diff options
Diffstat (limited to 'gcc/tree-vect-patterns.c')
| -rw-r--r-- | gcc/tree-vect-patterns.c | 22 |
1 files changed, 17 insertions, 5 deletions
diff --git a/gcc/tree-vect-patterns.c b/gcc/tree-vect-patterns.c index 429dd87..758d4bc 100644 --- a/gcc/tree-vect-patterns.c +++ b/gcc/tree-vect-patterns.c @@ -1016,10 +1016,8 @@ vect_pattern_recog_1 ( If vectorization succeeds, vect_transform_stmt will skip over {S1,S2,S3} (because they are marked as irrelevant). It will vectorize S6, and record - a pointer to the new vector stmt VS6 both from S6 (as usual), and also - from S4. We do that so that when we get to vectorizing stmts that use the - def of S4 (like S5 that uses a_0), we'll know where to take the relevant - vector-def from. S4 will be skipped, and S5 will be vectorized as usual: + a pointer to the new vector stmt VS6 from S6 (as usual). + S4 will be skipped, and S5 will be vectorized as usual: in_pattern_p related_stmt vec_stmt S1: a_i = .... - - - @@ -1035,7 +1033,21 @@ vect_pattern_recog_1 ( elsewhere), and we'll end up with: VS6: va_new = .... - VS5: ... = ..vuse(va_new).. */ + VS5: ... = ..vuse(va_new).. + + In case of more than one pattern statements, e.g., widen-mult with + intermediate type: + + S1 a_t = ; + S2 a_T = (TYPE) a_t; + '--> S3: a_it = (interm_type) a_t; + S4 prod_T = a_T * CONST; + '--> S5: prod_T' = a_it w* CONST; + + there may be other users of a_T outside the pattern. In that case S2 will + be marked as relevant (as well as S3), and both S2 and S3 will be analyzed + and vectorized. The vector stmt VS2 will be recorded in S2, and VS3 will + be recorded in S3. */ void vect_pattern_recog (loop_vec_info loop_vinfo) |