diff options
Diffstat (limited to 'gcc/tree-vect-patterns.c')
| -rw-r--r-- | gcc/tree-vect-patterns.c | 32 |
1 files changed, 14 insertions, 18 deletions
diff --git a/gcc/tree-vect-patterns.c b/gcc/tree-vect-patterns.c index f0add8c6074..482b5531797 100644 --- a/gcc/tree-vect-patterns.c +++ b/gcc/tree-vect-patterns.c @@ -831,9 +831,9 @@ vect_pattern_recog_1 ( } /* Mark the stmts that are involved in the pattern. */ - gsi_insert_before (&si, pattern_stmt, GSI_SAME_STMT); set_vinfo_for_stmt (pattern_stmt, new_stmt_vec_info (pattern_stmt, loop_vinfo, NULL)); + gimple_set_bb (pattern_stmt, gimple_bb (stmt)); pattern_stmt_info = vinfo_for_stmt (pattern_stmt); STMT_VINFO_RELATED_STMT (pattern_stmt_info) = stmt; @@ -856,8 +856,8 @@ vect_pattern_recog_1 ( LOOP_VINFO - a struct_loop_info of a loop in which we want to look for computation idioms. - Output - for each computation idiom that is detected we insert a new stmt - that provides the same functionality and that can be vectorized. We + Output - for each computation idiom that is detected we create a new stmt + that provides the same functionality and that can be vectorized. We also record some information in the struct_stmt_info of the relevant stmts, as explained below: @@ -872,52 +872,48 @@ vect_pattern_recog_1 ( S5: ... = ..use(a_0).. - - - Say the sequence {S1,S2,S3,S4} was detected as a pattern that can be - represented by a single stmt. We then: - - create a new stmt S6 that will replace the pattern. - - insert the new stmt S6 before the last stmt in the pattern + represented by a single stmt. We then: + - create a new stmt S6 equivalent to the pattern (the stmt is not + inserted into the code) - fill in the STMT_VINFO fields as follows: in_pattern_p related_stmt vec_stmt S1: a_i = .... - - - S2: a_2 = ..use(a_i).. - - - S3: a_1 = ..use(a_2).. - - - - > S6: a_new = .... - S4 - S4: a_0 = ..use(a_1).. true S6 - + '---> S6: a_new = .... - S4 - S5: ... = ..use(a_0).. - - - (the last stmt in the pattern (S4) and the new pattern stmt (S6) point - to each other through the RELATED_STMT field). + to each other through the RELATED_STMT field). S6 will be marked as relevant in vect_mark_stmts_to_be_vectorized instead of S4 because it will replace all its uses. Stmts {S1,S2,S3} will remain irrelevant unless used by stmts other than S4. If vectorization succeeds, vect_transform_stmt will skip over {S1,S2,S3} - (because they are marked as irrelevant). It will vectorize S6, and record + (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 + 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: + vector-def from. S4 will be skipped, and S5 will be vectorized as usual: in_pattern_p related_stmt vec_stmt S1: a_i = .... - - - S2: a_2 = ..use(a_i).. - - - S3: a_1 = ..use(a_2).. - - - > VS6: va_new = .... - - - - S6: a_new = .... - S4 VS6 S4: a_0 = ..use(a_1).. true S6 VS6 + '---> S6: a_new = .... - S4 VS6 > VS5: ... = ..vuse(va_new).. - - - S5: ... = ..use(a_0).. - - - - DCE could then get rid of {S1,S2,S3,S4,S5,S6} (if their defs are not used + DCE could then get rid of {S1,S2,S3,S4,S5} (if their defs are not used elsewhere), and we'll end up with: VS6: va_new = .... - VS5: ... = ..vuse(va_new).. - - If vectorization does not succeed, DCE will clean S6 away (its def is - not used), and we'll end up with the original sequence. -*/ + VS5: ... = ..vuse(va_new).. */ void vect_pattern_recog (loop_vec_info loop_vinfo) |