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iverilog/tgt-vvp/draw_net_input.c

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/*
* Copyright (c) 2001-2008 Stephen Williams (steve@icarus.com)
*
* This source code is free software; you can redistribute it
* and/or modify it in source code form under the terms of the GNU
* General Public License as published by the Free Software
* Foundation; either version 2 of the License, or (at your option)
* any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
*/
# include "vvp_priv.h"
#ifdef HAVE_MALLOC_H
# include <malloc.h>
#endif
# include <stdlib.h>
# include <math.h>
# include <string.h>
# include <inttypes.h>
# include <assert.h>
#ifdef __MINGW32__ /* MinGW has inconsistent %p output. */
#define snprintf _snprintf
#endif
static ivl_signal_type_t signal_type_of_nexus(ivl_nexus_t nex)
{
unsigned idx;
ivl_signal_type_t out = IVL_SIT_TRI;
for (idx = 0 ; idx < ivl_nexus_ptrs(nex) ; idx += 1) {
ivl_signal_type_t stype;
ivl_nexus_ptr_t ptr = ivl_nexus_ptr(nex, idx);
ivl_signal_t sig = ivl_nexus_ptr_sig(ptr);
if (sig == 0)
continue;
stype = ivl_signal_type(sig);
if (stype == IVL_SIT_REG)
continue;
if (stype == IVL_SIT_TRI)
continue;
if (stype == IVL_SIT_NONE)
continue;
out = stype;
}
return out;
}
static void draw_C4_repeated_constant(char bit_char, unsigned width)
{
unsigned idx;
fprintf(vvp_out, "C4<");
for (idx = 0 ; idx < width ; idx += 1)
fprintf(vvp_out, "%c", bit_char);
fprintf(vvp_out, ">");
}
static char* draw_C4_to_string(ivl_net_const_t cptr)
{
const char*bits = ivl_const_bits(cptr);
unsigned idx;
size_t result_len = 5 + ivl_const_width(cptr);
char*result = malloc(result_len);
char*dp = result;
strcpy(dp, "C4<");
dp += strlen(dp);
for (idx = 0 ; idx < ivl_const_width(cptr) ; idx += 1) {
char bitchar = bits[ivl_const_width(cptr)-idx-1];
*dp++ = bitchar;
assert((dp - result) < result_len);
}
strcpy(dp, ">");
return result;
}
static char* draw_C8_to_string(ivl_net_const_t cptr,
ivl_drive_t dr0, ivl_drive_t dr1)
{
size_t nresult = 5 + 3*ivl_const_width(cptr);
char*result = malloc(nresult);
const char*bits = ivl_const_bits(cptr);
unsigned idx;
char dr0c = "01234567"[dr0];
char dr1c = "01234567"[dr1];
char*dp = result;
strcpy(dp, "C8<");
dp += strlen(dp);
for (idx = 0 ; idx < ivl_const_width(cptr) ; idx += 1) {
switch (bits[ivl_const_width(cptr)-idx-1]) {
case '0':
*dp++ = dr0c;
*dp++ = dr0c;
*dp++ = '0';
break;
case '1':
*dp++ = dr1c;
*dp++ = dr1c;
*dp++ = '1';
break;
case 'x':
case 'X':
*dp++ = dr0c;
*dp++ = dr1c;
*dp++ = 'x';
break;
case 'z':
case 'Z':
*dp++ = '0';
*dp++ = '0';
*dp++ = 'z';
break;
default:
assert(0);
break;
}
assert(dp - result < nresult);
}
strcpy(dp, ">");
return result;
}
static struct vvp_nexus_data*new_nexus_data()
{
struct vvp_nexus_data*data = calloc(1, sizeof(struct vvp_nexus_data));
return data;
}
static int nexus_drive_is_strength_aware(ivl_nexus_ptr_t nptr)
{
if (ivl_nexus_ptr_drive0(nptr) != IVL_DR_STRONG)
return 1;
if (ivl_nexus_ptr_drive1(nptr) != IVL_DR_STRONG)
return 1;
ivl_net_logic_t log = ivl_nexus_ptr_log(nptr);
if (log != 0) {
/* These logic gates are able to generate unusual
strength values and so their outputs are considered
strength aware. */
if (ivl_logic_type(log) == IVL_LO_BUFIF0)
return 1;
if (ivl_logic_type(log) == IVL_LO_BUFIF1)
return 1;
if (ivl_logic_type(log) == IVL_LO_PMOS)
return 1;
if (ivl_logic_type(log) == IVL_LO_NMOS)
return 1;
if (ivl_logic_type(log) == IVL_LO_CMOS)
return 1;
}
return 0;
}
/*
* Given a nexus, look for a signal that has module delay
* paths. Return that signal. (There should be no more than 1.) If we
* don't find any, then return nil.
*/
static ivl_signal_t find_modpath(ivl_nexus_t nex)
{
unsigned idx;
for (idx = 0 ; idx < ivl_nexus_ptrs(nex) ; idx += 1) {
ivl_nexus_ptr_t ptr = ivl_nexus_ptr(nex,idx);
ivl_signal_t sig = ivl_nexus_ptr_sig(ptr);
if (sig == 0)
continue;
if (ivl_signal_npath(sig) == 0)
continue;
return sig;
}
return 0;
}
static void str_repeat(char*buf, const char*str, unsigned rpt)
{
unsigned idx;
size_t len = strlen(str);
for (idx = 0 ; idx < rpt ; idx += 1) {
strcpy(buf, str);
buf += len;
}
}
/*
* This function takes a nexus and looks for an input functor. It then
* draws to the output a string that represents that functor. What we
* are trying to do here is find the input to the net that is attached
* to this nexus.
*/
static char* draw_net_input_drive(ivl_nexus_t nex, ivl_nexus_ptr_t nptr)
{
unsigned nptr_pin = ivl_nexus_ptr_pin(nptr);
ivl_net_const_t cptr;
ivl_net_logic_t lptr;
ivl_signal_t sptr;
ivl_lpm_t lpm;
lptr = ivl_nexus_ptr_log(nptr);
if (lptr && (ivl_logic_type(lptr) == IVL_LO_BUFZ) && (nptr_pin == 0))
do {
if (! can_elide_bufz(lptr, nptr))
break;
return strdup(draw_net_input(ivl_logic_pin(lptr, 1)));
} while(0);
/* If this is a pulldown device, then there is a single pin
that drives a constant value to the entire width of the
vector. The driver normally drives a pull0 value, so a C8<>
constant is appropriate, but if the drive is really strong,
then we can draw a C4<> constant instead. */
if (lptr && (ivl_logic_type(lptr) == IVL_LO_PULLDOWN)) {
if (ivl_nexus_ptr_drive0(nptr) == IVL_DR_STRONG) {
size_t result_len = ivl_logic_width(lptr) + 5;
char*result = malloc(result_len);
char*dp = result;
strcpy(dp, "C4<");
dp += strlen(dp);
str_repeat(dp, "0", ivl_logic_width(lptr));
dp += ivl_logic_width(lptr);
*dp++ = '>';
*dp = 0;
assert((dp-result) <= result_len);
return result;
} else {
char val[4];
size_t result_len = 3*ivl_logic_width(lptr) + 5;
char*result = malloc(result_len);
char*dp = result;
val[0] = "01234567"[ivl_nexus_ptr_drive0(nptr)];
val[1] = val[0];
val[2] = '0';
val[3] = 0;
strcpy(dp, "C8<");
dp += strlen(dp);
str_repeat(dp, val, ivl_logic_width(lptr));
dp += 3*ivl_logic_width(lptr);
*dp++ = '>';
*dp = 0;
assert((dp-result) <= result_len);
return result;
}
}
if (lptr && (ivl_logic_type(lptr) == IVL_LO_PULLUP)) {
if (ivl_nexus_ptr_drive1(nptr) == IVL_DR_STRONG) {
size_t result_len = 5 + ivl_logic_width(lptr);
char*result = malloc(result_len);
char*dp = result;
strcpy(dp, "C4<");
dp += strlen(dp);
str_repeat(dp, "1", ivl_logic_width(lptr));
dp += ivl_logic_width(lptr);
*dp++ = '>';
*dp = 0;
assert((dp-result) <= result_len);
return result;
} else {
char val[4];
size_t result_len = 5 + 3*ivl_logic_width(lptr);
char*result = malloc(result_len);
char*dp = result;
val[0] = "01234567"[ivl_nexus_ptr_drive0(nptr)];
val[1] = val[0];
val[2] = '1';
val[3] = 0;
strcpy(dp, "C8<");
dp += strlen(dp);
str_repeat(dp, val, ivl_logic_width(lptr));
dp += 3*ivl_logic_width(lptr);
*dp++ = '>';
*dp = 0;
assert((dp-result) <= result_len);
return result;
}
}
if (lptr && (nptr_pin == 0)) {
char tmp[128];
snprintf(tmp, sizeof tmp, "L_%p", lptr);
return strdup(tmp);
}
sptr = ivl_nexus_ptr_sig(nptr);
if (sptr && (ivl_signal_type(sptr) == IVL_SIT_REG)) {
char tmp[128];
/* Input is a .var. This device may be a non-zero pin
because it may be an array of reg vectors. */
snprintf(tmp, sizeof tmp, "v%p_%u", sptr, nptr_pin);
if (ivl_signal_array_count(sptr) > 1) {
fprintf(vvp_out, "v%p_%u .array/port v%p, %u;\n",
sptr, nptr_pin, sptr, nptr_pin);
}
return strdup(tmp);
}
cptr = ivl_nexus_ptr_con(nptr);
if (cptr) {
/* Constants should have exactly 1 pin, with a literal value. */
assert(nptr_pin == 0);
char *result = 0;
switch (ivl_const_type(cptr)) {
case IVL_VT_LOGIC:
case IVL_VT_BOOL:
if ((ivl_nexus_ptr_drive0(nptr) == IVL_DR_STRONG)
&& (ivl_nexus_ptr_drive1(nptr) == IVL_DR_STRONG)) {
result = draw_C4_to_string(cptr);
} else {
result = draw_C8_to_string(cptr,
ivl_nexus_ptr_drive0(nptr),
ivl_nexus_ptr_drive1(nptr));
}
break;
case IVL_VT_REAL:
result = draw_Cr_to_string(ivl_const_real(cptr));
break;
default:
assert(0);
break;
}
ivl_expr_t d_rise = ivl_const_delay(cptr, 0);
ivl_expr_t d_fall = ivl_const_delay(cptr, 1);
ivl_expr_t d_decay = ivl_const_delay(cptr, 2);
/* We have a delayed constant, so we need to build some code. */
if (d_rise != 0) {
assert(number_is_immediate(d_rise, 64));
assert(number_is_immediate(d_fall, 64));
assert(number_is_immediate(d_decay, 64));
fprintf(vvp_out, "L_%p/d .functor BUFZ 1, %s, "
"C4<0>, C4<0>, C4<0>;\n", cptr, result);
fprintf(vvp_out, "L_%p .delay (%lu,%lu,%lu) L_%p/d;\n",
cptr, get_number_immediate(d_rise),
get_number_immediate(d_rise),
get_number_immediate(d_rise), cptr);
free(result);
char tmp[128];
snprintf(tmp, sizeof tmp, "L_%p", cptr);
result = strdup(tmp);
}
return result;
}
lpm = ivl_nexus_ptr_lpm(nptr);
if (lpm) switch (ivl_lpm_type(lpm)) {
case IVL_LPM_FF:
case IVL_LPM_ABS:
case IVL_LPM_ADD:
case IVL_LPM_ARRAY:
case IVL_LPM_CONCAT:
case IVL_LPM_CMP_EEQ:
case IVL_LPM_CMP_EQ:
case IVL_LPM_CMP_GE:
case IVL_LPM_CMP_GT:
case IVL_LPM_CMP_NE:
case IVL_LPM_CMP_NEE:
case IVL_LPM_RE_AND:
case IVL_LPM_RE_OR:
case IVL_LPM_RE_XOR:
case IVL_LPM_RE_NAND:
case IVL_LPM_RE_NOR:
case IVL_LPM_RE_XNOR:
case IVL_LPM_SFUNC:
case IVL_LPM_SHIFTL:
case IVL_LPM_SHIFTR:
case IVL_LPM_SIGN_EXT:
case IVL_LPM_SUB:
case IVL_LPM_MULT:
case IVL_LPM_MUX:
case IVL_LPM_POW:
case IVL_LPM_DIVIDE:
case IVL_LPM_MOD:
case IVL_LPM_UFUNC:
case IVL_LPM_PART_VP:
case IVL_LPM_PART_PV: /* NOTE: This is only a partial driver. */
case IVL_LPM_REPEAT:
if (ivl_lpm_q(lpm, 0) == nex) {
char tmp[128];
snprintf(tmp, sizeof tmp, "L_%p", lpm);
return strdup(tmp);
}
break;
}
fprintf(stderr, "internal error: no input to nexus %s\n",
ivl_nexus_name(nex));
assert(0);
return strdup("C<z>");
}
static char* draw_island_port(ivl_island_t island,
ivl_nexus_t nex, const char*src)
{
char result[64];
if (ivl_island_flag_test(island,0) == 0) {
fprintf(vvp_out, "I%p .island tran;\n", island);
ivl_island_flag_set(island,0,1);
}
fprintf(vvp_out, "p%p .port I%p, %s;\n", nex, island, src);
snprintf(result, sizeof result, "p%p", nex);
return strdup(result);
}
/*
* This function draws the input to a net into a string. What that
* means is that it returns a static string that can be used to
* represent a resolved driver to a nexus. If there are multiple
* drivers to the nexus, then it writes out the resolver declarations
* needed to perform strength resolution.
*
* The string that this returns is malloced, and that means that the
* caller must free the string or store it permanently. This function
* does *not* check for a previously calculated string. Use the
* draw_net_input for the general case.
*/
/* Omit LPMPART_BI device pin-data(0) drivers. */
# define OMIT_PART_BI_DATA 0x0001
char* draw_net_input_x(ivl_nexus_t nex,
ivl_nexus_ptr_t omit_ptr, int omit_flags,
struct vvp_nexus_data*nex_data)
{
ivl_island_t island = 0;
ivl_signal_type_t res;
char result[512];
unsigned idx;
int level;
unsigned ndrivers = 0;
static ivl_nexus_ptr_t *drivers = 0x0;
static unsigned adrivers = 0;
const char*resolv_type;
char*nex_private = 0;
/* Accumulate nex_data flags. */
int nex_flags = 0;
res = signal_type_of_nexus(nex);
switch (res) {
case IVL_SIT_TRI:
resolv_type = "tri";
break;
case IVL_SIT_TRI0:
resolv_type = "tri0";
nex_flags |= VVP_NEXUS_DATA_STR;
break;
case IVL_SIT_TRI1:
resolv_type = "tri1";
nex_flags |= VVP_NEXUS_DATA_STR;
break;
case IVL_SIT_TRIAND:
resolv_type = "triand";
break;
case IVL_SIT_TRIOR:
resolv_type = "trior";
break;
default:
fprintf(stderr, "vvp.tgt: Unsupported signal type: %u\n", res);
assert(0);
resolv_type = "tri";
break;
}
for (idx = 0 ; idx < ivl_nexus_ptrs(nex) ; idx += 1) {
ivl_lpm_t lpm_tmp;
ivl_switch_t sw = 0;
ivl_nexus_ptr_t nptr = ivl_nexus_ptr(nex, idx);
/* If this object is part of an island, then we'll be
making a port. Save the island cookie. */
if ( (sw = ivl_nexus_ptr_switch(nptr)) ) {
island = ivl_switch_island(sw);
}
/* If we are supposed to skip LPM_PART_BI data pins,
check that this driver is that. */
if ((omit_flags&OMIT_PART_BI_DATA)
&& (lpm_tmp = ivl_nexus_ptr_lpm(nptr))
&& (nex == ivl_lpm_data(lpm_tmp,0)))
continue;
if (nptr == omit_ptr)
continue;
/* Skip input only pins. */
if ((ivl_nexus_ptr_drive0(nptr) == IVL_DR_HiZ)
&& (ivl_nexus_ptr_drive1(nptr) == IVL_DR_HiZ))
continue;
/* Mark the strength-aware flag if the driver can
generate values other than the standard "6"
strength. */
if (nexus_drive_is_strength_aware(nptr))
nex_flags |= VVP_NEXUS_DATA_STR;
/* Save this driver. */
if (ndrivers >= adrivers) {
adrivers += 4;
drivers = realloc(drivers, adrivers*sizeof(ivl_nexus_ptr_t));
assert(drivers);
}
drivers[ndrivers] = nptr;
ndrivers += 1;
}
/* If the caller is collecting nexus information, then save
the nexus driver count in the nex_data. */
if (nex_data) {
nex_data->drivers_count = ndrivers;
nex_data->flags |= nex_flags;
}
/* If the nexus has no drivers, then send a constant HiZ into
the net. */
if (ndrivers == 0) {
unsigned idx, wid = width_of_nexus(nex);
char*tmp = malloc(wid + 5);
nex_private = tmp;
strcpy(tmp, "C4<");
tmp += strlen(tmp);
switch (res) {
case IVL_SIT_TRI:
for (idx = 0 ; idx < wid ; idx += 1)
*tmp++ = 'z';
break;
case IVL_SIT_TRI0:
for (idx = 0 ; idx < wid ; idx += 1)
*tmp++ = '0';
break;
case IVL_SIT_TRI1:
for (idx = 0 ; idx < wid ; idx += 1)
*tmp++ = '1';
break;
default:
assert(0);
}
*tmp++ = '>';
*tmp = 0;
if (island) {
char*tmp = draw_island_port(island, nex, nex_private);
free(nex_private);
nex_private = tmp;
}
return nex_private;
}
/* If the nexus has exactly one driver, then simply draw
it. Note that this will *not* work if the nexus is not a
TRI type nexus. */
if (ndrivers == 1 && res == IVL_SIT_TRI) {
ivl_signal_t path_sig = find_modpath(nex);
if (path_sig) {
char*nex_str = draw_net_input_drive(nex, drivers[0]);
char modpath_label[64];
snprintf(modpath_label, sizeof modpath_label,
"V_%p/m", path_sig);
nex_private = strdup(modpath_label);
draw_modpath(path_sig, nex_str);
} else {
nex_private = draw_net_input_drive(nex, drivers[0]);
}
if (island) {
char*tmp = draw_island_port(island, nex, nex_private);
free(nex_private);
nex_private = tmp;
}
return nex_private;
}
level = 0;
while (ndrivers) {
unsigned int inst;
for (inst = 0; inst < ndrivers; inst += 4) {
if (ndrivers > 4)
fprintf(vvp_out, "RS_%p/%d/%d .resolv tri",
nex, level, inst);
else
fprintf(vvp_out, "RS_%p .resolv %s",
nex, resolv_type);
for (idx = inst; idx < ndrivers && idx < inst+4; idx += 1) {
if (level) {
fprintf(vvp_out, ", RS_%p/%d/%d",
nex, level - 1, idx*4);
} else {
char*drive = draw_net_input_drive(nex, drivers[idx]);
fprintf(vvp_out, ", %s", drive);
free(drive);
}
}
for ( ; idx < inst+4 ; idx += 1) {
fprintf(vvp_out, ", ");
draw_C4_repeated_constant('z',width_of_nexus(nex));
}
fprintf(vvp_out, ";\n");
}
if (ndrivers > 4)
ndrivers = (ndrivers+3) / 4;
else
ndrivers = 0;
level += 1;
}
snprintf(result, sizeof result, "RS_%p", nex);
if (island)
nex_private = draw_island_port(island, nex, result);
else
nex_private = strdup(result);
return nex_private;
}
/*
* Get a cached description of the nexus input, or create one if this
* nexus has not been cached yet. This is a wrapper for the common
* case call to draw_net_input_x.
*/
const char*draw_net_input(ivl_nexus_t nex)
{
struct vvp_nexus_data*nex_data = (struct vvp_nexus_data*)
ivl_nexus_get_private(nex);
/* If this nexus already has a label, then its input is
already figured out. Just return the existing label. */
if (nex_data && nex_data->net_input)
return nex_data->net_input;
if (nex_data == 0) {
nex_data = new_nexus_data();
ivl_nexus_set_private(nex, nex_data);
}
assert(nex_data->net_input == 0);
nex_data->net_input = draw_net_input_x(nex, 0, 0, nex_data);
return nex_data->net_input;
}
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