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Merge pull request #1647 from YosysHQ/dave/sprintf 

ast: Add support for $sformatf system function
This commit is contained in:
David Shah 2020-02-02 14:53:46 +00:00 committed by GitHub
parent 1055b6b1dd 22c967e35e
commit 9f5613100b
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GPG Key ID: 4AEE18F83AFDEB23
3 changed files with 122 additions and 93 deletions
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1
frontends/ast/ast.h
View File

@ -244,6 +244,7 @@ namespace AST
void replace_variables(std::map<std::string, varinfo_t> &variables, AstNode *fcall);
AstNode *eval_const_function(AstNode *fcall);
bool is_simple_const_expr();
std::string process_format_str(const std::string &sformat, int next_arg, int stage, int width_hint, bool sign_hint);
// create a human-readable text representation of the AST (for debugging)
void dumpAst(FILE *f, std::string indent) const;

202
frontends/ast/simplify.cc
View File

@ -41,6 +41,103 @@ YOSYS_NAMESPACE_BEGIN
using namespace AST;
using namespace AST_INTERNAL;
// Process a format string and arguments for $display, $write, $sprintf, etc
std::string AstNode::process_format_str(const std::string &sformat, int next_arg, int stage, int width_hint, bool sign_hint) {
// Other arguments are placeholders. Process the string as we go through it
std::string sout;
for (size_t i = 0; i < sformat.length(); i++)
{
// format specifier
if (sformat[i] == '%')
{
// If there's no next character, that's a problem
if (i+1 >= sformat.length())
log_file_error(filename, linenum, "System task `%s' called with `%%' at end of string.\n", str.c_str());
char cformat = sformat[++i];
// %% is special, does not need a matching argument
if (cformat == '%')
{
sout += '%';
continue;
}
// Simplify the argument
AstNode *node_arg = nullptr;
// Everything from here on depends on the format specifier
switch (cformat)
{
case 's':
case 'S':
case 'd':
case 'D':
case 'x':
case 'X':
if (next_arg >= GetSize(children))
log_file_error(filename, linenum, "Missing argument for %%%c format specifier in system task `%s'.\n",
cformat, str.c_str());
node_arg = children[next_arg++];
while (node_arg->simplify(true, false, false, stage, width_hint, sign_hint, false)) { }
if (node_arg->type != AST_CONSTANT)
log_file_error(filename, linenum, "Failed to evaluate system task `%s' with non-constant argument.\n", str.c_str());
break;
case 'm':
case 'M':
break;
default:
log_file_error(filename, linenum, "System task `%s' called with invalid/unsupported format specifier.\n", str.c_str());
break;
}
switch (cformat)
{
case 's':
case 'S':
sout += node_arg->bitsAsConst().decode_string();
break;
case 'd':
case 'D':
{
char tmp[128];
snprintf(tmp, sizeof(tmp), "%d", node_arg->bitsAsConst().as_int());
sout += tmp;
}
break;
case 'x':
case 'X':
{
char tmp[128];
snprintf(tmp, sizeof(tmp), "%x", node_arg->bitsAsConst().as_int());
sout += tmp;
}
break;
case 'm':
case 'M':
sout += log_id(current_module->name);
break;
default:
log_abort();
}
}
// not a format specifier
else
sout += sformat[i];
}
return sout;
}
// convert the AST into a simpler AST that has all parameters substituted by their
// values, unrolled for-loops, expanded generate blocks, etc. when this function
// is done with an AST it can be converted into RTLIL using genRTLIL().
@ -216,99 +313,7 @@ bool AstNode::simplify(bool const_fold, bool at_zero, bool in_lvalue, int stage,
if (node_string->type != AST_CONSTANT)
log_file_error(filename, linenum, "Failed to evaluate system task `%s' with non-constant 1st argument.\n", str.c_str());
std::string sformat = node_string->bitsAsConst().decode_string();
// Other arguments are placeholders. Process the string as we go through it
std::string sout;
int next_arg = 1;
for (size_t i = 0; i < sformat.length(); i++)
{
// format specifier
if (sformat[i] == '%')
{
// If there's no next character, that's a problem
if (i+1 >= sformat.length())
log_file_error(filename, linenum, "System task `%s' called with `%%' at end of string.\n", str.c_str());
char cformat = sformat[++i];
// %% is special, does not need a matching argument
if (cformat == '%')
{
sout += '%';
continue;
}
// Simplify the argument
AstNode *node_arg = nullptr;
// Everything from here on depends on the format specifier
switch (cformat)
{
case 's':
case 'S':
case 'd':
case 'D':
case 'x':
case 'X':
if (next_arg >= GetSize(children))
log_file_error(filename, linenum, "Missing argument for %%%c format specifier in system task `%s'.\n",
cformat, str.c_str());
node_arg = children[next_arg++];
while (node_arg->simplify(true, false, false, stage, width_hint, sign_hint, false)) { }
if (node_arg->type != AST_CONSTANT)
log_file_error(filename, linenum, "Failed to evaluate system task `%s' with non-constant argument.\n", str.c_str());
break;
case 'm':
case 'M':
break;
default:
log_file_error(filename, linenum, "System task `%s' called with invalid/unsupported format specifier.\n", str.c_str());
break;
}
switch (cformat)
{
case 's':
case 'S':
sout += node_arg->bitsAsConst().decode_string();
break;
case 'd':
case 'D':
{
char tmp[128];
snprintf(tmp, sizeof(tmp), "%d", node_arg->bitsAsConst().as_int());
sout += tmp;
}
break;
case 'x':
case 'X':
{
char tmp[128];
snprintf(tmp, sizeof(tmp), "%x", node_arg->bitsAsConst().as_int());
sout += tmp;
}
break;
case 'm':
case 'M':
sout += log_id(current_module->name);
break;
default:
log_abort();
}
}
// not a format specifier
else
sout += sformat[i];
}
std::string sout = process_format_str(sformat, 1, stage, width_hint, sign_hint);
// Finally, print the message (only include a \n for $display, not for $write)
log("%s", sout.c_str());
if (str == "$display")
@ -2244,6 +2249,17 @@ skip_dynamic_range_lvalue_expansion:;
goto apply_newNode;
}
if (str == "\\$sformatf") {
AstNode *node_string = children[0];
while (node_string->simplify(true, false, false, stage, width_hint, sign_hint, false)) { }
if (node_string->type != AST_CONSTANT)
log_file_error(filename, linenum, "Failed to evaluate system function `%s' with non-constant 1st argument.\n", str.c_str());
std::string sformat = node_string->bitsAsConst().decode_string();
std::string sout = process_format_str(sformat, 1, stage, width_hint, sign_hint);
newNode = AstNode::mkconst_str(sout);
goto apply_newNode;
}
if (current_scope.count(str) != 0 && current_scope[str]->type == AST_DPI_FUNCTION)
{
AstNode *dpi_decl = current_scope[str];

12
tests/various/sformatf.ys Normal file
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@ -0,0 +1,12 @@
read_verilog <<EOT
module top;
localparam a = $sformatf("0x%x", 8'h5A);
localparam b = $sformatf("%d", 4'b011);
generate
if (a != "0x5a") $error("a incorrect!");
if (b != "3") $error("b incorrect!");
endgenerate
endmodule
EOT