> In our ARC port, we found the following situation after expand: > > (insn 23 22 24 5 (set (reg:SI 176) > (subreg:SI (mem/c:DI (plus:SI (reg/f:SI 147 virtual-stack-vars) > (const_int -268 [0xfffffffffffffef4])) [3 > tmpoutst.st_size+0 S8 A32]) 4)) t02.c:64 -1 (nil)) > > The virtual-stack-vars should be handled by GCC's VREGS step, in > instantiate_virtual_regs_in_insn(). However, this is not happening as the > subroutine is not designed to handle subregs of a mem. As a consequence, > virtual-stack-vars is not eliminated, and the compilation fails later on. > To solve this issue, I am proposing the attached patch on vregs, that > implements handling of such situation by > instantiate_virtual_regs_in_insn(). > > Can you please let me know if this is an acceptable solution for the given > issue?
Very likely not, there should be no SUBREGs of MEMs after expand. -- Eric Botcazou
