From: Kyrylo Tkachov <[email protected]>
Several field comments in ifcvt.h do not match the field they document.
noce_multiple_sets_info::unmodified_insn holds the insn from the original
block, not an insn we emitted, and need_cmov is documented with the opposite
meaning: it is set when the destination is live out, that is, when a plain
move will not do. noce_if_info::original_cost refers to a "next field" that
no longer exists. Fix those, fix two typos, and make ce_if_block::and_and_p
a bool, which is what it holds and how both ifcvt.cc and the frv target hooks
read it.
gcc/ChangeLog:
* ifcvt.h (struct ce_if_block): Make and_and_p a bool.
(struct noce_multiple_sets_info): Correct the unmodified_insn and
need_cmov comments.
(struct noce_if_info): Correct the insn_a/insn_b, speed_p and
original_cost comments.
Signed-off-by: Kyrylo Tkachov <[email protected]>
---
gcc/ifcvt.h | 19 ++++++++++---------
1 file changed, 10 insertions(+), 9 deletions(-)
diff --git a/gcc/ifcvt.h b/gcc/ifcvt.h
index 6d6521a51a2..806ad47158e 100644
--- a/gcc/ifcvt.h
+++ b/gcc/ifcvt.h
@@ -34,7 +34,7 @@ struct ce_if_block
int num_and_and_blocks; /* # of && blocks. */
int num_or_or_blocks; /* # of || blocks. */
int num_multiple_test_insns; /* # of insns in && and || blocks. */
- int and_and_p; /* Complex test is &&. */
+ bool and_and_p; /* Complex test is &&. */
int num_then_insns; /* # of insns in THEN block. */
int num_else_insns; /* # of insns in ELSE block. */
int pass; /* Pass number. */
@@ -50,9 +50,10 @@ struct noce_multiple_sets_info
/* The temporaries introduced to allow us to not consider register
overlap. */
rtx temporary;
- /* The insns we've emitted. */
+ /* The insn from the original block that this entry describes. */
rtx_insn *unmodified_insn;
- /* True if a simple move can be used instead of a conditional move. */
+ /* True if the destination is live out of the block, so the value has to be
+ selected with a conditional move rather than moved unconditionally. */
bool need_cmov;
};
@@ -80,7 +81,7 @@ struct noce_if_info
rtx_insn *cond_earliest;
/* Insns in the THEN and ELSE block. There is always just this
- one insns in those blocks. The insns are single_set insns.
+ one insn in those blocks. The insns are single_set insns.
If there was no ELSE block, INSN_B is the last insn before
COND_EARLIEST, or NULL_RTX. In the former case, the insn
operands are still valid, as if INSN_B was moved down below
@@ -115,14 +116,14 @@ struct noce_if_info
bool then_simple;
bool else_simple;
- /* True if we're optimisizing the control block for speed, false if
+ /* True if we're optimizing the control block for speed, false if
we're optimizing for size. */
bool speed_p;
- /* 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 weighted average
- of the costs for THEN_BB and ELSE_BB, as computed in the next field. */
+ /* An estimate of the cost of the original, un-converted if-region. It
+ covers COND and JUMP plus the arms: both arms when optimizing for size,
+ and their branch-probability-weighted average when optimizing for speed,
+ since then only one of them runs. See noce_original_region_cost. */
unsigned int original_cost;
/* Maximum permissible cost for the unconditional sequence we should
--
2.50.1 (Apple Git-155)
