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.
2019-09-11 Richard Sandiford <richard.sandif...@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.
Index: gcc/caller-save.c
===================================================================
--- gcc/caller-save.c 2019-09-11 19:47:24.402262786 +0100
+++ gcc/caller-save.c 2019-09-11 19:47:45.710112631 +0100
@@ -428,8 +428,6 @@ setup_save_areas (void)
REG_SET_TO_HARD_REG_SET (hard_regs_to_save,
&chain->live_throughout);
used_regs = call_insn_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 = call_insn_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 abi = call_insn_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 = call_insn_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 &= abi.full_reg_clobbers ();
for (regno = 0; regno < FIRST_PSEUDO_REGISTER; regno++)
if (TEST_HARD_REG_BIT (hard_regs_to_save, regno))
@@ -863,8 +854,7 @@ save_call_clobbered_regs (void)
if (cheap
&& HARD_REGISTER_P (cheap)
- && TEST_HARD_REG_BIT (call_used_or_fixed_regs,
- REGNO (cheap)))
+ && abi.clobbers_reg_p (GET_MODE (cheap), REGNO (cheap)))
{
rtx dest, newpat;
rtx pat = PATTERN (insn);
