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Added $past, $stable, $rose, $fell SVA functions

This commit is contained in:
Clifford Wolf 2016-09-19 01:30:07 +02:00
parent d009cdd6ee
commit aaa99c35bd
2 changed files with 141 additions and 2 deletions
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10
frontends/ast/genrtlil.cc
View File

@ -765,6 +765,16 @@ void AstNode::detectSignWidthWorker(int &width_hint, bool &sign_hint, bool *foun
}
break;
}
if (str == "\\$past") {
if (GetSize(children) > 0) {
sub_width_hint = 0;
sub_sign_hint = true;
children.at(0)->detectSignWidthWorker(sub_width_hint, sub_sign_hint);
width_hint = max(width_hint, sub_width_hint);
sign_hint = false;
}
break;
}
/* fall through */
// everything should have been handled above -> print error if not.

133
frontends/ast/simplify.cc
View File

@ -63,7 +63,7 @@ bool AstNode::simplify(bool const_fold, bool at_zero, bool in_lvalue, int stage,
#if 0
log("-------------\n");
log("AST simplify[%d] depth %d at %s:%d,\n", stage, recursion_counter, filename.c_str(), linenum);
log("AST simplify[%d] depth %d at %s:%d on %s %p:\n", stage, recursion_counter, filename.c_str(), linenum, type2str(type).c_str(), this);
log("const_fold=%d, at_zero=%d, in_lvalue=%d, stage=%d, width_hint=%d, sign_hint=%d, in_param=%d\n",
int(const_fold), int(at_zero), int(in_lvalue), int(stage), int(width_hint), int(sign_hint), int(in_param));
// dumpAst(NULL, "> ");
@ -522,6 +522,11 @@ bool AstNode::simplify(bool const_fold, bool at_zero, bool in_lvalue, int stage,
children_are_self_determined = true;
break;
case AST_FCALL:
case AST_TCALL:
children_are_self_determined = true;
break;
default:
width_hint = -1;
sign_hint = false;
@ -537,6 +542,9 @@ bool AstNode::simplify(bool const_fold, bool at_zero, bool in_lvalue, int stage,
detectSignWidth(width_hint, sign_hint);
}
if (type == AST_FCALL && str == "\\$past")
detectSignWidth(width_hint, sign_hint);
if (type == AST_TERNARY) {
int width_hint_left, width_hint_right;
bool sign_hint_left, sign_hint_right;
@ -1682,9 +1690,128 @@ skip_dynamic_range_lvalue_expansion:;
goto apply_newNode;
}
if (str == "\\$past")
{
if (width_hint <= 0)
goto replace_fcall_later;
int num_steps = 1;
if (GetSize(children) != 1 && GetSize(children) != 2)
log_error("System function %s got %d arguments, expected 1 or 2 at %s:%d.\n",
RTLIL::unescape_id(str).c_str(), int(children.size()), filename.c_str(), linenum);
if (!current_always_clocked)
log_error("System function %s is only allowed in clocked blocks at %s:%d.\n",
RTLIL::unescape_id(str).c_str(), filename.c_str(), linenum);
if (GetSize(children) == 2)
{
AstNode *buf = children[1]->clone();
while (buf->simplify(true, false, false, stage, width_hint, sign_hint, false)) { }
if (buf->type != AST_CONSTANT)
log_error("Failed to evaluate system function `%s' with non-constant value at %s:%d.\n", str.c_str(), filename.c_str(), linenum);
num_steps = buf->asInt(true);
delete buf;
}
AstNode *block = nullptr;
for (auto child : current_always->children)
if (child->type == AST_BLOCK)
block = child;
log_assert(block != nullptr);
int myidx = autoidx++;
AstNode *outreg = nullptr;
for (int i = 0; i < num_steps; i++)
{
AstNode *reg = new AstNode(AST_WIRE, new AstNode(AST_RANGE,
mkconst_int(width_hint-1, true), mkconst_int(0, true)));
reg->str = stringf("$past$%s:%d$%d$%d", filename.c_str(), linenum, myidx, i);
reg->is_reg = true;
current_ast_mod->children.push_back(reg);
while (reg->simplify(true, false, false, 1, -1, false, false)) { }
AstNode *regid = new AstNode(AST_IDENTIFIER);
regid->str = reg->str;
regid->id2ast = reg;
AstNode *rhs = nullptr;
if (outreg == nullptr) {
rhs = children.at(0)->clone();
} else {
rhs = new AstNode(AST_IDENTIFIER);
rhs->str = outreg->str;
rhs->id2ast = outreg;
}
block->children.push_back(new AstNode(AST_ASSIGN_LE, regid, rhs));
outreg = reg;
}
newNode = new AstNode(AST_IDENTIFIER);
newNode->str = outreg->str;
newNode->id2ast = outreg;
goto apply_newNode;
}
if (str == "\\$stable" || str == "\\$rose" || str == "\\$fell")
{
if (GetSize(children) != 1)
log_error("System function %s got %d arguments, expected 1 at %s:%d.\n",
RTLIL::unescape_id(str).c_str(), int(children.size()), filename.c_str(), linenum);
if (!current_always_clocked)
log_error("System function %s is only allowed in clocked blocks at %s:%d.\n",
RTLIL::unescape_id(str).c_str(), filename.c_str(), linenum);
AstNode *present = children.at(0)->clone();
AstNode *past = clone();
past->str = "\\$past";
if (str == "\\$stable")
newNode = new AstNode(AST_EQ, past, present);
else if (str == "\\$rose")
newNode = new AstNode(AST_LOGIC_AND, new AstNode(AST_LOGIC_NOT, past), present);
else if (str == "\\$fell")
newNode = new AstNode(AST_LOGIC_AND, past, new AstNode(AST_LOGIC_NOT, present));
else
log_abort();
goto apply_newNode;
}
if (str == "\\$rose" || str == "\\$fell")
{
if (GetSize(children) != 1)
log_error("System function %s got %d arguments, expected 1 at %s:%d.\n",
RTLIL::unescape_id(str).c_str(), int(children.size()), filename.c_str(), linenum);
if (!current_always_clocked)
log_error("System function %s is only allowed in clocked blocks at %s:%d.\n",
RTLIL::unescape_id(str).c_str(), filename.c_str(), linenum);
newNode = new AstNode(AST_EQ, children.at(0)->clone(), clone());
newNode->children.at(1)->str = "\\$past";
goto apply_newNode;
}
// $anyconst is mapped in AstNode::genRTLIL()
if (str == "\\$anyconst")
if (str == "\\$anyconst") {
recursion_counter--;
return false;
}
if (str == "\\$clog2")
{
@ -2092,6 +2219,8 @@ skip_dynamic_range_lvalue_expansion:;
did_something = true;
}
replace_fcall_later:;
// perform const folding when activated
if (const_fold)
{