diff options
Diffstat (limited to 'gcc/target.def')
| -rw-r--r-- | gcc/target.def | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/gcc/target.def b/gcc/target.def index 6462c94..7abb74e 100644 --- a/gcc/target.def +++ b/gcc/target.def @@ -5265,6 +5265,30 @@ forwarding logic, you can set @code{sri->extra_cost} to a negative amount.", secondary_reload_info *sri), default_secondary_reload) +DEFHOOK +(secondary_memory_needed_mode, + "If @code{SECONDARY_MEMORY_NEEDED} tells the compiler to use memory\n\ +when moving between two particular registers of mode @var{mode},\n\ +this hook specifies the mode that the memory should have.\n\ +\n\ +The default depends on @code{TARGET_LRA_P}. Without LRA, the default\n\ +is to use a word-sized mode for integral modes that are smaller than a\n\ +a word. This is right thing to do on most machines because it ensures\n\ +that all bits of the register are copied and prevents accesses to the\n\ +registers in a narrower mode, which some machines prohibit for\n\ +floating-point registers.\n\ +\n\ +However, this default behavior is not correct on some machines, such as\n\ +the DEC Alpha, that store short integers in floating-point registers\n\ +differently than in integer registers. On those machines, the default\n\ +widening will not work correctly and you must define this hook to\n\ +suppress that widening in some cases. See the file @file{alpha.c} for\n\ +details.\n\ +\n\ +With LRA, the default is to use @var{mode} unmodified.", + machine_mode, (machine_mode mode), + default_secondary_memory_needed_mode) + /* Given an rtx X being reloaded into a reg required to be in class CLASS, return the class of reg to actually use. */ DEFHOOK |