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Various ast changes for early expression width detection (prep for constfold fixes)

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This commit is contained in:
Clifford Wolf 2013-11-02 13:00:17 +01:00
parent 0b4a64ac6a
commit 943329c1dc
5 changed files with 146 additions and 30 deletions
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80
frontends/ast/genrtlil.cc
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@ -508,8 +508,10 @@ struct AST_INTERNAL::ProcessGenerator
void AstNode::detectSignWidthWorker(int &width_hint, bool &sign_hint)
{
std::string type_name;
bool dummy_sign_hint = true;
// int dummy_width_hint = -1;
bool sub_sign_hint = true;
int sub_width_hint = -1;
int this_width = 0;
AstNode *range = NULL;
switch (type)
{
@ -520,23 +522,81 @@ void AstNode::detectSignWidthWorker(int &width_hint, bool &sign_hint)
break;
case AST_IDENTIFIER:
if ((id2ast && !id2ast->is_signed) || children.size() > 0)
sign_hint = false;
width_hint = std::max(width_hint, genRTLIL().width);
if (!id2ast)
log_error("Failed to resolve identifier %s for width detection at %s:%d!\n", str.c_str(), filename.c_str(), linenum);
if ((id2ast->type == AST_PARAMETER || id2ast->type == AST_LOCALPARAM) && id2ast->children[0]->type == AST_CONSTANT) {
this_width = id2ast->children[0]->bits.size();
if (children.size() != 0)
range = children[0];
} else if (id2ast->type == AST_WIRE || id2ast->type == AST_AUTOWIRE) {
if (!id2ast->range_valid) {
if (id2ast->type == AST_AUTOWIRE)
this_width = 1;
else {
current_ast_mod->dumpAst(stdout, "");
printf("---\n");
dumpAst(stdout, "");
fflush(stdout);
log_error("Failed to detect with of signal access `%s' at %s:%d!\n", str.c_str(), filename.c_str(), linenum);
}
} else {
this_width = id2ast->range_left - id2ast->range_right + 1;
if (children.size() != 0)
range = children[0];
}
} else if (id2ast->type == AST_GENVAR) {
this_width = 32;
} else if (id2ast->type == AST_MEMORY) {
if (!id2ast->children[0]->range_valid)
log_error("Failed to detect with of memory access `%s' at %s:%d!\n", str.c_str(), filename.c_str(), linenum);
this_width = id2ast->children[0]->range_left - id2ast->children[0]->range_right + 1;
} else
log_error("Failed to detect width for identifier %s at %s:%d!\n", str.c_str(), filename.c_str(), linenum);
if (range) {
if (range->children.size() == 1)
this_width = 1;
else if (!range->range_valid) {
AstNode *left_at_zero_ast = children[0]->children[0]->clone();
AstNode *right_at_zero_ast = children[0]->children.size() >= 2 ? children[0]->children[1]->clone() : left_at_zero_ast->clone();
while (left_at_zero_ast->simplify(true, true, false, 1, -1, false)) { }
while (right_at_zero_ast->simplify(true, true, false, 1, -1, false)) { }
if (left_at_zero_ast->type != AST_CONSTANT || right_at_zero_ast->type != AST_CONSTANT)
log_error("Unsupported expression on dynamic range select on signal `%s' at %s:%d!\n",
str.c_str(), filename.c_str(), linenum);
this_width = left_at_zero_ast->integer - right_at_zero_ast->integer + 1;
delete left_at_zero_ast;
delete right_at_zero_ast;
} else
this_width = range->range_left - range->range_right + 1;
} else
width_hint = std::max(width_hint, this_width);
break;
case AST_TO_SIGNED:
children.at(0)->detectSignWidthWorker(width_hint, dummy_sign_hint);
children.at(0)->detectSignWidthWorker(width_hint, sub_sign_hint);
break;
case AST_TO_UNSIGNED:
children.at(0)->detectSignWidthWorker(width_hint, dummy_sign_hint);
children.at(0)->detectSignWidthWorker(width_hint, sub_sign_hint);
sign_hint = false;
break;
case AST_CONCAT:
for (auto child : children) {
sub_width_hint = 0;
sub_sign_hint = true;
child->detectSignWidthWorker(width_hint, sign_hint);
this_width += sub_width_hint;
}
width_hint = std::max(width_hint, this_width);
sign_hint = false;
break;
case AST_REPLICATE:
width_hint = std::max(width_hint, genRTLIL().width);
if (children[0]->type != AST_CONSTANT)
log_error("Left operand of replicate expression is not constant at %s:%d!\n", filename.c_str(), linenum);
children[1]->detectSignWidthWorker(sub_width_hint, sub_sign_hint);
width_hint = std::max(width_hint, children[0]->bitsAsConst().as_int() * sub_width_hint);
sign_hint = false;
break;
@ -797,8 +857,8 @@ RTLIL::SigSpec AstNode::genRTLIL(int width_hint, bool sign_hint)
if (!children[0]->range_valid) {
AstNode *left_at_zero_ast = children[0]->children[0]->clone();
AstNode *right_at_zero_ast = children[0]->children.size() >= 2 ? children[0]->children[1]->clone() : left_at_zero_ast->clone();
while (left_at_zero_ast->simplify(true, true, false, 1)) { }
while (right_at_zero_ast->simplify(true, true, false, 1)) { }
while (left_at_zero_ast->simplify(true, true, false, 1, -1, false)) { }
while (right_at_zero_ast->simplify(true, true, false, 1, -1, false)) { }
if (left_at_zero_ast->type != AST_CONSTANT || right_at_zero_ast->type != AST_CONSTANT)
log_error("Unsupported expression on dynamic range select on signal `%s' at %s:%d!\n",
str.c_str(), filename.c_str(), linenum);