verilator/src/V3Expand.cpp

899 lines
43 KiB
C++

// -*- mode: C++; c-file-style: "cc-mode" -*-
//*************************************************************************
// DESCRIPTION: Verilator: Add temporaries, such as for expand nodes
//
// Code available from: https://verilator.org
//
//*************************************************************************
//
// Copyright 2004-2020 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
//
//*************************************************************************
// V3Expand's Transformations:
//
// Each module:
// Expand verilated.h macros into internal micro optimizations (RTL)
// this will enable later optimizations.
// Wide operands become assignments to each word of the vector, (WORDSELs)
// Note in this case that the widthMin is not correct for the MSW of
// the vector. This must be accounted for if doing later constant
// propagation across signals.
//
//*************************************************************************
#include "config_build.h"
#include "verilatedos.h"
#include "V3Global.h"
#include "V3Expand.h"
#include "V3Ast.h"
#include <algorithm>
//######################################################################
// Expand state, as a visitor of each AstNode
class ExpandVisitor : public AstNVisitor {
private:
// NODE STATE
// AstNode::user1() -> bool. Processed
AstUser1InUse m_inuser1;
// STATE
AstNode* m_stmtp; // Current statement
// METHODS
VL_DEBUG_FUNC; // Declare debug()
int longOrQuadWidth(AstNode* nodep) {
return (nodep->width() + (VL_EDATASIZE - 1)) & ~(VL_EDATASIZE - 1);
}
V3Number notWideMask(AstNode* nodep) {
return V3Number(nodep, VL_EDATASIZE, ~VL_MASK_E(nodep->widthMin()));
}
V3Number wordMask(AstNode* nodep) {
if (nodep->isWide()) {
return V3Number(nodep, VL_EDATASIZE, VL_MASK_E(nodep->widthMin()));
} else {
V3Number mask(nodep, longOrQuadWidth(nodep));
mask.setMask(nodep->widthMin());
return mask;
}
}
void insertBefore(AstNode* placep, AstNode* newp) {
newp->user1(1); // Already processed, don't need to re-iterate
AstNRelinker linker;
placep->unlinkFrBack(&linker);
newp->addNext(placep);
linker.relink(newp);
}
void replaceWithDelete(AstNode* nodep, AstNode* newp) {
newp->user1(1); // Already processed, don't need to re-iterate
nodep->replaceWith(newp);
VL_DO_DANGLING(nodep->deleteTree(), nodep);
}
AstNode* newWordAssign(AstNodeAssign* placep, int word, AstNode* lhsp, AstNode* rhsp) {
AstAssign* newp = new AstAssign(placep->fileline(),
new AstWordSel(placep->fileline(), lhsp->cloneTree(true),
new AstConst(placep->fileline(), word)),
rhsp);
return newp;
}
void addWordAssign(AstNodeAssign* placep, int word, AstNode* lhsp, AstNode* rhsp) {
insertBefore(placep, newWordAssign(placep, word, lhsp, rhsp));
}
void addWordAssign(AstNodeAssign* placep, int word, AstNode* rhsp) {
addWordAssign(placep, word, placep->lhsp(), rhsp);
}
void fixCloneLvalue(AstNode* nodep) {
// In AstSel transforms, we call clone() on VarRefs that were lvalues,
// but are now being used on the RHS of the assignment
if (VN_IS(nodep, VarRef)) VN_CAST(nodep, VarRef)->lvalue(false);
// Iterate
if (nodep->op1p()) fixCloneLvalue(nodep->op1p());
if (nodep->op2p()) fixCloneLvalue(nodep->op2p());
if (nodep->op3p()) fixCloneLvalue(nodep->op3p());
if (nodep->op4p()) fixCloneLvalue(nodep->op4p());
}
AstNode* newAstWordSelClone(AstNode* nodep, int word) {
// Get the specified word number from a wide array
// Or, if it's a long/quad, do appropriate conversion to wide
// Concat may pass negative word numbers, that means it wants a zero
if (nodep->isWide() && word >= 0 && word < nodep->widthWords()) {
return new AstWordSel(nodep->fileline(), nodep->cloneTree(true),
new AstConst(nodep->fileline(), word));
} else if (nodep->isQuad() && word == 0) {
AstNode* quadfromp = nodep->cloneTree(true);
quadfromp->dtypeSetBitUnsized(VL_QUADSIZE, quadfromp->widthMin(), VSigning::UNSIGNED);
return new AstCCast(nodep->fileline(), quadfromp, VL_EDATASIZE);
} else if (nodep->isQuad() && word == 1) {
AstNode* quadfromp = nodep->cloneTree(true);
quadfromp->dtypeSetBitUnsized(VL_QUADSIZE, quadfromp->widthMin(), VSigning::UNSIGNED);
return new AstCCast(nodep->fileline(),
new AstShiftR(nodep->fileline(), quadfromp,
new AstConst(nodep->fileline(), VL_EDATASIZE),
VL_EDATASIZE),
VL_EDATASIZE);
} else if (!nodep->isWide() && !nodep->isQuad() && word == 0) {
return nodep->cloneTree(true);
} else { // Out of bounds
return new AstConst(nodep->fileline(), 0);
}
}
AstNode* newWordGrabShift(FileLine* fl, int word, AstNode* lhsp, int shift) {
// Extract the expression to grab the value for the specified word, if it's the shift
// of shift bits from lhsp
AstNode* newp;
// Negative word numbers requested for lhs when it's "before" what we want.
// We get a 0 then.
int othword = word - shift / VL_EDATASIZE;
AstNode* llowp = newAstWordSelClone(lhsp, othword);
if (int loffset = VL_BITBIT_E(shift)) {
AstNode* lhip = newAstWordSelClone(lhsp, othword - 1);
int nbitsonright = VL_EDATASIZE - loffset; // bits that end up in lword
newp = new AstOr(
fl,
new AstAnd(fl, new AstConst(fl, AstConst::SizedEData(), VL_MASK_E(loffset)),
new AstShiftR(fl, lhip, new AstConst(fl, nbitsonright), VL_EDATASIZE)),
new AstAnd(fl, new AstConst(fl, AstConst::SizedEData(), ~VL_MASK_E(loffset)),
new AstShiftL(fl, llowp, new AstConst(fl, loffset), VL_EDATASIZE)));
} else {
newp = llowp;
}
return newp;
}
AstNode* newWordSel(FileLine* fl, AstNode* fromp, AstNode* lsbp, int wordAdder) {
// Return equation to get the VL_BITWORD of a constant or non-constant
UASSERT_OBJ(fromp->isWide(), fromp, "Only need AstWordSel on wide from's");
if (wordAdder >= fromp->widthWords()) {
// e.g. "logic [95:0] var[0]; logic [0] sel; out = var[sel];"
// Squash before C++ to avoid getting a C++ compiler warning
// (even though code would be unreachable as presumably a
// AstCondBound is protecting above this node.
return new AstConst(fl, AstConst::SizedEData(), 0);
} else {
AstNode* wordp;
if (VN_IS(lsbp, Const)) {
wordp = new AstConst(lsbp->fileline(),
wordAdder + VL_BITWORD_E(VN_CAST(lsbp, Const)->toUInt()));
} else {
wordp = new AstShiftR(lsbp->fileline(), lsbp->cloneTree(true),
new AstConst(lsbp->fileline(), VL_EDATASIZE_LOG2),
VL_EDATASIZE);
if (wordAdder != 0) {
wordp = new AstAdd(lsbp->fileline(),
// This is indexing a arraysel, so a 32 bit constant is fine
new AstConst(lsbp->fileline(), wordAdder), wordp);
}
}
return new AstWordSel(fl, fromp, wordp);
}
}
AstNode* dropCondBound(AstNode* nodep) {
// Experimental only...
// If there's a CONDBOUND safety to keep arrays in bounds,
// we're going to AND it to a value that always fits inside a
// word, so we don't need it.
// if (VN_IS(nodep, CondBound) && VN_IS(VN_CAST(nodep, CondBound)->lhsp(), Lte)) {
// nodep = VN_CAST(nodep, CondBound)->rhsp();
//}
return nodep;
}
AstNode* newSelBitBit(AstNode* lsbp) {
// Return equation to get the VL_BITBIT of a constant or non-constant
if (VN_IS(lsbp, Const)) {
return new AstConst(lsbp->fileline(), VL_BITBIT_E(VN_CAST(lsbp, Const)->toUInt()));
} else {
return new AstAnd(lsbp->fileline(), new AstConst(lsbp->fileline(), VL_EDATASIZE - 1),
dropCondBound(lsbp)->cloneTree(true));
}
}
//====================
bool expandWide(AstNodeAssign* nodep, AstConst* rhsp) {
UINFO(8, " Wordize ASSIGN(CONST) " << nodep << endl);
// -> {for each_word{ ASSIGN(WORDSEL(wide,#),WORDSEL(CONST,#))}}
if (rhsp->num().isFourState()) {
rhsp->v3warn(E_UNSUPPORTED, // LCOV_EXCL_LINE // impossible?
"Unsupported: 4-state numbers in this context");
}
for (int w = 0; w < nodep->widthWords(); w++) {
addWordAssign(
nodep, w,
new AstConst(nodep->fileline(), AstConst::SizedEData(), rhsp->num().edataWord(w)));
}
return true;
}
//-------- Uniops
bool expandWide(AstNodeAssign* nodep, AstVarRef* rhsp) {
UINFO(8, " Wordize ASSIGN(VARREF) " << nodep << endl);
for (int w = 0; w < nodep->widthWords(); w++) {
addWordAssign(nodep, w, newAstWordSelClone(rhsp, w));
}
return true;
}
bool expandWide(AstNodeAssign* nodep, AstArraySel* rhsp) {
UINFO(8, " Wordize ASSIGN(ARRAYSEL) " << nodep << endl);
UASSERT_OBJ(!VN_IS(nodep->dtypep()->skipRefp(), UnpackArrayDType), nodep,
"ArraySel with unpacked arrays should have been removed in V3Slice");
for (int w = 0; w < nodep->widthWords(); w++) {
addWordAssign(nodep, w, newAstWordSelClone(rhsp, w));
}
return true;
}
bool expandWide(AstNodeAssign* nodep, AstNot* rhsp) {
UINFO(8, " Wordize ASSIGN(NOT) " << nodep << endl);
// -> {for each_word{ ASSIGN(WORDSEL(wide,#),NOT(WORDSEL(lhs,#))) }}
for (int w = 0; w < nodep->widthWords(); w++) {
addWordAssign(nodep, w,
new AstNot(rhsp->fileline(), newAstWordSelClone(rhsp->lhsp(), w)));
}
return true;
}
//-------- Biops
bool expandWide(AstNodeAssign* nodep, AstAnd* rhsp) {
UINFO(8, " Wordize ASSIGN(AND) " << nodep << endl);
for (int w = 0; w < nodep->widthWords(); w++) {
addWordAssign(nodep, w,
new AstAnd(nodep->fileline(), newAstWordSelClone(rhsp->lhsp(), w),
newAstWordSelClone(rhsp->rhsp(), w)));
}
return true;
}
bool expandWide(AstNodeAssign* nodep, AstOr* rhsp) {
UINFO(8, " Wordize ASSIGN(OR) " << nodep << endl);
for (int w = 0; w < nodep->widthWords(); w++) {
addWordAssign(nodep, w,
new AstOr(nodep->fileline(), newAstWordSelClone(rhsp->lhsp(), w),
newAstWordSelClone(rhsp->rhsp(), w)));
}
return true;
}
bool expandWide(AstNodeAssign* nodep, AstXor* rhsp) {
UINFO(8, " Wordize ASSIGN(XOR) " << nodep << endl);
for (int w = 0; w < nodep->widthWords(); w++) {
addWordAssign(nodep, w,
new AstXor(nodep->fileline(), newAstWordSelClone(rhsp->lhsp(), w),
newAstWordSelClone(rhsp->rhsp(), w)));
}
return true;
}
bool expandWide(AstNodeAssign* nodep, AstXnor* rhsp) {
UINFO(8, " Wordize ASSIGN(XNOR) " << nodep << endl);
for (int w = 0; w < nodep->widthWords(); w++) {
addWordAssign(nodep, w,
new AstXnor(nodep->fileline(), newAstWordSelClone(rhsp->lhsp(), w),
newAstWordSelClone(rhsp->rhsp(), w)));
}
return true;
}
//-------- Triops
bool expandWide(AstNodeAssign* nodep, AstNodeCond* rhsp) {
UINFO(8, " Wordize ASSIGN(COND) " << nodep << endl);
for (int w = 0; w < nodep->widthWords(); w++) {
addWordAssign(nodep, w,
new AstCond(nodep->fileline(), rhsp->condp()->cloneTree(true),
newAstWordSelClone(rhsp->expr1p(), w),
newAstWordSelClone(rhsp->expr2p(), w)));
}
return true;
}
// VISITORS
virtual void visit(AstExtend* nodep) VL_OVERRIDE {
if (nodep->user1SetOnce()) return; // Process once
iterateChildren(nodep);
if (nodep->isWide()) {
// See under ASSIGN(EXTEND)
} else {
AstNode* lhsp = nodep->lhsp()->unlinkFrBack();
AstNode* newp = lhsp;
if (nodep->isQuad()) {
if (lhsp->isQuad()) {
lhsp->dtypeFrom(nodep); // Just mark it, else nop
} else if (lhsp->isWide()) {
nodep->v3fatalSrc("extending larger thing into smaller?");
} else {
UINFO(8, " EXTEND(q<-l) " << nodep << endl);
newp = new AstCCast(nodep->fileline(), lhsp, nodep);
}
} else { // Long
UASSERT_OBJ(!(lhsp->isQuad() || lhsp->isWide()), nodep,
"extending larger thing into smaller?");
lhsp->dtypeFrom(nodep); // Just mark it, else nop
}
VL_DO_DANGLING(replaceWithDelete(nodep, newp), nodep);
}
}
virtual void visit(AstSel* nodep) VL_OVERRIDE {
if (nodep->user1SetOnce()) return; // Process once
iterateChildren(nodep);
// Remember, Sel's may have non-integer rhs, so need to optimize for that!
UASSERT_OBJ(nodep->widthMin() == nodep->widthConst(), nodep, "Width mismatch");
if (VN_IS(nodep->backp(), NodeAssign)
&& nodep == VN_CAST(nodep->backp(), NodeAssign)->lhsp()) {
// Sel is an LHS assignment select
} else if (nodep->isWide()) {
// See under ASSIGN(WIDE)
} else if (nodep->fromp()->isWide()) {
UINFO(8, " SEL(wide) " << nodep << endl);
// Selection amounts
// Check for constant shifts & save some constification work later.
// Grab lowest bit(s)
AstNode* lowwordp = newWordSel(nodep->fromp()->fileline(),
nodep->fromp()->cloneTree(true), nodep->lsbp(), 0);
if (nodep->isQuad() && !lowwordp->isQuad()) {
lowwordp = new AstCCast(nodep->fileline(), lowwordp, nodep);
}
AstNode* lowp = new AstShiftR(nodep->fileline(), lowwordp, newSelBitBit(nodep->lsbp()),
nodep->width());
// If > 1 bit, we might be crossing the word boundary
AstNode* midp = NULL;
V3Number zero(nodep, longOrQuadWidth(nodep));
if (nodep->widthConst() > 1) {
AstNode* midwordp = // SEL(from,[1+wordnum])
newWordSel(nodep->fromp()->fileline(), nodep->fromp()->cloneTree(true),
nodep->lsbp(), 1);
if (nodep->isQuad() && !midwordp->isQuad()) {
midwordp = new AstCCast(nodep->fileline(), midwordp, nodep);
}
// If we're selecting bit zero, then all 32 bits in word 1
// get shifted << by 32 bits
// else we need to form the lower word, so we << by 31 or less
// nbitsfromlow <= (lsb==0) ? 64-bitbit(lsb) : 32-bitbit(lsb)
AstNode* midshiftp
= new AstSub(nodep->lsbp()->fileline(),
new AstConst(nodep->lsbp()->fileline(), VL_EDATASIZE),
newSelBitBit(nodep->lsbp()));
if (nodep->isQuad()) {
midshiftp = new AstCond(
nodep->fileline(),
new AstEq(nodep->fileline(), new AstConst(nodep->fileline(), 0),
newSelBitBit(nodep->lsbp())),
new AstConst(nodep->lsbp()->fileline(), VL_EDATASIZE), midshiftp);
}
AstNode* midmayp
= new AstShiftL(nodep->fileline(), midwordp, midshiftp, nodep->width());
if (nodep->isQuad()) {
midp = midmayp; // Always grab from two words
} else {
midp = new AstCond(nodep->fileline(),
new AstEq(nodep->fileline(),
new AstConst(nodep->fileline(), 0),
newSelBitBit(nodep->lsbp())),
new AstConst(nodep->fileline(), zero), midmayp);
}
}
// If > 32 bits, we might be crossing the second word boundary
AstNode* hip = NULL;
if (nodep->widthConst() > VL_EDATASIZE) {
AstNode* hiwordp = // SEL(from,[2+wordnum])
newWordSel(nodep->fromp()->fileline(), nodep->fromp()->cloneTree(true),
nodep->lsbp(), 2);
if (nodep->isQuad() && !hiwordp->isQuad()) {
hiwordp = new AstCCast(nodep->fileline(), hiwordp, nodep);
}
AstNode* himayp
= new AstShiftL(nodep->fileline(), hiwordp,
// nbitsfromlow_and_mid <= 64-bitbit(lsb)
new AstSub(nodep->lsbp()->fileline(),
new AstConst(nodep->lsbp()->fileline(), 64),
newSelBitBit(nodep->lsbp())),
nodep->width());
// if (frombit==0) then ignore, else use it
hip = new AstCond(nodep->fileline(),
new AstEq(nodep->fileline(), new AstConst(nodep->fileline(), 0),
newSelBitBit(nodep->lsbp())),
new AstConst(nodep->fileline(), zero), himayp);
}
AstNode* newp = lowp;
if (midp) newp = new AstOr(nodep->fileline(), midp, newp);
if (hip) newp = new AstOr(nodep->fileline(), hip, newp);
newp->dtypeFrom(nodep);
VL_DO_DANGLING(replaceWithDelete(nodep, newp), nodep);
} else { // Long/Quad from Long/Quad
UINFO(8, " SEL->SHIFT " << nodep << endl);
AstNode* fromp = nodep->fromp()->unlinkFrBack();
AstNode* lsbp = nodep->lsbp()->unlinkFrBack();
if (nodep->isQuad() && !fromp->isQuad()) {
fromp = new AstCCast(nodep->fileline(), fromp, nodep);
}
AstNode* newp = new AstShiftR(
nodep->fileline(), fromp, dropCondBound(lsbp),
fromp->width()); // {large}>>32 requires 64-bit shift operation; then cast
newp->dtypeFrom(fromp);
if (!nodep->isQuad() && fromp->isQuad()) {
newp = new AstCCast(newp->fileline(), newp, nodep);
}
newp->dtypeFrom(nodep);
VL_DO_DANGLING(replaceWithDelete(nodep, newp), nodep);
}
}
bool expandWide(AstNodeAssign* nodep, AstSel* rhsp) {
UASSERT_OBJ(nodep->widthMin() == rhsp->widthConst(), nodep, "Width mismatch");
if (VN_IS(rhsp->lsbp(), Const) && VL_BITBIT_E(rhsp->lsbConst()) == 0) {
int lsb = rhsp->lsbConst();
UINFO(8, " Wordize ASSIGN(SEL,align) " << nodep << endl);
for (int w = 0; w < nodep->widthWords(); w++) {
addWordAssign(nodep, w, newAstWordSelClone(rhsp->fromp(), w + VL_BITWORD_E(lsb)));
}
return true;
} else {
UINFO(8, " Wordize ASSIGN(EXTRACT,misalign) " << nodep << endl);
for (int w = 0; w < nodep->widthWords(); w++) {
// Grab lowest bits
AstNode* lowwordp = newWordSel(rhsp->fileline(), rhsp->fromp()->cloneTree(true),
rhsp->lsbp(), w);
AstNode* lowp = new AstShiftR(rhsp->fileline(), lowwordp,
newSelBitBit(rhsp->lsbp()), VL_EDATASIZE);
// Upper bits
V3Number zero(nodep, VL_EDATASIZE, 0);
AstNode* midwordp = // SEL(from,[1+wordnum])
newWordSel(rhsp->fromp()->fileline(), rhsp->fromp()->cloneTree(true),
rhsp->lsbp(), w + 1);
AstNode* midshiftp = new AstSub(
rhsp->lsbp()->fileline(), new AstConst(rhsp->lsbp()->fileline(), VL_EDATASIZE),
newSelBitBit(rhsp->lsbp()));
AstNode* midmayp
= new AstShiftL(rhsp->fileline(), midwordp, midshiftp, VL_EDATASIZE);
AstNode* midp
= new AstCond(rhsp->fileline(),
new AstEq(rhsp->fileline(), new AstConst(rhsp->fileline(), 0),
newSelBitBit(rhsp->lsbp())),
new AstConst(rhsp->fileline(), zero), midmayp);
AstNode* newp = new AstOr(nodep->fileline(), midp, lowp);
addWordAssign(nodep, w, newp);
}
return true;
}
}
bool expandLhs(AstNodeAssign* nodep, AstSel* lhsp) {
// Possibilities
// destp: wide or narrow
// rhsp: wide (destp must be wide), narrow, or 1 bit wide
// rhsp: may be allones and can remove AND NOT gate
// lsbp: constant or variable
// Yuk.
bool destwide = lhsp->fromp()->isWide();
bool ones = nodep->rhsp()->isAllOnesV();
if (VN_IS(lhsp->lsbp(), Const)) {
// The code should work without this constant test, but it won't
// constify as nicely as we'd like.
AstNode* rhsp = nodep->rhsp()->unlinkFrBack();
AstNode* destp = lhsp->fromp()->unlinkFrBack();
int lsb = lhsp->lsbConst();
int msb = lhsp->msbConst();
V3Number maskset(nodep, destp->widthMin());
for (int bit = lsb; bit < (msb + 1); bit++) maskset.setBit(bit, 1);
V3Number maskold(nodep, destp->widthMin());
maskold.opNot(maskset);
if (destwide) {
UINFO(8, " ASSIGNSEL(const,wide) " << nodep << endl);
for (int w = 0; w < destp->widthWords(); w++) {
if (w >= VL_BITWORD_E(lsb) && w <= VL_BITWORD_E(msb)) {
// else we would just be setting it to the same exact value
AstNode* oldvalp = newAstWordSelClone(destp, w);
fixCloneLvalue(oldvalp);
if (!ones) {
oldvalp
= new AstAnd(lhsp->fileline(),
new AstConst(lhsp->fileline(), AstConst::SizedEData(),
maskold.edataWord(w)),
oldvalp);
}
addWordAssign(nodep, w, destp,
new AstOr(lhsp->fileline(), oldvalp,
newWordGrabShift(lhsp->fileline(), w, rhsp, lsb)));
}
}
VL_DO_DANGLING(rhsp->deleteTree(), rhsp);
VL_DO_DANGLING(destp->deleteTree(), destp);
} else {
UINFO(8, " ASSIGNSEL(const,narrow) " << nodep << endl);
if (destp->isQuad() && !rhsp->isQuad()) {
rhsp = new AstCCast(nodep->fileline(), rhsp, nodep);
}
AstNode* oldvalp = destp->cloneTree(true);
fixCloneLvalue(oldvalp);
if (!ones) {
oldvalp = new AstAnd(lhsp->fileline(), new AstConst(lhsp->fileline(), maskold),
oldvalp);
}
AstNode* newp = new AstOr(lhsp->fileline(), oldvalp,
new AstShiftL(lhsp->fileline(), rhsp,
new AstConst(lhsp->fileline(), lsb),
destp->width()));
newp = new AstAssign(nodep->fileline(), destp, newp);
insertBefore(nodep, newp);
}
return true;
} else { // non-const RHS
if (destwide && lhsp->widthConst() == 1) {
UINFO(8, " ASSIGNSEL(varlsb,wide,1bit) " << nodep << endl);
AstNode* rhsp = nodep->rhsp()->unlinkFrBack();
AstNode* destp = lhsp->fromp()->unlinkFrBack();
AstNode* oldvalp
= newWordSel(lhsp->fileline(), destp->cloneTree(true), lhsp->lsbp(), 0);
fixCloneLvalue(oldvalp);
if (!ones) {
oldvalp = new AstAnd(
lhsp->fileline(),
new AstNot(
lhsp->fileline(),
new AstShiftL(lhsp->fileline(), new AstConst(nodep->fileline(), 1),
// newSelBitBit may exceed the MSB of this variable.
// That's ok as we'd just AND with a larger value,
// but oldval would clip the upper bits to sanity
newSelBitBit(lhsp->lsbp()), VL_EDATASIZE)),
oldvalp);
}
// Restrict the shift amount to 0-31, see bug804.
AstNode* shiftp = new AstAnd(nodep->fileline(), lhsp->lsbp()->cloneTree(true),
new AstConst(nodep->fileline(), VL_EDATASIZE - 1));
AstNode* newp
= new AstOr(lhsp->fileline(), oldvalp,
new AstShiftL(lhsp->fileline(), rhsp, shiftp, VL_EDATASIZE));
newp = new AstAssign(nodep->fileline(),
newWordSel(nodep->fileline(), destp, lhsp->lsbp(), 0), newp);
insertBefore(nodep, newp);
return true;
} else if (destwide) {
UINFO(8, " ASSIGNSEL(varlsb,wide) -- NoOp -- " << nodep << endl);
// For wide destp, we can either form a equation for every destination word,
// with the appropriate long equation of if it's being written or not.
// Or, we can use a LHS variable arraysel with
// non-constant index to set the vector.
// Doing the variable arraysel is better for globals and large arrays,
// doing every word is better for temporaries and if we're setting most words
// since it may result in better substitution optimizations later.
// This results in so much code, we're better off leaving a function call.
// Reconsider if we get subexpression elimination.
return false;
} else {
UINFO(8, " ASSIGNSEL(varlsb,narrow) " << nodep << endl);
// nodep->dumpTree(cout, "- old: ");
AstNode* rhsp = nodep->rhsp()->unlinkFrBack();
AstNode* destp = lhsp->fromp()->unlinkFrBack();
AstNode* oldvalp = destp->cloneTree(true);
fixCloneLvalue(oldvalp);
V3Number maskwidth(nodep, destp->widthMin());
for (int bit = 0; bit < lhsp->widthConst(); bit++) maskwidth.setBit(bit, 1);
if (destp->isQuad() && !rhsp->isQuad()) {
rhsp = new AstCCast(nodep->fileline(), rhsp, nodep);
}
if (!ones) {
oldvalp = new AstAnd(
lhsp->fileline(),
new AstNot(lhsp->fileline(),
new AstShiftL(lhsp->fileline(),
new AstConst(nodep->fileline(), maskwidth),
lhsp->lsbp()->cloneTree(true), destp->width())),
oldvalp);
}
AstNode* newp
= new AstOr(lhsp->fileline(), oldvalp,
new AstShiftL(lhsp->fileline(), rhsp,
lhsp->lsbp()->cloneTree(true), destp->width()));
newp = new AstAssign(nodep->fileline(), destp, newp);
// newp->dumpTree(cout, "- new: ");
insertBefore(nodep, newp);
return true;
}
}
}
virtual void visit(AstConcat* nodep) VL_OVERRIDE {
if (nodep->user1SetOnce()) return; // Process once
iterateChildren(nodep);
if (nodep->isWide()) {
// See under ASSIGN(WIDE)
} else {
UINFO(8, " CONCAT " << nodep << endl);
AstNode* lhsp = nodep->lhsp()->unlinkFrBack();
AstNode* rhsp = nodep->rhsp()->unlinkFrBack();
int rhsshift = rhsp->widthMin();
if (nodep->isQuad() && !lhsp->isQuad()) {
lhsp = new AstCCast(nodep->fileline(), lhsp, nodep);
}
if (nodep->isQuad() && !rhsp->isQuad()) {
rhsp = new AstCCast(nodep->fileline(), rhsp, nodep);
}
AstNode* newp = new AstOr(nodep->fileline(),
new AstShiftL(nodep->fileline(), lhsp,
new AstConst(nodep->fileline(), rhsshift),
nodep->width()),
rhsp);
newp->dtypeFrom(nodep); // Unsigned
VL_DO_DANGLING(replaceWithDelete(nodep, newp), nodep);
}
}
bool expandWide(AstNodeAssign* nodep, AstConcat* rhsp) {
UINFO(8, " Wordize ASSIGN(CONCAT) " << nodep << endl);
// Lhs or Rhs may be word, long, or quad.
// newAstWordSelClone nicely abstracts the difference.
int rhsshift = rhsp->rhsp()->widthMin();
// Sometimes doing the words backwards is preferable.
// When we have x={x,foo} backwards is better, when x={foo,x} forward is better
// However V3Subst tends to rip this up, so not worth optimizing now.
for (int w = 0; w < rhsp->widthWords(); w++) {
addWordAssign(nodep, w,
new AstOr(rhsp->fileline(),
newWordGrabShift(rhsp->fileline(), w, rhsp->lhsp(), rhsshift),
newAstWordSelClone(rhsp->rhsp(), w)));
}
return true;
}
virtual void visit(AstReplicate* nodep) VL_OVERRIDE {
if (nodep->user1SetOnce()) return; // Process once
iterateChildren(nodep);
if (nodep->isWide()) {
// See under ASSIGN(WIDE)
} else {
AstNode* lhsp = nodep->lhsp()->unlinkFrBack();
AstNode* newp;
int lhswidth = lhsp->widthMin();
if (lhswidth == 1) {
UINFO(8, " REPLICATE(w1) " << nodep << endl);
newp = new AstNegate(nodep->fileline(), lhsp);
} else {
UINFO(8, " REPLICATE " << nodep << endl);
const AstConst* constp = VN_CAST(nodep->rhsp(), Const);
UASSERT_OBJ(constp, nodep,
"Replication value isn't a constant. Checked earlier!");
uint32_t times = constp->toUInt();
if (nodep->isQuad() && !lhsp->isQuad()) {
lhsp = new AstCCast(nodep->fileline(), lhsp, nodep);
}
newp = lhsp->cloneTree(true);
for (unsigned repnum = 1; repnum < times; repnum++) {
int rhsshift = repnum * lhswidth;
newp = new AstOr(nodep->fileline(),
new AstShiftL(nodep->fileline(), lhsp->cloneTree(true),
new AstConst(nodep->fileline(), rhsshift),
nodep->width()),
newp);
newp->dtypeFrom(nodep); // Unsigned
}
VL_DO_DANGLING(lhsp->deleteTree(), lhsp); // Never used
}
newp->dtypeFrom(nodep); // Unsigned
VL_DO_DANGLING(replaceWithDelete(nodep, newp), nodep);
}
}
bool expandWide(AstNodeAssign* nodep, AstReplicate* rhsp) {
UINFO(8, " Wordize ASSIGN(REPLICATE) " << nodep << endl);
AstNode* lhsp = rhsp->lhsp();
int lhswidth = lhsp->widthMin();
const AstConst* constp = VN_CAST(rhsp->rhsp(), Const);
UASSERT_OBJ(constp, rhsp, "Replication value isn't a constant. Checked earlier!");
uint32_t times = constp->toUInt();
for (int w = 0; w < rhsp->widthWords(); w++) {
AstNode* newp;
if (lhswidth == 1) {
newp = new AstNegate(nodep->fileline(), lhsp->cloneTree(true));
newp->dtypeSetLogicSized(VL_EDATASIZE,
VSigning::UNSIGNED); // Replicate always unsigned
} else {
newp = newAstWordSelClone(lhsp, w);
for (unsigned repnum = 1; repnum < times; repnum++) {
newp = new AstOr(
nodep->fileline(),
newWordGrabShift(rhsp->fileline(), w, lhsp, lhswidth * repnum), newp);
}
}
addWordAssign(nodep, w, newp);
}
return true;
}
virtual void visit(AstChangeXor* nodep) VL_OVERRIDE {
if (nodep->user1SetOnce()) return; // Process once
iterateChildren(nodep);
UINFO(8, " Wordize ChangeXor " << nodep << endl);
// -> (0=={or{for each_word{WORDSEL(lhs,#)^WORDSEL(rhs,#)}}}
AstNode* newp = NULL;
for (int w = 0; w < nodep->lhsp()->widthWords(); w++) {
AstNode* eqp = new AstXor(nodep->fileline(), newAstWordSelClone(nodep->lhsp(), w),
newAstWordSelClone(nodep->rhsp(), w));
newp = (newp == NULL) ? eqp : (new AstOr(nodep->fileline(), newp, eqp));
}
VL_DO_DANGLING(replaceWithDelete(nodep, newp), nodep);
}
void visitEqNeq(AstNodeBiop* nodep) {
if (nodep->user1SetOnce()) return; // Process once
iterateChildren(nodep);
if (nodep->lhsp()->isWide()) {
UINFO(8, " Wordize EQ/NEQ " << nodep << endl);
// -> (0=={or{for each_word{WORDSEL(lhs,#)^WORDSEL(rhs,#)}}}
AstNode* newp = NULL;
for (int w = 0; w < nodep->lhsp()->widthWords(); w++) {
AstNode* eqp = new AstXor(nodep->fileline(), newAstWordSelClone(nodep->lhsp(), w),
newAstWordSelClone(nodep->rhsp(), w));
newp = (newp == NULL) ? eqp : (new AstOr(nodep->fileline(), newp, eqp));
}
if (VN_IS(nodep, Neq)) {
newp
= new AstNeq(nodep->fileline(),
new AstConst(nodep->fileline(), AstConst::SizedEData(), 0), newp);
} else {
newp = new AstEq(nodep->fileline(),
new AstConst(nodep->fileline(), AstConst::SizedEData(), 0), newp);
}
VL_DO_DANGLING(replaceWithDelete(nodep, newp), nodep);
}
}
virtual void visit(AstEq* nodep) VL_OVERRIDE { visitEqNeq(nodep); }
virtual void visit(AstNeq* nodep) VL_OVERRIDE { visitEqNeq(nodep); }
virtual void visit(AstRedOr* nodep) VL_OVERRIDE {
if (nodep->user1SetOnce()) return; // Process once
iterateChildren(nodep);
if (nodep->lhsp()->isWide()) {
UINFO(8, " Wordize REDOR " << nodep << endl);
// -> (0!={or{for each_word{WORDSEL(lhs,#)}}}
AstNode* newp = NULL;
for (int w = 0; w < nodep->lhsp()->widthWords(); w++) {
AstNode* eqp = newAstWordSelClone(nodep->lhsp(), w);
newp = (newp == NULL) ? eqp : (new AstOr(nodep->fileline(), newp, eqp));
}
newp = new AstNeq(nodep->fileline(),
new AstConst(nodep->fileline(), AstConst::SizedEData(), 0), newp);
VL_DO_DANGLING(replaceWithDelete(nodep, newp), nodep);
} else {
UINFO(8, " REDOR->EQ " << nodep << endl);
AstNode* lhsp = nodep->lhsp()->unlinkFrBack();
AstNode* newp = new AstNeq(nodep->fileline(),
new AstConst(nodep->fileline(), AstConst::WidthedValue(),
longOrQuadWidth(nodep), 0),
lhsp);
VL_DO_DANGLING(replaceWithDelete(nodep, newp), nodep);
}
}
virtual void visit(AstRedAnd* nodep) VL_OVERRIDE {
if (nodep->user1SetOnce()) return; // Process once
iterateChildren(nodep);
if (nodep->lhsp()->isWide()) {
UINFO(8, " Wordize REDAND " << nodep << endl);
// -> (0!={and{for each_word{WORDSEL(lhs,#)}}}
AstNode* newp = NULL;
for (int w = 0; w < nodep->lhsp()->widthWords(); w++) {
AstNode* eqp = newAstWordSelClone(nodep->lhsp(), w);
if (w == nodep->lhsp()->widthWords() - 1) {
// Rather than doing a (slowish) ==##, we OR in the
// bits that aren't part of the mask
eqp = new AstOr(nodep->fileline(),
new AstConst(nodep->fileline(), notWideMask(nodep->lhsp())),
// Bug in cppcheck
// cppcheck-suppress memleak
eqp);
}
newp = (newp == NULL) ? eqp : (new AstAnd(nodep->fileline(), newp, eqp));
}
newp = new AstEq(
nodep->fileline(),
new AstConst(nodep->fileline(), AstConst::SizedEData(), VL_MASK_E(VL_EDATASIZE)),
newp);
VL_DO_DANGLING(replaceWithDelete(nodep, newp), nodep);
} else {
UINFO(8, " REDAND->EQ " << nodep << endl);
AstNode* lhsp = nodep->lhsp()->unlinkFrBack();
AstNode* newp = new AstEq(nodep->fileline(),
new AstConst(nodep->fileline(), wordMask(lhsp)), lhsp);
VL_DO_DANGLING(replaceWithDelete(nodep, newp), nodep);
}
}
virtual void visit(AstRedXor* nodep) VL_OVERRIDE {
if (nodep->user1SetOnce()) return; // Process once
iterateChildren(nodep);
if (nodep->lhsp()->isWide()) {
UINFO(8, " Wordize REDXOR " << nodep << endl);
// -> (0!={redxor{for each_word{XOR(WORDSEL(lhs,#))}}}
AstNode* newp = NULL;
for (int w = 0; w < nodep->lhsp()->widthWords(); w++) {
AstNode* eqp = newAstWordSelClone(nodep->lhsp(), w);
newp = (newp == NULL) ? eqp : (new AstXor(nodep->fileline(), newp, eqp));
}
newp = new AstRedXor(nodep->fileline(), newp);
UINFO(8, " Wordize REDXORnew " << newp << endl);
VL_DO_DANGLING(replaceWithDelete(nodep, newp), nodep);
}
// We don't reduce non-wide XORs, as its more efficient to use a temp register,
// which the inlined function does nicely.
}
virtual void visit(AstNodeStmt* nodep) VL_OVERRIDE {
if (nodep->user1SetOnce()) return; // Process once
if (!nodep->isStatement()) {
iterateChildren(nodep);
return;
}
m_stmtp = nodep;
iterateChildren(nodep);
m_stmtp = NULL;
}
virtual void visit(AstNodeAssign* nodep) VL_OVERRIDE {
if (nodep->user1SetOnce()) return; // Process once
m_stmtp = nodep;
iterateChildren(nodep);
bool did = false;
if (nodep->isWide() && ((VN_IS(nodep->lhsp(), VarRef) || VN_IS(nodep->lhsp(), ArraySel)))
&& !AstVar::scVarRecurse(nodep->lhsp()) // Need special function for SC
&& !AstVar::scVarRecurse(nodep->rhsp())) {
if (AstConst* rhsp = VN_CAST(nodep->rhsp(), Const)) {
did = expandWide(nodep, rhsp);
} else if (AstVarRef* rhsp = VN_CAST(nodep->rhsp(), VarRef)) {
did = expandWide(nodep, rhsp);
} else if (AstSel* rhsp = VN_CAST(nodep->rhsp(), Sel)) {
did = expandWide(nodep, rhsp);
} else if (AstArraySel* rhsp = VN_CAST(nodep->rhsp(), ArraySel)) {
did = expandWide(nodep, rhsp);
} else if (AstConcat* rhsp = VN_CAST(nodep->rhsp(), Concat)) {
did = expandWide(nodep, rhsp);
} else if (AstReplicate* rhsp = VN_CAST(nodep->rhsp(), Replicate)) {
did = expandWide(nodep, rhsp);
} else if (AstAnd* rhsp = VN_CAST(nodep->rhsp(), And)) {
did = expandWide(nodep, rhsp);
} else if (AstOr* rhsp = VN_CAST(nodep->rhsp(), Or)) {
did = expandWide(nodep, rhsp);
} else if (AstNot* rhsp = VN_CAST(nodep->rhsp(), Not)) {
did = expandWide(nodep, rhsp);
} else if (AstXor* rhsp = VN_CAST(nodep->rhsp(), Xor)) {
did = expandWide(nodep, rhsp);
} else if (AstXnor* rhsp = VN_CAST(nodep->rhsp(), Xnor)) {
did = expandWide(nodep, rhsp);
} else if (AstNodeCond* rhsp = VN_CAST(nodep->rhsp(), NodeCond)) {
did = expandWide(nodep, rhsp);
}
} else if (AstSel* lhsp = VN_CAST(nodep->lhsp(), Sel)) {
did = expandLhs(nodep, lhsp);
}
// Cleanup common code
if (did) VL_DO_DANGLING(nodep->unlinkFrBack()->deleteTree(), nodep);
m_stmtp = NULL;
}
//--------------------
virtual void visit(AstVar*) VL_OVERRIDE {} // Don't hit varrefs under vars
virtual void visit(AstNode* nodep) VL_OVERRIDE { iterateChildren(nodep); }
public:
// CONSTRUCTORS
explicit ExpandVisitor(AstNetlist* nodep) {
m_stmtp = NULL;
iterate(nodep);
}
virtual ~ExpandVisitor() {}
};
//----------------------------------------------------------------------
// Top loop
//######################################################################
// Expand class functions
void V3Expand::expandAll(AstNetlist* nodep) {
UINFO(2, __FUNCTION__ << ": " << endl);
{ ExpandVisitor visitor(nodep); } // Destruct before checking
V3Global::dumpCheckGlobalTree("expand", 0, v3Global.opt.dumpTreeLevel(__FILE__) >= 3);
}