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author | Bernd Schmidt <bernds@redhat.com> | 2016-11-24 12:22:16 +0000 |
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committer | Bernd Schmidt <bernds@gcc.gnu.org> | 2016-11-24 12:22:16 +0000 |
commit | 2d8fec87b11ecfad75f8cae7910e60e1a61ec61b (patch) | |
tree | 0f02bf897ae9de96a80362cdfcc9efabee71f99e /gcc/ifcvt.c | |
parent | 334442f282a9d61723a0a0f299ba5ad7b00763b8 (diff) | |
download | gcc-2d8fec87b11ecfad75f8cae7910e60e1a61ec61b.zip gcc-2d8fec87b11ecfad75f8cae7910e60e1a61ec61b.tar.gz gcc-2d8fec87b11ecfad75f8cae7910e60e1a61ec61b.tar.bz2 |
re PR rtl-optimization/78120 (If conversion no longer performed)
PR rtl-optimization/78120
* ifcvt.c (noce_conversion_profitable_p): Check original cost in all
cases, and additionally test against max_seq_cost for speed
optimization.
(noce_process_if_block): Compute an estimate for the original cost when
optimizing for speed, using the minimum of then and else block costs.
testsuite/
PR rtl-optimization/78120
* gcc.target/i386/pr78120.c: New test.
From-SVN: r242834
Diffstat (limited to 'gcc/ifcvt.c')
-rw-r--r-- | gcc/ifcvt.c | 31 |
1 files changed, 21 insertions, 10 deletions
diff --git a/gcc/ifcvt.c b/gcc/ifcvt.c index dbe2485..0fdd5b7 100644 --- a/gcc/ifcvt.c +++ b/gcc/ifcvt.c @@ -812,8 +812,10 @@ struct noce_if_info we're optimizing for size. */ bool speed_p; - /* The combined cost of COND, JUMP and the costs for THEN_BB and - ELSE_BB. */ + /* An estimate of the original costs. When optimizing for size, this is the + combined cost of COND, JUMP and the costs for THEN_BB and ELSE_BB. + When optimizing for speed, we use the costs of COND plus the minimum of + the costs for THEN_BB and ELSE_BB, as computed in the next field. */ unsigned int original_cost; /* Maximum permissible cost for the unconditional sequence we should @@ -852,12 +854,12 @@ noce_conversion_profitable_p (rtx_insn *seq, struct noce_if_info *if_info) /* Cost up the new sequence. */ unsigned int cost = seq_cost (seq, speed_p); + if (cost <= if_info->original_cost) + return true; + /* When compiling for size, we can make a reasonably accurately guess - at the size growth. */ - if (!speed_p) - return cost <= if_info->original_cost; - else - return cost <= if_info->max_seq_cost; + at the size growth. When compiling for speed, use the maximum. */ + return speed_p && cost <= if_info->max_seq_cost; } /* Helper function for noce_try_store_flag*. */ @@ -3441,15 +3443,24 @@ noce_process_if_block (struct noce_if_info *if_info) } } - if (! bb_valid_for_noce_process_p (then_bb, cond, &if_info->original_cost, + bool speed_p = optimize_bb_for_speed_p (test_bb); + unsigned int then_cost = 0, else_cost = 0; + if (!bb_valid_for_noce_process_p (then_bb, cond, &then_cost, &if_info->then_simple)) return false; if (else_bb - && ! bb_valid_for_noce_process_p (else_bb, cond, &if_info->original_cost, - &if_info->else_simple)) + && !bb_valid_for_noce_process_p (else_bb, cond, &else_cost, + &if_info->else_simple)) return false; + if (else_bb == NULL) + if_info->original_cost += then_cost; + else if (speed_p) + if_info->original_cost += MIN (then_cost, else_cost); + else + if_info->original_cost += then_cost + else_cost; + insn_a = last_active_insn (then_bb, FALSE); set_a = single_set (insn_a); gcc_assert (set_a); |