verilator/src/V3Width.cpp
2011-04-19 19:02:03 -05:00

1455 lines
63 KiB
C++
Raw Blame History

This file contains invisible Unicode characters

This file contains invisible Unicode characters that are indistinguishable to humans but may be processed differently by a computer. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

//*************************************************************************
// DESCRIPTION: Verilator: Expression width calculations
//
// Code available from: http://www.veripool.org/verilator
//
// AUTHORS: Wilson Snyder with Paul Wasson, Duane Gabli
//
//*************************************************************************
//
// Copyright 2003-2011 by Wilson Snyder. This program is free software; you can
// redistribute it and/or modify it under the terms of either the GNU
// Lesser General Public License Version 3 or the Perl Artistic License
// Version 2.0.
//
// Verilator 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.
//
//*************************************************************************
// V3Width's Transformations:
// Top down traversal:
// Determine width of sub-expressions
// width() = # bits upper expression wants, 0 for anything-goes
// widthUnsized() = # bits for unsized constant, or 0 if it's sized
// widthMin() = Alternative acceptable width for linting, or width() if sized
// Determine this subop's width, can be either:
// Fixed width X
// Unsized, min width X ('d5 is unsized, min 3 bits.)
// Pass up:
// width() = # bits this expression generates
// widthSized() = true if all constants sized, else false
// Compute size of this expression
// Lint warn about mismatches
// If expr size != subop fixed, bad
// If expr size < subop unsized minimum, bad
// If expr size != subop, edit netlist
// For == and similar ops, if multibit underneath, add a REDOR
// If subop larger, add a EXTRACT
// If subop smaller, add a EXTEND
// Pass size to sub-expressions if required (+/-* etc)
// FINAL = true.
// Subexpressions lint and extend as needed
//
//*************************************************************************
#include "config_build.h"
#include "verilatedos.h"
#include <cstdio>
#include <cstdarg>
#include <unistd.h>
#include "V3Global.h"
#include "V3Width.h"
#include "V3Signed.h"
#include "V3Number.h"
#include "V3Const.h"
#include "V3Task.h"
//######################################################################
// Width state, as a visitor of each AstNode
enum Stage { PRELIM=1,FINAL=2,BOTH=3 };
class WidthVP : public AstNUser {
// Parameters to pass down hierarchy with visit functions.
int m_width; // Expression width, for (2+2), it's 32 bits
int m_minWidth; // Minimum width, for (2+2), it's 2 bits, for 32'2+32'2 it's 32 bits
Stage m_stage; // If true, report errors
public:
WidthVP(int width, int minWidth, Stage stage) : m_width(width), m_minWidth(minWidth), m_stage(stage) {}
int width() const { return m_width; }
int widthMin() const { return m_minWidth?m_minWidth:m_width; }
bool prelim() const { return m_stage&1; }
bool final() const { return m_stage&2; }
};
//######################################################################
class WidthVisitor : public AstNVisitor {
private:
// STATE
int m_taskDepth; // Recursion check
bool m_paramsOnly; // Computing parameter value; limit operation
AstRange* m_cellRangep; // Range for arrayed instantiations, NULL for normal instantiations
AstNodeCase* m_casep; // Current case statement CaseItem is under
AstFunc* m_funcp; // Current function
// CLASSES
#define ANYSIZE 0
// METHODS
static int debug() {
static int level = -1;
if (VL_UNLIKELY(level < 0)) level = v3Global.opt.debugSrcLevel(__FILE__);
return level;
}
// VISITORS
// Naming: width_{output size rule}_{lhs rule}_{rhs rule}
// Widths: 1 bit out, lhs 1 bit
void width_O1_L1(AstNode* nodep, AstNUser* vup);
virtual void visit(AstLogNot* nodep, AstNUser* vup) { width_O1_L1(nodep,vup); }
virtual void visit(AstPslBool* nodep, AstNUser* vup) { width_O1_L1(nodep,vup); }
// Widths: 1 bit out, lhs 1 bit, rhs 1 bit
void width_O1_L1_R1(AstNode* nodep, AstNUser* vup);
virtual void visit(AstLogAnd* nodep, AstNUser* vup) { width_O1_L1_R1(nodep,vup); }
virtual void visit(AstLogOr* nodep, AstNUser* vup) { width_O1_L1_R1(nodep,vup); }
virtual void visit(AstLogIf* nodep, AstNUser* vup) { width_O1_L1_R1(nodep,vup); }
virtual void visit(AstLogIff* nodep, AstNUser* vup) { width_O1_L1_R1(nodep,vup); }
// Widths: 1 bit out, Any width lhs
void width_O1_L(AstNode* nodep, AstNUser* vup);
virtual void visit(AstRedAnd* nodep, AstNUser* vup) { width_O1_L(nodep,vup); }
virtual void visit(AstRedOr* nodep, AstNUser* vup) { width_O1_L(nodep,vup); }
virtual void visit(AstRedXnor* nodep, AstNUser* vup){ width_O1_L(nodep,vup); }
virtual void visit(AstRedXor* nodep,AstNUser* vup) { width_O1_L(nodep,vup); }
virtual void visit(AstIsUnknown* nodep,AstNUser* vup) { width_O1_L(nodep,vup); }
virtual void visit(AstOneHot* nodep,AstNUser* vup) { width_O1_L(nodep,vup); }
virtual void visit(AstOneHot0* nodep,AstNUser* vup) { width_O1_L(nodep,vup); }
// Widths: 1 bit out, lhs width == rhs width
void width_O1_L_Rlhs(AstNode* nodep, AstNUser* vup);
virtual void visit(AstEq* nodep, AstNUser* vup) { width_O1_L_Rlhs(nodep,vup); }
virtual void visit(AstEqCase* nodep, AstNUser* vup) { width_O1_L_Rlhs(nodep,vup); }
virtual void visit(AstEqWild* nodep, AstNUser* vup) { width_O1_L_Rlhs(nodep,vup); }
virtual void visit(AstGt* nodep, AstNUser* vup) { width_O1_L_Rlhs(nodep,vup); }
virtual void visit(AstGtS* nodep, AstNUser* vup) { width_O1_L_Rlhs(nodep,vup); }
virtual void visit(AstGte* nodep, AstNUser* vup) { width_O1_L_Rlhs(nodep,vup); }
virtual void visit(AstGteS* nodep, AstNUser* vup) { width_O1_L_Rlhs(nodep,vup); }
virtual void visit(AstLt* nodep, AstNUser* vup) { width_O1_L_Rlhs(nodep,vup); }
virtual void visit(AstLtS* nodep, AstNUser* vup) { width_O1_L_Rlhs(nodep,vup); }
virtual void visit(AstLte* nodep, AstNUser* vup) { width_O1_L_Rlhs(nodep,vup); }
virtual void visit(AstLteS* nodep, AstNUser* vup) { width_O1_L_Rlhs(nodep,vup); }
virtual void visit(AstNeq* nodep, AstNUser* vup) { width_O1_L_Rlhs(nodep,vup); }
virtual void visit(AstNeqCase* nodep, AstNUser* vup){ width_O1_L_Rlhs(nodep,vup); }
virtual void visit(AstNeqWild* nodep, AstNUser* vup){ width_O1_L_Rlhs(nodep,vup); }
// Widths: out width = lhs width = rhs width
void width_Omax_L_Rlhs(AstNode* nodep, AstNUser* vup);
virtual void visit(AstAnd* nodep, AstNUser* vup) { width_Omax_L_Rlhs(nodep,vup); }
virtual void visit(AstOr* nodep, AstNUser* vup) { width_Omax_L_Rlhs(nodep,vup); }
virtual void visit(AstXnor* nodep, AstNUser* vup) { width_Omax_L_Rlhs(nodep,vup); }
virtual void visit(AstXor* nodep, AstNUser* vup) { width_Omax_L_Rlhs(nodep,vup); }
virtual void visit(AstBufIf1* nodep, AstNUser* vup) { width_Omax_L_Rlhs(nodep,vup); }
// Multiple possible reasonable division width conversions. Just keep our code simple, they aren't common.
virtual void visit(AstModDiv* nodep, AstNUser* vup) { width_Omax_L_Rlhs(nodep,vup); }
virtual void visit(AstModDivS* nodep, AstNUser* vup) { width_Omax_L_Rlhs(nodep,vup); }
virtual void visit(AstDiv* nodep, AstNUser* vup) { width_Omax_L_Rlhs(nodep,vup); }
virtual void visit(AstDivS* nodep, AstNUser* vup) { width_Omax_L_Rlhs(nodep,vup); }
// Special warning suppression rules
virtual void visit(AstSub* nodep, AstNUser* vup) { width_Omax_L_Rlhs(nodep,vup); }
virtual void visit(AstAdd* nodep, AstNUser* vup) { width_Omax_L_Rlhs(nodep,vup); }
virtual void visit(AstMul* nodep, AstNUser* vup) { width_Omax_L_Rlhs(nodep,vup); }
virtual void visit(AstMulS* nodep, AstNUser* vup) { width_Omax_L_Rlhs(nodep,vup); }
// Widths: out width = lhs width, but upper matters
void width_Olhs_L(AstNodeUniop* nodep, AstNUser* vup);
virtual void visit(AstNot* nodep, AstNUser* vup) { width_Olhs_L(nodep,vup); }
virtual void visit(AstUnaryMin* nodep, AstNUser* vup) { width_Olhs_L(nodep,vup); }
// Widths: out width = lhs width, upper doesn't matter
void width_Olhs_Lforce(AstNodeUniop* nodep, AstNUser* vup);
virtual void visit(AstSigned* nodep, AstNUser* vup) { width_Olhs_Lforce(nodep,vup); }
virtual void visit(AstUnsigned* nodep, AstNUser* vup) { width_Olhs_Lforce(nodep,vup); }
// Widths: Output width from lhs, rhs<33 bits
void width_Olhs_L_R32(AstNode* nodep, AstNUser* vup);
virtual void visit(AstPow* nodep, AstNUser* vup) { width_Olhs_L_R32(nodep,vup); }
virtual void visit(AstPowS* nodep, AstNUser* vup) { width_Olhs_L_R32(nodep,vup); }
virtual void visit(AstShiftL* nodep, AstNUser* vup) { width_Olhs_L_R32(nodep,vup); }
virtual void visit(AstShiftR* nodep, AstNUser* vup) { width_Olhs_L_R32(nodep,vup); }
virtual void visit(AstShiftRS* nodep, AstNUser* vup) { width_Olhs_L_R32(nodep,vup); }
// Special cases. So many....
virtual void visit(AstNodeCond* nodep, AstNUser* vup) {
// op=cond?expr1:expr2 is a Good large example of the propagation mess
if (vup->c()->prelim()) { // First stage evaluation
// Just once, do the conditional, expect one bit out.
nodep->condp()->iterateAndNext(*this,WidthVP(1,1,BOTH).p());
// Determine sub expression widths only relying on what's in the subops
nodep->expr1p()->iterateAndNext(*this,WidthVP(ANYSIZE,0,PRELIM).p());
nodep->expr2p()->iterateAndNext(*this,WidthVP(ANYSIZE,0,PRELIM).p());
}
// Calculate width of this expression.
// First call (prelim()) vup->c()->width() is probably zero, so we'll return
// the size of this subexpression only.
// Second call (final()) vup->c()->width() is probably the expression size, so
// the expression includes the size of the output too.
int width = max(vup->c()->width(), max(nodep->expr1p()->width(), nodep->expr2p()->width()));
int mwidth = max(vup->c()->widthMin(), max(nodep->expr1p()->widthMin(), nodep->expr2p()->widthMin()));
nodep->width(width,mwidth);
if (vup->c()->final()) {
// Final width known, so make sure children recompute & check their sizes
nodep->expr1p()->iterateAndNext(*this,WidthVP(width,mwidth,FINAL).p());
nodep->expr2p()->iterateAndNext(*this,WidthVP(width,mwidth,FINAL).p());
// Error report and change sizes for suboperands of this node.
widthCheckReduce(nodep,"Conditional Expression",nodep->condp(),1,0);
widthCheck(nodep,"Conditional True",nodep->expr1p(),width,mwidth);
widthCheck(nodep,"Conditional False",nodep->expr2p(),width,mwidth);
}
}
virtual void visit(AstConcat* nodep, AstNUser* vup) {
if (vup->c()->prelim()) {
nodep->lhsp()->iterateAndNext(*this,WidthVP(ANYSIZE,0,BOTH).p());
nodep->rhsp()->iterateAndNext(*this,WidthVP(ANYSIZE,0,BOTH).p());
nodep->width(nodep->lhsp()->width() + nodep->rhsp()->width(),
nodep->lhsp()->widthMin() + nodep->rhsp()->widthMin());
// Cleanup zero width Verilog2001 {x,{0{foo}}} now,
// otherwise having width(0) will cause later assertions to fire
if (AstReplicate* repp=nodep->lhsp()->castReplicate()) {
if (repp->width()==0) { // Keep rhs
nodep->replaceWith(nodep->rhsp()->unlinkFrBack());
pushDeletep(nodep); nodep=NULL;
return;
}
}
if (AstReplicate* repp=nodep->rhsp()->castReplicate()) {
if (repp->width()==0) { // Keep lhs
nodep->replaceWith(nodep->lhsp()->unlinkFrBack());
pushDeletep(nodep); nodep=NULL;
return;
}
}
}
if (vup->c()->final()) {
if (!nodep->widthSized()) {
// See also error in V3Number
nodep->v3warn(WIDTHCONCAT,"Unsized numbers/parameters not allowed in concatenations.");
}
}
}
virtual void visit(AstReplicate* nodep, AstNUser* vup) {
if (vup->c()->prelim()) {
nodep->lhsp()->iterateAndNext(*this,WidthVP(ANYSIZE,0,BOTH).p());
nodep->rhsp()->iterateAndNext(*this,WidthVP(ANYSIZE,0,BOTH).p());
V3Const::constifyParamsEdit(nodep->rhsp()); // rhsp may change
AstConst* constp = nodep->rhsp()->castConst();
if (!constp) { nodep->v3error("Replication value isn't a constant."); return; }
uint32_t times = constp->toUInt();
if (times==0 && !nodep->backp()->castConcat()) { // Concat Visitor will clean it up.
nodep->v3error("Replication value of 0 is only legal under a concatenation."); times=1;
}
nodep->width((nodep->lhsp()->width() * times),
(nodep->lhsp()->widthMin() * times));
}
if (vup->c()->final()) {
if (!nodep->widthSized()) {
// See also error in V3Number
nodep->v3warn(WIDTHCONCAT,"Unsized numbers/parameters not allowed in replications.");
}
}
}
virtual void visit(AstRange* nodep, AstNUser* vup) {
// If there's an edit, then processes the edit'ee (can't just rely on iterateChildren because sometimes we for(...) here ourself
AstNode* selp = V3Width::widthSelNoIterEdit(nodep); if (selp!=nodep) { nodep=NULL; selp->iterate(*this,vup); return; }
if (vup->c()->prelim()) {
nodep->msbp()->iterateAndNext(*this,WidthVP(ANYSIZE,0,BOTH).p());
nodep->lsbp()->iterateAndNext(*this,WidthVP(ANYSIZE,0,BOTH).p());
int width = nodep->elementsConst();
if (width > (1<<28)) nodep->v3error("Width of bit range is huge; vector of over 1billion bits: 0x"<<hex<<width);
nodep->width(width,width);
if (nodep->littleEndian()) {
nodep->v3warn(LITENDIAN,"Little bit endian vector: MSB < LSB of bit range: "<<nodep->lsbConst()<<":"<<nodep->msbConst());
}
}
}
virtual void visit(AstSel* nodep, AstNUser* vup) {
if (vup->c()->prelim()) {
if (debug()>=9) nodep->dumpTree(cout,"-selWidth: ");
nodep->fromp()->iterateAndNext(*this,WidthVP(ANYSIZE,0,PRELIM).p());
nodep->lsbp()->iterateAndNext(*this,WidthVP(ANYSIZE,0,PRELIM).p());
nodep->widthp()->iterateAndNext(*this,WidthVP(ANYSIZE,0,BOTH).p());
V3Const::constifyParamsEdit(nodep->widthp()); // widthp may change
AstConst* widthConstp = nodep->widthp()->castConst();
if (!widthConstp) {
nodep->v3error("Width of bit extract isn't a constant");
nodep->width(1,1); return;
}
int width = nodep->widthConst();
nodep->width(width,width);
if (nodep->lsbp()->castConst()
&& nodep->msbConst() < nodep->lsbConst()) {
nodep->v3error("Unsupported: MSB < LSB of bit extract: "
<<nodep->msbConst()<<"<"<<nodep->lsbConst());
width = (nodep->lsbConst() - nodep->msbConst() + 1);
nodep->width(width,width);
nodep->widthp()->replaceWith(new AstConst(nodep->widthp()->fileline(),
width));
nodep->lsbp()->replaceWith(new AstConst(nodep->lsbp()->fileline(), 0));
}
// We're extracting, so just make sure the expression is at least wide enough.
if (nodep->fromp()->width() < width) {
nodep->v3error("Extracting "<<width
<<" bits from only "<<nodep->fromp()->width()<<" bit number");
// Extend it.
widthCheck(nodep,"errorless...",nodep->fromp(),width,width,true/*noerror*/);
}
// Check bit indexes.
// What is the MSB? We want the true MSB, not one starting at 0,
// because a 4 bit index is required to look at a one-bit variable[15:15]
int frommsb = nodep->fromp()->width() - 1;
int fromlsb = 0;
AstNodeVarRef* varrp = nodep->fromp()->castNodeVarRef();
if (varrp && varrp->varp()->basicp()->rangep()) { // Selecting a bit from a multibit register
frommsb = varrp->varp()->basicp()->msbMaxSelect(); // Corrected for negative lsb
fromlsb = varrp->varp()->basicp()->lsb();
}
int selwidth = V3Number::log2b(frommsb+1-1)+1; // Width to address a bit
nodep->fromp()->iterateAndNext(*this,WidthVP(selwidth,selwidth,FINAL).p());
nodep->lsbp()->iterateAndNext(*this,WidthVP(ANYSIZE,0,FINAL).p());
if (widthBad(nodep->lsbp(),selwidth,selwidth)
&& nodep->lsbp()->width()!=32) {
nodep->v3warn(WIDTH,"Bit extraction of var["<<frommsb<<":"<<fromlsb<<"] requires "
<<selwidth<<" bit index, not "
<<nodep->lsbp()->width()
<<(nodep->lsbp()->width()!=nodep->lsbp()->widthMin()
?" or "+cvtToStr(nodep->lsbp()->widthMin()):"")
<<" bits.");
if (!nodep->fileline()->warnIsOff(V3ErrorCode::WIDTH)) {
UINFO(1," Related node: "<<nodep<<endl);
if (varrp) UINFO(1," Related var: "<<varrp->varp()<<endl);
if (varrp) UINFO(1," Related dtype: "<<varrp->varp()->dtypep()<<endl);
}
}
if (nodep->lsbp()->castConst() && nodep->msbConst() > frommsb) {
// See also warning in V3Const
// We need to check here, because the widthCheck may silently
// add another SEL which will lose the out-of-range check
nodep->v3error("Selection index out of range: "
<<nodep->msbConst()<<":"<<nodep->lsbConst()
<<" outside "<<frommsb<<":"<<fromlsb);
UINFO(1," Related node: "<<nodep<<endl);
if (varrp) UINFO(1," Related var: "<<varrp->varp()<<endl);
if (varrp) UINFO(1," Related dtype: "<<varrp->varp()->dtypep()<<endl);
}
// iterate FINAL is two blocks above
widthCheck(nodep,"Extract Range",nodep->lsbp(),selwidth,selwidth,true);
}
}
virtual void visit(AstArraySel* nodep, AstNUser* vup) {
if (vup->c()->prelim()) {
nodep->bitp()->iterateAndNext(*this,WidthVP(ANYSIZE,0,BOTH).p());
nodep->fromp()->iterateAndNext(*this,WidthVP(ANYSIZE,0,PRELIM).p());
AstNode* basefromp = AstArraySel::baseFromp(nodep->fromp());
int dimension = AstArraySel::dimension(nodep->fromp());
AstNodeVarRef* varrp = basefromp->castNodeVarRef();
if (!varrp) nodep->v3fatalSrc("No VarRef found under ArraySel(s)");
//
int frommsb;
int fromlsb;
AstNodeDType* ddtypep = varrp->varp()->dtypeDimensionp(dimension);
if (AstArrayDType* adtypep = ddtypep->castArrayDType()) {
int outwidth = varrp->width(); // Width of variable
frommsb = adtypep->msb();
fromlsb = adtypep->lsb();
if (fromlsb>frommsb) {int t=frommsb; frommsb=fromlsb; fromlsb=t; }
// However, if the lsb<0 we may go negative, so need more bits!
if (fromlsb < 0) frommsb += -fromlsb;
nodep->width(outwidth,outwidth); // Width out = width of array
}
else {
nodep->v3fatalSrc("Array reference exceeds dimension of array");
frommsb = fromlsb = 0;
}
int selwidth = V3Number::log2b(frommsb+1-1)+1; // Width to address a bit
nodep->fromp()->iterateAndNext(*this,WidthVP(selwidth,selwidth,FINAL).p());
if (widthBad(nodep->bitp(),selwidth,selwidth)
&& nodep->bitp()->width()!=32) {
nodep->v3warn(WIDTH,"Bit extraction of array["<<frommsb<<":"<<fromlsb<<"] requires "
<<selwidth<<" bit index, not "
<<nodep->bitp()->width()
<<(nodep->bitp()->width()!=nodep->bitp()->widthMin()
?" or "+cvtToStr(nodep->bitp()->widthMin()):"")
<<" bits.");
if (!nodep->fileline()->warnIsOff(V3ErrorCode::WIDTH)) {
UINFO(1," Related node: "<<nodep<<endl);
if (varrp) UINFO(1," Related var: "<<varrp->varp()<<endl);
if (varrp) UINFO(1," Related depth: "<<dimension<<" dtype: "<<ddtypep<<endl);
}
}
widthCheck(nodep,"Extract Range",nodep->bitp(),selwidth,selwidth,true);
}
}
virtual void visit(AstSelBit* nodep, AstNUser* vup) {
// Just a quick check as after V3Param these nodes instead are AstSel's
AstNode* selp = V3Width::widthSelNoIterEdit(nodep); if (selp!=nodep) { nodep=NULL; selp->iterate(*this,vup); return; }
nodep->v3fatalSrc("AstSelBit should disappear after widthSel");
}
virtual void visit(AstSelExtract* nodep, AstNUser* vup) {
// Just a quick check as after V3Param these nodes instead are AstSel's
AstNode* selp = V3Width::widthSelNoIterEdit(nodep); if (selp!=nodep) { nodep=NULL; selp->iterate(*this,vup); return; }
nodep->v3fatalSrc("AstSelExtract should disappear after widthSel");
}
virtual void visit(AstSelPlus* nodep, AstNUser* vup) {
AstNode* selp = V3Width::widthSelNoIterEdit(nodep); if (selp!=nodep) { nodep=NULL; selp->iterate(*this,vup); return; }
nodep->v3fatalSrc("AstSelPlus should disappear after widthSel");
}
virtual void visit(AstSelMinus* nodep, AstNUser* vup) {
AstNode* selp = V3Width::widthSelNoIterEdit(nodep); if (selp!=nodep) { nodep=NULL; selp->iterate(*this,vup); return; }
nodep->v3fatalSrc("AstSelMinus should disappear after widthSel");
}
virtual void visit(AstExtend* nodep, AstNUser* vup) {
// Only created by this process, so we know width from here down it is correct.
}
virtual void visit(AstExtendS* nodep, AstNUser* vup) {
// Only created by signing process, so we know width from here down it is correct.
}
virtual void visit(AstConst* nodep, AstNUser* vup) {
if (vup && vup->c()->prelim()) {
if (nodep->num().sized()) {
nodep->width(nodep->num().width(), nodep->num().width());
} else {
nodep->width(nodep->num().width(), nodep->num().minWidth());
}
}
// We don't size the constant until we commit the widths, as need parameters
// to remain unsized, and numbers to remain unsized to avoid backp() warnings
}
virtual void visit(AstConstString* nodep, AstNUser* vup) {
nodep->rewidth();
}
virtual void visit(AstRand* nodep, AstNUser* vup) {
if (vup->c()->prelim()) {
nodep->width(32,32); // Says the spec
}
}
virtual void visit(AstTime* nodep, AstNUser*) {
nodep->width(64,64);
}
virtual void visit(AstUCFunc* nodep, AstNUser* vup) {
// Give it the size the user wants.
if (vup && vup->c()->prelim()) {
nodep->width(32,1); // We don't care
}
if (vup->c()->final()) {
nodep->width(vup->c()->width(),vup->c()->widthMin()); // We don't care
if (nodep->width()>64) nodep->v3error("Unsupported: $c can't generate wider than 64 bits");
}
// Just let all arguments seek their natural sizes
nodep->iterateChildren(*this,WidthVP(ANYSIZE,0,BOTH).p());
}
virtual void visit(AstCLog2* nodep, AstNUser* vup) {
if (vup->c()->prelim()) {
nodep->lhsp()->iterateAndNext(*this,WidthVP(ANYSIZE,0,BOTH).p());
nodep->width(32,32);
}
}
virtual void visit(AstCountOnes* nodep, AstNUser* vup) {
if (vup->c()->prelim()) {
nodep->lhsp()->iterateAndNext(*this,WidthVP(ANYSIZE,0,BOTH).p());
// If it's a 32 bit number, we need a 6 bit number as we need to return '32'.
int selwidth = V3Number::log2b(nodep->lhsp()->width())+1;
nodep->width(selwidth,selwidth);
}
}
virtual void visit(AstCvtPackString* nodep, AstNUser* vup) {
nodep->lhsp()->iterateAndNext(*this,WidthVP(ANYSIZE,0,BOTH).p());
}
virtual void visit(AstAttrOf* nodep, AstNUser*) {
nodep->fromp()->iterateAndNext(*this,WidthVP(ANYSIZE,0,BOTH).p());
nodep->width(32,1); // Approximation, unsized 32
}
virtual void visit(AstText* nodep, AstNUser* vup) {
// Only used in CStmts which don't care....
}
virtual void visit(AstScopeName* nodep, AstNUser* vup) {
nodep->width(64,1); // A pointer, but not that it matters
}
virtual void visit(AstArrayDType* nodep, AstNUser* vup) {
// Lower datatype determines the width
nodep->dtypep()->iterateAndNext(*this,vup);
// But also cleanup array size
nodep->arrayp()->iterateAndNext(*this,WidthVP(ANYSIZE,0,BOTH).p());
nodep->widthFrom(nodep->dtypep());
}
virtual void visit(AstBasicDType* nodep, AstNUser* vup) {
if (nodep->rangep()) {
nodep->rangep()->iterateAndNext(*this,WidthVP(ANYSIZE,0,BOTH).p());
nodep->widthFrom(nodep->rangep());
}
// else width in node is correct; it was set based on keyword().width()
// at construction time
}
virtual void visit(AstRefDType* nodep, AstNUser* vup) {
nodep->iterateChildren(*this, vup);
if (nodep->defp()) nodep->defp()->iterate(*this,vup);
nodep->widthFrom(nodep->dtypeSkipRefp());
}
virtual void visit(AstTypedef* nodep, AstNUser* vup) {
nodep->iterateChildren(*this, vup);
nodep->widthFrom(nodep->dtypep()->skipRefp());
}
virtual void visit(AstCast* nodep, AstNUser* vup) {
nodep->lhsp()->iterateAndNext(*this,WidthVP(ANYSIZE,0,BOTH).p());
nodep->dtypep()->iterateAndNext(*this,WidthVP(ANYSIZE,0,BOTH).p());
// When more general casts are supported, the cast elimination will be done later.
// For now, replace it ASAP, so widthing can propagate easily
// The cast may change signing, but we don't know the sign yet. Make it so.
// Note we don't sign lhsp() that would make the algorithm O(n^2) if lots of casting.
V3Width::widthParamsEdit(nodep->dtypep()); // MAY CHANGE dtypep()
AstBasicDType* basicp = nodep->dtypep()->basicp(); if (!basicp) nodep->v3fatalSrc("Unimplemented: Casting non-simple data type");
nodep->widthSignedFrom(basicp);
widthCheck(nodep,"Cast",nodep->lhsp(),nodep->width(),nodep->width(),true);
AstNode* newp = nodep->lhsp()->unlinkFrBack();
if (basicp->isSigned()) {
newp = new AstSigned(nodep->fileline(), newp);
} else {
newp = new AstUnsigned(nodep->fileline(), newp);
}
nodep->replaceWith(newp);
}
virtual void visit(AstVar* nodep, AstNUser* vup) {
//if (debug()) nodep->dumpTree(cout," InitPre: ");
// Must have deterministic constant width
// We can't skip this step when width()!=0, as creating a AstVar
// with non-constant range gets size 1, not size 0. So use didWidth().
if (nodep->didWidth()) { // Early exit if have circular parameter definition
if (!nodep->width()) {
if (!nodep->valuep()) nodep->v3fatalSrc("circular, but without value");
nodep->v3error("Variable's initial value is circular: "<<nodep->prettyName());
pushDeletep(nodep->valuep()->unlinkFrBack());
nodep->valuep(new AstConst(nodep->fileline(), 1));
} else {
return;
}
}
nodep->didWidth(true);
int width=1; int mwidth=1;
// Parameters if implicit untyped inherit from what they are assigned to
AstBasicDType* bdtypep = nodep->dtypep()->castBasicDType();
if (nodep->isParam() && bdtypep && bdtypep->implicit()) {
width = mwidth = 0;
if (nodep->valuep()) {
nodep->valuep()->iterateAndNext(*this,WidthVP(width,0,PRELIM).p());
// Although nodep will get a different width for parameters just below,
// we want the init numbers to retain their width/minwidth until parameters are replaced.
// This prevents width warnings at the location the parameter is substituted in
nodep->valuep()->iterateAndNext(*this,WidthVP(width,0,FINAL).p());
if (nodep->valuep()->widthSized()) {
width = mwidth = nodep->valuep()->width();
} else {
if (nodep->valuep()->width()>32) nodep->valuep()->v3warn(WIDTH,"Assigning >32 bit to unranged parameter (defaults to 32 bits)");
width = 32;
mwidth = nodep->valuep()->widthMin();
}
}
// Parameter sizes can come from the thing they get assigned from
// They then "stick" to that width.
if (!width) width=32; // Or, if nothing, they're 32 bits.
if (bdtypep->rangep()) bdtypep->rangep()->unlinkFrBackWithNext()->deleteTree();
bdtypep->rangep(new AstRange(nodep->fileline(),width-1,0));
nodep->dtypep()->iterateAndNext(*this,WidthVP(ANYSIZE,0,BOTH).p());
}
else { // non param or sized param
nodep->dtypep()->iterateAndNext(*this,WidthVP(ANYSIZE,0,BOTH).p());
width = nodep->dtypep()->width(); mwidth = nodep->dtypep()->widthMin();
if (nodep->valuep()) {
nodep->valuep()->iterateAndNext(*this,WidthVP(width,0,BOTH).p());
//if (debug()) nodep->dumpTree(cout," final: ");
}
}
nodep->width(width,mwidth);
// See above note about valuep()->...FINAL
if (nodep->valuep()) widthCheck(nodep,"Initial value",nodep->valuep(),width,mwidth);
UINFO(4,"varWidthed "<<nodep<<endl);
//if (debug()) nodep->dumpTree(cout," InitOut: ");
}
virtual void visit(AstNodeVarRef* nodep, AstNUser* vup) {
if (nodep->varp()->width()==0) {
// Var hasn't been widthed, so make it so.
nodep->varp()->iterate(*this);
}
//if (debug()>=9) { nodep->dumpTree(cout," VRin "); nodep->varp()->dumpTree(cout," forvar "); }
// Note genvar's are also entered as integers
if (nodep->backp()->castNodeAssign() && nodep->lvalue()) { // On LHS
// Consider Integers on LHS to sized (else may be unsized.)
nodep->width(nodep->varp()->width(), nodep->varp()->width());
} else {
nodep->widthFrom(nodep->varp());
}
//if (debug()>=9) nodep->dumpTree(cout," VRout ");
}
virtual void visit(AstEnumDType* nodep, AstNUser* vup) {
UINFO(5," ENUMDTYPE "<<nodep<<endl);
nodep->dtypep()->iterateAndNext(*this,WidthVP(ANYSIZE,0,BOTH).p());
nodep->widthFrom(nodep->dtypep());
// Assign widths
nodep->itemsp()->iterateAndNext(*this,WidthVP(nodep->width(),nodep->widthMin(),BOTH).p());
// Assign missing values
V3Number num (nodep->fileline(), nodep->width(), 0);
V3Number one (nodep->fileline(), nodep->width(), 1);
map<V3Number,AstEnumItem*> inits;
for (AstEnumItem* itemp = nodep->itemsp(); itemp; itemp=itemp->nextp()->castEnumItem()) {
if (itemp->valuep()) {
if (debug()>=9) { UINFO(0,"EnumInit "<<itemp<<endl); itemp->valuep()->dumpTree(cout,"-EnumInit: "); }
V3Const::constifyParamsEdit(itemp->valuep()); // itemp may change
if (!itemp->valuep()->castConst()) {
itemp->valuep()->v3error("Enum value isn't a constant");
itemp->valuep()->unlinkFrBack()->deleteTree();
}
}
if (!itemp->valuep()) itemp->valuep(new AstConst(itemp->fileline(), num));
num.opAssign(itemp->valuep()->castConst()->num());
// Look for duplicates
if (inits.find(num) != inits.end()) {
itemp->v3error("Overlapping enumeration value: "<<itemp->prettyName());
inits.find(num)->second->v3error("... Location of original declaration");
} else {
inits.insert(make_pair(num,itemp));
}
num.opAdd(one, itemp->valuep()->castConst()->num());
}
}
virtual void visit(AstEnumItem* nodep, AstNUser* vup) {
UINFO(5," ENUMITEM "<<nodep<<endl);
int width = vup->c()->width();
int mwidth = vup->c()->widthMin();
nodep->width(width, mwidth);
if (nodep->valuep()) {
nodep->valuep()->iterateAndNext(*this,WidthVP(width,mwidth,BOTH).p());
widthCheck(nodep,"Enum value",nodep->valuep(),width,mwidth);
}
}
virtual void visit(AstEnumItemRef* nodep, AstNUser* vup) {
if (nodep->itemp()->width()==0) {
// We need to do the whole enum en-mass
AstNode* enump = nodep->itemp();
if (!enump) nodep->v3fatalSrc("EnumItemRef not linked");
for (; enump; enump=enump->backp()) {
if (enump->castEnumDType()) break;
}
if (!enump) nodep->v3fatalSrc("EnumItemRef can't deref back to a Enum");
enump->iterate(*this,vup);
}
nodep->widthFrom(nodep->itemp()->valuep());
}
virtual void visit(AstPslClocked* nodep, AstNUser*) {
nodep->propp()->iterateAndNext(*this,WidthVP(1,1,BOTH).p());
nodep->sensesp()->iterateAndNext(*this);
if (nodep->disablep()) {
nodep->disablep()->iterateAndNext(*this,WidthVP(1,1,BOTH).p());
widthCheckReduce(nodep,"Disable",nodep->disablep(),1,1); // it's like an if() condition.
}
widthCheckReduce(nodep,"Property",nodep->propp(),1,1); // it's like an if() condition.
nodep->width(1,1);
}
//--------------------
// Top levels
virtual void visit(AstNodeCase* nodep, AstNUser*) {
// TOP LEVEL NODE
AstNodeCase* lastCasep = m_casep;
m_casep = nodep;
nodep->exprp()->iterateAndNext(*this,WidthVP(ANYSIZE,0,PRELIM).p());
for (AstCaseItem* nextp, *itemp = nodep->itemsp(); itemp; itemp=nextp) {
nextp = itemp->nextp()->castCaseItem(); // Prelim may cause the node to get replaced
itemp->iterate(*this,WidthVP(ANYSIZE,0,PRELIM).p()); itemp=NULL;
}
int width = nodep->exprp()->width();
int mwidth = nodep->exprp()->widthMin();
for (AstCaseItem* itemp = nodep->itemsp(); itemp; itemp=itemp->nextp()->castCaseItem()) {
width = max(width,itemp->width());
mwidth = max(mwidth,itemp->widthMin());
}
nodep->exprp()->iterateAndNext(*this,WidthVP(width,mwidth,FINAL).p());
for (AstCaseItem* itemp = nodep->itemsp(); itemp; itemp=itemp->nextp()->castCaseItem()) {
itemp->iterate(*this,WidthVP(width,mwidth,FINAL).p());
}
widthCheck(nodep,"Case expression",nodep->exprp(),width,mwidth);
m_casep = lastCasep;
}
virtual void visit(AstCaseItem* nodep, AstNUser* vup) {
// Same for both prelim() and final()
if (!m_casep->castGenCase()) nodep->bodysp()->iterateAndNext(*this);
if (!nodep->condsp()) {
// Else "default:" of the case, just return benign value
nodep->width(vup->c()->width(),vup->c()->widthMin());
} else {
// Need to look across multiple case values for one set of statements
int width = nodep->condsp()->width();
int mwidth = nodep->condsp()->widthMin();
for (AstNode* nextp, *condp = nodep->condsp(); condp; condp=nextp) {
nextp = condp->nextp(); // Prelim may cause the node to get replaced
condp->iterate(*this,vup); condp=NULL;
}
for (AstNode* condp = nodep->condsp(); condp; condp=condp->nextp()) {
width = max(width,condp->width());
mwidth = max(mwidth,condp->widthMin());
if (vup->c()->final()) {
widthCheck(nodep,"Case Item",condp,vup->c()->width(),vup->c()->widthMin());
}
}
nodep->width(width,mwidth);
}
}
virtual void visit(AstNodeFor* nodep, AstNUser*) {
// TOP LEVEL NODE
nodep->initsp()->iterateAndNext(*this);
nodep->condp()->iterateAndNext(*this,WidthVP(1,1,BOTH).p());
if (!nodep->castGenFor()) nodep->bodysp()->iterateAndNext(*this);
nodep->incsp()->iterateAndNext(*this);
widthCheckReduce(nodep,"For Test Condition",nodep->condp(),1,1); // it's like an if() condition.
}
virtual void visit(AstRepeat* nodep, AstNUser*) {
nodep->countp()->iterateAndNext(*this,WidthVP(ANYSIZE,0,BOTH).p());
nodep->bodysp()->iterateAndNext(*this);
}
virtual void visit(AstWhile* nodep, AstNUser*) {
// TOP LEVEL NODE
nodep->precondsp()->iterateAndNext(*this);
nodep->condp()->iterateAndNext(*this,WidthVP(1,1,BOTH).p());
nodep->bodysp()->iterateAndNext(*this);
nodep->incsp()->iterateAndNext(*this);
widthCheckReduce(nodep,"For Test Condition",nodep->condp(),1,1); // it's like an if() condition.
}
virtual void visit(AstNodeIf* nodep, AstNUser*) {
// TOP LEVEL NODE
//if (debug()) nodep->dumpTree(cout," IfPre: ");
if (!nodep->castGenIf()) { // for m_paramsOnly
nodep->ifsp()->iterateAndNext(*this);
nodep->elsesp()->iterateAndNext(*this);
}
nodep->condp()->iterateAndNext(*this,WidthVP(1,1,BOTH).p());
widthCheckReduce(nodep,"If",nodep->condp(),1,1); // it's like an if() condition.
//if (debug()) nodep->dumpTree(cout," IfOut: ");
}
virtual void visit(AstNodeAssign* nodep, AstNUser*) {
// TOP LEVEL NODE
//if (debug()) nodep->dumpTree(cout," AssignPre: ");
nodep->lhsp()->iterateAndNext(*this,WidthVP(ANYSIZE,0,BOTH).p());
nodep->rhsp()->iterateAndNext(*this,WidthVP(ANYSIZE,0,PRELIM).p());
if (!nodep->lhsp()->widthSized()) nodep->v3fatalSrc("How can LHS be unsized?");
int awidth = nodep->lhsp()->width();
if (awidth==0) {
awidth = nodep->rhsp()->width(); // Parameters can propagate by unsized assignment
}
nodep->rhsp()->iterateAndNext(*this,WidthVP(awidth,awidth,FINAL).p());
nodep->width(awidth,awidth); // We know the assign will truncate, so rather
//UINFO(0,"aw "<<awidth<<" w"<<nodep->rhsp()->width()<<" m"<<nodep->rhsp()->widthMin()<<endl);
// than using "width" and have the optimizer truncate the result, we do
// it using the normal width reduction checks.
widthCheck(nodep,"Assign RHS",nodep->rhsp(),awidth,awidth);
//if (debug()) nodep->dumpTree(cout," AssignOut: ");
}
virtual void visit(AstSFormatF* nodep, AstNUser*) {
// Excludes NodeDisplay, see below
// TOP LEVEL NODE
// Just let all arguments seek their natural sizes
nodep->iterateChildren(*this,WidthVP(ANYSIZE,0,BOTH).p());
}
virtual void visit(AstDisplay* nodep, AstNUser*) {
if (nodep->filep()) {
nodep->filep()->iterateAndNext(*this,WidthVP(64,64,BOTH).p());
widthCheck(nodep,"file_descriptor (see docs)",nodep->filep(),64,64);
}
// Just let all arguments seek their natural sizes
nodep->iterateChildren(*this,WidthVP(ANYSIZE,0,BOTH).p());
}
virtual void visit(AstFOpen* nodep, AstNUser*) {
nodep->filep()->iterateAndNext(*this,WidthVP(64,64,BOTH).p());
nodep->filenamep()->iterateAndNext(*this,WidthVP(ANYSIZE,0,BOTH).p());
nodep->modep()->iterateAndNext(*this,WidthVP(ANYSIZE,0,BOTH).p());
widthCheck(nodep,"file_descriptor (see docs)",nodep->filep(),64,64);
}
virtual void visit(AstFClose* nodep, AstNUser*) {
nodep->filep()->iterateAndNext(*this,WidthVP(64,64,BOTH).p());
widthCheck(nodep,"file_descriptor (see docs)",nodep->filep(),64,64);
}
virtual void visit(AstFEof* nodep, AstNUser*) {
nodep->filep()->iterateAndNext(*this,WidthVP(64,64,BOTH).p());
nodep->width(1,1);
widthCheck(nodep,"file_descriptor (see docs)",nodep->filep(),64,64);
}
virtual void visit(AstFFlush* nodep, AstNUser*) {
if (nodep->filep()) {
nodep->filep()->iterateAndNext(*this,WidthVP(64,64,BOTH).p());
widthCheck(nodep,"file_descriptor (see docs)",nodep->filep(),64,64);
}
}
virtual void visit(AstFGetC* nodep, AstNUser* vup) {
nodep->filep()->iterateAndNext(*this,WidthVP(64,64,BOTH).p());
if (vup->c()->prelim()) {
nodep->width(32,8);
}
widthCheck(nodep,"file_descriptor (see docs)",nodep->filep(),64,64);
}
virtual void visit(AstFGetS* nodep, AstNUser* vup) {
nodep->filep()->iterateAndNext(*this,WidthVP(64,64,BOTH).p());
nodep->strgp()->iterateAndNext(*this,WidthVP(ANYSIZE,0,BOTH).p());
if (vup->c()->prelim()) {
nodep->width(32,32);
}
widthCheck(nodep,"file_descriptor (see docs)",nodep->filep(),64,64);
}
virtual void visit(AstFScanF* nodep, AstNUser* vup) {
nodep->filep()->iterateAndNext(*this,WidthVP(64,64,BOTH).p());
nodep->exprsp()->iterateAndNext(*this,WidthVP(ANYSIZE,0,BOTH).p());
if (vup->c()->prelim()) {
nodep->width(32,32);
}
widthCheck(nodep,"file_descriptor (see docs)",nodep->filep(),64,64);
}
virtual void visit(AstSScanF* nodep, AstNUser* vup) {
nodep->fromp()->iterateAndNext(*this,WidthVP(ANYSIZE,0,BOTH).p());
nodep->exprsp()->iterateAndNext(*this,WidthVP(ANYSIZE,0,BOTH).p());
if (vup->c()->prelim()) {
nodep->width(32,32);
}
}
virtual void visit(AstSysIgnore* nodep, AstNUser* vup) {
nodep->exprsp()->iterateAndNext(*this,WidthVP(ANYSIZE,0,BOTH).p());
}
virtual void visit(AstReadMem* nodep, AstNUser*) {
nodep->filenamep()->iterateAndNext(*this,WidthVP(ANYSIZE,0,BOTH).p());
nodep->memp()->iterateAndNext(*this,WidthVP(ANYSIZE,0,BOTH).p());
nodep->lsbp()->iterateAndNext(*this,WidthVP(ANYSIZE,0,BOTH).p());
nodep->msbp()->iterateAndNext(*this,WidthVP(ANYSIZE,0,BOTH).p());
}
virtual void visit(AstTestPlusArgs* nodep, AstNUser* vup) {
nodep->width(32,32);
}
virtual void visit(AstValuePlusArgs* nodep, AstNUser* vup) {
nodep->exprsp()->iterateAndNext(*this,WidthVP(ANYSIZE,0,BOTH).p());
nodep->width(32,32);
}
virtual void visit(AstUCStmt* nodep, AstNUser*) {
// TOP LEVEL NODE
// Just let all arguments seek their natural sizes
nodep->iterateChildren(*this,WidthVP(ANYSIZE,0,BOTH).p());
}
virtual void visit(AstPslCover* nodep, AstNUser*) {
// TOP LEVEL NODE
nodep->propp()->iterateAndNext(*this,WidthVP(1,1,BOTH).p());
nodep->stmtsp()->iterateChildren(*this,WidthVP(ANYSIZE,0,BOTH).p());
widthCheckReduce(nodep,"Property",nodep->propp(),1,1); // it's like an if() condition.
}
virtual void visit(AstPslAssert* nodep, AstNUser*) {
// TOP LEVEL NODE
nodep->propp()->iterateAndNext(*this,WidthVP(1,1,BOTH).p());
widthCheckReduce(nodep,"Property",nodep->propp(),1,1); // it's like an if() condition.
}
virtual void visit(AstVAssert* nodep, AstNUser*) {
// TOP LEVEL NODE
nodep->propp()->iterateAndNext(*this,WidthVP(1,1,BOTH).p());
nodep->passsp()->iterateAndNext(*this);
nodep->failsp()->iterateAndNext(*this);
widthCheckReduce(nodep,"Property",nodep->propp(),1,1); // it's like an if() condition.
}
virtual void visit(AstPin* nodep, AstNUser*) {
//if (debug()) nodep->dumpTree(cout,"- PinPre: ");
// TOP LEVEL NODE
if (nodep->modVarp() && nodep->modVarp()->isGParam()) {
// Widthing handled as special init() case
nodep->iterateChildren(*this,WidthVP(ANYSIZE,0,BOTH).p());
} else if (!m_paramsOnly){
if (nodep->modVarp()->width()==0) {
// Var hasn't been widthed, so make it so.
nodep->modVarp()->iterate(*this);
}
// Very much like like an assignment, but which side is LH/RHS
// depends on pin being a in/output/inout.
nodep->exprp()->iterateAndNext(*this,WidthVP(ANYSIZE,0,PRELIM).p());
int pinwidth = nodep->modVarp()->width();
int expwidth = nodep->exprp()->width();
bool inputPin = nodep->modVarp()->isInput();
int awidth;
if (m_cellRangep) {
int numInsts = m_cellRangep->width();
if (expwidth == pinwidth) {
awidth = pinwidth; // Arrayed instants: widths match so connect to each instance
} else if (expwidth == pinwidth*numInsts) {
awidth = pinwidth; // Arrayed instants: one bit for each of the instants (each assign is 1 pinwidth wide)
} else {
// Must be a error according to spec
// (Because we need to know if to connect to one or all instants)
nodep->v3error("Port connection "<<nodep->prettyName()<<" as part of a module instance array "
<<" requires "<<pinwidth<<" or "<<pinwidth*numInsts
<<" bits, but connection's "<<nodep->exprp()->prettyTypeName()
<<" generates "<<expwidth<<" bits.");
awidth = expwidth;
}
} else {
if (nodep->modVarp()->isTristate()) {
if (pinwidth != expwidth) {
nodep->v3error("Unsupported: Port connection "<<nodep->prettyName()<<" to inout signal "
<<" requires "<<pinwidth
<<" bits, but connection's "<<nodep->exprp()->prettyTypeName()
<<" generates "<<expwidth<<" bits.");
// otherwise would need some mess to force both sides to proper size
}
}
if (inputPin) {
// input pin is lhs, expr is rhs; resize expr to match
awidth = pinwidth;
} else {
// output pin is rhs, expr is lhs
// We can't make the RANGE/EXTEND until V3Inst phase, as need RHS of assignment
awidth = expwidth;
}
}
nodep->width(awidth,awidth);
nodep->exprp()->iterateAndNext(*this,WidthVP(awidth,awidth,FINAL).p());
if (!m_cellRangep) {
widthCheckPin(nodep, nodep->exprp(), pinwidth, inputPin);
}
}
//if (debug()) nodep->dumpTree(cout,"- PinOut: ");
}
virtual void visit(AstCell* nodep, AstNUser*) {
if (!m_paramsOnly) {
if (nodep->rangep()) {
m_cellRangep = nodep->rangep();
nodep->rangep()->iterateAndNext(*this,WidthVP(ANYSIZE,0,BOTH).p());
}
nodep->pinsp()->iterateAndNext(*this);
}
nodep->paramsp()->iterateAndNext(*this);
m_cellRangep = NULL;
}
virtual void visit(AstNodeFTask* nodep, AstNUser* vup) {
// Grab width from the output variable (if it's a function)
UINFO(5," FTASK "<<nodep<<endl);
if (nodep->width()==0) {
// Function hasn't been widthed, so make it so.
nodep->iterateChildren(*this);
if (nodep->fvarp()) {
nodep->width(nodep->fvarp()->width(), nodep->fvarp()->width());
}
}
m_funcp = NULL;
}
virtual void visit(AstReturn* nodep, AstNUser* vup) {
if (!m_funcp) {
if (nodep->lhsp()) { // Return w/o value ok other places
nodep->v3error("Return with return value isn't underneath a function");
}
} else {
if (nodep->lhsp()) {
// Function hasn't been widthed, so make it so.
nodep->iterateChildren(*this,WidthVP(ANYSIZE,0,BOTH).p());
nodep->widthSignedFrom(m_funcp->fvarp());
}
}
}
virtual void visit(AstFuncRef* nodep, AstNUser* vup) {
visit(nodep->castNodeFTaskRef(), vup);
nodep->widthSignedFrom(nodep->taskp());
//if (debug()) nodep->dumpTree(cout," FuncOut: ");
}
virtual void visit(AstNodeFTaskRef* nodep, AstNUser* vup) {
// Function hasn't been widthed, so make it so.
if (!nodep->taskp()) nodep->v3fatalSrc("Unlinked");
if (nodep->taskp()->width()==0) {
if (m_taskDepth > 100) {
nodep->v3error("Unsupported: Recursive function or task call");
nodep->width(1,1);
nodep->taskp()->width(1,1);
return;
}
m_taskDepth++;
nodep->taskp()->iterate(*this);
m_taskDepth--;
}
// And do the arguments to the task/function too
for (int accept_mode=1; accept_mode>=0; accept_mode--) { // Avoid duplicate code; just do inner stuff twice
V3TaskConnects tconnects = V3Task::taskConnects(nodep, nodep->taskp()->stmtsp());
bool lastloop = false;
for (V3TaskConnects::iterator it=tconnects.begin(); !lastloop && it!=tconnects.end(); ++it) {
AstVar* portp = it->first;
AstNode* pinp = it->second;
if (pinp!=NULL) { // Else argument error we'll find later
if (accept_mode) {
// Prelim may cause the node to get replaced; we've lost our
// pointer, so need to iterate separately later
if (portp->attrSFormat()
&& (!pinp->castSFormatF() || pinp->nextp())) { // Not already done
UINFO(4," sformat via metacomment: "<<nodep<<endl);
AstNRelinker handle;
pinp->unlinkFrBackWithNext(&handle); // Format + additional args, if any
AstNode* argsp = NULL;
if (pinp->nextp()) argsp = pinp->nextp()->unlinkFrBackWithNext();
string format;
if (pinp->castConst()) format = pinp->castConst()->num().toString();
else pinp->v3error("Format to $display-like function must have constant format string");
AstSFormatF* newp = new AstSFormatF(nodep->fileline(), format, false, argsp);
if (!newp->scopeNamep() && newp->formatScopeTracking()) {
newp->scopeNamep(new AstScopeName(newp->fileline()));
}
handle.relink(newp);
// Connection list is now incorrect (has extra args in it).
lastloop = true; // so exit early; next loop will correct it
}
else if (portp->basicp() && portp->basicp()->keyword()==AstBasicDTypeKwd::STRING
&& !pinp->castCvtPackString()
&& !pinp->castSFormatF() // Already generates a string
&& !(pinp->castVarRef() && pinp->castVarRef()->varp()->basicp()->keyword()==AstBasicDTypeKwd::STRING)) {
UINFO(4," Add CvtPackString: "<<pinp<<endl);
AstNRelinker handle;
pinp->unlinkFrBack(&handle); // No next, that's the next pin
AstNode* newp = new AstCvtPackString(pinp->fileline(), pinp);
handle.relink(newp);
pinp = newp;
}
pinp->accept(*this,WidthVP(portp->width(),portp->widthMin(),PRELIM).p()); pinp=NULL;
} else {
// Do PRELIM again, because above accept may have exited early due to node replacement
pinp->accept(*this,WidthVP(portp->width(),portp->widthMin(),BOTH).p());
if ((portp->isOutput() || portp->isInout())
&& pinp->width() != portp->width()) {
pinp->v3error("Unsupported: Function output argument '"<<portp->prettyName()<<"'"
<<" requires "<<pinp->width()
<<" bits, but connection's "<<pinp->prettyTypeName()
<<" generates "<<portp->width()<<" bits.");
// otherwise would need some mess to force both sides to proper size
// (get an ASSIGN with EXTEND on the lhs instead of rhs)
}
if (portp->basicp() && !portp->basicp()->isOpaque()) {
widthCheck(nodep,"Function Argument",pinp,portp->width(),portp->widthMin());
}
}
}
}
}
}
virtual void visit(AstNetlist* nodep, AstNUser*) {
// Iterate modules backwards, in bottom-up order. That's faster
nodep->iterateChildrenBackwards(*this);
}
//--------------------
// Default
virtual void visit(AstNode* nodep, AstNUser* vup) {
// Default: Just iterate
if (vup) nodep->v3fatalSrc("Visit function missing? Widthed expectation for this node: "<<nodep);
nodep->iterateChildren(*this);
}
// METHODS
bool widthBad (AstNode* nodep, int expWidth, int expWidthMin);
void widthCheck (AstNode* nodep, const char* side,
AstNode* underp, int expWidth, int expWidthMin,
bool ignoreWarn=false);
void widthCheckReduce (AstNode* nodep, const char* side,
AstNode* underp, int expWidth, int expWidthMin,
bool ignoreWarn=false);
void widthCheckPin (AstNode* nodep, AstNode* underp, int expWidth, bool inputPin);
bool fixAutoExtend (AstNode*& nodepr, int expWidth);
void fixWidthExtend (AstNode* nodep, int expWidth);
void fixWidthReduce (AstNode* nodep, int expWidth);
public:
// CONSTUCTORS
WidthVisitor(bool paramsOnly) {
m_paramsOnly = paramsOnly;
m_taskDepth = 0;
m_cellRangep = NULL;
m_casep = NULL;
m_funcp = NULL;
}
AstNode* mainAcceptEdit(AstNode* nodep) {
return nodep->acceptSubtreeReturnEdits(*this, WidthVP(ANYSIZE,0,BOTH).p());
}
virtual ~WidthVisitor() {}
};
//----------------------------------------------------------------------
// METHODs
bool WidthVisitor::widthBad (AstNode* nodep, int expWidth, int expWidthMin) {
if (nodep->width()==0) nodep->v3fatalSrc("Under node "<<nodep->prettyTypeName()<<" has no expected width?? Missing Visitor func?");
if (expWidth==0) nodep->v3fatalSrc("Node "<<nodep->prettyTypeName()<<" has no expected width?? Missing Visitor func?");
if (expWidthMin==0) expWidthMin = expWidth;
if (nodep->widthSized() && nodep->width() != expWidthMin) return true;
if (!nodep->widthSized() && nodep->widthMin() > expWidthMin) return true;
return false;
}
void WidthVisitor::fixWidthExtend (AstNode* nodep, int expWidth) {
// Fix the width mismatch by extending or truncating bits
// Truncation is rarer, but can occur: parameter [3:0] FOO = 64'h12312;
// A(CONSTwide)+B becomes A(CONSTwidened)+B
// A(somewide)+B becomes A(TRUNC(somewide,width))+B
// or A(EXTRACT(somewide,width,0))+B
UINFO(4," widthExtend_old: "<<nodep<<endl);
AstConst* constp = nodep->castConst();
if (constp && !nodep->isSigned()) {
// Save later constant propagation work, just right-size it.
V3Number num (nodep->fileline(), expWidth);
num.opAssign(constp->num());
num.isSigned(nodep->isSigned());
AstNode* newp = new AstConst(nodep->fileline(), num);
constp->replaceWith(newp);
pushDeletep(constp); constp=NULL;
nodep=newp;
} else if (expWidth<nodep->width()) {
// Trunc - Extract
AstNRelinker linker;
nodep->unlinkFrBack(&linker);
AstNode* newp = new AstSel(nodep->fileline(), nodep, 0, expWidth);
linker.relink(newp);
nodep=newp;
} else {
// Extend
AstNRelinker linker;
nodep->unlinkFrBack(&linker);
AstNode* newp = (nodep->isSigned()
? (new AstExtendS(nodep->fileline(), nodep))->castNode()
: (new AstExtend (nodep->fileline(), nodep))->castNode());
linker.relink(newp);
nodep=newp;
}
nodep->width(expWidth,expWidth);
UINFO(4," _new: "<<nodep<<endl);
}
void WidthVisitor::fixWidthReduce (AstNode* nodep, int expWidth) {
// Fix the width mismatch by adding a reduction OR operator
// IF (A(CONSTwide)) becomes IF (A(CONSTreduced))
// IF (A(somewide)) becomes IF (A(REDOR(somewide)))
// Attempt to fix it quietly
UINFO(4," widthReduce_old: "<<nodep<<endl);
AstConst* constp = nodep->castConst();
if (constp) {
V3Number num (nodep->fileline(), expWidth);
num.opRedOr(constp->num());
num.isSigned(constp->isSigned());
AstNode* newp = new AstConst(nodep->fileline(), num);
constp->replaceWith(newp);
nodep=newp;
} else {
AstNRelinker linker;
nodep->unlinkFrBack(&linker);
AstNode* newp = new AstRedOr(nodep->fileline(), nodep);
linker.relink(newp);
nodep=newp;
}
nodep->width(expWidth,expWidth);
UINFO(4," _new: "<<nodep<<endl);
}
bool WidthVisitor::fixAutoExtend (AstNode*& nodepr, int expWidth) {
// For SystemVerilog '0,'1,'x,'z, autoextend and don't warn
if (AstConst* constp = nodepr->castConst()) {
if (constp->num().autoExtend() && !constp->num().sized() && constp->width()==1) {
// Make it the proper size. Careful of proper extension of 0's/1's
V3Number num (constp->fileline(), expWidth);
num.opRepl(constp->num(), expWidth); // {width{'1}}
AstNode* newp = new AstConst(constp->fileline(), num);
// Spec says always unsigned with proper width
if (debug()>4) constp->dumpTree(cout," fixAutoExtend_old: ");
if (debug()>4) newp->dumpTree(cout," _new: ");
constp->replaceWith(newp);
constp->deleteTree(); constp=NULL;
// Tell caller the new constp, and that we changed it.
nodepr = newp;
return true;
}
}
return false; // No change
}
void WidthVisitor::widthCheck (AstNode* nodep, const char* side,
AstNode* underp, int expWidth, int expWidthMin,
bool ignoreWarn) {
//UINFO(9,"wchk "<<side<<endl<<" "<<nodep<<endl<<" "<<underp<<endl<<" e"<<expWidth<<" m"<<expWidthMin<<" i"<<ignoreWarn<<endl);
if (expWidthMin==0) expWidthMin = expWidth;
bool bad = widthBad(underp,expWidth,expWidthMin);
if (bad && fixAutoExtend(underp/*ref*/,expWidth)) bad=false; // Changes underp
if (underp->castConst() && underp->castConst()->num().isFromString()
&& expWidth > underp->width()
&& (((expWidth - underp->width()) % 8) == 0)) { // At least it's character sized
// reg [31:0] == "foo" we'll consider probably fine.
// Maybe this should be a special warning? Not for now.
ignoreWarn = true;
}
if ((nodep->castAdd() && underp->width()==1 && underp->isOne())
|| (nodep->castSub() && underp->width()==1 && underp->isOne() && 0==strcmp(side,"RHS"))) {
// "foo + 1'b1", or "foo - 1'b1" are very common, people assume they extend correctly
ignoreWarn = true;
}
if (bad && !ignoreWarn) {
if (debug()>4) nodep->backp()->dumpTree(cout," back: ");
nodep->v3warn(WIDTH,"Operator "<<nodep->prettyTypeName()
<<" expects "<<expWidth
<<(expWidth!=expWidthMin?" or "+cvtToStr(expWidthMin):"")
<<" bits on the "<<side<<", but "<<side<<"'s "
<<underp->prettyTypeName()<<" generates "<<underp->width()
<<(underp->width()!=underp->widthMin()
?" or "+cvtToStr(underp->widthMin()):"")
<<" bits.");
}
if (bad || underp->width()!=expWidth) {
fixWidthExtend(underp, expWidth); underp=NULL;//Changed
}
}
void WidthVisitor::widthCheckReduce (AstNode* nodep, const char* side,
AstNode* underp, int expWidth, int expWidthMin,
bool ignoreWarn) {
// Before calling this, iterate into underp with FINAL state, so numbers get resized appropriately
if (expWidthMin==0) expWidthMin = expWidth;
if (expWidth!=1) nodep->v3fatalSrc("Only for binary functions");
bool bad = widthBad(underp,expWidth,expWidthMin);
if (bad) {
if (!ignoreWarn) {
if (debug()>4) nodep->backp()->dumpTree(cout," back: ");
nodep->v3warn(WIDTH,"Logical Operator "<<nodep->prettyTypeName()
<<" expects 1 bit on the "<<side<<", but "<<side<<"'s "
<<underp->prettyTypeName()<<" generates "<<underp->width()
<<(underp->width()!=underp->widthMin()
?" or "+cvtToStr(underp->widthMin()):"")
<<" bits.");
}
fixWidthReduce(underp, expWidth); underp=NULL;//Changed
}
}
void WidthVisitor::widthCheckPin (AstNode* nodep, AstNode* underp, int expWidth, bool inputPin) {
// Before calling this, iterate into underp with FINAL state, so numbers get resized appropriately
bool bad = widthBad(underp,expWidth,expWidth);
if (bad && fixAutoExtend(underp/*ref*/,expWidth)) bad=false; // Changes underp
if (bad) {
nodep->v3warn(WIDTH,(inputPin?"Input":"Output")
<<" port connection "<<nodep->prettyName()
<<" expects "<<expWidth
<<" bits but connection's "
<<underp->prettyTypeName()<<" generates "<<underp->width()
<<(underp->width()!=underp->widthMin()
?" or "+cvtToStr(underp->widthMin()):"")
<<" bits.");
}
// We only fix input mismatches
if (bad && inputPin) {
fixWidthExtend(underp, expWidth); underp=NULL;//Changed
}
}
void WidthVisitor::width_O1_L1(AstNode* nodep, AstNUser* vup) {
// Widths: 1 bit out, lhs 1 bit
// We calculate the width of the UNDER expression.
// We then check its width to see if it's legal, and edit if not
// We finally set the width of our output
if (nodep->op2p()) nodep->v3fatalSrc("For unary ops only!");
if (vup->c()->prelim()) {
nodep->op1p()->iterateAndNext(*this,WidthVP(1,0,BOTH).p());
}
nodep->width(1,1);
if (vup->c()->final()) {
widthCheckReduce(nodep,"LHS",nodep->op1p(),1,1);
}
}
void WidthVisitor::width_O1_L1_R1(AstNode* nodep, AstNUser* vup) {
// Widths: 1 bit out, lhs 1 bit, rhs 1 bit
if (!nodep->op2p()) nodep->v3fatalSrc("For binary ops only!");
if (vup->c()->prelim()) {
nodep->op1p()->iterateAndNext(*this,WidthVP(1,0,BOTH).p());
nodep->op2p()->iterateAndNext(*this,WidthVP(1,0,BOTH).p());
}
nodep->width(1,1);
if (vup->c()->final()) {
widthCheckReduce(nodep,"LHS",nodep->op1p(),1,1);
widthCheckReduce(nodep,"RHS",nodep->op2p(),1,1);
}
}
void WidthVisitor::width_O1_L(AstNode* nodep, AstNUser* vup) {
// Widths: 1 bit out, Any width lhs
if (nodep->op2p()) nodep->v3fatalSrc("For unary ops only!");
if (vup->c()->prelim()) {
nodep->op1p()->iterateAndNext(*this,WidthVP(ANYSIZE,0,BOTH).p());
}
nodep->width(1,1);
}
void WidthVisitor::width_O1_L_Rlhs(AstNode* nodep, AstNUser* vup) {
// Widths: 1 bit out, lhs width == rhs width
if (!nodep->op2p()) nodep->v3fatalSrc("For binary ops only!");
if (vup->c()->prelim()) {
nodep->op1p()->iterateAndNext(*this,WidthVP(ANYSIZE,0,PRELIM).p());
nodep->op2p()->iterateAndNext(*this,WidthVP(ANYSIZE,0,PRELIM).p());
}
int width = max(nodep->op1p()->width(), nodep->op2p()->width());
int ewidth = max(nodep->op1p()->widthMin(), nodep->op2p()->widthMin());
nodep->width(1,1);
if (vup->c()->final()) {
nodep->op1p()->iterateAndNext(*this,WidthVP(width,ewidth,FINAL).p());
nodep->op2p()->iterateAndNext(*this,WidthVP(width,ewidth,FINAL).p());
widthCheck(nodep,"LHS",nodep->op1p(),width,ewidth);
widthCheck(nodep,"RHS",nodep->op2p(),width,ewidth);
}
}
void WidthVisitor::width_Olhs_L(AstNodeUniop* nodep, AstNUser* vup) {
// Widths: out width = lhs width
// "Interim results shall take the max of operands, including LHS of assignments"
if (nodep->op2p()) nodep->v3fatalSrc("For unary ops only!");
if (vup->c()->prelim()) {
nodep->lhsp()->iterateAndNext(*this,WidthVP(ANYSIZE,0,PRELIM).p());
}
int width = max(vup->c()->width(), nodep->lhsp()->width());
int ewidth = max(vup->c()->widthMin(), nodep->lhsp()->widthMin());
nodep->width(width,ewidth);
if (vup->c()->final()) {
nodep->lhsp()->iterateAndNext(*this,WidthVP(width,ewidth,FINAL).p());
widthCheck(nodep,"LHS",nodep->lhsp(),width,ewidth);
}
}
void WidthVisitor::width_Olhs_Lforce(AstNodeUniop* nodep, AstNUser* vup) {
// Widths: out width = lhs width
// It always comes exactly from LHS; ignores any upper operand
if (nodep->op2p()) nodep->v3fatalSrc("For unary ops only!");
if (vup->c()->prelim()) {
nodep->lhsp()->iterateAndNext(*this,WidthVP(ANYSIZE,0,PRELIM).p());
}
int width = nodep->lhsp()->width();
int ewidth = nodep->lhsp()->width(); // Not minWidth; force it.
nodep->width(width,ewidth);
if (vup->c()->final()) {
// Final call, so make sure children check their sizes
nodep->lhsp()->iterateAndNext(*this,WidthVP(width,ewidth,FINAL).p());
widthCheck(nodep,"LHS",nodep->lhsp(),width,ewidth);
}
}
void WidthVisitor::width_Olhs_L_R32(AstNode* nodep, AstNUser* vup) {
// Widths: Output width from lhs, rhs<33 bits
if (!nodep->op2p()) nodep->v3fatalSrc("For binary ops only!");
if (vup->c()->prelim()) {
nodep->op1p()->iterateAndNext(*this,WidthVP(ANYSIZE,0,PRELIM).p());
nodep->op2p()->iterateAndNext(*this,WidthVP(ANYSIZE,0,BOTH).p());
}
int width = max(vup->c()->width(), nodep->op1p()->width());
int ewidth = max(vup->c()->widthMin(), nodep->op1p()->widthMin());
nodep->width(width,ewidth);
if (vup->c()->final()) {
nodep->op1p()->iterateAndNext(*this,WidthVP(width,ewidth,FINAL).p());
widthCheck(nodep,"LHS",nodep->op1p(),width,ewidth);
if (nodep->op2p()->width()>32)
nodep->op2p()->v3error("Unsupported: Shifting of by a over 32 bit number isn't supported."
<<" (This isn't a shift of 32 bits, but a shift of 2^32, or 4 billion!)\n");
}
}
void WidthVisitor::width_Omax_L_Rlhs(AstNode* nodep, AstNUser* vup) {
// Widths: out width = lhs width = rhs width
if (!nodep->op2p()) nodep->v3fatalSrc("For binary ops only!");
// If errors are off, we need to follow the spec; thus we really need to do the max()
// because the rhs could be larger, and we need to have proper editing to get the widths
// to be the same for our operations.
if (vup->c()->prelim()) { // First stage evaluation
// Determine expression widths only relying on what's in the subops
nodep->op1p()->iterateAndNext(*this,WidthVP(ANYSIZE,0,PRELIM).p());
nodep->op2p()->iterateAndNext(*this,WidthVP(ANYSIZE,0,PRELIM).p());
}
int width = max(vup->c()->width(), max(nodep->op1p()->width(), nodep->op2p()->width()));
int mwidth = max(vup->c()->widthMin(), max(nodep->op1p()->widthMin(), nodep->op2p()->widthMin()));
nodep->width(width,mwidth);
if (vup->c()->final()) {
// Final call, so make sure children check their sizes
nodep->op1p()->iterateAndNext(*this,WidthVP(width,mwidth,FINAL).p());
nodep->op2p()->iterateAndNext(*this,WidthVP(width,mwidth,FINAL).p());
// Some warning suppressions
bool lhsOk=false; bool rhsOk = false;
if (nodep->castAdd() || nodep->castSub()) {
lhsOk = (mwidth == (nodep->op1p()->widthMin()+1)); // Ok if user wants extra bit from carry
rhsOk = (mwidth == (nodep->op2p()->widthMin()+1)); // Ok if user wants extra bit from carry
} else if (nodep->castMul() || nodep->castMulS()) {
lhsOk = (mwidth >= (nodep->op1p()->widthMin()));
rhsOk = (mwidth >= (nodep->op2p()->widthMin()));
}
// Error report and change sizes for suboperands of this node.
widthCheck(nodep,"LHS",nodep->op1p(),width,mwidth,lhsOk);
widthCheck(nodep,"RHS",nodep->op2p(),width,mwidth,rhsOk);
}
}
//######################################################################
class WidthCommitVisitor : public AstNVisitor {
// Now that all widthing is complete,
// Copy all width() to widthMin(). V3Const expects this
private:
// VISITORS
virtual void visit(AstConst* nodep, AstNUser*) {
nodep->width(nodep->width(),nodep->width());
if ((nodep->width() != nodep->num().width()) || !nodep->num().sized()) {
V3Number num (nodep->fileline(), nodep->width());
num.opAssign(nodep->num());
num.isSigned(nodep->isSigned());
AstNode* newp = new AstConst(nodep->fileline(), num);
nodep->replaceWith(newp);
//if (debug()>4) nodep->dumpTree(cout," fixConstSize_old: ");
//if (debug()>4) newp->dumpTree(cout," _new: ");
pushDeletep(nodep); nodep=NULL;
}
}
virtual void visit(AstNode* nodep, AstNUser*) {
nodep->width(nodep->width(),nodep->width());
nodep->iterateChildren(*this);
}
virtual void visit(AstNodePreSel* nodep, AstNUser*) {
// This check could go anywhere after V3Param
nodep->v3fatalSrc("Presels should have been removed before this point");
}
public:
// CONSTUCTORS
WidthCommitVisitor(AstNetlist* nodep) {
nodep->accept(*this);
}
virtual ~WidthCommitVisitor() {}
};
//######################################################################
// Width class functions
void V3Width::width(AstNetlist* nodep) {
UINFO(2,__FUNCTION__<<": "<<endl);
// We should do it in bottom-up module order, but it works in any order.
WidthVisitor visitor (false);
(void)visitor.mainAcceptEdit(nodep);
}
AstNode* V3Width::widthParamsEdit(AstNode* nodep) {
UINFO(4,__FUNCTION__<<": "<<endl);
// We should do it in bottom-up module order, but it works in any order.
WidthVisitor visitor (true);
nodep = visitor.mainAcceptEdit(nodep);
nodep = V3Signed::signedParamsEdit(nodep);
return nodep;
}
AstNode* V3Width::widthParamsEditIfNeed(AstNode* nodep) {
if (!nodep->width()) {
nodep = V3Width::widthParamsEdit(nodep);
}
return nodep;
}
void V3Width::widthCommit(AstNetlist* nodep) {
UINFO(2,__FUNCTION__<<": "<<endl);
WidthCommitVisitor visitor (nodep);
}