https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90877
--- Comment #1 from hjl at gcc dot gnu.org <hjl at gcc dot gnu.org> --- Author: hjl Date: Fri Jun 14 15:41:43 2019 New Revision: 272294 URL: https://gcc.gnu.org/viewcvs?rev=272294&root=gcc&view=rev Log: i386: Update SSE <-> integer move costs Since inline_secondary_memory_needed has /* ??? This is a lie. We do have moves between mmx/general, and for mmx/sse2. But by saying we need secondary memory we discourage the register allocator from using the mmx registers unless needed. */ if (MMX_CLASS_P (class1) != MMX_CLASS_P (class2)) return true; moves between MMX and non-MMX units require secondary memory. There is no need to check moves between MMX and integer units. struct processor_costs has: const int mmxsse_to_integer; /* cost of moving mmxsse register to integer. */ const int ssemmx_to_integer; /* cost of moving integer to mmxsse register. */ This patch also renames mmxsse_to_integer to sse_to_integer and ssemmx_to_integer to integer_to_sse. Tested on Linux/x86-64. PR target/90877 * config/i386/i386-features.c (dimode_scalar_chain::compute_convert_gain): Replace mmxsse_to_integer with sse_to_integer. * config/i386/i386.c (ix86_register_move_cost): Verify that moves between MMX and non-MMX units require secondary memory. Correct costs of moves between SSE and integer units. * config/i386/i386.h (processor_costs): Rename cost of moving SSE register to integer to sse_to_integer. Rename cost of moving integer register to SSE to integer_to_sse. Modified: trunk/gcc/ChangeLog trunk/gcc/config/i386/i386-features.c trunk/gcc/config/i386/i386.c trunk/gcc/config/i386/i386.h
