RA sometimes will use lowest the cost of the mode with all different regclasses w/o check if it's hard_regno_mode_ok. It's impossible to put modes whose size > 8 into MASK_REGS, ajdust the cost to avoid potential performance issue.
Bootstrapped and regtested on x86_64-pc-linux-gnu{-m32,}. Ok for trunk? gcc/ChangeLog: * config/i386/i386.cc (inline_memory_move_cost): Return 100 for MASK_REGS when MODE_SIZE > 8. --- gcc/config/i386/i386.cc | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/gcc/config/i386/i386.cc b/gcc/config/i386/i386.cc index 2cc8e9548a9..2581b800a06 100644 --- a/gcc/config/i386/i386.cc +++ b/gcc/config/i386/i386.cc @@ -19847,9 +19847,12 @@ inline_memory_move_cost (machine_mode mode, enum reg_class regclass, int in) index = 1; break; /* DImode loads and stores assumed to cost the same as SImode. */ - default: + case 4: + case 8: index = 2; break; + default: + return 100; } if (in == 2) -- 2.39.1.388.g2fc9e9ca3c