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author | dje <dje@138bc75d-0d04-0410-961f-82ee72b054a4> | 1997-03-28 22:38:24 +0000 |
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committer | dje <dje@138bc75d-0d04-0410-961f-82ee72b054a4> | 1997-03-28 22:38:24 +0000 |
commit | 0a29623e46c985fd4d9e42d26f0d32feb5efdd74 (patch) | |
tree | 999c5704b3c88aeabc57a507f7efc9001f0fad46 /gcc/reorg.c | |
parent | 6e5fdcc08a0ece1ac98b7c4c75ae064d7286c539 (diff) | |
download | gcc-0a29623e46c985fd4d9e42d26f0d32feb5efdd74.tar.gz |
* reorg.c (mostly_true_jump): Use REG_BR_PROB notes when
flag_branch_probabilities.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@13819 138bc75d-0d04-0410-961f-82ee72b054a4
Diffstat (limited to 'gcc/reorg.c')
-rw-r--r-- | gcc/reorg.c | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/gcc/reorg.c b/gcc/reorg.c index 8f08afb054b..8cd44731a5e 100644 --- a/gcc/reorg.c +++ b/gcc/reorg.c @@ -1350,6 +1350,26 @@ mostly_true_jump (jump_insn, condition) int rare_dest = rare_destination (target_label); int rare_fallthrough = rare_destination (NEXT_INSN (jump_insn)); + /* If branch probabilities are available, then use that number since it + always gives a correct answer. */ + if (flag_branch_probabilities) + { + rtx note = find_reg_note (jump_insn, REG_BR_PROB, 0);; + if (note) + { + int prob = XINT (note, 0); + + if (prob >= REG_BR_PROB_BASE * 9 / 10) + return 2; + else if (prob >= REG_BR_PROB_BASE / 2) + return 1; + else if (prob >= REG_BR_PROB_BASE / 10) + return 0; + else + return -1; + } + } + /* If this is a branch outside a loop, it is highly unlikely. */ if (GET_CODE (PATTERN (jump_insn)) == SET && GET_CODE (SET_SRC (PATTERN (jump_insn))) == IF_THEN_ELSE |