Hi Julian! On 2019-10-06T15:32:36-0700, Julian Brown <jul...@codesourcery.com> wrote: > This patch factors out some code in gimplify_scan_omp_clauses into two > new outlined functions.
Yay for such simplification, and yay for documenting what's going on! > Previously approved here: > > https://gcc.gnu.org/ml/gcc-patches/2018-12/msg01309.html > > FAOD, OK for trunk? I have not reviewed whether it's a suitable refactoring; I'm not at all familiar with that code. I started to "functionally" review it by re-inlining your outlined code, and checking the differences to the original code. Additionally to the 'gcc_assert' item I just raised with Jakub, there are a few more things I don't understand: > gcc/ > * gimplify.c (insert_struct_comp_map, check_base_and_compare_lt): New. > (gimplify_scan_omp_clauses): Outline duplicated code into calls to > above two functions. > --- > gcc/gimplify.c | 307 ++++++++++++++++++++++++++++--------------------- > 1 file changed, 174 insertions(+), 133 deletions(-) > --- a/gcc/gimplify.c > +++ b/gcc/gimplify.c > @@ -8120,6 +8120,160 @@ gimplify_omp_depend (tree *list_p, gimple_seq *pre_p) > return 1; > } > > +/* Insert a GOMP_MAP_ALLOC or GOMP_MAP_RELEASE node following a > + GOMP_MAP_STRUCT mapping. C is an always_pointer mapping. STRUCT_NODE is > + the struct node to insert the new mapping after (when the struct node is > + initially created). PREV_NODE is the first of two or three mappings for a > + pointer, and is either: > + - the node before C, when a pair of mappings is used, e.g. for a C/C++ > + array section. > + - not the node before C. This is true when we have a > reference-to-pointer > + type (with a mapping for the reference and for the pointer), or for > + Fortran derived-type mappings with a GOMP_MAP_TO_PSET. > + If SCP is non-null, the new node is inserted before *SCP. > + if SCP is null, the new node is inserted before PREV_NODE. > + The return type is: > + - PREV_NODE, if SCP is non-null. > + - The newly-created ALLOC or RELEASE node, if SCP is null. > + - The second newly-created ALLOC or RELEASE node, if we are mapping a > + reference to a pointer. */ > + > +static tree > +insert_struct_comp_map (enum tree_code code, tree c, tree struct_node, > + tree prev_node, tree *scp) > +{ > + enum gomp_map_kind mkind > + = ((code == OMP_TARGET_EXIT_DATA || code == OACC_EXIT_DATA) > + ? GOMP_MAP_RELEASE : GOMP_MAP_ALLOC); The original code does not handle 'OACC_EXIT_DATA', so that will be a change separate from this refactoring? > + > + tree c2 = build_omp_clause (OMP_CLAUSE_LOCATION (c), OMP_CLAUSE_MAP); > + tree cl = scp ? prev_node : c2; > + OMP_CLAUSE_SET_MAP_KIND (c2, mkind); > + OMP_CLAUSE_DECL (c2) = unshare_expr (OMP_CLAUSE_DECL (c)); > + OMP_CLAUSE_CHAIN (c2) = scp ? *scp : prev_node; > + OMP_CLAUSE_SIZE (c2) = TYPE_SIZE_UNIT (ptr_type_node); > + if (struct_node) > + OMP_CLAUSE_CHAIN (struct_node) = c2; > + > + /* We might need to create an additional mapping if we have a reference to > a > + pointer (in C++). Don't do this if we have something other than a > + GOMP_MAP_ALWAYS_POINTER though, i.e. a GOMP_MAP_TO_PSET. */ > + if (OMP_CLAUSE_CHAIN (prev_node) != c > + && OMP_CLAUSE_CODE (OMP_CLAUSE_CHAIN (prev_node)) == OMP_CLAUSE_MAP > + && (OMP_CLAUSE_MAP_KIND (OMP_CLAUSE_CHAIN (prev_node)) > + == GOMP_MAP_ALWAYS_POINTER)) In the original code, and with 'prev_node' being '*prev_list_p', this condition was just 'if (OMP_CLAUSE_CHAIN (*prev_list_p) != c)', without the 'GOMP_MAP_ALWAYS_POINTER' handling, so that'd be another change separate from this refactoring? > + { > + tree c4 = OMP_CLAUSE_CHAIN (prev_node); > + tree c3 = build_omp_clause (OMP_CLAUSE_LOCATION (c), OMP_CLAUSE_MAP); > + OMP_CLAUSE_SET_MAP_KIND (c3, mkind); > + OMP_CLAUSE_DECL (c3) = unshare_expr (OMP_CLAUSE_DECL (c4)); > + OMP_CLAUSE_SIZE (c3) = TYPE_SIZE_UNIT (ptr_type_node); > + OMP_CLAUSE_CHAIN (c3) = prev_node; > + if (!scp) > + OMP_CLAUSE_CHAIN (c2) = c3; > + else > + cl = c3; > + } > + > + if (scp) > + *scp = c2; > + > + return cl; > +} > + > +/* Called initially with ORIG_BASE non-null, sets PREV_BITPOS and > PREV_POFFSET > + to the offset of the field given in BASE. Return type is 1 if BASE is > equal > + to *ORIG_BASE after stripping off ARRAY_REF and INDIRECT_REF nodes and > + calling get_inner_reference, else 0. > + > + Called subsequently with ORIG_BASE null, compares the offset of the field > + given in BASE to PREV_BITPOS, PREV_POFFSET. Returns -1 if the base object > + has changed, 0 if the new value has a higher bit position than that > + described by the aforementioned arguments, or 1 if the new value is less > + than them. Used for (insertion) sorting components after a > GOMP_MAP_STRUCT > + mapping. */ Hmm, that doesn't seem to be the most intuitive API: the 'orig_base' handling, specifically. (See my struggle below.) > + > +static int > +check_base_and_compare_lt (tree base, tree *orig_base, tree decl, > + poly_int64 *prev_bitpos, > + poly_offset_int *prev_poffset) > +{ > + tree offset; > + poly_int64 bitsize, bitpos; > + machine_mode mode; > + int unsignedp, reversep, volatilep = 0; > + poly_offset_int poffset; > + > + if (orig_base) > + { > + while (TREE_CODE (base) == ARRAY_REF) > + base = TREE_OPERAND (base, 0); > + > + if (TREE_CODE (base) == INDIRECT_REF) > + base = TREE_OPERAND (base, 0); > + } > + else > + { > + if (TREE_CODE (base) == ARRAY_REF) > + { > + while (TREE_CODE (base) == ARRAY_REF) > + base = TREE_OPERAND (base, 0); > + if (TREE_CODE (base) != COMPONENT_REF > + || TREE_CODE (TREE_TYPE (base)) != ARRAY_TYPE) > + return -1; > + } > + else if (TREE_CODE (base) == INDIRECT_REF > + && TREE_CODE (TREE_OPERAND (base, 0)) == COMPONENT_REF > + && (TREE_CODE (TREE_TYPE (TREE_OPERAND (base, 0))) > + == REFERENCE_TYPE)) > + base = TREE_OPERAND (base, 0); > + } > + > + base = get_inner_reference (base, &bitsize, &bitpos, &offset, &mode, > + &unsignedp, &reversep, &volatilep); > + > + if (orig_base) > + *orig_base = base; > + > + if ((TREE_CODE (base) == INDIRECT_REF > + || (TREE_CODE (base) == MEM_REF > + && integer_zerop (TREE_OPERAND (base, 1)))) > + && DECL_P (TREE_OPERAND (base, 0)) > + && TREE_CODE (TREE_TYPE (TREE_OPERAND (base, 0))) == REFERENCE_TYPE) > + base = TREE_OPERAND (base, 0); > + > + gcc_assert (offset == NULL_TREE || poly_int_tree_p (offset)); > + > + if (offset) > + poffset = wi::to_poly_offset (offset); > + else > + poffset = 0; > + > + if (maybe_ne (bitpos, 0)) > + poffset += bits_to_bytes_round_down (bitpos); > + I find the block of code following below until the end of the function a bit unwieldy to (a) understand, and (b) relate to the original code: > + if (orig_base) > + { > + gcc_assert (base == decl); > + > + *prev_bitpos = bitpos; > + *prev_poffset = poffset; > + > + return *orig_base == base; > + } > + else > + { > + if (base != decl) > + return -1; > + > + return (maybe_lt (*prev_poffset, poffset) > + || (known_eq (*prev_poffset, poffset) > + && maybe_lt (*prev_bitpos, bitpos))); > + } > + > + return 0; > +} Can this be done differently, to make it easier to understand? For example, would it help if that code was not outlined into 'insert_struct_comp_map', but kept in its original places? At least on first sight that seemsa reasonable thing to do, given that it's just two separate variants/code paths (as guarded by 'if (orig_base)'), where the first of two calls takes the first branch ('orig_base' supplied), and the other caller takes the second branch ('orig_base' not supplied). If you tell me that's not feasible, then I shall again try to understand that code in the form you've proposed. Grüße Thomas > @@ -8660,29 +8814,14 @@ gimplify_scan_omp_clauses (tree *list_p, gimple_seq > *pre_p, > } > } > > - tree offset; > - poly_int64 bitsize, bitpos; > - machine_mode mode; > - int unsignedp, reversep, volatilep = 0; > - tree base = OMP_CLAUSE_DECL (c); > - while (TREE_CODE (base) == ARRAY_REF) > - base = TREE_OPERAND (base, 0); > - if (TREE_CODE (base) == INDIRECT_REF) > - base = TREE_OPERAND (base, 0); > - base = get_inner_reference (base, &bitsize, &bitpos, &offset, > - &mode, &unsignedp, &reversep, > - &volatilep); > - tree orig_base = base; > - if ((TREE_CODE (base) == INDIRECT_REF > - || (TREE_CODE (base) == MEM_REF > - && integer_zerop (TREE_OPERAND (base, 1)))) > - && DECL_P (TREE_OPERAND (base, 0)) > - && (TREE_CODE (TREE_TYPE (TREE_OPERAND (base, 0))) > - == REFERENCE_TYPE)) > - base = TREE_OPERAND (base, 0); > - gcc_assert (base == decl > - && (offset == NULL_TREE > - || poly_int_tree_p (offset))); > + tree orig_base; > + poly_int64 bitpos1; > + poly_offset_int offset1; > + > + int base_eq_orig_base > + = check_base_and_compare_lt (OMP_CLAUSE_DECL (c), > + &orig_base, decl, &bitpos1, > + &offset1); > > splay_tree_node n > = splay_tree_lookup (ctx->variables, (splay_tree_key)decl); > @@ -8693,7 +8832,7 @@ gimplify_scan_omp_clauses (tree *list_p, gimple_seq > *pre_p, > tree l = build_omp_clause (OMP_CLAUSE_LOCATION (c), > OMP_CLAUSE_MAP); > OMP_CLAUSE_SET_MAP_KIND (l, GOMP_MAP_STRUCT); > - if (orig_base != base) > + if (!base_eq_orig_base) > OMP_CLAUSE_DECL (l) = unshare_expr (orig_base); > else > OMP_CLAUSE_DECL (l) = decl; > @@ -8703,32 +8842,8 @@ gimplify_scan_omp_clauses (tree *list_p, gimple_seq > *pre_p, > struct_map_to_clause->put (decl, l); > if (ptr) > { > - enum gomp_map_kind mkind > - = code == OMP_TARGET_EXIT_DATA > - ? GOMP_MAP_RELEASE : GOMP_MAP_ALLOC; > - tree c2 = build_omp_clause (OMP_CLAUSE_LOCATION (c), > - OMP_CLAUSE_MAP); > - OMP_CLAUSE_SET_MAP_KIND (c2, mkind); > - OMP_CLAUSE_DECL (c2) > - = unshare_expr (OMP_CLAUSE_DECL (c)); > - OMP_CLAUSE_CHAIN (c2) = *prev_list_p; > - OMP_CLAUSE_SIZE (c2) > - = TYPE_SIZE_UNIT (ptr_type_node); > - OMP_CLAUSE_CHAIN (l) = c2; > - if (OMP_CLAUSE_CHAIN (*prev_list_p) != c) > - { > - tree c4 = OMP_CLAUSE_CHAIN (*prev_list_p); > - tree c3 > - = build_omp_clause (OMP_CLAUSE_LOCATION (c), > - OMP_CLAUSE_MAP); > - OMP_CLAUSE_SET_MAP_KIND (c3, mkind); > - OMP_CLAUSE_DECL (c3) > - = unshare_expr (OMP_CLAUSE_DECL (c4)); > - OMP_CLAUSE_SIZE (c3) > - = TYPE_SIZE_UNIT (ptr_type_node); > - OMP_CLAUSE_CHAIN (c3) = *prev_list_p; > - OMP_CLAUSE_CHAIN (c2) = c3; > - } > + insert_struct_comp_map (code, c, l, *prev_list_p, > + NULL); > *prev_list_p = l; > prev_list_p = NULL; > } > @@ -8738,7 +8853,7 @@ gimplify_scan_omp_clauses (tree *list_p, gimple_seq > *pre_p, > *list_p = l; > list_p = &OMP_CLAUSE_CHAIN (l); > } > - if (orig_base != base && code == OMP_TARGET) > + if (!base_eq_orig_base && code == OMP_TARGET) > { > tree c2 = build_omp_clause (OMP_CLAUSE_LOCATION (c), > OMP_CLAUSE_MAP); > @@ -8761,13 +8876,6 @@ gimplify_scan_omp_clauses (tree *list_p, gimple_seq > *pre_p, > tree *sc = NULL, *scp = NULL; > if (GOMP_MAP_ALWAYS_P (OMP_CLAUSE_MAP_KIND (c)) || ptr) > n->value |= GOVD_SEEN; > - poly_offset_int o1, o2; > - if (offset) > - o1 = wi::to_poly_offset (offset); > - else > - o1 = 0; > - if (maybe_ne (bitpos, 0)) > - o1 += bits_to_bytes_round_down (bitpos); > sc = &OMP_CLAUSE_CHAIN (*osc); > if (*sc != c > && (OMP_CLAUSE_MAP_KIND (*sc) > @@ -8785,44 +8893,14 @@ gimplify_scan_omp_clauses (tree *list_p, gimple_seq > *pre_p, > break; > else > { > - tree offset2; > - poly_int64 bitsize2, bitpos2; > - base = OMP_CLAUSE_DECL (*sc); > - if (TREE_CODE (base) == ARRAY_REF) > - { > - while (TREE_CODE (base) == ARRAY_REF) > - base = TREE_OPERAND (base, 0); > - if (TREE_CODE (base) != COMPONENT_REF > - || (TREE_CODE (TREE_TYPE (base)) > - != ARRAY_TYPE)) > - break; > - } > - else if (TREE_CODE (base) == INDIRECT_REF > - && (TREE_CODE (TREE_OPERAND (base, 0)) > - == COMPONENT_REF) > - && (TREE_CODE (TREE_TYPE > - (TREE_OPERAND (base, 0))) > - == REFERENCE_TYPE)) > - base = TREE_OPERAND (base, 0); > - base = get_inner_reference (base, &bitsize2, > - &bitpos2, &offset2, > - &mode, &unsignedp, > - &reversep, &volatilep); > - if ((TREE_CODE (base) == INDIRECT_REF > - || (TREE_CODE (base) == MEM_REF > - && integer_zerop (TREE_OPERAND (base, > - 1)))) > - && DECL_P (TREE_OPERAND (base, 0)) > - && (TREE_CODE (TREE_TYPE (TREE_OPERAND (base, > - 0))) > - == REFERENCE_TYPE)) > - base = TREE_OPERAND (base, 0); > - if (base != decl) > + tree sc_decl = OMP_CLAUSE_DECL (*sc); > + int same_decl_offset_lt > + = check_base_and_compare_lt (sc_decl, NULL, decl, > + &bitpos1, &offset1); > + if (same_decl_offset_lt == -1) > break; > if (scp) > continue; > - gcc_assert (offset == NULL_TREE > - || poly_int_tree_p (offset)); > tree d1 = OMP_CLAUSE_DECL (*sc); > tree d2 = OMP_CLAUSE_DECL (c); > while (TREE_CODE (d1) == ARRAY_REF) > @@ -8851,14 +8929,7 @@ gimplify_scan_omp_clauses (tree *list_p, gimple_seq > *pre_p, > remove = true; > break; > } > - if (offset2) > - o2 = wi::to_poly_offset (offset2); > - else > - o2 = 0; > - o2 += bits_to_bytes_round_down (bitpos2); > - if (maybe_lt (o1, o2) > - || (known_eq (o1, o2) > - && maybe_lt (bitpos, bitpos2))) > + if (same_decl_offset_lt) > { > if (ptr) > scp = sc; > @@ -8873,38 +8944,8 @@ gimplify_scan_omp_clauses (tree *list_p, gimple_seq > *pre_p, > size_one_node); > if (ptr) > { > - tree c2 = build_omp_clause (OMP_CLAUSE_LOCATION (c), > - OMP_CLAUSE_MAP); > - tree cl = NULL_TREE; > - enum gomp_map_kind mkind > - = code == OMP_TARGET_EXIT_DATA > - ? GOMP_MAP_RELEASE : GOMP_MAP_ALLOC; > - OMP_CLAUSE_SET_MAP_KIND (c2, mkind); > - OMP_CLAUSE_DECL (c2) > - = unshare_expr (OMP_CLAUSE_DECL (c)); > - OMP_CLAUSE_CHAIN (c2) = scp ? *scp : *prev_list_p; > - OMP_CLAUSE_SIZE (c2) > - = TYPE_SIZE_UNIT (ptr_type_node); > - cl = scp ? *prev_list_p : c2; > - if (OMP_CLAUSE_CHAIN (*prev_list_p) != c) > - { > - tree c4 = OMP_CLAUSE_CHAIN (*prev_list_p); > - tree c3 > - = build_omp_clause (OMP_CLAUSE_LOCATION (c), > - OMP_CLAUSE_MAP); > - OMP_CLAUSE_SET_MAP_KIND (c3, mkind); > - OMP_CLAUSE_DECL (c3) > - = unshare_expr (OMP_CLAUSE_DECL (c4)); > - OMP_CLAUSE_SIZE (c3) > - = TYPE_SIZE_UNIT (ptr_type_node); > - OMP_CLAUSE_CHAIN (c3) = *prev_list_p; > - if (!scp) > - OMP_CLAUSE_CHAIN (c2) = c3; > - else > - cl = c3; > - } > - if (scp) > - *scp = c2; > + tree cl = insert_struct_comp_map (code, c, NULL, > + *prev_list_p, scp); > if (sc == prev_list_p) > { > *sc = cl; Grüße Thomas
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