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improved const function support

This commit is contained in:
Clifford Wolf 2014-06-06 22:55:02 +02:00
parent 5c10d2ee36
commit 76da2fe172
3 changed files with 41 additions and 5 deletions
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1
frontends/ast/ast.h
View File

@ -202,6 +202,7 @@ namespace AST
// additional functionality for evaluating constant functions
struct varinfo_t { RTLIL::Const val; int offset; bool is_signed; };
bool has_const_only_constructs();
void replace_variables(std::map<std::string, varinfo_t> &variables, AstNode *fcall);
AstNode *eval_const_function(AstNode *fcall);

2
frontends/ast/genrtlil.cc
View File

@ -579,7 +579,7 @@ struct AST_INTERNAL::ProcessGenerator
break;
default:
assert(0);
log_abort();
}
}
};

43
frontends/ast/simplify.cc
View File

@ -606,6 +606,12 @@ bool AstNode::simplify(bool const_fold, bool at_zero, bool in_lvalue, int stage,
goto apply_newNode;
}
if (type == AST_WHILE)
log_error("While loops are only allowed in constant functions at %s:%d!\n", filename.c_str(), linenum);
if (type == AST_REPEAT)
log_error("Repeat loops are only allowed in constant functions at %s:%d!\n", filename.c_str(), linenum);
// unroll for loops and generate-for blocks
if ((type == AST_GENFOR || type == AST_FOR) && children.size() != 0)
{
@ -1181,7 +1187,7 @@ skip_dynamic_range_lvalue_expansion:;
log_error("Can't resolve task name `%s' at %s:%d.\n", str.c_str(), filename.c_str(), linenum);
}
if (in_param)
if (in_param || current_scope[str]->has_const_only_constructs())
{
bool all_args_const = true;
for (auto child : children) {
@ -1197,7 +1203,10 @@ skip_dynamic_range_lvalue_expansion:;
goto apply_newNode;
}
log_error("Non-constant function call in constant expression at %s:%d.\n", filename.c_str(), linenum);
if (in_param)
log_error("Non-constant function call in constant expression at %s:%d.\n", filename.c_str(), linenum);
else
log_error("Function %s can only be called with constant arguments at %s:%d.\n", str.c_str(), filename.c_str(), linenum);
}
AstNode *decl = current_scope[str];
@ -1819,6 +1828,19 @@ void AstNode::meminfo(int &mem_width, int &mem_size, int &addr_bits)
addr_bits++;
}
bool AstNode::has_const_only_constructs()
{
if (type == AST_WHILE || type == AST_REPEAT)
return true;
if (type == AST_FCALL && current_scope.count(str))
if (current_scope[str]->has_const_only_constructs())
return true;
for (auto child : children)
if (child->AstNode::has_const_only_constructs())
return true;
return false;
}
// helper function for AstNode::eval_const_function()
void AstNode::replace_variables(std::map<std::string, AstNode::varinfo_t> &variables, AstNode *fcall)
{
@ -1915,7 +1937,7 @@ AstNode *AstNode::eval_const_function(AstNode *fcall)
log_error("Non-constant expression in constant function at %s:%d (called from %s:%d). X\n",
stmt->filename.c_str(), stmt->linenum, fcall->filename.c_str(), fcall->linenum);
if (stmt->children.at(0)->type != AST_IDENTIFIER || !stmt->children.at(0)->children.empty())
if (stmt->children.at(0)->type != AST_IDENTIFIER)
log_error("Unsupported composite left hand side in constant function at %s:%d (called from %s:%d).\n",
stmt->filename.c_str(), stmt->linenum, fcall->filename.c_str(), fcall->linenum);
@ -1923,7 +1945,20 @@ AstNode *AstNode::eval_const_function(AstNode *fcall)
log_error("Assignment to non-local variable in constant function at %s:%d (called from %s:%d).\n",
stmt->filename.c_str(), stmt->linenum, fcall->filename.c_str(), fcall->linenum);
variables[stmt->children.at(0)->str].val = stmt->children.at(1)->bitsAsConst(variables[stmt->children.at(0)->str].val.bits.size());
if (stmt->children.at(0)->children.empty()) {
variables[stmt->children.at(0)->str].val = stmt->children.at(1)->bitsAsConst(variables[stmt->children.at(0)->str].val.bits.size());
} else {
AstNode *range = stmt->children.at(0)->children.at(0);
if (!range->range_valid)
log_error("Non-constant range in %s:%d (called from %s:%d).\n",
range->filename.c_str(), range->linenum, fcall->filename.c_str(), fcall->linenum);
int offset = std::min(range->range_left, range->range_right);
int width = std::min(std::abs(range->range_left - range->range_right) + 1, width);
varinfo_t &v = variables[stmt->children.at(0)->str];
RTLIL::Const r = stmt->children.at(1)->bitsAsConst(v.val.bits.size());
for (int i = 0; i < width; i++)
v.val.bits.at(i+offset-v.offset) = r.bits.at(i);
}
delete block->children.front();
block->children.erase(block->children.begin());