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Merge pull request #2378 from udif/pr_dollar_high_low

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Added $high(), $low(), $left(), $right()
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clairexen 2020-10-01 18:17:36 +02:00 • committed by GitHub
commit 7e2fc2eaeb
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4 changed files with 159 additions and 31 deletions
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6
frontends/ast/ast.cc
View file

@ -336,6 +336,12 @@ void AstNode::dumpAst(FILE *f, std::string indent) const
fprintf(f, " %d", v);
fprintf(f, " ]");
}
if (!multirange_swapped.empty()) {
fprintf(f, " multirange_swapped=[");
for (auto v : multirange_swapped)
fprintf(f, " %d", v);
fprintf(f, " ]");
}
if (is_enum) {
fprintf(f, " type=enum");
}

1
frontends/ast/ast.h
View file

@ -202,6 +202,7 @@ 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
// this is set by simplify and used during RTLIL generation
AstNode *id2ast;

122
frontends/ast/simplify.cc
View file

@ -1504,11 +1504,13 @@ bool AstNode::simplify(bool const_fold, bool at_zero, bool in_lvalue, int stage,
{
int total_size = 1;
multirange_dimensions.clear();
multirange_swapped.clear();
for (auto range : children[1]->children) {
if (!range->range_valid)
log_file_error(filename, location.first_line, "Non-constant range on memory decl.\n");
multirange_dimensions.push_back(min(range->range_left, range->range_right));
multirange_dimensions.push_back(max(range->range_left, range->range_right) - min(range->range_left, range->range_right) + 1);
multirange_swapped.push_back(range->range_swapped);
total_size *= multirange_dimensions.back();
}
delete children[1];
@ -1521,6 +1523,7 @@ bool AstNode::simplify(bool const_fold, bool at_zero, bool in_lvalue, int stage,
{
AstNode *index_expr = nullptr;
integer = children[0]->children.size(); // save original number of dimensions for $size() etc.
for (int i = 0; 2*i < GetSize(id2ast->multirange_dimensions); i++)
{
if (GetSize(children[0]->children) <= i)
@ -1719,6 +1722,7 @@ bool AstNode::simplify(bool const_fold, bool at_zero, bool in_lvalue, int stage,
newNode = new AstNode(AST_IDENTIFIER, children[1]->clone());
newNode->str = wire_id;
newNode->integer = integer; // save original number of dimensions for $size() etc.
newNode->id2ast = wire;
goto apply_newNode;
}
@ -2831,26 +2835,28 @@ skip_dynamic_range_lvalue_expansion:;
goto apply_newNode;
}
if (str == "\\$size" || str == "\\$bits")
if (str == "\\$size" || str == "\\$bits" || str == "\\$high" || str == "\\$low" || str == "\\$left" || str == "\\$right")
{
if (str == "\\$bits" && children.size() != 1)
log_file_error(filename, location.first_line, "System function %s got %d arguments, expected 1.\n",
RTLIL::unescape_id(str).c_str(), int(children.size()));
if (str == "\\$size" && children.size() != 1 && children.size() != 2)
log_file_error(filename, location.first_line, "System function %s got %d arguments, expected 1 or 2.\n",
RTLIL::unescape_id(str).c_str(), int(children.size()));
int dim = 1;
if (str == "\\$size" && children.size() == 2) {
AstNode *buf = children[1]->clone();
// Evaluate constant expression
while (buf->simplify(true, false, false, stage, width_hint, sign_hint, false)) { }
dim = buf->asInt(false);
delete buf;
if (str == "\\$bits") {
if (children.size() != 1)
log_file_error(filename, location.first_line, "System function %s got %d arguments, expected 1.\n",
RTLIL::unescape_id(str).c_str(), int(children.size()));
} else {
if (children.size() != 1 && children.size() != 2)
log_file_error(filename, location.first_line, "System function %s got %d arguments, expected 1 or 2.\n",
RTLIL::unescape_id(str).c_str(), int(children.size()));
if (children.size() == 2) {
AstNode *buf = children[1]->clone();
// Evaluate constant expression
while (buf->simplify(true, false, false, stage, width_hint, sign_hint, false)) { }
dim = buf->asInt(false);
delete buf;
}
}
AstNode *buf = children[0]->clone();
int mem_depth = 1;
int result, high = 0, low = 0, left = 0, right = 0, width = 1; // defaults for a simple wire
AstNode *id_ast = NULL;
// Is this needed?
@ -2863,6 +2869,31 @@ skip_dynamic_range_lvalue_expansion:;
id_ast = current_scope.at(buf->str);
if (!id_ast)
log_file_error(filename, location.first_line, "Failed to resolve identifier %s for width detection!\n", buf->str.c_str());
// a slice of our identifier means we advance to the next dimension, e.g. $size(a[3])
if (buf->children.size() > 0) {
// something is hanging below this identifier
if (buf->children[0]->type == AST_RANGE && buf->integer == 0)
// if integer == 0, this node was originally created as AST_RANGE so it's dimension is 1
dim++;
// more than one range, e.g. $size(a[3][2])
else // created an AST_MULTIRANGE, converted to AST_RANGE, but original dimension saved in 'integer' field
dim += buf->integer; // increment by multirange size
}
// We have 4 cases:
// wire x; ==> AST_WIRE, no AST_RANGE children
// wire [1:0]x; ==> AST_WIRE, AST_RANGE children
// wire [1:0]x[1:0]; ==> AST_MEMORY, two AST_RANGE children (1st for packed, 2nd for unpacked)
// wire [1:0]x[1:0][1:0]; ==> AST_MEMORY, one AST_RANGE child (0) for packed, then AST_MULTIRANGE child (1) for unpacked
// (updated: actually by the time we are here, AST_MULTIRANGE is converted into one big AST_RANGE)
// case 0 handled by default
if ((id_ast->type == AST_WIRE || id_ast->type == AST_MEMORY) && id_ast->children.size() > 0) {
// handle packed array left/right for case 1, and cases 2/3 when requesting the last dimension (packed side)
AstNode *wire_range = id_ast->children[0];
left = wire_range->children[0]->integer;
right = wire_range->children[1]->integer;
high = max(left, right);
low = min(left, right);
}
if (id_ast->type == AST_MEMORY) {
// We got here only if the argument is a memory
// Otherwise $size() and $bits() return the expression width
@ -2875,29 +2906,58 @@ skip_dynamic_range_lvalue_expansion:;
} else
log_file_error(filename, location.first_line, "Unknown memory depth AST type in `%s'!\n", buf->str.c_str());
} else {
// $size()
// $size(), $left(), $right(), $high(), $low()
int dims = 1;
if (mem_range->type == AST_RANGE) {
if (!mem_range->range_valid)
log_file_error(filename, location.first_line, "Failed to detect width of memory access `%s'!\n", buf->str.c_str());
int dims;
if (id_ast->multirange_dimensions.empty())
dims = 1;
else
if (id_ast->multirange_dimensions.empty()) {
if (!mem_range->range_valid)
log_file_error(filename, location.first_line, "Failed to detect width of memory access `%s'!\n", buf->str.c_str());
if (dim == 1) {
left = mem_range->range_right;
right = mem_range->range_left;
high = max(left, right);
low = min(left, right);
}
} else {
dims = GetSize(id_ast->multirange_dimensions)/2;
if (dim == 1)
width_hint = (dims > 1) ? id_ast->multirange_dimensions[1] : (mem_range->range_left - mem_range->range_right + 1);
else if (dim <= dims) {
width_hint = id_ast->multirange_dimensions[2*dim-1];
} else if ((dim > dims+1) || (dim < 0))
log_file_error(filename, location.first_line, "Dimension %d out of range in `%s', as it only has dimensions 1..%d!\n", dim, buf->str.c_str(), dims+1);
} else
if (dim <= dims) {
width_hint = id_ast->multirange_dimensions[2*dim-1];
high = id_ast->multirange_dimensions[2*dim-2] + id_ast->multirange_dimensions[2*dim-1] - 1;
low = id_ast->multirange_dimensions[2*dim-2];
if (id_ast->multirange_swapped[dim-1]) {
left = low;
right = high;
} else {
right = low;
left = high;
}
} else if ((dim > dims+1) || (dim < 0))
log_file_error(filename, location.first_line, "Dimension %d out of range in `%s', as it only has dimensions 1..%d!\n", dim, buf->str.c_str(), dims+1);
}
} else {
log_file_error(filename, location.first_line, "Unknown memory depth AST type in `%s'!\n", buf->str.c_str());
}
}
}
width = high - low + 1;
} else {
width = width_hint;
}
delete buf;
newNode = mkconst_int(width_hint * mem_depth, false);
if (str == "\\$high")
result = high;
else if (str == "\\$low")
result = low;
else if (str == "\\$left")
result = left;
else if (str == "\\$right")
result = right;
else if (str == "\\$size")
result = width;
else {
result = width * mem_depth;
}
newNode = mkconst_int(result, false);
goto apply_newNode;
}