diff options
Diffstat (limited to 'gcc/tree-vectorizer.h')
| -rw-r--r-- | gcc/tree-vectorizer.h | 48 |
1 files changed, 25 insertions, 23 deletions
diff --git a/gcc/tree-vectorizer.h b/gcc/tree-vectorizer.h index 9be4d15..828a541 100644 --- a/gcc/tree-vectorizer.h +++ b/gcc/tree-vectorizer.h @@ -390,7 +390,6 @@ is_a_helper <_bb_vec_info *>::test (vec_info *i) return i->kind == vec_info::bb; } - /* In general, we can divide the vector statements in a vectorized loop into related groups ("rgroups") and say that for each rgroup there is some nS such that the rgroup operates on nS values from one scalar @@ -420,19 +419,21 @@ is_a_helper <_bb_vec_info *>::test (vec_info *i) In classical vectorization, each iteration of the vector loop would handle exactly VF iterations of the original scalar loop. However, - in a fully-masked loop, a particular iteration of the vector loop - might handle fewer than VF iterations of the scalar loop. The vector - lanes that correspond to iterations of the scalar loop are said to be - "active" and the other lanes are said to be "inactive". - - In a fully-masked loop, many rgroups need to be masked to ensure that - they have no effect for the inactive lanes. Each such rgroup needs a - sequence of booleans in the same order as above, but with each (i,j) - replaced by a boolean that indicates whether iteration i is active. - This sequence occupies nV vector masks that again have nL lanes each. - Thus the mask sequence as a whole consists of VF independent booleans - that are each repeated nS times. - + in vector loops that are able to operate on partial vectors, a + particular iteration of the vector loop might handle fewer than VF + iterations of the scalar loop. The vector lanes that correspond to + iterations of the scalar loop are said to be "active" and the other + lanes are said to be "inactive". + + In such vector loops, many rgroups need to be controlled to ensure + that they have no effect for the inactive lanes. Conceptually, each + such rgroup needs a sequence of booleans in the same order as above, + but with each (i,j) replaced by a boolean that indicates whether + iteration i is active. This sequence occupies nV vector controls + that again have nL lanes each. Thus the control sequence as a whole + consists of VF independent booleans that are each repeated nS times. + + Taking mask-based approach as a partially-populated vectors example. We make the simplifying assumption that if a sequence of nV masks is suitable for one (nS,nL) pair, we can reuse it for (nS/2,nL/2) by VIEW_CONVERTing it. This holds for all current targets that support @@ -472,20 +473,21 @@ is_a_helper <_bb_vec_info *>::test (vec_info *i) first level being indexed by nV - 1 (since nV == 0 doesn't exist) and the second being indexed by the mask index 0 <= i < nV. */ -/* The masks needed by rgroups with nV vectors, according to the - description above. */ -struct rgroup_masks { - /* The largest nS for all rgroups that use these masks. */ +/* The controls (like masks) needed by rgroups with nV vectors, + according to the description above. */ +struct rgroup_controls { + /* The largest nS for all rgroups that use these controls. */ unsigned int max_nscalars_per_iter; - /* The type of mask to use, based on the highest nS recorded above. */ - tree mask_type; + /* The type of control to use, based on the highest nS recorded above. + For mask-based approach, it's used for mask_type. */ + tree type; - /* A vector of nV masks, in iteration order. */ - vec<tree> masks; + /* A vector of nV controls, in iteration order. */ + vec<tree> controls; }; -typedef auto_vec<rgroup_masks> vec_loop_masks; +typedef auto_vec<rgroup_controls> vec_loop_masks; typedef auto_vec<std::pair<data_reference*, tree> > drs_init_vec; |