diff options
| author | Richard Sandiford <richard.sandiford@arm.com> | 2019-10-02 07:37:10 +0000 |
|---|---|---|
| committer | Richard Sandiford <richard.sandiford@arm.com> | 2019-10-02 07:37:10 +0000 |
| commit | 3788347bb851286e6eb30e39f7d4d1128e09050c (patch) | |
| tree | d29b20b9358a62cfb213ea3187e21dd34668432f /gcc/lra-lives.c | |
| parent | 97c752540c8185fd682866c6de377e29409b01b4 (diff) | |
[LRA] Don't make eliminable registers live (PR91957)
One effect of https://gcc.gnu.org/ml/gcc-patches/2019-09/msg00802.html
was to strengthen the sanity check in lra_assigns so that it checks
whether reg_renumber is consistent with the whole conflict set.
This duly tripped on csky for a pseudo that had been allocated
to the eliminated frame pointer. (csky doesn't have a separate
hard frame pointer.)
lra-lives uses:
/* Set of hard regs (except eliminable ones) currently live. */
static HARD_REG_SET hard_regs_live;
to track the set of live directly-referenced hard registers, and it
correctly implements the exclusion when setting up the initial set:
hard_regs_live &= ~eliminable_regset;
But later calls to make_hard_regno_live and make_hard_regno_dead
would process eliminable registers like other registers, recording
conflicts for them and potentially making them live. (Note that
after r266086, make_hard_regno_dead adds conflicts for registers
that are already marked dead.) I think this would have had the
effect of pessimising targets without a separate hard frame pointer.
2019-10-02 Richard Sandiford <richard.sandiford@arm.com>
gcc/
PR middle-end/91957
* lra-lives.c (make_hard_regno_dead): Don't record conflicts for
eliminable registers.
(make_hard_regno_live): Likewise, and don't make them live.
git-svn-id: https://gcc.gnu.org/svn/gcc/trunk@276440 138bc75d-0d04-0410-961f-82ee72b054a4
Diffstat (limited to 'gcc/lra-lives.c')
| -rw-r--r-- | gcc/lra-lives.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/gcc/lra-lives.c b/gcc/lra-lives.c index 389a79d701d..1d1525ca2e5 100644 --- a/gcc/lra-lives.c +++ b/gcc/lra-lives.c @@ -281,7 +281,8 @@ static void make_hard_regno_live (int regno) { lra_assert (HARD_REGISTER_NUM_P (regno)); - if (TEST_HARD_REG_BIT (hard_regs_live, regno)) + if (TEST_HARD_REG_BIT (hard_regs_live, regno) + || TEST_HARD_REG_BIT (eliminable_regset, regno)) return; SET_HARD_REG_BIT (hard_regs_live, regno); sparseset_set_bit (start_living, regno); @@ -295,6 +296,9 @@ make_hard_regno_live (int regno) static void make_hard_regno_dead (int regno) { + if (TEST_HARD_REG_BIT (eliminable_regset, regno)) + return; + lra_assert (HARD_REGISTER_NUM_P (regno)); unsigned int i; EXECUTE_IF_SET_IN_SPARSESET (pseudos_live, i) |