mipsisa64-elf-gcc -S -O2 -msmartmips gcc.target/mips/smartmips-lwxs.c -DNOMIPS16=
does not produce an LWXS instruction. This doesn't really matter much, since SmartMIPS is only for 32-bit processors, but: (a) it works for 64-bit ILP32 ABIs like n32 and o64. (b) within gcc, there is an abstraction layer between "Do we have SmartMIPS?" and "Can we use LWXS?". So I think it's worth having a Pmode==DImode version anyway. I'm filing this for 4.5 or later; it isn't something we'd fix in 4,4 or earlier. -- Summary: There should be a Pmode == DImode version of the MIPS lwxs pattern Product: gcc Version: 4.4.0 Status: UNCONFIRMED Keywords: missed-optimization Severity: normal Priority: P3 Component: target AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: rsandifo at gcc dot gnu dot org GCC target triplet: mipsisa64-elf http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38599