diff options
Diffstat (limited to 'gcc/config/sh/sh.c')
| -rw-r--r-- | gcc/config/sh/sh.c | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/gcc/config/sh/sh.c b/gcc/config/sh/sh.c index b89d048..eb19c42 100644 --- a/gcc/config/sh/sh.c +++ b/gcc/config/sh/sh.c @@ -291,6 +291,7 @@ static reg_class_t sh_secondary_reload (bool, rtx, reg_class_t, static bool sh_legitimate_address_p (machine_mode, rtx, bool); static rtx sh_legitimize_address (rtx, rtx, machine_mode); static rtx sh_delegitimize_address (rtx); +static bool sh_cannot_substitute_mem_equiv_p (rtx); static int shmedia_target_regs_stack_space (HARD_REG_SET *); static int shmedia_reserve_space_for_target_registers_p (int, HARD_REG_SET *); static int shmedia_target_regs_stack_adjust (HARD_REG_SET *); @@ -630,6 +631,9 @@ static const struct attribute_spec sh_attribute_table[] = #undef TARGET_LEGITIMATE_ADDRESS_P #define TARGET_LEGITIMATE_ADDRESS_P sh_legitimate_address_p +#undef TARGET_CANNOT_SUBSTITUTE_MEM_EQUIV_P +#define TARGET_CANNOT_SUBSTITUTE_MEM_EQUIV_P sh_cannot_substitute_mem_equiv_p + #undef TARGET_TRAMPOLINE_INIT #define TARGET_TRAMPOLINE_INIT sh_trampoline_init #undef TARGET_TRAMPOLINE_ADJUST_ADDRESS @@ -13214,6 +13218,24 @@ sh_secondary_reload (bool in_p, rtx x, reg_class_t rclass_i, return NO_REGS; } +/* Return true if SUBST can't safely replace its equivalent during RA. */ +static bool +sh_cannot_substitute_mem_equiv_p (rtx) +{ + if (TARGET_SHMEDIA) + return false; + + /* If SUBST is mem[base+index] or QI/HImode mem[base+disp], the insn + uses R0 and may cause spill failure when R0 is already used. + We have to return true for that case at least. + Moreover SH has strong R0 parity and also have not enough numbers of + the hard registers to make the equiv substitution win in the size + and the speed on average working sets. The pseudos produced to + hold the equiv values can't get good hard registers for bad cases + and end up memory save/restore insns which make the code worse. */ + return true; +} + static void sh_conditional_register_usage (void) { |