diff options
Diffstat (limited to 'gcc/tree-data-ref.h')
| -rw-r--r-- | gcc/tree-data-ref.h | 168 |
1 files changed, 65 insertions, 103 deletions
diff --git a/gcc/tree-data-ref.h b/gcc/tree-data-ref.h index e339d9844e5..2edee2c7716 100644 --- a/gcc/tree-data-ref.h +++ b/gcc/tree-data-ref.h @@ -26,48 +26,73 @@ Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA #include "omega.h" /* - The first location accessed by data-ref in the loop is the address of data-ref's - base (BASE_ADDRESS) plus the initial offset from the base. We divide the initial offset - into two parts: loop invariant offset (OFFSET) and constant offset (INIT). - STEP is the stride of data-ref in the loop in bytes. + innermost_loop_behavior describes the evolution of the address of the memory + reference in the innermost enclosing loop. The address is expressed as + BASE + STEP * # of iteration, and base is further decomposed as the base + pointer (BASE_ADDRESS), loop invariant offset (OFFSET) and + constant offset (INIT). Examples, in loop nest + + for (i = 0; i < 100; i++) + for (j = 3; j < 100; j++) Example 1 Example 2 - data-ref a[j].b[i][j] a + x + 16B (a is int*) + data-ref a[j].b[i][j] *(p + x + 16B + 4B * j) - First location info: - base_address &a a - offset j_0*D_j + i_0*D_i x - init C_b + C_a 16 + innermost_loop_behavior + base_address &a p + offset i * D_i x + init 3 * D_j + offsetof (b) 28 step D_j 4 - access_fn NULL {16, +, 1} - - Base object info: - base_object a NULL - access_fn <access_fns of indexes of b> NULL */ -struct first_location_in_loop +struct innermost_loop_behavior { tree base_address; tree offset; tree init; tree step; - /* Access function related to first location in the loop. */ - VEC(tree,heap) *access_fns; + + /* Alignment information. ALIGNED_TO is set to the largest power of two + that divides OFFSET. */ + tree aligned_to; }; -struct base_object_info +/* Describes the evolutions of indices of the memory reference. The indices + are indices of the ARRAY_REFs and the operands of INDIRECT_REFs. + For ARRAY_REFs, BASE_OBJECT is the reference with zeroed indices + (note that this reference does not have to be valid, if zero does not + belong to the range of the array; hence it is not recommended to use + BASE_OBJECT in any code generation). For INDIRECT_REFs, the address is + set to the loop-invariant part of the address of the object, except for + the constant offset. For the examples above, + + base_object: a[0].b[0][0] *(p + x + 4B * j_0) + indices: {j_0, +, 1}_2 {16, +, 4}_2 + {i_0, +, 1}_1 + {j_0, +, 1}_2 +*/ + +struct indices { /* The object. */ tree base_object; - /* A list of chrecs. Access functions related to BASE_OBJECT. */ + /* A list of chrecs. Access functions of the indices. */ VEC(tree,heap) *access_fns; }; -enum data_ref_type { - ARRAY_REF_TYPE, - POINTER_REF_TYPE +struct dr_alias +{ + /* The alias information that should be used for new pointers to this + location. SYMBOL_TAG is either a DECL or a SYMBOL_MEMORY_TAG. */ + tree symbol_tag; + subvar_t subvars; + struct ptr_info_def *ptr_info; + + /* The set of virtual operands corresponding to this memory reference, + serving as a description of the alias information for the memory + reference. This could be eliminated if we had alias oracle. */ + bitmap vops; }; struct data_reference @@ -75,7 +100,7 @@ struct data_reference /* A pointer to the statement that contains this DR. */ tree stmt; - /* A pointer to the ARRAY_REF node. */ + /* A pointer to the memory reference. */ tree ref; /* Auxiliary info specific to a pass. */ @@ -84,58 +109,14 @@ struct data_reference /* True when the data reference is in RHS of a stmt. */ bool is_read; - /* First location accessed by the data-ref in the loop. */ - struct first_location_in_loop first_location; + /* Behavior of the memory reference in the innermost loop. */ + struct innermost_loop_behavior innermost; - /* Base object related info. */ - struct base_object_info object_info; + /* Decomposition to indices for alias analysis. */ + struct indices indices; - /* Aliasing information. This field represents the symbol that - should be aliased by a pointer holding the address of this data - reference. If the original data reference was a pointer - dereference, then this field contains the memory tag that should - be used by the new vector-pointer. */ - tree memtag; - struct ptr_info_def *ptr_info; - subvar_t subvars; - - /* Alignment information. - MISALIGNMENT is the offset of the data-reference from its base in bytes. - ALIGNED_TO is the maximum data-ref's alignment. - - Example 1, - for i - for (j = 3; j < N; j++) - a[j].b[i][j] = 0; - - For a[j].b[i][j], the offset from base (calculated in get_inner_reference() - will be 'i * C_i + j * C_j + C'. - We try to substitute the variables of the offset expression - with initial_condition of the corresponding access_fn in the loop. - 'i' cannot be substituted, since its access_fn in the inner loop is i. 'j' - will be substituted with 3. - - Example 2 - for (j = 3; j < N; j++) - a[j].b[5][j] = 0; - - Here the offset expression (j * C_j + C) will not contain variables after - substitution of j=3 (3*C_j + C). - - Misalignment can be calculated only if all the variables can be - substituted with constants, otherwise, we record maximum possible alignment - in ALIGNED_TO. In Example 1, since 'i' cannot be substituted, - MISALIGNMENT will be NULL_TREE, and the biggest divider of C_i (a power of - 2) will be recorded in ALIGNED_TO. - - In Example 2, MISALIGNMENT will be the value of 3*C_j + C in bytes, and - ALIGNED_TO will be NULL_TREE. - */ - tree misalignment; - tree aligned_to; - - /* The type of the data-ref. */ - enum data_ref_type type; + /* Alias information for the data reference. */ + struct dr_alias alias; }; typedef struct data_reference *data_reference_p; @@ -144,37 +125,20 @@ DEF_VEC_ALLOC_P (data_reference_p, heap); #define DR_STMT(DR) (DR)->stmt #define DR_REF(DR) (DR)->ref -#define DR_BASE_OBJECT(DR) (DR)->object_info.base_object -#define DR_TYPE(DR) (DR)->type -#define DR_ACCESS_FNS(DR)\ - (DR_TYPE(DR) == ARRAY_REF_TYPE ? \ - (DR)->object_info.access_fns : (DR)->first_location.access_fns) +#define DR_BASE_OBJECT(DR) (DR)->indices.base_object +#define DR_ACCESS_FNS(DR) (DR)->indices.access_fns #define DR_ACCESS_FN(DR, I) VEC_index (tree, DR_ACCESS_FNS (DR), I) #define DR_NUM_DIMENSIONS(DR) VEC_length (tree, DR_ACCESS_FNS (DR)) #define DR_IS_READ(DR) (DR)->is_read -#define DR_BASE_ADDRESS(DR) (DR)->first_location.base_address -#define DR_OFFSET(DR) (DR)->first_location.offset -#define DR_INIT(DR) (DR)->first_location.init -#define DR_STEP(DR) (DR)->first_location.step -#define DR_MEMTAG(DR) (DR)->memtag -#define DR_ALIGNED_TO(DR) (DR)->aligned_to -#define DR_OFFSET_MISALIGNMENT(DR) (DR)->misalignment -#define DR_PTR_INFO(DR) (DR)->ptr_info -#define DR_SUBVARS(DR) (DR)->subvars -#define DR_SET_ACCESS_FNS(DR, ACC_FNS) \ -{ \ - if (DR_TYPE(DR) == ARRAY_REF_TYPE) \ - (DR)->object_info.access_fns = ACC_FNS; \ - else \ - (DR)->first_location.access_fns = ACC_FNS; \ -} -#define DR_FREE_ACCESS_FNS(DR) \ -{ \ - if (DR_TYPE(DR) == ARRAY_REF_TYPE) \ - VEC_free (tree, heap, (DR)->object_info.access_fns); \ - else \ - VEC_free (tree, heap, (DR)->first_location.access_fns); \ -} +#define DR_BASE_ADDRESS(DR) (DR)->innermost.base_address +#define DR_OFFSET(DR) (DR)->innermost.offset +#define DR_INIT(DR) (DR)->innermost.init +#define DR_STEP(DR) (DR)->innermost.step +#define DR_SYMBOL_TAG(DR) (DR)->alias.symbol_tag +#define DR_PTR_INFO(DR) (DR)->alias.ptr_info +#define DR_SUBVARS(DR) (DR)->alias.subvars +#define DR_VOPS(DR) (DR)->alias.vops +#define DR_ALIGNED_TO(DR) (DR)->innermost.aligned_to enum data_dependence_direction { dir_positive, @@ -335,8 +299,6 @@ DEF_VEC_O (data_ref_loc); DEF_VEC_ALLOC_O (data_ref_loc, heap); bool get_references_in_stmt (tree, VEC (data_ref_loc, heap) **); -extern tree find_data_references_in_loop (struct loop *, - VEC (data_reference_p, heap) **); extern void compute_data_dependences_for_loop (struct loop *, bool, VEC (data_reference_p, heap) **, VEC (ddr_p, heap) **); |