Remove global call sets: caller-save.c

All caller-save.c uses of "|= fixed_reg_set" added in a previous patch
were redundant, since the sets are later ANDed with ~fixed_reg_set.

2019-09-30  Richard Sandiford  <richard.sandiford@arm.com>

gcc/
	* caller-save.c (setup_save_areas): Remove redundant |s of
	fixed_reg_set.
	(save_call_clobbered_regs): Likewise.  Use the call ABI rather
	than call_used_or_fixed_regs to decide whether a REG_RETURNED
	value is useful.

From-SVN: r276313
This commit is contained in:
Richard Sandiford 2019-09-30 16:20:08 +00:00 committed by Richard Sandiford
parent 737d6a1a17
commit 7392e5d888
2 changed files with 12 additions and 13 deletions

View File

@ -1,3 +1,11 @@
2019-09-30 Richard Sandiford <richard.sandiford@arm.com>
* caller-save.c (setup_save_areas): Remove redundant |s of
fixed_reg_set.
(save_call_clobbered_regs): Likewise. Use the call ABI rather
than call_used_or_fixed_regs to decide whether a REG_RETURNED
value is useful.
2019-09-30 Richard Sandiford <richard.sandiford@arm.com>
* rtl.h (predefined_function_abi): Declare.

View File

@ -428,8 +428,6 @@ setup_save_areas (void)
REG_SET_TO_HARD_REG_SET (hard_regs_to_save,
&chain->live_throughout);
used_regs = insn_callee_abi (insn).full_reg_clobbers ();
/* ??? This preserves traditional behavior; it might not be needed. */
used_regs |= fixed_reg_set;
/* Record all registers set in this call insn. These don't
need to be saved. N.B. the call insn might set a subreg
@ -513,9 +511,6 @@ setup_save_areas (void)
REG_SET_TO_HARD_REG_SET (hard_regs_to_save,
&chain->live_throughout);
used_regs = insn_callee_abi (insn).full_reg_clobbers ();
/* ??? This preserves traditional behavior; it might not
be needed. */
used_regs |= fixed_reg_set;
/* Record all registers set in this call insn. These don't
need to be saved. N.B. the call insn might set a subreg
@ -793,7 +788,6 @@ save_call_clobbered_regs (void)
{
unsigned regno;
HARD_REG_SET hard_regs_to_save;
HARD_REG_SET call_def_reg_set;
reg_set_iterator rsi;
rtx cheap;
@ -840,15 +834,12 @@ save_call_clobbered_regs (void)
note_stores (insn, mark_set_regs, &this_insn_sets);
/* Compute which hard regs must be saved before this call. */
function_abi callee_abi = insn_callee_abi (insn);
hard_regs_to_save &= ~(fixed_reg_set
| this_insn_sets
| hard_regs_saved);
hard_regs_to_save &= savable_regs;
call_def_reg_set = insn_callee_abi (insn).full_reg_clobbers ();
/* ??? This preserves traditional behavior; it might not
be needed. */
call_def_reg_set |= fixed_reg_set;
hard_regs_to_save &= call_def_reg_set;
hard_regs_to_save &= callee_abi.full_reg_clobbers ();
for (regno = 0; regno < FIRST_PSEUDO_REGISTER; regno++)
if (TEST_HARD_REG_BIT (hard_regs_to_save, regno))
@ -863,8 +854,8 @@ save_call_clobbered_regs (void)
if (cheap
&& HARD_REGISTER_P (cheap)
&& TEST_HARD_REG_BIT (call_used_or_fixed_regs,
REGNO (cheap)))
&& callee_abi.clobbers_reg_p (GET_MODE (cheap),
REGNO (cheap)))
{
rtx dest, newpat;
rtx pat = PATTERN (insn);