aboutsummaryrefslogtreecommitdiffstats
path: root/frontends
diff options
context:
space:
mode:
authorDag Lem <dag@nimrod.no>2022-11-12 08:48:25 +0100
committerDag Lem <dag@nimrod.no>2022-11-12 08:48:25 +0100
commitbab88630c28b43851162772c2ce35666357d8933 (patch)
tree96e2dc4f9c1e552281b4f2b8260ced1783f856d0 /frontends
parenta217450524e21222d8d32bd448f1ea2291685258 (diff)
downloadyosys-bab88630c28b43851162772c2ce35666357d8933.tar.gz
yosys-bab88630c28b43851162772c2ce35666357d8933.tar.bz2
yosys-bab88630c28b43851162772c2ce35666357d8933.zip
Support for arrays with swapped ranges within structs
This also corrects the implementation of C type arrays within structs. Fixes #3550
Diffstat (limited to 'frontends')
-rw-r--r--frontends/ast/ast.h2
-rw-r--r--frontends/ast/simplify.cc40
2 files changed, 32 insertions, 10 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 49bf9af09..923aaa156 100644
--- a/frontends/ast/simplify.cc
+++ b/frontends/ast/simplify.cc
@@ -285,10 +285,16 @@ 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)
{
// 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]);
}
@@ -321,18 +327,22 @@ 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];
- 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-type 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);
}
+ } else {
+ 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)
@@ -347,8 +357,11 @@ static int size_packed_struct(AstNode *snode, int base_offset)
struct_array_packing_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 +441,16 @@ 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)
{
+ 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]
@@ -447,6 +468,7 @@ static AstNode *make_struct_index_range(AstNode *node, AstNode *rnode, int strid
static AstNode *slice_range(AstNode *rnode, AstNode *snode)
{
// apply the bit slice indicated by snode to the range rnode
+ // TODO: Check for swapped indexes - see make_struct_index_range
log_assert(rnode->type==AST_RANGE);
auto left = rnode->children[0];
auto right = rnode->children[1];
@@ -474,13 +496,13 @@ AstNode *AST::make_struct_member_range(AstNode *node, AstNode *member_node)
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]);
delete element_range;