diff --git a/src/V3Reloop.cpp b/src/V3Reloop.cpp index d9b6aeabc..facf7497e 100644 --- a/src/V3Reloop.cpp +++ b/src/V3Reloop.cpp @@ -18,12 +18,12 @@ // Each CFunc: // Look for a series of assignments that would look better in a loop: // -// ASSIGN(ARRAYREF(var, #), ARRAYREF(var, #)) -// ASSIGN(ARRAYREF(var, #+1), ARRAYREF(var, #+1)) +// ASSIGN(ARRAYREF(var, #), ARRAYREF(var, #+C)) +// ASSIGN(ARRAYREF(var, #+1), ARRAYREF(var, #+1+C)) // -> // Create __Vilp local variable // FOR(__Vilp = low; __Vilp <= high; ++__Vlip) -// ASSIGN(ARRAYREF(var, __Vilp), ARRAYREF(var, __Vilp)) +// ASSIGN(ARRAYREF(var, __Vilp), ARRAYREF(var, __Vilp + C)) // // Likewise vector assign to the same constant converted to a loop. // @@ -61,6 +61,7 @@ private: AstNodeSel* m_mgSelRp = nullptr; // Parent select, nullptr = constant AstNodeVarRef* m_mgVarrefLp = nullptr; // Parent varref AstNodeVarRef* m_mgVarrefRp = nullptr; // Parent varref, nullptr = constant + int64_t m_mgOffset = 0; // Index offset AstConst* m_mgConstRp = nullptr; // Parent RHS constant, nullptr = sel uint32_t m_mgIndexLo = 0; // Merge range uint32_t m_mgIndexHi = 0; // Merge range @@ -83,38 +84,50 @@ private: if (!m_mgAssignps.empty()) { uint32_t items = m_mgIndexHi - m_mgIndexLo + 1; UINFO(9, "End merge iter=" << items << " " << m_mgIndexHi << ":" << m_mgIndexLo << " " - << m_mgAssignps[0] << endl); + << m_mgOffset << " " << m_mgAssignps[0] << endl); if (items >= RELOOP_MIN_ITERS) { UINFO(6, "Reloop merging items=" << items << " " << m_mgIndexHi << ":" - << m_mgIndexLo << " " << m_mgAssignps[0] << endl); + << m_mgIndexLo << " " << m_mgOffset << " " + << m_mgAssignps[0] << endl); ++m_statReloops; m_statReItems += items; // Transform first assign into for loop body - AstNodeAssign* bodyp = m_mgAssignps.front(); + AstNodeAssign* const bodyp = m_mgAssignps.front(); UASSERT_OBJ(bodyp->lhsp() == m_mgSelLp, bodyp, "Corrupt queue/state"); - FileLine* fl = bodyp->fileline(); - AstVar* itp = findCreateVarTemp(fl, m_mgCfuncp); + FileLine* const fl = bodyp->fileline(); + AstVar* const itp = findCreateVarTemp(fl, m_mgCfuncp); - AstNode* initp = new AstAssign(fl, new AstVarRef(fl, itp, VAccess::WRITE), - new AstConst(fl, m_mgIndexLo)); - AstNode* condp = new AstLte(fl, new AstVarRef(fl, itp, VAccess::READ), - new AstConst(fl, m_mgIndexHi)); - AstNode* incp = new AstAssign( + if (m_mgOffset > 0) { + UASSERT_OBJ(m_mgIndexLo >= m_mgOffset, bodyp, + "Reloop iteration starts at negative index"); + m_mgIndexLo -= m_mgOffset; + m_mgIndexHi -= m_mgOffset; + } + + AstNode* const initp = new AstAssign(fl, new AstVarRef(fl, itp, VAccess::WRITE), + new AstConst(fl, m_mgIndexLo)); + AstNode* const condp = new AstLte(fl, new AstVarRef(fl, itp, VAccess::READ), + new AstConst(fl, m_mgIndexHi)); + AstNode* const incp = new AstAssign( fl, new AstVarRef(fl, itp, VAccess::WRITE), new AstAdd(fl, new AstConst(fl, 1), new AstVarRef(fl, itp, VAccess::READ))); - AstWhile* whilep = new AstWhile(fl, condp, nullptr, incp); + AstWhile* const whilep = new AstWhile(fl, condp, nullptr, incp); initp->addNext(whilep); bodyp->replaceWith(initp); whilep->addBodysp(bodyp); // Replace constant index with new loop index - AstNode* lbitp = m_mgSelLp->bitp(); - lbitp->replaceWith(new AstVarRef(fl, itp, VAccess::READ)); + AstNode* const offsetp + = m_mgOffset == 0 ? nullptr : new AstConst(fl, std::abs(m_mgOffset)); + AstNode* const lbitp = m_mgSelLp->bitp(); + AstNode* const lvrefp = new AstVarRef(fl, itp, VAccess::READ); + lbitp->replaceWith(m_mgOffset > 0 ? new AstAdd(fl, lvrefp, offsetp) : lvrefp); VL_DO_DANGLING(lbitp->deleteTree(), lbitp); if (m_mgSelRp) { // else constant and no replace - AstNode* rbitp = m_mgSelRp->bitp(); - rbitp->replaceWith(new AstVarRef(fl, itp, VAccess::READ)); + AstNode* const rbitp = m_mgSelRp->bitp(); + AstNode* const rvrefp = new AstVarRef(fl, itp, VAccess::READ); + rbitp->replaceWith(m_mgOffset < 0 ? new AstAdd(fl, rvrefp, offsetp) : rvrefp); VL_DO_DANGLING(rbitp->deleteTree(), lbitp); } if (debug() >= 9) initp->dumpTree(cout, "-new: "); @@ -133,6 +146,7 @@ private: m_mgSelRp = nullptr; m_mgVarrefLp = nullptr; m_mgVarrefRp = nullptr; + m_mgOffset = 0; m_mgConstRp = nullptr; } } @@ -143,6 +157,7 @@ private: { m_cfuncp = nodep; iterateChildren(nodep); + mergeEnd(); // Finish last pending merge, if any } } virtual void visit(AstNodeAssign* nodep) override { @@ -155,7 +170,7 @@ private: return; } // Of a constant index - AstConst* lbitp = VN_CAST(lselp->bitp(), Const); + AstConst* const lbitp = VN_CAST(lselp->bitp(), Const); if (!lbitp) { mergeEnd(); return; @@ -164,53 +179,58 @@ private: mergeEnd(); return; } - uint32_t index = lbitp->toUInt(); + const uint32_t lindex = lbitp->toUInt(); // Of variable - AstNodeVarRef* lvarrefp = VN_CAST(lselp->fromp(), NodeVarRef); + AstNodeVarRef* const lvarrefp = VN_CAST(lselp->fromp(), NodeVarRef); if (!lvarrefp) { mergeEnd(); return; } // RHS is a constant or a select - AstConst* rconstp = VN_CAST(nodep->rhsp(), Const); - AstNodeSel* rselp = VN_CAST(nodep->rhsp(), NodeSel); + AstConst* const rconstp = VN_CAST(nodep->rhsp(), Const); + AstNodeSel* const rselp = VN_CAST(nodep->rhsp(), NodeSel); AstNodeVarRef* rvarrefp = nullptr; + uint32_t rindex = lindex; if (rconstp) { // Ok - } else { - if (!rselp) { - mergeEnd(); - return; - } - AstConst* rbitp = VN_CAST(rselp->bitp(), Const); + } else if (rselp) { + AstConst* const rbitp = VN_CAST(rselp->bitp(), Const); rvarrefp = VN_CAST(rselp->fromp(), NodeVarRef); - if (!rbitp || rbitp->toUInt() != index || !rvarrefp - || lvarrefp->varp() == rvarrefp->varp()) { + if (!rbitp || !rvarrefp || lvarrefp->varp() == rvarrefp->varp()) { mergeEnd(); return; } + rindex = rbitp->toUInt(); + } else { + mergeEnd(); + return; } if (m_mgSelLp) { // Old merge - if (m_mgCfuncp == m_cfuncp && m_mgNextp == nodep && m_mgSelLp->same(lselp) - && m_mgVarrefLp->same(lvarrefp) - && (m_mgConstRp - ? (rconstp && m_mgConstRp->same(rconstp)) - : (rselp && m_mgSelRp->same(rselp) && m_mgVarrefRp->same(rvarrefp))) - && (index == m_mgIndexLo - 1 || index == m_mgIndexHi + 1)) { + if (m_mgCfuncp == m_cfuncp // In same function + && m_mgNextp == nodep // Consecutive node + && m_mgVarrefLp->same(lvarrefp) // Same array on left hand side + && (m_mgConstRp // On the right hand side either ... + ? (rconstp && m_mgConstRp->same(rconstp)) // ... same constant + : (rselp && m_mgVarrefRp->same(rvarrefp))) // ... or same array + && (lindex == m_mgIndexLo - 1 || lindex == m_mgIndexHi + 1) // Left index +/- 1 + && (m_mgConstRp || lindex == rindex + m_mgOffset) // Same right index offset + ) { // Sequentially next to last assign; continue merge - if (index == m_mgIndexLo - 1) { - m_mgIndexLo = index; - } else if (index == m_mgIndexHi + 1) { - m_mgIndexHi = index; + if (lindex == m_mgIndexLo - 1) { + m_mgIndexLo = lindex; + } else if (lindex == m_mgIndexHi + 1) { + m_mgIndexHi = lindex; } - UINFO(9, "Continue merge i=" << index << " " << m_mgIndexHi << ":" << m_mgIndexLo + UINFO(9, "Continue merge i=" << lindex << " " << m_mgIndexHi << ":" << m_mgIndexLo << " " << nodep << endl); m_mgAssignps.push_back(nodep); m_mgNextp = nodep->nextp(); return; } else { - // This assign doesn't merge with previous assign, + UINFO(9, "End merge i=" + << lindex << " " << m_mgIndexHi << ":" << m_mgIndexLo << " " << nodep + << endl); // This assign doesn't merge with previous assign, // but should start a new merge mergeEnd(); } @@ -224,10 +244,11 @@ private: m_mgSelRp = rselp; m_mgVarrefLp = lvarrefp; m_mgVarrefRp = rvarrefp; + m_mgOffset = static_cast(lindex) - static_cast(rindex); m_mgConstRp = rconstp; - m_mgIndexLo = index; - m_mgIndexHi = index; - UINFO(9, "Start merge i=" << index << " " << nodep << endl); + m_mgIndexLo = lindex; + m_mgIndexHi = lindex; + UINFO(9, "Start merge i=" << lindex << " o=" << m_mgOffset << nodep << endl); } //-------------------- virtual void visit(AstVar*) override {} // Accelerate diff --git a/test_regress/t/t_reloop_offset.out b/test_regress/t/t_reloop_offset.out new file mode 100644 index 000000000..bc7054287 --- /dev/null +++ b/test_regress/t/t_reloop_offset.out @@ -0,0 +1,17 @@ +shift down 1 +oarray[63] is 0 +oarray[62] is 63 +oarray[61] is 62 +oarray[32] is 33 +oarray[ 2] is 3 +oarray[ 1] is 2 +oarray[ 0] is 1 +shift up 2 +oarray[63] is 61 +oarray[62] is 60 +oarray[61] is 59 +oarray[32] is 30 +oarray[ 2] is 0 +oarray[ 1] is 2 +oarray[ 0] is 1 +*-* All Finished *-* diff --git a/test_regress/t/t_reloop_offset.pl b/test_regress/t/t_reloop_offset.pl new file mode 100755 index 000000000..02f1f01fc --- /dev/null +++ b/test_regress/t/t_reloop_offset.pl @@ -0,0 +1,33 @@ +#!/usr/bin/env perl +if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); die; } +# DESCRIPTION: Verilator: Verilog Test driver/expect definition +# +# Copyright 2003 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 + +scenarios(simulator => 1); + +compile( + verilator_flags2 => ["-unroll-count 1024", + $Self->wno_unopthreads_for_few_cores(), + "--stats"], + ); + +execute( + check_finished => 1, + expect_filename => $Self->{golden_filename}, + ); + +if ($Self->{vlt}) { + # Note, with vltmt this might be split differently, so only checking vlt + file_grep($Self->{stats}, qr/Optimizations, Reloop iterations\s+(\d+)/i, + 125); + file_grep($Self->{stats}, qr/Optimizations, Reloops\s+(\d+)/i, + 2); +} + +ok(1); +1; diff --git a/test_regress/t/t_reloop_offset.v b/test_regress/t/t_reloop_offset.v new file mode 100755 index 000000000..b4bfc4198 --- /dev/null +++ b/test_regress/t/t_reloop_offset.v @@ -0,0 +1,50 @@ +// DESCRIPTION: Verilator: Verilog Test module +// +// This file ONLY is placed under the Creative Commons Public Domain, for +// any use, without warranty, 2020 by Geza Lore. +// SPDX-License-Identifier: CC0-1.0 + +`define show(x) $display("oarray[%2d] is %2d", x, oarray[x]) + +module t (/*AUTOARG*/); + + int iarray [63:0]; + int oarray [63:0]; + + initial begin + for (int i = 0; i < 64 ; i = i + 1) begin + iarray[i] = i; + oarray[i] = 0; + end + + for (int i = 0; i < 63; i = i + 1) begin + oarray[i] = iarray[i + 1]; + end + + $display("shift down 1"); + `show(63); + `show(62); + `show(61); + `show(32); + `show(2); + `show(1); + `show(0); + + for (int i = 63; i >= 2 ; i = i - 1) begin + oarray[i] = iarray[i - 2]; + end + + $display("shift up 2"); + `show(63); + `show(62); + `show(61); + `show(32); + `show(2); + `show(1); + `show(0); + + $write("*-* All Finished *-*\n"); + $finish; + end + +endmodule