diff options
| -rw-r--r-- | frontends/ast/ast.h | 2 | ||||
| -rw-r--r-- | frontends/ast/simplify.cc | 80 | ||||
| -rw-r--r-- | tests/svtypes/struct_array.sv | 131 |
3 files changed, 192 insertions, 21 deletions
diff --git a/frontends/ast/ast.h b/frontends/ast/ast.h index 80497c131..142ec0801 100644 --- a/frontends/ast/ast.h +++ b/frontends/ast/ast.h @@ -203,7 +203,7 @@ namespace AST // if this is a multirange memory then this vector contains offset and length of each dimension std::vector<int> multirange_dimensions; - std::vector<bool> multirange_swapped; // true if range is swapped, not used for structs + std::vector<bool> multirange_swapped; // true if range is swapped // this is set by simplify and used during RTLIL generation AstNode *id2ast; diff --git a/frontends/ast/simplify.cc b/frontends/ast/simplify.cc index c932e2c49..57237f4b3 100644 --- a/frontends/ast/simplify.cc +++ b/frontends/ast/simplify.cc @@ -273,9 +273,9 @@ static int range_width(AstNode *node, AstNode *rnode) return rnode->range_left - rnode->range_right + 1; } -[[noreturn]] static void struct_array_packing_error(AstNode *node) +[[noreturn]] static void struct_array_dimension_error(AstNode *node) { - log_file_error(node->filename, node->location.first_line, "Unpacked array in packed struct/union member %s\n", node->str.c_str()); + log_file_error(node->filename, node->location.first_line, "Currently limited to two dimensions in packed struct/union member %s\n", node->str.c_str()); } static void save_struct_array_width(AstNode *node, int width) @@ -285,10 +285,18 @@ static void save_struct_array_width(AstNode *node, int width) } +static void save_struct_range_swapped(AstNode *node, bool range_swapped) +{ + node->multirange_swapped.push_back(range_swapped); + +} + static int get_struct_array_width(AstNode *node) { + // This function is only useful for up to two array dimensions. + log_assert(node->multirange_dimensions.size() <= 2); // the stride for the array, 1 if not an array - return (node->multirange_dimensions.empty() ? 1 : node->multirange_dimensions.back()); + return (node->multirange_dimensions.size() != 2 ? 1 : node->multirange_dimensions[1]); } @@ -318,37 +326,47 @@ static int size_packed_struct(AstNode *snode, int base_offset) // member width e.g. bit [7:0] a width = range_width(node, node->children[0]); if (node->children.size() == 2) { + // Unpacked array. Note that this is a Yosys extension; only packed data types + // and integer data types are allowed in packed structs / unions in SystemVerilog. if (node->children[1]->type == AST_RANGE) { - // unpacked array e.g. bit [63:0] a [0:3] + // Unpacked array, e.g. bit [63:0] a [0:3] auto rnode = node->children[1]; - int array_count = range_width(node, rnode); - if (array_count == 1) { - // C-type array size e.g. bit [63:0] a [4] - array_count = rnode->range_left; - } + // C-style array size, e.g. bit [63:0] a [4] + bool c_type = rnode->children.size() == 1; + int array_count = c_type ? rnode->range_left : range_width(node, rnode); + save_struct_array_width(node, array_count); + save_struct_range_swapped(node, rnode->range_swapped || c_type); save_struct_array_width(node, width); + save_struct_range_swapped(node, node->children[0]->range_swapped); width *= array_count; } else { - // array element must be single bit for a packed array - struct_array_packing_error(node); + // Currently limited to at most two dimensions. + struct_array_dimension_error(node); } + } else { + // Vector. + save_struct_array_width(node, width); + save_struct_range_swapped(node, node->children[0]->range_swapped); } // range nodes are now redundant for (AstNode *child : node->children) delete child; node->children.clear(); } - else if (node->children.size() == 1 && node->children[0]->type == AST_MULTIRANGE) { + else if (node->children.size() > 0 && node->children[0]->type == AST_MULTIRANGE) { // packed 2D array, e.g. bit [3:0][63:0] a auto rnode = node->children[0]; - if (rnode->children.size() != 2) { - // packed arrays can only be 2D - struct_array_packing_error(node); + if (node->children.size() != 1 || rnode->children.size() != 2) { + // Currently limited to at most two dimensions. + struct_array_dimension_error(node); } int array_count = range_width(node, rnode->children[0]); + save_struct_array_width(node, array_count); + save_struct_range_swapped(node, rnode->children[0]->range_swapped); width = range_width(node, rnode->children[1]); save_struct_array_width(node, width); + save_struct_range_swapped(node, rnode->children[1]->range_swapped); width *= array_count; // range nodes are now redundant for (AstNode *child : node->children) @@ -428,8 +446,18 @@ static AstNode *offset_indexed_range(int offset, int stride, AstNode *left_expr, return new AstNode(AST_RANGE, left, right); } -static AstNode *make_struct_index_range(AstNode *node, AstNode *rnode, int stride, int offset) +static AstNode *make_struct_index_range(AstNode *node, AstNode *rnode, int stride, int offset, AstNode *member_node) { + // This function should be rewritten to support more than two array dimensions. + log_assert(member_node->multirange_dimensions.size() <= 2 && member_node->multirange_swapped.size() <= 2); + if (member_node->multirange_swapped[0]) { + // The struct item has swapped range; swap index into the struct accordingly. + int msb = member_node->multirange_dimensions[0] - 1; + for (auto &expr : rnode->children) { + expr = new AstNode(AST_SUB, node_int(msb), expr); + } + } + // generate a range node to perform either bit or array indexing if (rnode->children.size() == 1) { // index e.g. s.a[i] @@ -444,8 +472,18 @@ static AstNode *make_struct_index_range(AstNode *node, AstNode *rnode, int strid } } -static AstNode *slice_range(AstNode *rnode, AstNode *snode) +static AstNode *slice_range(AstNode *rnode, AstNode *snode, AstNode *member_node) { + // This function should be rewritten to support more than two array dimensions. + log_assert(member_node->multirange_dimensions.size() <= 2 && member_node->multirange_swapped.size() <= 2); + if (member_node->multirange_swapped[1]) { + // The second dimension has swapped range; swap index into the struct accordingly. + int msb = member_node->multirange_dimensions[1] - 1; + for (auto &expr : snode->children) { + expr = new AstNode(AST_SUB, node_int(msb), expr); + } + } + // apply the bit slice indicated by snode to the range rnode log_assert(rnode->type==AST_RANGE); auto left = rnode->children[0]; @@ -471,18 +509,20 @@ AstNode *AST::make_struct_member_range(AstNode *node, AstNode *member_node) // no range operations apply, return the whole width return make_range(range_left, range_right); } + // This function should be rewritten to support more than two array dimensions. + log_assert(member_node->multirange_dimensions.size() <= 2 && member_node->multirange_swapped.size() <= 2); int stride = get_struct_array_width(member_node); if (node->children.size() == 1 && node->children[0]->type == AST_RANGE) { // bit or array indexing e.g. s.a[2] or s.a[1:0] - return make_struct_index_range(node, node->children[0], stride, range_right); + return make_struct_index_range(node, node->children[0], stride, range_right, member_node); } else if (node->children.size() == 1 && node->children[0]->type == AST_MULTIRANGE) { // multirange, i.e. bit slice after array index, e.g. s.a[i][p:q] log_assert(stride > 1); auto mrnode = node->children[0]; - auto element_range = make_struct_index_range(node, mrnode->children[0], stride, range_right); + auto element_range = make_struct_index_range(node, mrnode->children[0], stride, range_right, member_node); // then apply bit slice range - auto range = slice_range(element_range, mrnode->children[1]); + auto range = slice_range(element_range, mrnode->children[1], member_node); delete element_range; return range; } diff --git a/tests/svtypes/struct_array.sv b/tests/svtypes/struct_array.sv index 873f7befd..f69c4c577 100644 --- a/tests/svtypes/struct_array.sv +++ b/tests/svtypes/struct_array.sv @@ -39,4 +39,135 @@ module top; always_comb assert(s2==80'hFC00_4200_0012_3400_FFFC); + // Same as s2, but with little endian addressing + struct packed { + bit [0:7] [7:0] a; // 8 element packed array of bytes + bit [0:15] b; // filler for non-zero offset + } s3; + + initial begin + s3 = '0; + + s3.a[5:6] = 16'h1234; + s3.a[2] = 8'h42; + + s3.a[0] = '1; + s3.a[0][1:0] = '0; + + s3.b = '1; + s3.b[14:15] = '0; + end + + always_comb assert(s3==80'hFC00_4200_0012_3400_FFFC); + + // Same as s3, but with little endian bit addressing + struct packed { + bit [0:7] [0:7] a; // 8 element packed array of bytes + bit [0:15] b; // filler for non-zero offset + } s3_b; + + initial begin + s3_b = '0; + + s3_b.a[5:6] = 16'h1234; + s3_b.a[2] = 8'h42; + + s3_b.a[0] = '1; + s3_b.a[0][6:7] = '0; + + s3_b.b = '1; + s3_b.b[14:15] = '0; + end + + always_comb assert(s3_b==80'hFC00_4200_0012_3400_FFFC); + +`ifndef VERIFIC + // Note that the tests below for unpacked arrays in structs rely on the + // fact that they are actually packed in Yosys. + + // Same as s2, but using unpacked array syntax + struct packed { + bit [7:0] a [7:0]; // 8 element unpacked array of bytes + bit [15:0] b; // filler for non-zero offset + } s4; + + initial begin + s4 = '0; + + s4.a[2:1] = 16'h1234; + s4.a[5] = 8'h42; + + s4.a[7] = '1; + s4.a[7][1:0] = '0; + + s4.b = '1; + s4.b[1:0] = '0; + end + + always_comb assert(s4==80'hFC00_4200_0012_3400_FFFC); + + // Same as s3, but using unpacked array syntax + struct packed { + bit [7:0] a [0:7]; // 8 element unpacked array of bytes + bit [0:15] b; // filler for non-zero offset + } s5; + + initial begin + s5 = '0; + + s5.a[5:6] = 16'h1234; + s5.a[2] = 8'h42; + + s5.a[0] = '1; + s5.a[0][1:0] = '0; + + s5.b = '1; + s5.b[14:15] = '0; + end + + always_comb assert(s5==80'hFC00_4200_0012_3400_FFFC); + + // Same as s5, but with little endian bit addressing + struct packed { + bit [0:7] a [0:7]; // 8 element unpacked array of bytes + bit [0:15] b; // filler for non-zero offset + } s5_b; + + initial begin + s5_b = '0; + + s5_b.a[5:6] = 16'h1234; + s5_b.a[2] = 8'h42; + + s5_b.a[0] = '1; + s5_b.a[0][6:7] = '0; + + s5_b.b = '1; + s5_b.b[14:15] = '0; + end + + always_comb assert(s5_b==80'hFC00_4200_0012_3400_FFFC); + + // Same as s5, but using C-type unpacked array syntax + struct packed { + bit [7:0] a [8]; // 8 element unpacked array of bytes + bit [0:15] b; // filler for non-zero offset + } s6; + + initial begin + s6 = '0; + + s6.a[5:6] = 16'h1234; + s6.a[2] = 8'h42; + + s6.a[0] = '1; + s6.a[0][1:0] = '0; + + s6.b = '1; + s6.b[14:15] = '0; + end + + always_comb assert(s6==80'hFC00_4200_0012_3400_FFFC); +`endif + endmodule |