diff options
| -rw-r--r-- | gcc/ChangeLog | 5 | ||||
| -rw-r--r-- | gcc/global.c | 5 | ||||
| -rw-r--r-- | gcc/local-alloc.c | 5 | ||||
| -rw-r--r-- | gcc/regs.h | 6 | ||||
| -rw-r--r-- | gcc/tm.texi | 11 |
5 files changed, 30 insertions, 2 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 4075787acd7..be78bfb1448 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -24,6 +24,11 @@ Wed Sep 30 18:29:26 1998 Jeffrey A Law (law@cygnus.com) Wed Sep 30 18:19:27 1998 Michael Hayes <m.hayes@elec.canterbury.ac.nz> + * regs.h (HARD_REGNO_CALL_PART_CLOBBERED): New macro. + * local-alloc.c (find_free_reg): Use it. + * global.c (find_reg): Likewise. + * tm.texi: Document HARD_REGNO_CALL_PART_CLOBBERED. + * regs.h (HARD_REGNO_CALLER_SAVE_MODE): New macro. * caller-save.c (init_caller_save): Use it. * tm.texi: Document HARD_REGNO_CALLER_SAVE_MODE. diff --git a/gcc/global.c b/gcc/global.c index a3d7e023283..3b0c0ec7a4c 100644 --- a/gcc/global.c +++ b/gcc/global.c @@ -976,7 +976,10 @@ find_reg (allocno, losers, alt_regs_p, accept_call_clobbered, retrying) int regno = i; #endif if (! TEST_HARD_REG_BIT (used, regno) - && HARD_REGNO_MODE_OK (regno, mode)) + && HARD_REGNO_MODE_OK (regno, mode) + && (allocno_calls_crossed[allocno] == 0 + || accept_call_clobbered + || ! HARD_REGNO_CALL_PART_CLOBBERED (regno, mode))) { register int j; register int lim = regno + HARD_REGNO_NREGS (regno, mode); diff --git a/gcc/local-alloc.c b/gcc/local-alloc.c index 5dbde5218f8..3049a988007 100644 --- a/gcc/local-alloc.c +++ b/gcc/local-alloc.c @@ -2043,7 +2043,10 @@ find_free_reg (class, mode, qty, accept_call_clobbered, just_try_suggested, int regno = i; #endif if (! TEST_HARD_REG_BIT (first_used, regno) - && HARD_REGNO_MODE_OK (regno, mode)) + && HARD_REGNO_MODE_OK (regno, mode) + && (qty_n_calls_crossed[qty] == 0 + || accept_call_clobbered + || ! HARD_REGNO_CALL_PART_CLOBBERED (regno, mode))) { register int j; register int size1 = HARD_REGNO_NREGS (regno, mode); diff --git a/gcc/regs.h b/gcc/regs.h index 02bdf92c1f5..a4065e6e371 100644 --- a/gcc/regs.h +++ b/gcc/regs.h @@ -217,6 +217,12 @@ extern int caller_save_needed; choose_hard_reg_mode (REGNO, NREGS) #endif +/* Registers that get partially clobbered by a call in a given mode. + These must not be call used registers. */ +#ifndef HARD_REGNO_CALL_PART_CLOBBERED +#define HARD_REGNO_CALL_PART_CLOBBERED(REGNO, MODE) 0 +#endif + /* Allocated in local_alloc. */ /* A list of SCRATCH rtl allocated by local-alloc. */ diff --git a/gcc/tm.texi b/gcc/tm.texi index a42eb67a619..463ae8ef6c0 100644 --- a/gcc/tm.texi +++ b/gcc/tm.texi @@ -1333,6 +1333,17 @@ If a register has 0 in @code{CALL_USED_REGISTERS}, the compiler automatically saves it on function entry and restores it on function exit, if the register is used within the function. +@findex HARD_REGNO_CALL_PART_CLOBBERED +@item HARD_REGNO_CALL_PART_CLOBBERED (@var{regno}, @var{mode}) +@cindex call-used register +@cindex call-clobbered register +@cindex call-saved register +A C expression that is non-zero if it is not permissible to store a +value of mode @var{mode} in hard register number @var{regno} across a +call without some part of it being clobbered. For most machines this +macro need not be defined. It is only required for machines that do not +preserve the entire contents of a register across a call. + @findex CONDITIONAL_REGISTER_USAGE @findex fixed_regs @findex call_used_regs |