verilator/src/V3Premit.cpp
Yutetsu TAKATSUKASA 0102efd4ea
Support unpacked array in DPI-C (#2648)
* Add tests for unpacked array in DPI-C

* Add more generic parameter generator to AstNodes

* Supports multi dimensional array in DPI ( DPI argmuments <=> Verilator internal type conversion)

consider typedef in V3Task

fix export test

fix inout for scalar

support export func of time

* V3Premit does not show an error for wide words nor ArraySel

* Unnecessary pack func for unapcked array does not appear anymore

* Support unpacked array in runtime header

- Add an overload for lvalue VL_CVT_PACK_STR_NN
- Allow conversion from void *

* touch up tests for codacy advices

* resolve free functions. no functional change intended.
2020-11-19 22:02:58 +09:00

416 lines
16 KiB
C++

// -*- mode: C++; c-file-style: "cc-mode" -*-
//*************************************************************************
// DESCRIPTION: Verilator: Add temporaries, such as for premit nodes
//
// Code available from: https://verilator.org
//
//*************************************************************************
//
// Copyright 2003-2020 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.
// SPDX-License-Identifier: LGPL-3.0-only OR Artistic-2.0
//
//*************************************************************************
// V3Premit's Transformations:
//
// Each module:
// For each wide OP, make a a temporary variable with the wide value
// For each deep expression, assign expression to temporary.
//
// Each display (independent transformation; here as Premit is a good point)
// If autoflush, insert a flush
//
//*************************************************************************
#include "config_build.h"
#include "verilatedos.h"
#include "V3Global.h"
#include "V3Premit.h"
#include "V3Ast.h"
#include <algorithm>
//######################################################################
// Structure for global state
class PremitAssignVisitor final : public AstNVisitor {
private:
// NODE STATE
// AstVar::user4() // bool; occurs on LHS of current assignment
AstUser4InUse m_inuser4;
// STATE
bool m_noopt = false; // Disable optimization of variables in this block
// METHODS
VL_DEBUG_FUNC; // Declare debug()
// VISITORS
virtual void visit(AstNodeAssign* nodep) override {
// AstNode::user4ClearTree(); // Implied by AstUser4InUse
// LHS first as fewer varrefs
iterateAndNextNull(nodep->lhsp());
// Now find vars marked as lhs
iterateAndNextNull(nodep->rhsp());
}
virtual void visit(AstVarRef* nodep) override {
// it's LHS var is used so need a deep temporary
if (nodep->access().isWriteOrRW()) {
nodep->varp()->user4(true);
} else {
if (nodep->varp()->user4()) {
if (!m_noopt) UINFO(4, "Block has LHS+RHS var: " << nodep << endl);
m_noopt = true;
}
}
}
virtual void visit(AstNode* nodep) override { iterateChildren(nodep); }
public:
// CONSTRUCTORS
explicit PremitAssignVisitor(AstNodeAssign* nodep) {
UINFO(4, " PremitAssignVisitor on " << nodep << endl);
iterate(nodep);
}
virtual ~PremitAssignVisitor() override = default;
bool noOpt() const { return m_noopt; }
};
//######################################################################
// Premit state, as a visitor of each AstNode
class PremitVisitor final : public AstNVisitor {
private:
// NODE STATE
// AstNodeMath::user() -> bool. True if iterated already
// AstShiftL::user2() -> bool. True if converted to conditional
// AstShiftR::user2() -> bool. True if converted to conditional
// *::user4() -> See PremitAssignVisitor
AstUser1InUse m_inuser1;
AstUser2InUse m_inuser2;
// STATE
AstNodeModule* m_modp = nullptr; // Current module
AstCFunc* m_cfuncp = nullptr; // Current block
AstNode* m_stmtp = nullptr; // Current statement
AstWhile* m_inWhilep = nullptr; // Inside while loop, special statement additions
AstTraceInc* m_inTracep = nullptr; // Inside while loop, special statement additions
bool m_assignLhs = false; // Inside assignment lhs, don't breakup extracts
// METHODS
VL_DEBUG_FUNC; // Declare debug()
bool assignNoTemp(AstNodeAssign* nodep) {
return (VN_IS(nodep->lhsp(), VarRef) && !AstVar::scVarRecurse(nodep->lhsp())
&& VN_IS(nodep->rhsp(), Const));
}
void checkNode(AstNode* nodep) {
// Consider adding a temp for this expression.
// We need to avoid adding temps to the following:
// ASSIGN(x, *here*)
// ASSIGN(CONST*here*, VARREF(!sc))
// ARRAYSEL(*here*, ...) (No wides can be in any argument but first,
// so we don't check which arg is wide)
// ASSIGN(x, SEL*HERE*(ARRAYSEL()...) (m_assignLhs==true handles this.)
// UINFO(9, " Check: " << nodep << endl);
// UINFO(9, " Detail stmtp=" << (m_stmtp?"Y":"N") << " U=" << (nodep->user1()?"Y":"N")
// << " IW=" << (nodep->isWide()?"Y":"N") << endl);
if (m_stmtp && !nodep->user1()) { // Not already done
if (nodep->isWide()) {
if (m_assignLhs) {
} else if (nodep->firstAbovep() && VN_IS(nodep->firstAbovep(), NodeAssign)
&& assignNoTemp(VN_CAST(nodep->firstAbovep(), NodeAssign))) {
// Not much point if it's just a direct assignment to a constant
} else if (VN_IS(nodep->backp(), Sel)
&& VN_CAST(nodep->backp(), Sel)->widthp() == nodep) {
// AstSel::width must remain a constant
} else if ((nodep->firstAbovep() && VN_IS(nodep->firstAbovep(), ArraySel))
|| ((VN_IS(m_stmtp, CCall) || VN_IS(m_stmtp, CStmt))
&& VN_IS(nodep, ArraySel))) {
// ArraySel's are pointer refs, ignore
} else {
UINFO(4, "Cre Temp: " << nodep << endl);
createDeepTemp(nodep, false);
}
}
}
}
AstVar* getBlockTemp(AstNode* nodep) {
string newvarname = (string("__Vtemp") + cvtToStr(m_modp->varNumGetInc()));
AstVar* varp
= new AstVar(nodep->fileline(), AstVarType::STMTTEMP, newvarname, nodep->dtypep());
m_cfuncp->addInitsp(varp);
return varp;
}
void insertBeforeStmt(AstNode* newp) {
// Insert newp before m_stmtp
if (m_inWhilep) {
// Statements that are needed for the 'condition' in a while
// actually have to be put before & after the loop, since we
// can't do any statements in a while's (cond).
m_inWhilep->addPrecondsp(newp);
} else if (m_inTracep) {
m_inTracep->addPrecondsp(newp);
} else if (m_stmtp) {
AstNRelinker linker;
m_stmtp->unlinkFrBack(&linker);
newp->addNext(m_stmtp);
linker.relink(newp);
} else {
newp->v3fatalSrc("No statement insertion point.");
}
}
void createDeepTemp(AstNode* nodep, bool noSubst) {
if (debug() > 8) nodep->dumpTree(cout, "deepin:");
AstNRelinker linker;
nodep->unlinkFrBack(&linker);
AstVar* varp = getBlockTemp(nodep);
if (noSubst) varp->noSubst(true); // Do not remove varrefs to this in V3Const
// Replace node tree with reference to var
AstVarRef* newp = new AstVarRef(nodep->fileline(), varp, VAccess::READ);
linker.relink(newp);
// Put assignment before the referencing statement
AstAssign* assp = new AstAssign(
nodep->fileline(), new AstVarRef(nodep->fileline(), varp, VAccess::WRITE), nodep);
insertBeforeStmt(assp);
if (debug() > 8) assp->dumpTree(cout, "deepou:");
nodep->user1(true); // Don't add another assignment
}
// VISITORS
virtual void visit(AstNodeModule* nodep) override {
UINFO(4, " MOD " << nodep << endl);
VL_RESTORER(m_modp);
{
m_modp = nodep;
m_cfuncp = nullptr;
iterateChildren(nodep);
}
}
virtual void visit(AstCFunc* nodep) override {
VL_RESTORER(m_cfuncp);
{
m_cfuncp = nodep;
iterateChildren(nodep);
}
}
void startStatement(AstNode* nodep) {
m_assignLhs = false;
if (m_cfuncp) m_stmtp = nodep;
}
virtual void visit(AstWhile* nodep) override {
UINFO(4, " WHILE " << nodep << endl);
startStatement(nodep);
iterateAndNextNull(nodep->precondsp());
startStatement(nodep);
m_inWhilep = nodep;
iterateAndNextNull(nodep->condp());
m_inWhilep = nullptr;
startStatement(nodep);
iterateAndNextNull(nodep->bodysp());
iterateAndNextNull(nodep->incsp());
m_stmtp = nullptr;
}
virtual void visit(AstNodeAssign* nodep) override {
startStatement(nodep);
{
bool noopt = PremitAssignVisitor(nodep).noOpt();
if (noopt && !nodep->user1()) {
// Need to do this even if not wide, as e.g. a select may be on a wide operator
UINFO(4, "Deep temp for LHS/RHS\n");
createDeepTemp(nodep->rhsp(), false);
}
}
iterateAndNextNull(nodep->rhsp());
m_assignLhs = true;
iterateAndNextNull(nodep->lhsp());
m_assignLhs = false;
m_stmtp = nullptr;
}
virtual void visit(AstNodeStmt* nodep) override {
if (!nodep->isStatement()) {
iterateChildren(nodep);
return;
}
UINFO(4, " STMT " << nodep << endl);
startStatement(nodep);
iterateChildren(nodep);
m_stmtp = nullptr;
}
virtual void visit(AstTraceInc* nodep) override {
startStatement(nodep);
m_inTracep = nodep;
iterateChildren(nodep);
m_inTracep = nullptr;
m_stmtp = nullptr;
}
void visitShift(AstNodeBiop* nodep) {
// Shifts of > 32/64 bits in C++ will wrap-around and generate non-0s
if (!nodep->user2SetOnce()) {
UINFO(4, " ShiftFix " << nodep << endl);
const AstConst* shiftp = VN_CAST(nodep->rhsp(), Const);
if (shiftp && shiftp->num().mostSetBitP1() > 32) {
shiftp->v3error(
"Unsupported: Shifting of by 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");
}
if (nodep->widthMin() <= 64 // Else we'll use large operators which work right
// C operator's width must be < maximum shift which is
// based on Verilog width
&& nodep->width() < (1LL << nodep->rhsp()->widthMin())) {
AstNRelinker replaceHandle;
nodep->unlinkFrBack(&replaceHandle);
AstNode* constzerop;
int m1value
= nodep->widthMin() - 1; // Constant of width-1; not changing dtype width
if (nodep->signedFlavor()) {
// Then over shifting gives the sign bit, not all zeros
// Note *NOT* clean output -- just like normal shift!
// Create equivalent of VL_SIGNONES_(node_width)
constzerop = new AstNegate(
nodep->fileline(),
new AstShiftR(nodep->fileline(), nodep->lhsp()->cloneTree(false),
new AstConst(nodep->fileline(), m1value), nodep->width()));
} else {
constzerop = new AstConst(nodep->fileline(), AstConst::WidthedValue(),
nodep->width(), 0);
}
constzerop->dtypeFrom(nodep); // unsigned
AstNode* constwidthp = new AstConst(nodep->fileline(), AstConst::WidthedValue(),
nodep->rhsp()->widthMin(), m1value);
constwidthp->dtypeFrom(nodep->rhsp()); // unsigned
AstCond* newp = new AstCond(
nodep->fileline(),
new AstGte(nodep->fileline(), constwidthp, nodep->rhsp()->cloneTree(false)),
nodep, constzerop);
replaceHandle.relink(newp);
}
}
iterateChildren(nodep);
checkNode(nodep);
}
virtual void visit(AstShiftL* nodep) override { visitShift(nodep); }
virtual void visit(AstShiftR* nodep) override { visitShift(nodep); }
virtual void visit(AstShiftRS* nodep) override { visitShift(nodep); }
// Operators
virtual void visit(AstNodeTermop* nodep) override {
iterateChildren(nodep);
checkNode(nodep);
}
virtual void visit(AstNodeUniop* nodep) override {
iterateChildren(nodep);
checkNode(nodep);
}
virtual void visit(AstNodeBiop* nodep) override {
iterateChildren(nodep);
checkNode(nodep);
}
virtual void visit(AstUCFunc* nodep) override {
iterateChildren(nodep);
checkNode(nodep);
}
virtual void visit(AstSel* nodep) override {
iterateAndNextNull(nodep->fromp());
{ // Only the 'from' is part of the assignment LHS
VL_RESTORER(m_assignLhs);
m_assignLhs = false;
iterateAndNextNull(nodep->lsbp());
iterateAndNextNull(nodep->widthp());
}
checkNode(nodep);
}
virtual void visit(AstArraySel* nodep) override {
iterateAndNextNull(nodep->fromp());
{ // Only the 'from' is part of the assignment LHS
VL_RESTORER(m_assignLhs);
m_assignLhs = false;
iterateAndNextNull(nodep->bitp());
}
checkNode(nodep);
}
virtual void visit(AstAssocSel* nodep) override {
iterateAndNextNull(nodep->fromp());
{ // Only the 'from' is part of the assignment LHS
VL_RESTORER(m_assignLhs);
m_assignLhs = false;
iterateAndNextNull(nodep->bitp());
}
checkNode(nodep);
}
virtual void visit(AstConst* nodep) override {
iterateChildren(nodep);
checkNode(nodep);
}
virtual void visit(AstNodeCond* nodep) override {
iterateChildren(nodep);
if (nodep->expr1p()->isWide() && !VN_IS(nodep->condp(), Const)
&& !VN_IS(nodep->condp(), VarRef)) {
// We're going to need the expression several times in the expanded code,
// so might as well make it a common expression
createDeepTemp(nodep->condp(), false);
}
checkNode(nodep);
}
// Autoflush
virtual void visit(AstDisplay* nodep) override {
startStatement(nodep);
iterateChildren(nodep);
m_stmtp = nullptr;
if (v3Global.opt.autoflush()) {
AstNode* searchp = nodep->nextp();
while (searchp && VN_IS(searchp, Comment)) searchp = searchp->nextp();
if (searchp && VN_IS(searchp, Display)
&& nodep->filep()->sameGateTree(VN_CAST(searchp, Display)->filep())) {
// There's another display next; we can just wait to flush
} else {
UINFO(4, "Autoflush " << nodep << endl);
nodep->addNextHere(new AstFFlush(nodep->fileline(),
AstNode::cloneTreeNull(nodep->filep(), true)));
}
}
}
virtual void visit(AstSFormatF* nodep) override {
iterateChildren(nodep);
// Any strings sent to a display must be var of string data type,
// to avoid passing a pointer to a temporary.
for (AstNode* expp = nodep->exprsp(); expp; expp = expp->nextp()) {
if (expp->dtypep()->basicp() && expp->dtypep()->basicp()->isString()
&& !VN_IS(expp, VarRef)) {
createDeepTemp(expp, true);
}
}
}
//--------------------
// Default: Just iterate
virtual void visit(AstVar*) override {} // Don't hit varrefs under vars
virtual void visit(AstNode* nodep) override { iterateChildren(nodep); }
public:
// CONSTRUCTORS
explicit PremitVisitor(AstNetlist* nodep) { iterate(nodep); }
virtual ~PremitVisitor() override = default;
};
//----------------------------------------------------------------------
// Top loop
//######################################################################
// Premit class functions
void V3Premit::premitAll(AstNetlist* nodep) {
UINFO(2, __FUNCTION__ << ": " << endl);
{ PremitVisitor visitor(nodep); } // Destruct before checking
V3Global::dumpCheckGlobalTree("premit", 0, v3Global.opt.dumpTreeLevel(__FILE__) >= 3);
}