build triplet: powerpc*-linux, i686-linux http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19708