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Generalise structs and add support for packed unions.

This commit is contained in:
Peter Crozier 2020-05-12 14:25:33 +01:00
parent 0b6b47ca67
commit f482c9c016
8 changed files with 209 additions and 59 deletions
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2
README.md
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@ -556,7 +556,7 @@ from SystemVerilog:
- enums are supported (including inside packages)
- but are currently not strongly typed
- structs are supported
- packed structs and unions are supported.
- SystemVerilog interfaces (SVIs) are supported. Modports for specifying whether
ports are inputs or outputs are supported.

1
frontends/ast/ast.cc
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@ -172,6 +172,7 @@ std::string AST::type2str(AstNodeType type)
X(AST_WIRETYPE)
X(AST_TYPEDEF)
X(AST_STRUCT)
X(AST_UNION)
X(AST_STRUCT_ITEM)
#undef X
default:

1
frontends/ast/ast.h
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@ -158,6 +158,7 @@ namespace AST
AST_WIRETYPE,
AST_TYPEDEF,
AST_STRUCT,
AST_UNION,
AST_STRUCT_ITEM
};

1
frontends/ast/genrtlil.cc
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@ -992,6 +992,7 @@ RTLIL::SigSpec AstNode::genRTLIL(int width_hint, bool sign_hint)
case AST_MODPORTMEMBER:
case AST_TYPEDEF:
case AST_STRUCT:
case AST_UNION:
break;
case AST_INTERFACEPORT: {
// If a port in a module with unknown type is found, mark it with the attribute 'is_interface'

146
frontends/ast/simplify.cc
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@ -250,6 +250,97 @@ static AstNode *make_range(int left, int right, bool is_signed = false)
return range;
}
int size_packed_struct(AstNode *snode, int base_offset)
{
// Struct members will be laid out in the structure contiguously from left to right.
// Union members all have zero offset from the start of the union.
// Determine total packed size and assign offsets. Store these in the member node.
bool is_union = (snode->type == AST_UNION);
int offset = 0;
int packed_width = -1;
// examine members from last to first
for (auto it = snode->children.rbegin(); it != snode->children.rend(); ++it) {
auto node = *it;
int width;
if (node->type == AST_STRUCT || node->type == AST_UNION) {
// embedded struct or union
width = size_packed_struct(node, base_offset + offset);
}
else {
log_assert(node->type == AST_STRUCT_ITEM);
if (node->children.size() == 1 && node->children[0]->type == AST_RANGE) {
auto rnode = node->children[0];
width = (rnode->range_swapped ? rnode->range_right - rnode->range_left :
rnode->range_left - rnode->range_right) + 1;
// range nodes are now redundant
node->children.clear();
}
else if (node->range_left < 0) {
// 1 bit signal: bit, logic or reg
width = 1;
}
else {
// already resolved and compacted
width = node->range_left - node->range_right + 1;
}
if (is_union) {
node->range_right = base_offset;
node->range_left = base_offset + width - 1;
}
else {
node->range_right = base_offset + offset;
node->range_left = base_offset + offset + width - 1;
}
node->range_valid = true;
}
if (is_union) {
// check that all members have the same size
if (packed_width == -1) {
// first member
packed_width = width;
}
else {
if (packed_width != width) {
log_file_error(node->filename, node->location.first_line, "member %s of a packed union has %d bits, expecting %d\n", node->str.c_str(), width, packed_width);
}
}
}
else {
offset += width;
}
}
return (is_union ? packed_width : offset);
}
static void add_members_to_scope(AstNode *snode, std::string name)
{
// add all the members in a struct or union to local scope
// in case later referenced in assignments
log_assert(snode->type==AST_STRUCT || snode->type==AST_UNION);
for (auto *node : snode->children) {
if (node->type != AST_STRUCT_ITEM) {
// embedded struct or union
add_members_to_scope(node, name + "." + node->str);
}
else {
auto member_name = name + "." + node->str;
current_scope[member_name] = node;
}
}
}
static int get_max_offset(AstNode *node)
{
// get the width from the MS member in the struct
// as members are laid out from left to right in the packed wire
log_assert(node->type==AST_STRUCT || node->type==AST_UNION);
while (node->type != AST_STRUCT_ITEM) {
node = node->children[0];
}
return node->range_left;
}
static AstNode *make_packed_struct(AstNode *template_node, std::string &name)
{
// create a wire for the packed struct
@ -257,18 +348,14 @@ static AstNode *make_packed_struct(AstNode *template_node, std::string &name)
wnode->str = name;
wnode->is_logic = true;
wnode->range_valid = true;
// get the width from the MS member in the template
// as members are laid out from left to right
int offset = template_node->children[0]->range_left;
wnode->is_signed = template_node->is_signed;
int offset = get_max_offset(template_node);
auto range = make_range(offset, 0);
wnode->children.push_back(range);
// make sure this node is the one in scope for this name
current_scope[name] = wnode;
// add members to scope
for (auto *node : template_node->children) {
auto member_name = name + "." + node->str;
current_scope[member_name] = node;
}
// add all the struct members to scope under the wire's name
add_members_to_scope(template_node, name);
return wnode;
}
@ -672,46 +759,25 @@ bool AstNode::simplify(bool const_fold, bool at_zero, bool in_lvalue, int stage,
break;
case AST_STRUCT:
//log("STRUCT %d %d %d\n", stage, basic_prep, in_param);
case AST_UNION:
if (!basic_prep) {
//dumpAst(NULL, "1> ");
for (auto *node : children) {
// resolve any ranges
while (!node->basic_prep && node->simplify(true, false, false, stage, -1, false, false)) {
did_something = true;
}
}
basic_prep = true;
// The members will be laid out in the structure contiguously from left to right.
// Determine total packed size and assign offsets. Store these in the member node.
// dumpAst(NULL, "2> ");
int offset = 0;
for (auto it = children.rbegin(); it != children.rend(); ++it) {
auto node = *it;
if (is_signed)
node->is_signed = true;
int width;
if (node->children.size() == 1 && node->children[0]->type == AST_RANGE) {
auto rnode = node->children[0];
width = (rnode->range_swapped ? rnode->range_right - rnode->range_left :
rnode->range_left - rnode->range_right) + 1;
// range nodes are now redundant
node->children.clear();
}
else {
width = 1;
}
node->range_right = offset;
node->range_left = offset + width - 1;
node->range_valid = true;
offset += width;
}
if (!str.empty()) {
// instance rather than just a type in a typedef
// so add a wire for the packed structure
// determine member offsets and widths
size_packed_struct(this, 0);
// instance rather than just a type in a typedef or outer struct?
if (!str.empty() && str[0] == '\\') {
// instance so add a wire for the packed structure
auto wnode = make_packed_struct(this, str);
log_assert(current_ast_mod);
current_ast_mod->children.push_back(wnode);
}
basic_prep = true;
}
break;
@ -1036,7 +1102,7 @@ bool AstNode::simplify(bool const_fold, bool at_zero, bool in_lvalue, int stage,
if (type == AST_TYPEDEF) {
log_assert(children.size() == 1);
auto type_node = children[0];
log_assert(type_node->type == AST_WIRE || type_node->type == AST_MEMORY || type_node->type == AST_STRUCT);
log_assert(type_node->type == AST_WIRE || type_node->type == AST_MEMORY || type_node->type == AST_STRUCT || type_node->type == AST_UNION);
while (type_node->simplify(const_fold, at_zero, in_lvalue, stage, width_hint, sign_hint, in_param)) {
did_something = true;
}
@ -1061,7 +1127,7 @@ bool AstNode::simplify(bool const_fold, bool at_zero, bool in_lvalue, int stage,
// Ensure typedef itself is fully simplified
while (template_node->simplify(const_fold, at_zero, in_lvalue, stage, width_hint, sign_hint, in_param)) {};
if (template_node->type == AST_STRUCT) {
if (template_node->type == AST_STRUCT || template_node->type == AST_UNION) {
// replace with wire representing the packed structure
newNode = make_packed_struct(template_node, str);
current_scope[str] = this;

2
frontends/verilog/verilog_lexer.l
View File

@ -265,6 +265,7 @@ static bool isUserType(std::string &s)
"bit" { SV_KEYWORD(TOK_LOGIC); }
"int" { SV_KEYWORD(TOK_INT); }
"byte" { SV_KEYWORD(TOK_BYTE); }
"shortint" { SV_KEYWORD(TOK_SHORTINT); }
"eventually" { if (formal_mode) return TOK_EVENTUALLY; SV_KEYWORD(TOK_EVENTUALLY); }
"s_eventually" { if (formal_mode) return TOK_EVENTUALLY; SV_KEYWORD(TOK_EVENTUALLY); }
@ -285,6 +286,7 @@ static bool isUserType(std::string &s)
"enum" { SV_KEYWORD(TOK_ENUM); }
"typedef" { SV_KEYWORD(TOK_TYPEDEF); }
"struct" { SV_KEYWORD(TOK_STRUCT); }
"union" { SV_KEYWORD(TOK_UNION); }
"packed" { SV_KEYWORD(TOK_PACKED); }
[0-9][0-9_]* {

48
frontends/verilog/verilog_parser.y
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@ -238,6 +238,7 @@ static void rewriteAsMemoryNode(AstNode *node, AstNode *rangeNode)
%union {
std::string *string;
struct YOSYS_NAMESPACE_PREFIX AST::AstNode *ast;
YOSYS_NAMESPACE_PREFIX AST::AstNodeType type;
YOSYS_NAMESPACE_PREFIX dict<YOSYS_NAMESPACE_PREFIX RTLIL::IdString, YOSYS_NAMESPACE_PREFIX AST::AstNode*> *al;
struct specify_target *specify_target_ptr;
struct specify_triple *specify_triple_ptr;
@ -269,7 +270,7 @@ static void rewriteAsMemoryNode(AstNode *node, AstNode *rangeNode)
%token TOK_POS_INDEXED TOK_NEG_INDEXED TOK_PROPERTY TOK_ENUM TOK_TYPEDEF
%token TOK_RAND TOK_CONST TOK_CHECKER TOK_ENDCHECKER TOK_EVENTUALLY
%token TOK_INCREMENT TOK_DECREMENT TOK_UNIQUE TOK_PRIORITY
%token TOK_STRUCT TOK_PACKED TOK_UNSIGNED TOK_INT TOK_BYTE
%token TOK_STRUCT TOK_PACKED TOK_UNSIGNED TOK_INT TOK_BYTE TOK_SHORTINT TOK_UNION
%type <ast> range range_or_multirange non_opt_range non_opt_multirange range_or_signed_int
%type <ast> wire_type expr basic_expr concat_list rvalue lvalue lvalue_concat_list
@ -278,6 +279,7 @@ static void rewriteAsMemoryNode(AstNode *node, AstNode *rangeNode)
%type <ast> opt_enum_init enum_type struct_type non_wire_data_type
%type <boolean> opt_signed opt_property unique_case_attr always_comb_or_latch always_or_always_ff
%type <al> attr case_attr
%type <type> struct_union
%type <specify_target_ptr> specify_target
%type <specify_triple_ptr> specify_triple specify_opt_triple
@ -328,7 +330,6 @@ design:
param_decl design |
localparam_decl design |
typedef_decl design |
struct_decl design |
package design |
interface design |
/* empty */;
@ -569,7 +570,6 @@ package_body:
package_body_stmt:
typedef_decl
| struct_decl
| localparam_decl
| param_decl
;
@ -601,7 +601,7 @@ interface_body:
interface_body interface_body_stmt |;
interface_body_stmt:
param_decl | localparam_decl | typedef_decl | struct_decl | defparam_decl | wire_decl | always_stmt | assign_stmt |
param_decl | localparam_decl | typedef_decl | defparam_decl | wire_decl | always_stmt | assign_stmt |
modport_stmt;
non_opt_delay:
@ -1442,6 +1442,7 @@ enum_base_type: type_atom type_signing
type_atom: TOK_INTEGER { astbuf1->is_reg = true; addRange(astbuf1); } // 4-state signed
| TOK_INT { astbuf1->is_reg = true; addRange(astbuf1); } // 2-state signed
| TOK_SHORTINT { astbuf1->is_reg = true; addRange(astbuf1, 15, 0); } // 2-state signed
| TOK_BYTE { astbuf1->is_reg = true; addRange(astbuf1, 7, 0); } // 2-state signed
;
@ -1467,6 +1468,7 @@ enum_name_decl:
auto node = astbuf1->clone();
node->str = *$1;
delete $1;
SET_AST_NODE_LOC(node, @1, @1);
delete node->children[0];
node->children[0] = $2 ?: new AstNode(AST_NONE);
astbuf2->children.push_back(node);
@ -1490,6 +1492,7 @@ enum_var: TOK_ID {
ast_stack.back()->children.push_back(node);
node->str = *$1;
delete $1;
SET_AST_NODE_LOC(node, @1, @1);
node->is_enum = true;
}
;
@ -1497,23 +1500,29 @@ enum_var: TOK_ID {
enum_decl: enum_type enum_var_list ';' { delete $1; }
;
/////////
// struct
/////////
//////////////////
// struct or union
//////////////////
struct_decl: struct_type struct_var_list ';' { delete astbuf2; }
;
struct_type: TOK_STRUCT { astbuf2 = new AstNode(AST_STRUCT); } opt_packed '{' struct_member_list '}' { $$ = astbuf2; }
struct_type: struct_union { astbuf2 = new AstNode($1); } opt_packed '{' struct_member_list '}' { $$ = astbuf2; }
;
struct_union:
TOK_STRUCT { $$ = AST_STRUCT; }
| TOK_UNION { $$ = AST_UNION; }
;
opt_packed: TOK_PACKED opt_signed_struct
| { frontend_verilog_yyerror("Only STRUCT PACKED supported at this time"); }
| { frontend_verilog_yyerror("Only PACKED supported at this time"); }
;
opt_signed_struct:
TOK_SIGNED { astbuf2->is_signed = true; }
| TOK_UNSIGNED
| TOK_UNSIGNED { astbuf2->is_signed = false; }
| // default is unsigned
;
@ -1532,11 +1541,13 @@ member_name_list:
member_name: TOK_ID {
astbuf1->str = $1->substr(1);
delete $1;
astbuf2->children.push_back(astbuf1->clone());
auto member_node = astbuf1->clone();
SET_AST_NODE_LOC(member_node, @1, @1);
astbuf2->children.push_back(member_node);
}
;
struct_member_type: { astbuf1 = new AstNode(AST_STRUCT_ITEM); } member_type_token_list { SET_RULE_LOC(@$, @2, @$); }
struct_member_type: { astbuf1 = new AstNode(AST_STRUCT_ITEM); } member_type_token_list
;
member_type_token_list:
@ -1544,12 +1555,18 @@ member_type_token_list:
| hierarchical_type_id {
// use a clone of the typedef definition nodes
auto template_node = copyTypeDefinition(*$1);
if (template_node->type != AST_WIRE) {
delete $1;
switch (template_node->type) {
case AST_WIRE:
template_node->type = AST_STRUCT_ITEM;
break;
case AST_STRUCT:
case AST_UNION:
break;
default:
frontend_verilog_yyerror("Invalid type for struct member: %s", type2str(template_node->type).c_str());
}
template_node->type = AST_STRUCT_ITEM;
delete astbuf1;
delete $1;
astbuf1 = template_node;
}
;
@ -1565,6 +1582,7 @@ struct_var_list: struct_var
struct_var: TOK_ID { auto *var_node = astbuf2->clone();
var_node->str = *$1;
delete $1;
SET_AST_NODE_LOC(var_node, @1, @1);
ast_stack.back()->children.push_back(var_node);
}
;

61
tests/svtypes/union_simple.sv Normal file
View File

@ -0,0 +1,61 @@
module top;
typedef struct packed {
byte a,b,c,d;
} byte4_t;
typedef union packed {
int x;
byte4_t y;
} w_t;
w_t w;
assign w.x = 'h42;
always_comb begin
assert(w.y.d == 8'h42);
end
typedef logic[4:0] reg_addr_t;
typedef logic[6:0] opcode_t;
typedef struct packed {
bit [6:0] func7;
reg_addr_t rs2;
reg_addr_t rs1;
bit [2:0] func3;
reg_addr_t rd;
opcode_t opcode;
} R_t;
typedef struct packed {
bit[11:0] imm;
reg_addr_t rs1;
bit[2:0] func3;
reg_addr_t rd;
opcode_t opcode;
} I_t;
typedef struct packed {
bit[19:0] imm;
reg_addr_t rd;
opcode_t opcode;
} U_t;
typedef union packed {
R_t r;
I_t i;
U_t u;
} instruction_t;
instruction_t ir1;
assign ir1 = 32'h0AA01EB7; // lui t4,0xAA01
always_comb begin
assert(ir1.u.opcode == 'h37);
assert(ir1.r.opcode == 'h37);
assert(ir1.u.rd == 'd29);
assert(ir1.r.rd == 'd29);
assert(ir1.u.imm == 'hAA01);
end
endmodule