From 777c589e8576b3f8fbe6621efffb1224b1f372b7 Mon Sep 17 00:00:00 2001 From: Dag Lem Date: Sun, 5 Feb 2023 11:01:37 +0100 Subject: [PATCH] Handle range offsets in packed arrays within packed structs This brings the metadata for packed arrays in packed structs in line with the metadata for unpacked arrays, and correctly handles the case when both lsb and msb in an address range are non-zero. --- frontends/ast/simplify.cc | 53 ++++++++++++++++++++--------------- tests/svtypes/struct_array.sv | 20 +++++++++++++ 2 files changed, 51 insertions(+), 22 deletions(-) diff --git a/frontends/ast/simplify.cc b/frontends/ast/simplify.cc index 2dbabca28..5f9f9f49c 100644 --- a/frontends/ast/simplify.cc +++ b/frontends/ast/simplify.cc @@ -278,17 +278,21 @@ static int range_width(AstNode *node, AstNode *rnode) log_file_error(node->filename, node->location.first_line, "Unpacked array in packed struct/union member %s\n", node->str.c_str()); } -static void save_struct_array_width(AstNode *node, int width) +static void save_struct_range_dimensions(AstNode *node, AstNode *rnode) { - // stash the stride for the array - node->multirange_dimensions.push_back(width); - + node->multirange_dimensions.push_back(rnode->range_right); + node->multirange_dimensions.push_back(range_width(node, rnode)); + node->multirange_swapped.push_back(rnode->range_swapped); } -static void save_struct_range_swapped(AstNode *node, bool range_swapped) +static int get_struct_range_offset(AstNode *node, int dimension) { - node->multirange_swapped.push_back(range_swapped); + return node->multirange_dimensions[2*dimension]; +} +static int get_struct_range_width(AstNode *node, int dimension) +{ + return node->multirange_dimensions[2*dimension + 1]; } static int size_packed_struct(AstNode *snode, int base_offset) @@ -322,14 +326,17 @@ static int size_packed_struct(AstNode *snode, int base_offset) if (node->children[1]->type == AST_RANGE) { // Unpacked array, e.g. bit [63:0] a [0:3] auto rnode = node->children[1]; - // 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; + if (rnode->children.size() == 1) { + // C-style array size, e.g. bit [63:0] a [4] + node->multirange_dimensions.push_back(0); + node->multirange_dimensions.push_back(rnode->range_left); + node->multirange_swapped.push_back(true); + width *= rnode->range_left; + } else { + save_struct_range_dimensions(node, rnode); + width *= range_width(node, rnode); + } + save_struct_range_dimensions(node, node->children[0]); } else { // The Yosys extension for unpacked arrays in packed structs / unions @@ -338,8 +345,7 @@ static int size_packed_struct(AstNode *snode, int base_offset) } } else { // Vector - save_struct_array_width(node, width); - save_struct_range_swapped(node, node->children[0]->range_swapped); + save_struct_range_dimensions(node, node->children[0]); } // range nodes are now redundant for (AstNode *child : node->children) @@ -355,10 +361,8 @@ static int size_packed_struct(AstNode *snode, int base_offset) } width = 1; for (auto rnode : node->children[0]->children) { - int rwidth = range_width(node, rnode); - save_struct_array_width(node, rwidth); - save_struct_range_swapped(node, rnode->range_swapped); - width *= rwidth; + save_struct_range_dimensions(node, rnode); + width *= range_width(node, rnode); } // range nodes are now redundant for (AstNode *child : node->children) @@ -422,9 +426,14 @@ static AstNode *normalize_struct_index(AstNode *expr, AstNode *member_node, int { expr = expr->clone(); + int offset = get_struct_range_offset(member_node, dimension); + if (offset) { + expr = new AstNode(AST_SUB, expr, node_int(offset)); + } + if (member_node->multirange_swapped[dimension]) { // The dimension has swapped range; swap index into the struct accordingly. - int msb = member_node->multirange_dimensions[dimension] - 1; + int msb = get_struct_range_width(member_node, dimension) - 1; expr = new AstNode(AST_SUB, node_int(msb), expr); } @@ -433,7 +442,7 @@ static AstNode *normalize_struct_index(AstNode *expr, AstNode *member_node, int static AstNode *struct_index_lsb_offset(AstNode *lsb_offset, AstNode *rnode, AstNode *member_node, int dimension, int &stride) { - stride /= member_node->multirange_dimensions[dimension]; + stride /= get_struct_range_width(member_node, dimension); auto right = normalize_struct_index(rnode->children.back(), member_node, dimension); auto offset = stride > 1 ? multiply_by_const(right, stride) : right; return new AstNode(AST_ADD, lsb_offset, offset); diff --git a/tests/svtypes/struct_array.sv b/tests/svtypes/struct_array.sv index 739f202ab..a0b84640d 100644 --- a/tests/svtypes/struct_array.sv +++ b/tests/svtypes/struct_array.sv @@ -141,6 +141,26 @@ module top; always_comb assert(s3_llb==80'hFC00_4200_0012_3400_FFFC); + struct packed { + bit [-10:-3] [-2:-1] [5:2] a; + bit [0:15] b; // filler for non-zero offset + } s3_off; + + initial begin + s3_off = '0; + + s3_off.a[-5:-4] = 16'h1234; + s3_off.a[-8] = 8'h42; + + s3_off.a[-10] = '1; + s3_off.a[-10][-1][3:0] = '0; + + s3_off.b = '1; + s3_off.b[14:15] = '0; + end + + always_comb assert(s3_off==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.