diff options
| author | sayle <sayle@138bc75d-0d04-0410-961f-82ee72b054a4> | 2004-07-06 21:50:47 +0000 |
|---|---|---|
| committer | sayle <sayle@138bc75d-0d04-0410-961f-82ee72b054a4> | 2004-07-06 21:50:47 +0000 |
| commit | 6bc02093c0f3fd324b8ab0732a24059e233bc215 (patch) | |
| tree | 002fe8f401ebeb12dbd0037128fbc763942657be /gcc/ifcvt.c | |
| parent | 1f445250410fd24b8185675685c85d401fb9538d (diff) | |
| download | gcc-6bc02093c0f3fd324b8ab0732a24059e233bc215.tar.gz | |
* ifcvt.c (struct noce_if_info): Add a Boolean b_unconditional field.
(noce_try_sign_mask): Tweak rtx_cost check if t is evaluated anyway.
(noce_process_if_block): Initialize if_info.b_unconditional if insn_b
is currently executed unconditionally, i.e. not in "else_bb".
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@84172 138bc75d-0d04-0410-961f-82ee72b054a4
Diffstat (limited to 'gcc/ifcvt.c')
| -rw-r--r-- | gcc/ifcvt.c | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/gcc/ifcvt.c b/gcc/ifcvt.c index 0be64727d35..03efaba2ebb 100644 --- a/gcc/ifcvt.c +++ b/gcc/ifcvt.c @@ -579,6 +579,8 @@ struct noce_if_info rtx insn_a, insn_b; rtx x, a, b; rtx jump, cond, cond_earliest; + /* True if "b" was originally evaluated unconditionally. */ + bool b_unconditional; }; static rtx noce_emit_store_flag (struct noce_if_info *, rtx, int, int); @@ -1730,8 +1732,11 @@ noce_try_sign_mask (struct noce_if_info *if_info) if (GET_MODE (m) != mode) return FALSE; - /* This is only profitable if T is cheap. */ - if (rtx_cost (t, SET) >= COSTS_N_INSNS (2)) + /* This is only profitable if T is cheap, or T is unconditionally + executed/evaluated in the original insn sequence. */ + if (rtx_cost (t, SET) >= COSTS_N_INSNS (2) + && (!if_info->b_unconditional + || t != if_info->b)) return FALSE; start_sequence (); @@ -1983,6 +1988,7 @@ noce_process_if_block (struct ce_if_block * ce_info) if_info.x = x; if_info.a = a; if_info.b = b; + if_info.b_unconditional = else_bb == 0; /* Try optimizations in some approximation of a useful order. */ /* ??? Should first look to see if X is live incoming at all. If it |