annotate src/share/vm/opto/addnode.cpp @ 17:ff5961f4c095

6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long) Reviewed-by: kvn, rasbold
author never
date Wed, 05 Dec 2007 09:01:00 -0800
parents a61af66fc99e
children 4d428c5b4cb3
rev   line source
duke@0 1 /*
duke@0 2 * Copyright 1997-2006 Sun Microsystems, Inc. All Rights Reserved.
duke@0 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
duke@0 4 *
duke@0 5 * This code is free software; you can redistribute it and/or modify it
duke@0 6 * under the terms of the GNU General Public License version 2 only, as
duke@0 7 * published by the Free Software Foundation.
duke@0 8 *
duke@0 9 * This code is distributed in the hope that it will be useful, but WITHOUT
duke@0 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
duke@0 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
duke@0 12 * version 2 for more details (a copy is included in the LICENSE file that
duke@0 13 * accompanied this code).
duke@0 14 *
duke@0 15 * You should have received a copy of the GNU General Public License version
duke@0 16 * 2 along with this work; if not, write to the Free Software Foundation,
duke@0 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
duke@0 18 *
duke@0 19 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
duke@0 20 * CA 95054 USA or visit www.sun.com if you need additional information or
duke@0 21 * have any questions.
duke@0 22 *
duke@0 23 */
duke@0 24
duke@0 25 // Portions of code courtesy of Clifford Click
duke@0 26
duke@0 27 #include "incls/_precompiled.incl"
duke@0 28 #include "incls/_addnode.cpp.incl"
duke@0 29
duke@0 30 #define MAXFLOAT ((float)3.40282346638528860e+38)
duke@0 31
duke@0 32 // Classic Add functionality. This covers all the usual 'add' behaviors for
duke@0 33 // an algebraic ring. Add-integer, add-float, add-double, and binary-or are
duke@0 34 // all inherited from this class. The various identity values are supplied
duke@0 35 // by virtual functions.
duke@0 36
duke@0 37
duke@0 38 //=============================================================================
duke@0 39 //------------------------------hash-------------------------------------------
duke@0 40 // Hash function over AddNodes. Needs to be commutative; i.e., I swap
duke@0 41 // (commute) inputs to AddNodes willy-nilly so the hash function must return
duke@0 42 // the same value in the presence of edge swapping.
duke@0 43 uint AddNode::hash() const {
duke@0 44 return (uintptr_t)in(1) + (uintptr_t)in(2) + Opcode();
duke@0 45 }
duke@0 46
duke@0 47 //------------------------------Identity---------------------------------------
duke@0 48 // If either input is a constant 0, return the other input.
duke@0 49 Node *AddNode::Identity( PhaseTransform *phase ) {
duke@0 50 const Type *zero = add_id(); // The additive identity
duke@0 51 if( phase->type( in(1) )->higher_equal( zero ) ) return in(2);
duke@0 52 if( phase->type( in(2) )->higher_equal( zero ) ) return in(1);
duke@0 53 return this;
duke@0 54 }
duke@0 55
duke@0 56 //------------------------------commute----------------------------------------
duke@0 57 // Commute operands to move loads and constants to the right.
duke@0 58 static bool commute( Node *add, int con_left, int con_right ) {
duke@0 59 Node *in1 = add->in(1);
duke@0 60 Node *in2 = add->in(2);
duke@0 61
duke@0 62 // Convert "1+x" into "x+1".
duke@0 63 // Right is a constant; leave it
duke@0 64 if( con_right ) return false;
duke@0 65 // Left is a constant; move it right.
duke@0 66 if( con_left ) {
duke@0 67 add->swap_edges(1, 2);
duke@0 68 return true;
duke@0 69 }
duke@0 70
duke@0 71 // Convert "Load+x" into "x+Load".
duke@0 72 // Now check for loads
duke@0 73 if( in2->is_Load() ) return false;
duke@0 74 // Left is a Load and Right is not; move it right.
duke@0 75 if( in1->is_Load() ) {
duke@0 76 add->swap_edges(1, 2);
duke@0 77 return true;
duke@0 78 }
duke@0 79
duke@0 80 PhiNode *phi;
duke@0 81 // Check for tight loop increments: Loop-phi of Add of loop-phi
duke@0 82 if( in1->is_Phi() && (phi = in1->as_Phi()) && !phi->is_copy() && phi->region()->is_Loop() && phi->in(2)==add)
duke@0 83 return false;
duke@0 84 if( in2->is_Phi() && (phi = in2->as_Phi()) && !phi->is_copy() && phi->region()->is_Loop() && phi->in(2)==add){
duke@0 85 add->swap_edges(1, 2);
duke@0 86 return true;
duke@0 87 }
duke@0 88
duke@0 89 // Otherwise, sort inputs (commutativity) to help value numbering.
duke@0 90 if( in1->_idx > in2->_idx ) {
duke@0 91 add->swap_edges(1, 2);
duke@0 92 return true;
duke@0 93 }
duke@0 94 return false;
duke@0 95 }
duke@0 96
duke@0 97 //------------------------------Idealize---------------------------------------
duke@0 98 // If we get here, we assume we are associative!
duke@0 99 Node *AddNode::Ideal(PhaseGVN *phase, bool can_reshape) {
duke@0 100 const Type *t1 = phase->type( in(1) );
duke@0 101 const Type *t2 = phase->type( in(2) );
duke@0 102 int con_left = t1->singleton();
duke@0 103 int con_right = t2->singleton();
duke@0 104
duke@0 105 // Check for commutative operation desired
duke@0 106 if( commute(this,con_left,con_right) ) return this;
duke@0 107
duke@0 108 AddNode *progress = NULL; // Progress flag
duke@0 109
duke@0 110 // Convert "(x+1)+2" into "x+(1+2)". If the right input is a
duke@0 111 // constant, and the left input is an add of a constant, flatten the
duke@0 112 // expression tree.
duke@0 113 Node *add1 = in(1);
duke@0 114 Node *add2 = in(2);
duke@0 115 int add1_op = add1->Opcode();
duke@0 116 int this_op = Opcode();
duke@0 117 if( con_right && t2 != Type::TOP && // Right input is a constant?
duke@0 118 add1_op == this_op ) { // Left input is an Add?
duke@0 119
duke@0 120 // Type of left _in right input
duke@0 121 const Type *t12 = phase->type( add1->in(2) );
duke@0 122 if( t12->singleton() && t12 != Type::TOP ) { // Left input is an add of a constant?
duke@0 123 // Check for rare case of closed data cycle which can happen inside
duke@0 124 // unreachable loops. In these cases the computation is undefined.
duke@0 125 #ifdef ASSERT
duke@0 126 Node *add11 = add1->in(1);
duke@0 127 int add11_op = add11->Opcode();
duke@0 128 if( (add1 == add1->in(1))
duke@0 129 || (add11_op == this_op && add11->in(1) == add1) ) {
duke@0 130 assert(false, "dead loop in AddNode::Ideal");
duke@0 131 }
duke@0 132 #endif
duke@0 133 // The Add of the flattened expression
duke@0 134 Node *x1 = add1->in(1);
duke@0 135 Node *x2 = phase->makecon( add1->as_Add()->add_ring( t2, t12 ));
duke@0 136 PhaseIterGVN *igvn = phase->is_IterGVN();
duke@0 137 if( igvn ) {
duke@0 138 set_req_X(2,x2,igvn);
duke@0 139 set_req_X(1,x1,igvn);
duke@0 140 } else {
duke@0 141 set_req(2,x2);
duke@0 142 set_req(1,x1);
duke@0 143 }
duke@0 144 progress = this; // Made progress
duke@0 145 add1 = in(1);
duke@0 146 add1_op = add1->Opcode();
duke@0 147 }
duke@0 148 }
duke@0 149
duke@0 150 // Convert "(x+1)+y" into "(x+y)+1". Push constants down the expression tree.
duke@0 151 if( add1_op == this_op && !con_right ) {
duke@0 152 Node *a12 = add1->in(2);
duke@0 153 const Type *t12 = phase->type( a12 );
duke@0 154 if( t12->singleton() && t12 != Type::TOP && (add1 != add1->in(1)) ) {
duke@0 155 add2 = add1->clone();
duke@0 156 add2->set_req(2, in(2));
duke@0 157 add2 = phase->transform(add2);
duke@0 158 set_req(1, add2);
duke@0 159 set_req(2, a12);
duke@0 160 progress = this;
duke@0 161 add2 = a12;
duke@0 162 }
duke@0 163 }
duke@0 164
duke@0 165 // Convert "x+(y+1)" into "(x+y)+1". Push constants down the expression tree.
duke@0 166 int add2_op = add2->Opcode();
duke@0 167 if( add2_op == this_op && !con_left ) {
duke@0 168 Node *a22 = add2->in(2);
duke@0 169 const Type *t22 = phase->type( a22 );
duke@0 170 if( t22->singleton() && t22 != Type::TOP && (add2 != add2->in(1)) ) {
duke@0 171 Node *addx = add2->clone();
duke@0 172 addx->set_req(1, in(1));
duke@0 173 addx->set_req(2, add2->in(1));
duke@0 174 addx = phase->transform(addx);
duke@0 175 set_req(1, addx);
duke@0 176 set_req(2, a22);
duke@0 177 progress = this;
duke@0 178 }
duke@0 179 }
duke@0 180
duke@0 181 return progress;
duke@0 182 }
duke@0 183
duke@0 184 //------------------------------Value-----------------------------------------
duke@0 185 // An add node sums it's two _in. If one input is an RSD, we must mixin
duke@0 186 // the other input's symbols.
duke@0 187 const Type *AddNode::Value( PhaseTransform *phase ) const {
duke@0 188 // Either input is TOP ==> the result is TOP
duke@0 189 const Type *t1 = phase->type( in(1) );
duke@0 190 const Type *t2 = phase->type( in(2) );
duke@0 191 if( t1 == Type::TOP ) return Type::TOP;
duke@0 192 if( t2 == Type::TOP ) return Type::TOP;
duke@0 193
duke@0 194 // Either input is BOTTOM ==> the result is the local BOTTOM
duke@0 195 const Type *bot = bottom_type();
duke@0 196 if( (t1 == bot) || (t2 == bot) ||
duke@0 197 (t1 == Type::BOTTOM) || (t2 == Type::BOTTOM) )
duke@0 198 return bot;
duke@0 199
duke@0 200 // Check for an addition involving the additive identity
duke@0 201 const Type *tadd = add_of_identity( t1, t2 );
duke@0 202 if( tadd ) return tadd;
duke@0 203
duke@0 204 return add_ring(t1,t2); // Local flavor of type addition
duke@0 205 }
duke@0 206
duke@0 207 //------------------------------add_identity-----------------------------------
duke@0 208 // Check for addition of the identity
duke@0 209 const Type *AddNode::add_of_identity( const Type *t1, const Type *t2 ) const {
duke@0 210 const Type *zero = add_id(); // The additive identity
duke@0 211 if( t1->higher_equal( zero ) ) return t2;
duke@0 212 if( t2->higher_equal( zero ) ) return t1;
duke@0 213
duke@0 214 return NULL;
duke@0 215 }
duke@0 216
duke@0 217
duke@0 218 //=============================================================================
duke@0 219 //------------------------------Idealize---------------------------------------
duke@0 220 Node *AddINode::Ideal(PhaseGVN *phase, bool can_reshape) {
duke@0 221 int op1 = in(1)->Opcode();
duke@0 222 int op2 = in(2)->Opcode();
duke@0 223 // Fold (con1-x)+con2 into (con1+con2)-x
duke@0 224 if( op1 == Op_SubI ) {
duke@0 225 const Type *t_sub1 = phase->type( in(1)->in(1) );
duke@0 226 const Type *t_2 = phase->type( in(2) );
duke@0 227 if( t_sub1->singleton() && t_2->singleton() && t_sub1 != Type::TOP && t_2 != Type::TOP )
duke@0 228 return new (phase->C, 3) SubINode(phase->makecon( add_ring( t_sub1, t_2 ) ),
duke@0 229 in(1)->in(2) );
duke@0 230 // Convert "(a-b)+(c-d)" into "(a+c)-(b+d)"
duke@0 231 if( op2 == Op_SubI ) {
duke@0 232 // Check for dead cycle: d = (a-b)+(c-d)
duke@0 233 assert( in(1)->in(2) != this && in(2)->in(2) != this,
duke@0 234 "dead loop in AddINode::Ideal" );
duke@0 235 Node *sub = new (phase->C, 3) SubINode(NULL, NULL);
duke@0 236 sub->init_req(1, phase->transform(new (phase->C, 3) AddINode(in(1)->in(1), in(2)->in(1) ) ));
duke@0 237 sub->init_req(2, phase->transform(new (phase->C, 3) AddINode(in(1)->in(2), in(2)->in(2) ) ));
duke@0 238 return sub;
duke@0 239 }
duke@0 240 }
duke@0 241
duke@0 242 // Convert "x+(0-y)" into "(x-y)"
duke@0 243 if( op2 == Op_SubI && phase->type(in(2)->in(1)) == TypeInt::ZERO )
duke@0 244 return new (phase->C, 3) SubINode(in(1), in(2)->in(2) );
duke@0 245
duke@0 246 // Convert "(0-y)+x" into "(x-y)"
duke@0 247 if( op1 == Op_SubI && phase->type(in(1)->in(1)) == TypeInt::ZERO )
duke@0 248 return new (phase->C, 3) SubINode( in(2), in(1)->in(2) );
duke@0 249
duke@0 250 // Convert (x>>>z)+y into (x+(y<<z))>>>z for small constant z and y.
duke@0 251 // Helps with array allocation math constant folding
duke@0 252 // See 4790063:
duke@0 253 // Unrestricted transformation is unsafe for some runtime values of 'x'
duke@0 254 // ( x == 0, z == 1, y == -1 ) fails
duke@0 255 // ( x == -5, z == 1, y == 1 ) fails
duke@0 256 // Transform works for small z and small negative y when the addition
duke@0 257 // (x + (y << z)) does not cross zero.
duke@0 258 // Implement support for negative y and (x >= -(y << z))
duke@0 259 // Have not observed cases where type information exists to support
duke@0 260 // positive y and (x <= -(y << z))
duke@0 261 if( op1 == Op_URShiftI && op2 == Op_ConI &&
duke@0 262 in(1)->in(2)->Opcode() == Op_ConI ) {
duke@0 263 jint z = phase->type( in(1)->in(2) )->is_int()->get_con() & 0x1f; // only least significant 5 bits matter
duke@0 264 jint y = phase->type( in(2) )->is_int()->get_con();
duke@0 265
duke@0 266 if( z < 5 && -5 < y && y < 0 ) {
duke@0 267 const Type *t_in11 = phase->type(in(1)->in(1));
duke@0 268 if( t_in11 != Type::TOP && (t_in11->is_int()->_lo >= -(y << z)) ) {
duke@0 269 Node *a = phase->transform( new (phase->C, 3) AddINode( in(1)->in(1), phase->intcon(y<<z) ) );
duke@0 270 return new (phase->C, 3) URShiftINode( a, in(1)->in(2) );
duke@0 271 }
duke@0 272 }
duke@0 273 }
duke@0 274
duke@0 275 return AddNode::Ideal(phase, can_reshape);
duke@0 276 }
duke@0 277
duke@0 278
duke@0 279 //------------------------------Identity---------------------------------------
duke@0 280 // Fold (x-y)+y OR y+(x-y) into x
duke@0 281 Node *AddINode::Identity( PhaseTransform *phase ) {
duke@0 282 if( in(1)->Opcode() == Op_SubI && phase->eqv(in(1)->in(2),in(2)) ) {
duke@0 283 return in(1)->in(1);
duke@0 284 }
duke@0 285 else if( in(2)->Opcode() == Op_SubI && phase->eqv(in(2)->in(2),in(1)) ) {
duke@0 286 return in(2)->in(1);
duke@0 287 }
duke@0 288 return AddNode::Identity(phase);
duke@0 289 }
duke@0 290
duke@0 291
duke@0 292 //------------------------------add_ring---------------------------------------
duke@0 293 // Supplied function returns the sum of the inputs. Guaranteed never
duke@0 294 // to be passed a TOP or BOTTOM type, these are filtered out by
duke@0 295 // pre-check.
duke@0 296 const Type *AddINode::add_ring( const Type *t0, const Type *t1 ) const {
duke@0 297 const TypeInt *r0 = t0->is_int(); // Handy access
duke@0 298 const TypeInt *r1 = t1->is_int();
duke@0 299 int lo = r0->_lo + r1->_lo;
duke@0 300 int hi = r0->_hi + r1->_hi;
duke@0 301 if( !(r0->is_con() && r1->is_con()) ) {
duke@0 302 // Not both constants, compute approximate result
duke@0 303 if( (r0->_lo & r1->_lo) < 0 && lo >= 0 ) {
duke@0 304 lo = min_jint; hi = max_jint; // Underflow on the low side
duke@0 305 }
duke@0 306 if( (~(r0->_hi | r1->_hi)) < 0 && hi < 0 ) {
duke@0 307 lo = min_jint; hi = max_jint; // Overflow on the high side
duke@0 308 }
duke@0 309 if( lo > hi ) { // Handle overflow
duke@0 310 lo = min_jint; hi = max_jint;
duke@0 311 }
duke@0 312 } else {
duke@0 313 // both constants, compute precise result using 'lo' and 'hi'
duke@0 314 // Semantics define overflow and underflow for integer addition
duke@0 315 // as expected. In particular: 0x80000000 + 0x80000000 --> 0x0
duke@0 316 }
duke@0 317 return TypeInt::make( lo, hi, MAX2(r0->_widen,r1->_widen) );
duke@0 318 }
duke@0 319
duke@0 320
duke@0 321 //=============================================================================
duke@0 322 //------------------------------Idealize---------------------------------------
duke@0 323 Node *AddLNode::Ideal(PhaseGVN *phase, bool can_reshape) {
duke@0 324 int op1 = in(1)->Opcode();
duke@0 325 int op2 = in(2)->Opcode();
duke@0 326 // Fold (con1-x)+con2 into (con1+con2)-x
duke@0 327 if( op1 == Op_SubL ) {
duke@0 328 const Type *t_sub1 = phase->type( in(1)->in(1) );
duke@0 329 const Type *t_2 = phase->type( in(2) );
duke@0 330 if( t_sub1->singleton() && t_2->singleton() && t_sub1 != Type::TOP && t_2 != Type::TOP )
duke@0 331 return new (phase->C, 3) SubLNode(phase->makecon( add_ring( t_sub1, t_2 ) ),
duke@0 332 in(1)->in(2) );
duke@0 333 // Convert "(a-b)+(c-d)" into "(a+c)-(b+d)"
duke@0 334 if( op2 == Op_SubL ) {
duke@0 335 // Check for dead cycle: d = (a-b)+(c-d)
duke@0 336 assert( in(1)->in(2) != this && in(2)->in(2) != this,
duke@0 337 "dead loop in AddLNode::Ideal" );
duke@0 338 Node *sub = new (phase->C, 3) SubLNode(NULL, NULL);
duke@0 339 sub->init_req(1, phase->transform(new (phase->C, 3) AddLNode(in(1)->in(1), in(2)->in(1) ) ));
duke@0 340 sub->init_req(2, phase->transform(new (phase->C, 3) AddLNode(in(1)->in(2), in(2)->in(2) ) ));
duke@0 341 return sub;
duke@0 342 }
duke@0 343 }
duke@0 344
duke@0 345 // Convert "x+(0-y)" into "(x-y)"
duke@0 346 if( op2 == Op_SubL && phase->type(in(2)->in(1)) == TypeLong::ZERO )
duke@0 347 return new (phase->C, 3) SubLNode(in(1), in(2)->in(2) );
duke@0 348
duke@0 349 // Convert "X+X+X+X+X...+X+Y" into "k*X+Y" or really convert "X+(X+Y)"
duke@0 350 // into "(X<<1)+Y" and let shift-folding happen.
duke@0 351 if( op2 == Op_AddL &&
duke@0 352 in(2)->in(1) == in(1) &&
duke@0 353 op1 != Op_ConL &&
duke@0 354 0 ) {
duke@0 355 Node *shift = phase->transform(new (phase->C, 3) LShiftLNode(in(1),phase->intcon(1)));
duke@0 356 return new (phase->C, 3) AddLNode(shift,in(2)->in(2));
duke@0 357 }
duke@0 358
duke@0 359 return AddNode::Ideal(phase, can_reshape);
duke@0 360 }
duke@0 361
duke@0 362
duke@0 363 //------------------------------Identity---------------------------------------
duke@0 364 // Fold (x-y)+y OR y+(x-y) into x
duke@0 365 Node *AddLNode::Identity( PhaseTransform *phase ) {
duke@0 366 if( in(1)->Opcode() == Op_SubL && phase->eqv(in(1)->in(2),in(2)) ) {
duke@0 367 return in(1)->in(1);
duke@0 368 }
duke@0 369 else if( in(2)->Opcode() == Op_SubL && phase->eqv(in(2)->in(2),in(1)) ) {
duke@0 370 return in(2)->in(1);
duke@0 371 }
duke@0 372 return AddNode::Identity(phase);
duke@0 373 }
duke@0 374
duke@0 375
duke@0 376 //------------------------------add_ring---------------------------------------
duke@0 377 // Supplied function returns the sum of the inputs. Guaranteed never
duke@0 378 // to be passed a TOP or BOTTOM type, these are filtered out by
duke@0 379 // pre-check.
duke@0 380 const Type *AddLNode::add_ring( const Type *t0, const Type *t1 ) const {
duke@0 381 const TypeLong *r0 = t0->is_long(); // Handy access
duke@0 382 const TypeLong *r1 = t1->is_long();
duke@0 383 jlong lo = r0->_lo + r1->_lo;
duke@0 384 jlong hi = r0->_hi + r1->_hi;
duke@0 385 if( !(r0->is_con() && r1->is_con()) ) {
duke@0 386 // Not both constants, compute approximate result
duke@0 387 if( (r0->_lo & r1->_lo) < 0 && lo >= 0 ) {
duke@0 388 lo =min_jlong; hi = max_jlong; // Underflow on the low side
duke@0 389 }
duke@0 390 if( (~(r0->_hi | r1->_hi)) < 0 && hi < 0 ) {
duke@0 391 lo = min_jlong; hi = max_jlong; // Overflow on the high side
duke@0 392 }
duke@0 393 if( lo > hi ) { // Handle overflow
duke@0 394 lo = min_jlong; hi = max_jlong;
duke@0 395 }
duke@0 396 } else {
duke@0 397 // both constants, compute precise result using 'lo' and 'hi'
duke@0 398 // Semantics define overflow and underflow for integer addition
duke@0 399 // as expected. In particular: 0x80000000 + 0x80000000 --> 0x0
duke@0 400 }
duke@0 401 return TypeLong::make( lo, hi, MAX2(r0->_widen,r1->_widen) );
duke@0 402 }
duke@0 403
duke@0 404
duke@0 405 //=============================================================================
duke@0 406 //------------------------------add_of_identity--------------------------------
duke@0 407 // Check for addition of the identity
duke@0 408 const Type *AddFNode::add_of_identity( const Type *t1, const Type *t2 ) const {
duke@0 409 // x ADD 0 should return x unless 'x' is a -zero
duke@0 410 //
duke@0 411 // const Type *zero = add_id(); // The additive identity
duke@0 412 // jfloat f1 = t1->getf();
duke@0 413 // jfloat f2 = t2->getf();
duke@0 414 //
duke@0 415 // if( t1->higher_equal( zero ) ) return t2;
duke@0 416 // if( t2->higher_equal( zero ) ) return t1;
duke@0 417
duke@0 418 return NULL;
duke@0 419 }
duke@0 420
duke@0 421 //------------------------------add_ring---------------------------------------
duke@0 422 // Supplied function returns the sum of the inputs.
duke@0 423 // This also type-checks the inputs for sanity. Guaranteed never to
duke@0 424 // be passed a TOP or BOTTOM type, these are filtered out by pre-check.
duke@0 425 const Type *AddFNode::add_ring( const Type *t0, const Type *t1 ) const {
duke@0 426 // We must be adding 2 float constants.
duke@0 427 return TypeF::make( t0->getf() + t1->getf() );
duke@0 428 }
duke@0 429
duke@0 430 //------------------------------Ideal------------------------------------------
duke@0 431 Node *AddFNode::Ideal(PhaseGVN *phase, bool can_reshape) {
duke@0 432 if( IdealizedNumerics && !phase->C->method()->is_strict() ) {
duke@0 433 return AddNode::Ideal(phase, can_reshape); // commutative and associative transforms
duke@0 434 }
duke@0 435
duke@0 436 // Floating point additions are not associative because of boundary conditions (infinity)
duke@0 437 return commute(this,
duke@0 438 phase->type( in(1) )->singleton(),
duke@0 439 phase->type( in(2) )->singleton() ) ? this : NULL;
duke@0 440 }
duke@0 441
duke@0 442
duke@0 443 //=============================================================================
duke@0 444 //------------------------------add_of_identity--------------------------------
duke@0 445 // Check for addition of the identity
duke@0 446 const Type *AddDNode::add_of_identity( const Type *t1, const Type *t2 ) const {
duke@0 447 // x ADD 0 should return x unless 'x' is a -zero
duke@0 448 //
duke@0 449 // const Type *zero = add_id(); // The additive identity
duke@0 450 // jfloat f1 = t1->getf();
duke@0 451 // jfloat f2 = t2->getf();
duke@0 452 //
duke@0 453 // if( t1->higher_equal( zero ) ) return t2;
duke@0 454 // if( t2->higher_equal( zero ) ) return t1;
duke@0 455
duke@0 456 return NULL;
duke@0 457 }
duke@0 458 //------------------------------add_ring---------------------------------------
duke@0 459 // Supplied function returns the sum of the inputs.
duke@0 460 // This also type-checks the inputs for sanity. Guaranteed never to
duke@0 461 // be passed a TOP or BOTTOM type, these are filtered out by pre-check.
duke@0 462 const Type *AddDNode::add_ring( const Type *t0, const Type *t1 ) const {
duke@0 463 // We must be adding 2 double constants.
duke@0 464 return TypeD::make( t0->getd() + t1->getd() );
duke@0 465 }
duke@0 466
duke@0 467 //------------------------------Ideal------------------------------------------
duke@0 468 Node *AddDNode::Ideal(PhaseGVN *phase, bool can_reshape) {
duke@0 469 if( IdealizedNumerics && !phase->C->method()->is_strict() ) {
duke@0 470 return AddNode::Ideal(phase, can_reshape); // commutative and associative transforms
duke@0 471 }
duke@0 472
duke@0 473 // Floating point additions are not associative because of boundary conditions (infinity)
duke@0 474 return commute(this,
duke@0 475 phase->type( in(1) )->singleton(),
duke@0 476 phase->type( in(2) )->singleton() ) ? this : NULL;
duke@0 477 }
duke@0 478
duke@0 479
duke@0 480 //=============================================================================
duke@0 481 //------------------------------Identity---------------------------------------
duke@0 482 // If one input is a constant 0, return the other input.
duke@0 483 Node *AddPNode::Identity( PhaseTransform *phase ) {
duke@0 484 return ( phase->type( in(Offset) )->higher_equal( TypeX_ZERO ) ) ? in(Address) : this;
duke@0 485 }
duke@0 486
duke@0 487 //------------------------------Idealize---------------------------------------
duke@0 488 Node *AddPNode::Ideal(PhaseGVN *phase, bool can_reshape) {
duke@0 489 // Bail out if dead inputs
duke@0 490 if( phase->type( in(Address) ) == Type::TOP ) return NULL;
duke@0 491
duke@0 492 // If the left input is an add of a constant, flatten the expression tree.
duke@0 493 const Node *n = in(Address);
duke@0 494 if (n->is_AddP() && n->in(Base) == in(Base)) {
duke@0 495 const AddPNode *addp = n->as_AddP(); // Left input is an AddP
duke@0 496 assert( !addp->in(Address)->is_AddP() ||
duke@0 497 addp->in(Address)->as_AddP() != addp,
duke@0 498 "dead loop in AddPNode::Ideal" );
duke@0 499 // Type of left input's right input
duke@0 500 const Type *t = phase->type( addp->in(Offset) );
duke@0 501 if( t == Type::TOP ) return NULL;
duke@0 502 const TypeX *t12 = t->is_intptr_t();
duke@0 503 if( t12->is_con() ) { // Left input is an add of a constant?
duke@0 504 // If the right input is a constant, combine constants
duke@0 505 const Type *temp_t2 = phase->type( in(Offset) );
duke@0 506 if( temp_t2 == Type::TOP ) return NULL;
duke@0 507 const TypeX *t2 = temp_t2->is_intptr_t();
duke@0 508 if( t2->is_con() ) {
duke@0 509 // The Add of the flattened expression
duke@0 510 set_req(Address, addp->in(Address));
duke@0 511 set_req(Offset , phase->MakeConX(t2->get_con() + t12->get_con()));
duke@0 512 return this; // Made progress
duke@0 513 }
duke@0 514 // Else move the constant to the right. ((A+con)+B) into ((A+B)+con)
duke@0 515 set_req(Address, phase->transform(new (phase->C, 4) AddPNode(in(Base),addp->in(Address),in(Offset))));
duke@0 516 set_req(Offset , addp->in(Offset));
duke@0 517 return this;
duke@0 518 }
duke@0 519 }
duke@0 520
duke@0 521 // Raw pointers?
duke@0 522 if( in(Base)->bottom_type() == Type::TOP ) {
duke@0 523 // If this is a NULL+long form (from unsafe accesses), switch to a rawptr.
duke@0 524 if (phase->type(in(Address)) == TypePtr::NULL_PTR) {
duke@0 525 Node* offset = in(Offset);
duke@0 526 return new (phase->C, 2) CastX2PNode(offset);
duke@0 527 }
duke@0 528 }
duke@0 529
duke@0 530 // If the right is an add of a constant, push the offset down.
duke@0 531 // Convert: (ptr + (offset+con)) into (ptr+offset)+con.
duke@0 532 // The idea is to merge array_base+scaled_index groups together,
duke@0 533 // and only have different constant offsets from the same base.
duke@0 534 const Node *add = in(Offset);
duke@0 535 if( add->Opcode() == Op_AddX && add->in(1) != add ) {
duke@0 536 const Type *t22 = phase->type( add->in(2) );
duke@0 537 if( t22->singleton() && (t22 != Type::TOP) ) { // Right input is an add of a constant?
duke@0 538 set_req(Address, phase->transform(new (phase->C, 4) AddPNode(in(Base),in(Address),add->in(1))));
duke@0 539 set_req(Offset, add->in(2));
duke@0 540 return this; // Made progress
duke@0 541 }
duke@0 542 }
duke@0 543
duke@0 544 return NULL; // No progress
duke@0 545 }
duke@0 546
duke@0 547 //------------------------------bottom_type------------------------------------
duke@0 548 // Bottom-type is the pointer-type with unknown offset.
duke@0 549 const Type *AddPNode::bottom_type() const {
duke@0 550 if (in(Address) == NULL) return TypePtr::BOTTOM;
duke@0 551 const TypePtr *tp = in(Address)->bottom_type()->isa_ptr();
duke@0 552 if( !tp ) return Type::TOP; // TOP input means TOP output
duke@0 553 assert( in(Offset)->Opcode() != Op_ConP, "" );
duke@0 554 const Type *t = in(Offset)->bottom_type();
duke@0 555 if( t == Type::TOP )
duke@0 556 return tp->add_offset(Type::OffsetTop);
duke@0 557 const TypeX *tx = t->is_intptr_t();
duke@0 558 intptr_t txoffset = Type::OffsetBot;
duke@0 559 if (tx->is_con()) { // Left input is an add of a constant?
duke@0 560 txoffset = tx->get_con();
duke@0 561 if (txoffset != (int)txoffset)
duke@0 562 txoffset = Type::OffsetBot; // oops: add_offset will choke on it
duke@0 563 }
duke@0 564 return tp->add_offset(txoffset);
duke@0 565 }
duke@0 566
duke@0 567 //------------------------------Value------------------------------------------
duke@0 568 const Type *AddPNode::Value( PhaseTransform *phase ) const {
duke@0 569 // Either input is TOP ==> the result is TOP
duke@0 570 const Type *t1 = phase->type( in(Address) );
duke@0 571 const Type *t2 = phase->type( in(Offset) );
duke@0 572 if( t1 == Type::TOP ) return Type::TOP;
duke@0 573 if( t2 == Type::TOP ) return Type::TOP;
duke@0 574
duke@0 575 // Left input is a pointer
duke@0 576 const TypePtr *p1 = t1->isa_ptr();
duke@0 577 // Right input is an int
duke@0 578 const TypeX *p2 = t2->is_intptr_t();
duke@0 579 // Add 'em
duke@0 580 intptr_t p2offset = Type::OffsetBot;
duke@0 581 if (p2->is_con()) { // Left input is an add of a constant?
duke@0 582 p2offset = p2->get_con();
duke@0 583 if (p2offset != (int)p2offset)
duke@0 584 p2offset = Type::OffsetBot; // oops: add_offset will choke on it
duke@0 585 }
duke@0 586 return p1->add_offset(p2offset);
duke@0 587 }
duke@0 588
duke@0 589 //------------------------Ideal_base_and_offset--------------------------------
duke@0 590 // Split an oop pointer into a base and offset.
duke@0 591 // (The offset might be Type::OffsetBot in the case of an array.)
duke@0 592 // Return the base, or NULL if failure.
duke@0 593 Node* AddPNode::Ideal_base_and_offset(Node* ptr, PhaseTransform* phase,
duke@0 594 // second return value:
duke@0 595 intptr_t& offset) {
duke@0 596 if (ptr->is_AddP()) {
duke@0 597 Node* base = ptr->in(AddPNode::Base);
duke@0 598 Node* addr = ptr->in(AddPNode::Address);
duke@0 599 Node* offs = ptr->in(AddPNode::Offset);
duke@0 600 if (base == addr || base->is_top()) {
duke@0 601 offset = phase->find_intptr_t_con(offs, Type::OffsetBot);
duke@0 602 if (offset != Type::OffsetBot) {
duke@0 603 return addr;
duke@0 604 }
duke@0 605 }
duke@0 606 }
duke@0 607 offset = Type::OffsetBot;
duke@0 608 return NULL;
duke@0 609 }
duke@0 610
never@17 611 //------------------------------unpack_offsets----------------------------------
never@17 612 // Collect the AddP offset values into the elements array, giving up
never@17 613 // if there are more than length.
never@17 614 int AddPNode::unpack_offsets(Node* elements[], int length) {
never@17 615 int count = 0;
never@17 616 Node* addr = this;
never@17 617 Node* base = addr->in(AddPNode::Base);
never@17 618 while (addr->is_AddP()) {
never@17 619 if (addr->in(AddPNode::Base) != base) {
never@17 620 // give up
never@17 621 return -1;
never@17 622 }
never@17 623 elements[count++] = addr->in(AddPNode::Offset);
never@17 624 if (count == length) {
never@17 625 // give up
never@17 626 return -1;
never@17 627 }
never@17 628 addr = addr->in(AddPNode::Address);
never@17 629 }
never@17 630 return count;
never@17 631 }
never@17 632
duke@0 633 //------------------------------match_edge-------------------------------------
duke@0 634 // Do we Match on this edge index or not? Do not match base pointer edge
duke@0 635 uint AddPNode::match_edge(uint idx) const {
duke@0 636 return idx > Base;
duke@0 637 }
duke@0 638
duke@0 639 //---------------------------mach_bottom_type----------------------------------
duke@0 640 // Utility function for use by ADLC. Implements bottom_type for matched AddP.
duke@0 641 const Type *AddPNode::mach_bottom_type( const MachNode* n) {
duke@0 642 Node* base = n->in(Base);
duke@0 643 const Type *t = base->bottom_type();
duke@0 644 if ( t == Type::TOP ) {
duke@0 645 // an untyped pointer
duke@0 646 return TypeRawPtr::BOTTOM;
duke@0 647 }
duke@0 648 const TypePtr* tp = t->isa_oopptr();
duke@0 649 if ( tp == NULL ) return t;
duke@0 650 if ( tp->_offset == TypePtr::OffsetBot ) return tp;
duke@0 651
duke@0 652 // We must carefully add up the various offsets...
duke@0 653 intptr_t offset = 0;
duke@0 654 const TypePtr* tptr = NULL;
duke@0 655
duke@0 656 uint numopnds = n->num_opnds();
duke@0 657 uint index = n->oper_input_base();
duke@0 658 for ( uint i = 1; i < numopnds; i++ ) {
duke@0 659 MachOper *opnd = n->_opnds[i];
duke@0 660 // Check for any interesting operand info.
duke@0 661 // In particular, check for both memory and non-memory operands.
duke@0 662 // %%%%% Clean this up: use xadd_offset
duke@0 663 int con = opnd->constant();
duke@0 664 if ( con == TypePtr::OffsetBot ) goto bottom_out;
duke@0 665 offset += con;
duke@0 666 con = opnd->constant_disp();
duke@0 667 if ( con == TypePtr::OffsetBot ) goto bottom_out;
duke@0 668 offset += con;
duke@0 669 if( opnd->scale() != 0 ) goto bottom_out;
duke@0 670
duke@0 671 // Check each operand input edge. Find the 1 allowed pointer
duke@0 672 // edge. Other edges must be index edges; track exact constant
duke@0 673 // inputs and otherwise assume the worst.
duke@0 674 for ( uint j = opnd->num_edges(); j > 0; j-- ) {
duke@0 675 Node* edge = n->in(index++);
duke@0 676 const Type* et = edge->bottom_type();
duke@0 677 const TypeX* eti = et->isa_intptr_t();
duke@0 678 if ( eti == NULL ) {
duke@0 679 // there must be one pointer among the operands
duke@0 680 guarantee(tptr == NULL, "must be only one pointer operand");
duke@0 681 tptr = et->isa_oopptr();
duke@0 682 guarantee(tptr != NULL, "non-int operand must be pointer");
duke@0 683 continue;
duke@0 684 }
duke@0 685 if ( eti->_hi != eti->_lo ) goto bottom_out;
duke@0 686 offset += eti->_lo;
duke@0 687 }
duke@0 688 }
duke@0 689 guarantee(tptr != NULL, "must be exactly one pointer operand");
duke@0 690 return tptr->add_offset(offset);
duke@0 691
duke@0 692 bottom_out:
duke@0 693 return tp->add_offset(TypePtr::OffsetBot);
duke@0 694 }
duke@0 695
duke@0 696 //=============================================================================
duke@0 697 //------------------------------Identity---------------------------------------
duke@0 698 Node *OrINode::Identity( PhaseTransform *phase ) {
duke@0 699 // x | x => x
duke@0 700 if (phase->eqv(in(1), in(2))) {
duke@0 701 return in(1);
duke@0 702 }
duke@0 703
duke@0 704 return AddNode::Identity(phase);
duke@0 705 }
duke@0 706
duke@0 707 //------------------------------add_ring---------------------------------------
duke@0 708 // Supplied function returns the sum of the inputs IN THE CURRENT RING. For
duke@0 709 // the logical operations the ring's ADD is really a logical OR function.
duke@0 710 // This also type-checks the inputs for sanity. Guaranteed never to
duke@0 711 // be passed a TOP or BOTTOM type, these are filtered out by pre-check.
duke@0 712 const Type *OrINode::add_ring( const Type *t0, const Type *t1 ) const {
duke@0 713 const TypeInt *r0 = t0->is_int(); // Handy access
duke@0 714 const TypeInt *r1 = t1->is_int();
duke@0 715
duke@0 716 // If both args are bool, can figure out better types
duke@0 717 if ( r0 == TypeInt::BOOL ) {
duke@0 718 if ( r1 == TypeInt::ONE) {
duke@0 719 return TypeInt::ONE;
duke@0 720 } else if ( r1 == TypeInt::BOOL ) {
duke@0 721 return TypeInt::BOOL;
duke@0 722 }
duke@0 723 } else if ( r0 == TypeInt::ONE ) {
duke@0 724 if ( r1 == TypeInt::BOOL ) {
duke@0 725 return TypeInt::ONE;
duke@0 726 }
duke@0 727 }
duke@0 728
duke@0 729 // If either input is not a constant, just return all integers.
duke@0 730 if( !r0->is_con() || !r1->is_con() )
duke@0 731 return TypeInt::INT; // Any integer, but still no symbols.
duke@0 732
duke@0 733 // Otherwise just OR them bits.
duke@0 734 return TypeInt::make( r0->get_con() | r1->get_con() );
duke@0 735 }
duke@0 736
duke@0 737 //=============================================================================
duke@0 738 //------------------------------Identity---------------------------------------
duke@0 739 Node *OrLNode::Identity( PhaseTransform *phase ) {
duke@0 740 // x | x => x
duke@0 741 if (phase->eqv(in(1), in(2))) {
duke@0 742 return in(1);
duke@0 743 }
duke@0 744
duke@0 745 return AddNode::Identity(phase);
duke@0 746 }
duke@0 747
duke@0 748 //------------------------------add_ring---------------------------------------
duke@0 749 const Type *OrLNode::add_ring( const Type *t0, const Type *t1 ) const {
duke@0 750 const TypeLong *r0 = t0->is_long(); // Handy access
duke@0 751 const TypeLong *r1 = t1->is_long();
duke@0 752
duke@0 753 // If either input is not a constant, just return all integers.
duke@0 754 if( !r0->is_con() || !r1->is_con() )
duke@0 755 return TypeLong::LONG; // Any integer, but still no symbols.
duke@0 756
duke@0 757 // Otherwise just OR them bits.
duke@0 758 return TypeLong::make( r0->get_con() | r1->get_con() );
duke@0 759 }
duke@0 760
duke@0 761 //=============================================================================
duke@0 762 //------------------------------add_ring---------------------------------------
duke@0 763 // Supplied function returns the sum of the inputs IN THE CURRENT RING. For
duke@0 764 // the logical operations the ring's ADD is really a logical OR function.
duke@0 765 // This also type-checks the inputs for sanity. Guaranteed never to
duke@0 766 // be passed a TOP or BOTTOM type, these are filtered out by pre-check.
duke@0 767 const Type *XorINode::add_ring( const Type *t0, const Type *t1 ) const {
duke@0 768 const TypeInt *r0 = t0->is_int(); // Handy access
duke@0 769 const TypeInt *r1 = t1->is_int();
duke@0 770
duke@0 771 // Complementing a boolean?
duke@0 772 if( r0 == TypeInt::BOOL && ( r1 == TypeInt::ONE
duke@0 773 || r1 == TypeInt::BOOL))
duke@0 774 return TypeInt::BOOL;
duke@0 775
duke@0 776 if( !r0->is_con() || !r1->is_con() ) // Not constants
duke@0 777 return TypeInt::INT; // Any integer, but still no symbols.
duke@0 778
duke@0 779 // Otherwise just XOR them bits.
duke@0 780 return TypeInt::make( r0->get_con() ^ r1->get_con() );
duke@0 781 }
duke@0 782
duke@0 783 //=============================================================================
duke@0 784 //------------------------------add_ring---------------------------------------
duke@0 785 const Type *XorLNode::add_ring( const Type *t0, const Type *t1 ) const {
duke@0 786 const TypeLong *r0 = t0->is_long(); // Handy access
duke@0 787 const TypeLong *r1 = t1->is_long();
duke@0 788
duke@0 789 // If either input is not a constant, just return all integers.
duke@0 790 if( !r0->is_con() || !r1->is_con() )
duke@0 791 return TypeLong::LONG; // Any integer, but still no symbols.
duke@0 792
duke@0 793 // Otherwise just OR them bits.
duke@0 794 return TypeLong::make( r0->get_con() ^ r1->get_con() );
duke@0 795 }
duke@0 796
duke@0 797 //=============================================================================
duke@0 798 //------------------------------add_ring---------------------------------------
duke@0 799 // Supplied function returns the sum of the inputs.
duke@0 800 const Type *MaxINode::add_ring( const Type *t0, const Type *t1 ) const {
duke@0 801 const TypeInt *r0 = t0->is_int(); // Handy access
duke@0 802 const TypeInt *r1 = t1->is_int();
duke@0 803
duke@0 804 // Otherwise just MAX them bits.
duke@0 805 return TypeInt::make( MAX2(r0->_lo,r1->_lo), MAX2(r0->_hi,r1->_hi), MAX2(r0->_widen,r1->_widen) );
duke@0 806 }
duke@0 807
duke@0 808 //=============================================================================
duke@0 809 //------------------------------Idealize---------------------------------------
duke@0 810 // MINs show up in range-check loop limit calculations. Look for
duke@0 811 // "MIN2(x+c0,MIN2(y,x+c1))". Pick the smaller constant: "MIN2(x+c0,y)"
duke@0 812 Node *MinINode::Ideal(PhaseGVN *phase, bool can_reshape) {
duke@0 813 Node *progress = NULL;
duke@0 814 // Force a right-spline graph
duke@0 815 Node *l = in(1);
duke@0 816 Node *r = in(2);
duke@0 817 // Transform MinI1( MinI2(a,b), c) into MinI1( a, MinI2(b,c) )
duke@0 818 // to force a right-spline graph for the rest of MinINode::Ideal().
duke@0 819 if( l->Opcode() == Op_MinI ) {
duke@0 820 assert( l != l->in(1), "dead loop in MinINode::Ideal" );
duke@0 821 r = phase->transform(new (phase->C, 3) MinINode(l->in(2),r));
duke@0 822 l = l->in(1);
duke@0 823 set_req(1, l);
duke@0 824 set_req(2, r);
duke@0 825 return this;
duke@0 826 }
duke@0 827
duke@0 828 // Get left input & constant
duke@0 829 Node *x = l;
duke@0 830 int x_off = 0;
duke@0 831 if( x->Opcode() == Op_AddI && // Check for "x+c0" and collect constant
duke@0 832 x->in(2)->is_Con() ) {
duke@0 833 const Type *t = x->in(2)->bottom_type();
duke@0 834 if( t == Type::TOP ) return NULL; // No progress
duke@0 835 x_off = t->is_int()->get_con();
duke@0 836 x = x->in(1);
duke@0 837 }
duke@0 838
duke@0 839 // Scan a right-spline-tree for MINs
duke@0 840 Node *y = r;
duke@0 841 int y_off = 0;
duke@0 842 // Check final part of MIN tree
duke@0 843 if( y->Opcode() == Op_AddI && // Check for "y+c1" and collect constant
duke@0 844 y->in(2)->is_Con() ) {
duke@0 845 const Type *t = y->in(2)->bottom_type();
duke@0 846 if( t == Type::TOP ) return NULL; // No progress
duke@0 847 y_off = t->is_int()->get_con();
duke@0 848 y = y->in(1);
duke@0 849 }
duke@0 850 if( x->_idx > y->_idx && r->Opcode() != Op_MinI ) {
duke@0 851 swap_edges(1, 2);
duke@0 852 return this;
duke@0 853 }
duke@0 854
duke@0 855
duke@0 856 if( r->Opcode() == Op_MinI ) {
duke@0 857 assert( r != r->in(2), "dead loop in MinINode::Ideal" );
duke@0 858 y = r->in(1);
duke@0 859 // Check final part of MIN tree
duke@0 860 if( y->Opcode() == Op_AddI &&// Check for "y+c1" and collect constant
duke@0 861 y->in(2)->is_Con() ) {
duke@0 862 const Type *t = y->in(2)->bottom_type();
duke@0 863 if( t == Type::TOP ) return NULL; // No progress
duke@0 864 y_off = t->is_int()->get_con();
duke@0 865 y = y->in(1);
duke@0 866 }
duke@0 867
duke@0 868 if( x->_idx > y->_idx )
duke@0 869 return new (phase->C, 3) MinINode(r->in(1),phase->transform(new (phase->C, 3) MinINode(l,r->in(2))));
duke@0 870
duke@0 871 // See if covers: MIN2(x+c0,MIN2(y+c1,z))
duke@0 872 if( !phase->eqv(x,y) ) return NULL;
duke@0 873 // If (y == x) transform MIN2(x+c0, MIN2(x+c1,z)) into
duke@0 874 // MIN2(x+c0 or x+c1 which less, z).
duke@0 875 return new (phase->C, 3) MinINode(phase->transform(new (phase->C, 3) AddINode(x,phase->intcon(MIN2(x_off,y_off)))),r->in(2));
duke@0 876 } else {
duke@0 877 // See if covers: MIN2(x+c0,y+c1)
duke@0 878 if( !phase->eqv(x,y) ) return NULL;
duke@0 879 // If (y == x) transform MIN2(x+c0,x+c1) into x+c0 or x+c1 which less.
duke@0 880 return new (phase->C, 3) AddINode(x,phase->intcon(MIN2(x_off,y_off)));
duke@0 881 }
duke@0 882
duke@0 883 }
duke@0 884
duke@0 885 //------------------------------add_ring---------------------------------------
duke@0 886 // Supplied function returns the sum of the inputs.
duke@0 887 const Type *MinINode::add_ring( const Type *t0, const Type *t1 ) const {
duke@0 888 const TypeInt *r0 = t0->is_int(); // Handy access
duke@0 889 const TypeInt *r1 = t1->is_int();
duke@0 890
duke@0 891 // Otherwise just MIN them bits.
duke@0 892 return TypeInt::make( MIN2(r0->_lo,r1->_lo), MIN2(r0->_hi,r1->_hi), MAX2(r0->_widen,r1->_widen) );
duke@0 893 }