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-rw-r--r--frontends/ast/ast.h2
-rw-r--r--frontends/ast/simplify.cc40
-rw-r--r--tests/svtypes/struct_array.sv87
3 files changed, 118 insertions, 11 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;
diff --git a/tests/svtypes/struct_array.sv b/tests/svtypes/struct_array.sv
index 873f7befd..d33d18da2 100644
--- a/tests/svtypes/struct_array.sv
+++ b/tests/svtypes/struct_array.sv
@@ -1,7 +1,6 @@
// test for array indexing in structures
module top;
-
struct packed {
bit [5:0] [7:0] a; // 6 element packed array of bytes
bit [15:0] b; // filler for non-zero offset
@@ -39,4 +38,90 @@ 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);
+
+ // 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 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);
endmodule