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| author | Andreas Krebbel <krebbel@linux.ibm.com> | 2019-06-06 11:35:04 +0000 |
|---|---|---|
| committer | Andreas Krebbel <krebbel@gcc.gnu.org> | 2019-06-06 11:35:04 +0000 |
| commit | 891f31f9a45dec393e8c1919427a4f136b554863 (patch) | |
| tree | 97d3b3e6608fac4176c7e192fa0e1e80a7c062ff | |
| parent | a96ed9f7d9b68237b507d454f014d1871c0435d5 (diff) | |
| download | gcc-891f31f9a45dec393e8c1919427a4f136b554863.zip gcc-891f31f9a45dec393e8c1919427a4f136b554863.tar.gz gcc-891f31f9a45dec393e8c1919427a4f136b554863.tar.bz2 | |
re PR rtl-optimization/88751 (Performance regression reload vs lra)
Fix PR88751
This patch implements a small improvement for the heuristic in lra
which decides when it has to activate the simpler register allocation
algorithm.
gcc/ChangeLog:
2019-06-06 Andreas Krebbel <krebbel@linux.ibm.com>
PR rtl-optimization/88751
* ira.c (ira): Use the number of the actually referenced registers
when calculating the threshold.
From-SVN: r271996
| -rw-r--r-- | gcc/ChangeLog | 6 | ||||
| -rw-r--r-- | gcc/ira.c | 9 |
2 files changed, 14 insertions, 1 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 9dbe57a..012af38 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,9 @@ +2019-06-06 Andreas Krebbel <krebbel@linux.ibm.com> + + PR rtl-optimization/88751 + * ira.c (ira): Use the number of the actually referenced registers + when calculating the threshold. + 2019-06-06 Jakub Jelinek <jakub@redhat.com> * configure: Regenerate. @@ -5198,6 +5198,8 @@ ira (FILE *f) int ira_max_point_before_emit; bool saved_flag_caller_saves = flag_caller_saves; enum ira_region saved_flag_ira_region = flag_ira_region; + unsigned int i; + int num_used_regs = 0; clear_bb_flags (); @@ -5213,12 +5215,17 @@ ira (FILE *f) ira_conflicts_p = optimize > 0; + /* Determine the number of pseudos actually requiring coloring. */ + for (i = FIRST_PSEUDO_REGISTER; i < DF_REG_SIZE (df); i++) + num_used_regs += !!(DF_REG_USE_COUNT (i) + DF_REG_DEF_COUNT (i)); + /* If there are too many pseudos and/or basic blocks (e.g. 10K pseudos and 10K blocks or 100K pseudos and 1K blocks), we will use simplified and faster algorithms in LRA. */ lra_simple_p = (ira_use_lra_p - && max_reg_num () >= (1 << 26) / last_basic_block_for_fn (cfun)); + && num_used_regs >= (1 << 26) / last_basic_block_for_fn (cfun)); + if (lra_simple_p) { /* It permits to skip live range splitting in LRA. */ |