1 //===-- SparcV9RegClassInfo.cpp - Register class def'ns for SparcV9 -------===//
3 // The LLVM Compiler Infrastructure
5 // This file was developed by the LLVM research group and is distributed under
6 // the University of Illinois Open Source License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file defines the methods used by the SparcV9 register allocator
11 // to pick registers of various classes. Most of this code should be
12 // considered part of the register allocator.
14 //===----------------------------------------------------------------------===//
16 #include "llvm/Type.h"
17 #include "SparcV9RegClassInfo.h"
18 #include "SparcV9Internals.h"
19 #include "SparcV9RegInfo.h"
20 #include "RegAlloc/RegAllocCommon.h"
21 #include "RegAlloc/IGNode.h"
26 //-----------------------------------------------------------------------------
27 // Int Register Class - method for coloring a node in the interference graph.
30 // Record the colors/suggested colors of all neighbors.
32 // If there is a suggested color, try to allocate it
33 // If there is no call interf, try to allocate volatile, then non volatile
34 // If there is call interf, try to allocate non-volatile. If that fails
35 // try to allocate a volatile and insert save across calls
36 // If both above fail, spill.
38 //-----------------------------------------------------------------------------
39 void SparcV9IntRegClass::colorIGNode(IGNode * Node,
40 const std::vector<bool> &IsColorUsedArr) const
42 LiveRange *LR = Node->getParentLR();
45 std::cerr << "\nColoring LR [CallInt=" << LR->isCallInterference() <<"]:"
48 if (LR->hasSuggestedColor()) {
49 unsigned SugCol = LR->getSuggestedColor();
50 if (!IsColorUsedArr[SugCol]) {
51 if (LR->isSuggestedColorUsable()) {
52 // if the suggested color is volatile, we should use it only if
53 // there are no call interferences. Otherwise, it will get spilled.
55 std::cerr << "\n -Coloring with sug color: " << SugCol;
57 LR->setColor(LR->getSuggestedColor());
60 std::cerr << "\n Couldn't alloc Sug col - LR volatile & calls interf";
62 } else if (DEBUG_RA) { // can't allocate the suggested col
63 std::cerr << "\n Could NOT allocate the suggested color (already used) "
68 unsigned SearchStart; // start pos of color in pref-order
69 bool ColorFound= false; // have we found a color yet?
71 //if this Node is between calls
72 if (! LR->isCallInterference()) {
73 // start with volatiles (we can allocate volatiles safely)
74 SearchStart = SparcV9IntRegClass::StartOfAllRegs;
76 // start with non volatiles (no non-volatiles)
77 SearchStart = SparcV9IntRegClass::StartOfNonVolatileRegs;
80 unsigned c=0; // color
82 // find first unused color
83 for (c=SearchStart; c < SparcV9IntRegClass::NumOfAvailRegs; c++) {
84 if (!IsColorUsedArr[c]) {
91 LR->setColor(c); // first color found in preferred order
92 if (DEBUG_RA) std::cerr << "\n Colored after first search with col " << c;
95 // if color is not found because of call interference
96 // try even finding a volatile color and insert save across calls
98 else if (LR->isCallInterference()) {
99 // start from 0 - try to find even a volatile this time
100 SearchStart = SparcV9IntRegClass::StartOfAllRegs;
102 // find first unused volatile color
103 for(c=SearchStart; c < SparcV9IntRegClass::StartOfNonVolatileRegs; c++) {
104 if (! IsColorUsedArr[c]) {
112 // get the live range corresponding to live var
113 // since LR span across calls, must save across calls
116 std::cerr << "\n Colored after SECOND search with col " << c;
121 // If we couldn't find a color regardless of call interference - i.e., we
122 // don't have either a volatile or non-volatile color left
125 LR->markForSpill(); // no color found - must spill
128 //-----------------------------------------------------------------------------
129 // Int CC Register Class - method for coloring a node in the interference graph.
133 // If (node has any interferences)
134 // /* all interference operations can use only one register! */
135 // mark the LR for spilling
137 // if (the LR is a 64-bit comparison) use %xcc
138 // else /*32-bit or smaller*/ use %icc
141 // Note: The third name (%ccr) is essentially an assembly mnemonic and
142 // depends solely on the opcode, so the name can be chosen in EmitAssembly.
143 //-----------------------------------------------------------------------------
144 void SparcV9IntCCRegClass::colorIGNode(IGNode *Node,
145 const std::vector<bool> &IsColorUsedArr) const
147 if (Node->getNumOfNeighbors() > 0)
148 Node->getParentLR()->markForSpill();
150 // Mark the appropriate register in any case (even if it needs to be spilled)
151 // because there is only one possible register, but more importantly, the
152 // spill algorithm cannot find it. In particular, we have to choose
153 // whether to use %xcc or %icc based on type of value compared
155 const LiveRange* ccLR = Node->getParentLR();
156 const Type* setCCType = (* ccLR->begin())->getType(); // any Value in LR
157 assert(setCCType->isIntegral() || isa<PointerType>(setCCType));
158 int ccReg = ((isa<PointerType>(setCCType) || setCCType == Type::LongTy)
162 // Let's just make sure values of two different types have not been
163 // coalesced into this LR.
164 for (LiveRange::const_iterator I=ccLR->begin(), E=ccLR->end(); I!=E; ++I) {
165 const Type* ccType = (*I)->getType();
166 assert((ccReg == xcc && (isa<PointerType>(ccType)
167 || ccType == Type::LongTy)) ||
168 (ccReg == icc && ccType->isIntegral() && ccType != Type::LongTy)
169 && "Comparisons needing different intCC regs coalesced in LR!");
173 Node->setColor(ccReg); // only one int cc reg is available
177 void SparcV9FloatCCRegClass::colorIGNode(IGNode *Node,
178 const std::vector<bool> &IsColorUsedArr) const {
179 for(unsigned c = 0; c != 4; ++c)
180 if (!IsColorUsedArr[c]) { // find unused color
185 Node->getParentLR()->markForSpill();
190 //-----------------------------------------------------------------------------
191 // Float Register Class - method for coloring a node in the interference graph.
195 // If the LR is a double try to allocate f32 - f63
196 // If the above fails or LR is single precision
197 // If the LR does not interfere with a call
198 // start allocating from f0
199 // Else start allocating from f6
200 // If a color is still not found because LR interferes with a call
201 // Search in f0 - f6. If found mark for spill across calls.
202 // If a color is still not fond, mark for spilling
204 //----------------------------------------------------------------------------
205 void SparcV9FloatRegClass::colorIGNode(IGNode * Node,
206 const std::vector<bool> &IsColorUsedArr) const
208 LiveRange *LR = Node->getParentLR();
211 // Check that the correct colors have been are marked for fp-doubles.
213 // FIXME: This is old code that is no longer needed. Temporarily converting
214 // it into a big assertion just to check that the replacement logic
215 // (invoking SparcV9FloatRegClass::markColorsUsed() directly from
216 // RegClass::colorIGNode) works correctly.
218 // In fact, this entire function should be identical to
219 // SparcV9IntRegClass::colorIGNode(), and perhaps can be
220 // made into a general case in CodeGen/RegAlloc/RegClass.cpp.
222 unsigned NumNeighbors = Node->getNumOfNeighbors(); // total # of neighbors
223 for(unsigned n=0; n < NumNeighbors; n++) { // for each neigh
224 IGNode *NeighIGNode = Node->getAdjIGNode(n);
225 LiveRange *NeighLR = NeighIGNode->getParentLR();
227 if (NeighLR->hasColor()) {
228 assert(IsColorUsedArr[ NeighLR->getColor() ]);
229 if (NeighLR->getType() == Type::DoubleTy)
230 assert(IsColorUsedArr[ NeighLR->getColor()+1 ]);
232 } else if (NeighLR->hasSuggestedColor() &&
233 NeighLR-> isSuggestedColorUsable() ) {
235 // if the neighbour can use the suggested color
236 assert(IsColorUsedArr[ NeighLR->getSuggestedColor() ]);
237 if (NeighLR->getType() == Type::DoubleTy)
238 assert(IsColorUsedArr[ NeighLR->getSuggestedColor()+1 ]);
243 // **NOTE: We don't check for call interferences in allocating suggested
244 // color in this class since ALL registers are volatile. If this fact
245 // changes, we should change the following part
246 //- see SparcV9IntRegClass::colorIGNode()
248 if( LR->hasSuggestedColor() ) {
249 if( ! IsColorUsedArr[ LR->getSuggestedColor() ] ) {
250 LR->setColor( LR->getSuggestedColor() );
252 } else if (DEBUG_RA) { // can't allocate the suggested col
253 std::cerr << " Could NOT allocate the suggested color for LR " << *LR
259 int ColorFound = -1; // have we found a color yet?
260 bool isCallInterf = LR->isCallInterference();
262 // if value is a double - search the double only region (f32 - f63)
263 // i.e. we try to allocate f32 - f63 first for doubles since singles
264 // cannot go there. By doing that, we provide more space for singles
267 if (LR->getType() == Type::DoubleTy)
268 ColorFound = findFloatColor( LR, 32, 64, IsColorUsedArr );
270 if (ColorFound >= 0) { // if we could find a color
271 LR->setColor(ColorFound);
275 // if we didn't find a color because the LR was single precision or
276 // all f32-f63 range is filled, we try to allocate a register from
277 // the f0 - f31 region
279 unsigned SearchStart; // start pos of color in pref-order
281 //if this Node is between calls (i.e., no call interferences )
282 if (! isCallInterf) {
283 // start with volatiles (we can allocate volatiles safely)
284 SearchStart = SparcV9FloatRegClass::StartOfAllRegs;
286 // start with non volatiles (no non-volatiles)
287 SearchStart = SparcV9FloatRegClass::StartOfNonVolatileRegs;
290 ColorFound = findFloatColor(LR, SearchStart, 32, IsColorUsedArr);
293 if (ColorFound >= 0) { // if we could find a color
294 LR->setColor(ColorFound);
296 } else if (isCallInterf) {
297 // We are here because there is a call interference and no non-volatile
298 // color could be found.
299 // Now try to allocate even a volatile color
300 ColorFound = findFloatColor(LR, SparcV9FloatRegClass::StartOfAllRegs,
301 SparcV9FloatRegClass::StartOfNonVolatileRegs,
305 if (ColorFound >= 0) {
306 LR->setColor(ColorFound); // first color found in preferred order
308 // we are here because no color could be found
309 LR->markForSpill(); // no color found - must spill
313 //-----------------------------------------------------------------------------
314 // This method marks the registers used for a given register number.
315 // This marks a single register for Float regs, but the R,R+1 pair
316 // for double-precision registers.
317 //-----------------------------------------------------------------------------
319 void SparcV9FloatRegClass::markColorsUsed(unsigned RegInClass,
322 std::vector<bool> &IsColorUsedArr) const
324 if (UserRegType == SparcV9RegInfo::FPDoubleRegType ||
325 RegTypeWanted == SparcV9RegInfo::FPDoubleRegType) {
326 // This register is used as or is needed as a double-precision reg.
327 // We need to mark the [even,odd] pair corresponding to this reg.
328 // Get the even numbered register corresponding to this reg.
329 unsigned EvenRegInClass = RegInClass & ~1u;
330 assert(EvenRegInClass+1 < NumOfAllRegs &&
331 EvenRegInClass+1 < IsColorUsedArr.size());
332 IsColorUsedArr[EvenRegInClass] = true;
333 IsColorUsedArr[EvenRegInClass+1] = true;
336 assert(RegInClass < NumOfAllRegs && RegInClass < IsColorUsedArr.size());
337 assert(UserRegType == RegTypeWanted
338 && "Something other than FP single/double types share a reg class?");
339 IsColorUsedArr[RegInClass] = true;
343 // This method finds unused registers of the specified register type,
344 // using the given "used" flag array IsColorUsedArr. It checks a single
345 // entry in the array directly for float regs, and checks the pair [R,R+1]
346 // for double-precision registers
347 // It returns -1 if no unused color is found.
349 int SparcV9FloatRegClass::findUnusedColor(int RegTypeWanted,
350 const std::vector<bool> &IsColorUsedArr) const
352 if (RegTypeWanted == SparcV9RegInfo::FPDoubleRegType) {
353 unsigned NC = 2 * this->getNumOfAvailRegs();
354 assert(IsColorUsedArr.size() == NC && "Invalid colors-used array");
355 for (unsigned c = 0; c < NC; c+=2)
356 if (!IsColorUsedArr[c]) {
357 assert(!IsColorUsedArr[c+1] && "Incorrect used regs for FP double!");
363 return TargetRegClassInfo::findUnusedColor(RegTypeWanted, IsColorUsedArr);
366 //-----------------------------------------------------------------------------
367 // Helper method for coloring a node of Float Reg class.
368 // Finds the first available color in the range [Start,End] depending on the
369 // type of the Node (i.e., float/double)
370 //-----------------------------------------------------------------------------
372 int SparcV9FloatRegClass::findFloatColor(const LiveRange *LR,
375 const std::vector<bool> &IsColorUsedArr) const
377 if (LR->getType() == Type::DoubleTy) {
378 // find first unused color for a double
379 assert(Start % 2 == 0 && "Odd register number could be used for double!");
380 for (unsigned c=Start; c < End ; c+= 2)
381 if (!IsColorUsedArr[c]) {
382 assert(!IsColorUsedArr[c+1] &&
383 "Incorrect marking of used regs for SparcV9 FP double!");
387 // find first unused color for a single
388 for (unsigned c = Start; c < End; c++)
389 if (!IsColorUsedArr[c])
397 } // End llvm namespace