The attached test case is causing a spurious dependency violation message from the assembler. The problem seems to be that the assembler is clearing all qp mutex relations after a call, but the compiler does not emit .pred.rel.mutex after them.
$ gcc -O2 -c -save-temps xdisp.c xdisp.s: Assembler messages: xdisp.s:114: Warning: Use of 'mov' may violate WAW dependency 'GR%, % in 1 - 127' (impliedf), specific resource number is 16 xdisp.s:113: Warning: This is the location of the conflicting usage -- Summary: Insufficient qp-mutex declarations Product: gcc Version: 4.4.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: target AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: schwab at suse dot de GCC target triplet: ia64-*-* http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36898