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() <<"]:";
49 if (LR->hasSuggestedColor()) {
50 unsigned SugCol = LR->getSuggestedColor();
51 if (!IsColorUsedArr[SugCol]) {
52 if (LR->isSuggestedColorUsable()) {
53 // if the suggested color is volatile, we should use it only if
54 // there are no call interferences. Otherwise, it will get spilled.
56 std::cerr << "\n -Coloring with sug color: " << SugCol;
58 LR->setColor(LR->getSuggestedColor());
61 std::cerr << "\n Couldn't alloc Sug col - LR volatile & calls interf";
63 } else if (DEBUG_RA) { // can't allocate the suggested col
64 std::cerr << "\n Could NOT allocate the suggested color (already used) ";
65 printSet(*LR); std::cerr << "\n";
69 unsigned SearchStart; // start pos of color in pref-order
70 bool ColorFound= false; // have we found a color yet?
72 //if this Node is between calls
73 if (! LR->isCallInterference()) {
74 // start with volatiles (we can allocate volatiles safely)
75 SearchStart = SparcV9IntRegClass::StartOfAllRegs;
77 // start with non volatiles (no non-volatiles)
78 SearchStart = SparcV9IntRegClass::StartOfNonVolatileRegs;
81 unsigned c=0; // color
83 // find first unused color
84 for (c=SearchStart; c < SparcV9IntRegClass::NumOfAvailRegs; c++) {
85 if (!IsColorUsedArr[c]) {
92 LR->setColor(c); // first color found in preferred order
93 if (DEBUG_RA) std::cerr << "\n Colored after first search with col " << c;
96 // if color is not found because of call interference
97 // try even finding a volatile color and insert save across calls
99 else if (LR->isCallInterference()) {
100 // start from 0 - try to find even a volatile this time
101 SearchStart = SparcV9IntRegClass::StartOfAllRegs;
103 // find first unused volatile color
104 for(c=SearchStart; c < SparcV9IntRegClass::StartOfNonVolatileRegs; c++) {
105 if (! IsColorUsedArr[c]) {
113 // get the live range corresponding to live var
114 // since LR span across calls, must save across calls
117 std::cerr << "\n Colored after SECOND search with col " << c;
122 // If we couldn't find a color regardless of call interference - i.e., we
123 // don't have either a volatile or non-volatile color left
126 LR->markForSpill(); // no color found - must spill
129 //-----------------------------------------------------------------------------
130 // Int CC Register Class - method for coloring a node in the interference graph.
134 // If (node has any interferences)
135 // /* all interference operations can use only one register! */
136 // mark the LR for spilling
138 // if (the LR is a 64-bit comparison) use %xcc
139 // else /*32-bit or smaller*/ use %icc
142 // Note: The third name (%ccr) is essentially an assembly mnemonic and
143 // depends solely on the opcode, so the name can be chosen in EmitAssembly.
144 //-----------------------------------------------------------------------------
145 void SparcV9IntCCRegClass::colorIGNode(IGNode *Node,
146 const std::vector<bool> &IsColorUsedArr) const
148 if (Node->getNumOfNeighbors() > 0)
149 Node->getParentLR()->markForSpill();
151 // Mark the appropriate register in any case (even if it needs to be spilled)
152 // because there is only one possible register, but more importantly, the
153 // spill algorithm cannot find it. In particular, we have to choose
154 // whether to use %xcc or %icc based on type of value compared
156 const LiveRange* ccLR = Node->getParentLR();
157 const Type* setCCType = (* ccLR->begin())->getType(); // any Value in LR
158 assert(setCCType->isIntegral() || isa<PointerType>(setCCType));
159 int ccReg = ((isa<PointerType>(setCCType) || setCCType == Type::LongTy)
163 // Let's just make sure values of two different types have not been
164 // coalesced into this LR.
165 for (ValueSet::const_iterator I=ccLR->begin(), E=ccLR->end(); I!=E; ++I) {
166 const Type* ccType = (*I)->getType();
167 assert((ccReg == xcc && (isa<PointerType>(ccType)
168 || ccType == Type::LongTy)) ||
169 (ccReg == icc && ccType->isIntegral() && ccType != Type::LongTy)
170 && "Comparisons needing different intCC regs coalesced in LR!");
174 Node->setColor(ccReg); // only one int cc reg is available
178 void SparcV9FloatCCRegClass::colorIGNode(IGNode *Node,
179 const std::vector<bool> &IsColorUsedArr) const {
180 for(unsigned c = 0; c != 4; ++c)
181 if (!IsColorUsedArr[c]) { // find unused color
186 Node->getParentLR()->markForSpill();
191 //-----------------------------------------------------------------------------
192 // Float Register Class - method for coloring a node in the interference graph.
196 // If the LR is a double try to allocate f32 - f63
197 // If the above fails or LR is single precision
198 // If the LR does not interfere with a call
199 // start allocating from f0
200 // Else start allocating from f6
201 // If a color is still not found because LR interferes with a call
202 // Search in f0 - f6. If found mark for spill across calls.
203 // If a color is still not fond, mark for spilling
205 //----------------------------------------------------------------------------
206 void SparcV9FloatRegClass::colorIGNode(IGNode * Node,
207 const std::vector<bool> &IsColorUsedArr) const
209 LiveRange *LR = Node->getParentLR();
212 // Check that the correct colors have been are marked for fp-doubles.
214 // FIXME: This is old code that is no longer needed. Temporarily converting
215 // it into a big assertion just to check that the replacement logic
216 // (invoking SparcV9FloatRegClass::markColorsUsed() directly from
217 // RegClass::colorIGNode) works correctly.
219 // In fact, this entire function should be identical to
220 // SparcV9IntRegClass::colorIGNode(), and perhaps can be
221 // made into a general case in CodeGen/RegAlloc/RegClass.cpp.
223 unsigned NumNeighbors = Node->getNumOfNeighbors(); // total # of neighbors
224 for(unsigned n=0; n < NumNeighbors; n++) { // for each neigh
225 IGNode *NeighIGNode = Node->getAdjIGNode(n);
226 LiveRange *NeighLR = NeighIGNode->getParentLR();
228 if (NeighLR->hasColor()) {
229 assert(IsColorUsedArr[ NeighLR->getColor() ]);
230 if (NeighLR->getType() == Type::DoubleTy)
231 assert(IsColorUsedArr[ NeighLR->getColor()+1 ]);
233 } else if (NeighLR->hasSuggestedColor() &&
234 NeighLR-> isSuggestedColorUsable() ) {
236 // if the neighbour can use the suggested color
237 assert(IsColorUsedArr[ NeighLR->getSuggestedColor() ]);
238 if (NeighLR->getType() == Type::DoubleTy)
239 assert(IsColorUsedArr[ NeighLR->getSuggestedColor()+1 ]);
244 // **NOTE: We don't check for call interferences in allocating suggested
245 // color in this class since ALL registers are volatile. If this fact
246 // changes, we should change the following part
247 //- see SparcV9IntRegClass::colorIGNode()
249 if( LR->hasSuggestedColor() ) {
250 if( ! IsColorUsedArr[ LR->getSuggestedColor() ] ) {
251 LR->setColor( LR->getSuggestedColor() );
253 } else if (DEBUG_RA) { // can't allocate the suggested col
254 std::cerr << " Could NOT allocate the suggested color for LR ";
255 printSet(*LR); std::cerr << "\n";
260 int ColorFound = -1; // have we found a color yet?
261 bool isCallInterf = LR->isCallInterference();
263 // if value is a double - search the double only region (f32 - f63)
264 // i.e. we try to allocate f32 - f63 first for doubles since singles
265 // cannot go there. By doing that, we provide more space for singles
268 if (LR->getType() == Type::DoubleTy)
269 ColorFound = findFloatColor( LR, 32, 64, IsColorUsedArr );
271 if (ColorFound >= 0) { // if we could find a color
272 LR->setColor(ColorFound);
276 // if we didn't find a color because the LR was single precision or
277 // all f32-f63 range is filled, we try to allocate a register from
278 // the f0 - f31 region
280 unsigned SearchStart; // start pos of color in pref-order
282 //if this Node is between calls (i.e., no call interferences )
283 if (! isCallInterf) {
284 // start with volatiles (we can allocate volatiles safely)
285 SearchStart = SparcV9FloatRegClass::StartOfAllRegs;
287 // start with non volatiles (no non-volatiles)
288 SearchStart = SparcV9FloatRegClass::StartOfNonVolatileRegs;
291 ColorFound = findFloatColor(LR, SearchStart, 32, IsColorUsedArr);
294 if (ColorFound >= 0) { // if we could find a color
295 LR->setColor(ColorFound);
297 } else if (isCallInterf) {
298 // We are here because there is a call interference and no non-volatile
299 // color could be found.
300 // Now try to allocate even a volatile color
301 ColorFound = findFloatColor(LR, SparcV9FloatRegClass::StartOfAllRegs,
302 SparcV9FloatRegClass::StartOfNonVolatileRegs,
306 if (ColorFound >= 0) {
307 LR->setColor(ColorFound); // first color found in preferred order
309 // we are here because no color could be found
310 LR->markForSpill(); // no color found - must spill
314 //-----------------------------------------------------------------------------
315 // This method marks the registers used for a given register number.
316 // This marks a single register for Float regs, but the R,R+1 pair
317 // for double-precision registers.
318 //-----------------------------------------------------------------------------
320 void SparcV9FloatRegClass::markColorsUsed(unsigned RegInClass,
323 std::vector<bool> &IsColorUsedArr) const
325 if (UserRegType == SparcV9RegInfo::FPDoubleRegType ||
326 RegTypeWanted == SparcV9RegInfo::FPDoubleRegType) {
327 // This register is used as or is needed as a double-precision reg.
328 // We need to mark the [even,odd] pair corresponding to this reg.
329 // Get the even numbered register corresponding to this reg.
330 unsigned EvenRegInClass = RegInClass & ~1u;
331 assert(EvenRegInClass+1 < NumOfAllRegs &&
332 EvenRegInClass+1 < IsColorUsedArr.size());
333 IsColorUsedArr[EvenRegInClass] = true;
334 IsColorUsedArr[EvenRegInClass+1] = true;
337 assert(RegInClass < NumOfAllRegs && RegInClass < IsColorUsedArr.size());
338 assert(UserRegType == RegTypeWanted
339 && "Something other than FP single/double types share a reg class?");
340 IsColorUsedArr[RegInClass] = true;
344 // This method finds unused registers of the specified register type,
345 // using the given "used" flag array IsColorUsedArr. It checks a single
346 // entry in the array directly for float regs, and checks the pair [R,R+1]
347 // for double-precision registers
348 // It returns -1 if no unused color is found.
350 int SparcV9FloatRegClass::findUnusedColor(int RegTypeWanted,
351 const std::vector<bool> &IsColorUsedArr) const
353 if (RegTypeWanted == SparcV9RegInfo::FPDoubleRegType) {
354 unsigned NC = 2 * this->getNumOfAvailRegs();
355 assert(IsColorUsedArr.size() == NC && "Invalid colors-used array");
356 for (unsigned c = 0; c < NC; c+=2)
357 if (!IsColorUsedArr[c]) {
358 assert(!IsColorUsedArr[c+1] && "Incorrect used regs for FP double!");
364 return TargetRegClassInfo::findUnusedColor(RegTypeWanted, IsColorUsedArr);
367 //-----------------------------------------------------------------------------
368 // Helper method for coloring a node of Float Reg class.
369 // Finds the first available color in the range [Start,End] depending on the
370 // type of the Node (i.e., float/double)
371 //-----------------------------------------------------------------------------
373 int SparcV9FloatRegClass::findFloatColor(const LiveRange *LR,
376 const std::vector<bool> &IsColorUsedArr) const
378 if (LR->getType() == Type::DoubleTy) {
379 // find first unused color for a double
380 assert(Start % 2 == 0 && "Odd register number could be used for double!");
381 for (unsigned c=Start; c < End ; c+= 2)
382 if (!IsColorUsedArr[c]) {
383 assert(!IsColorUsedArr[c+1] &&
384 "Incorrect marking of used regs for SparcV9 FP double!");
388 // find first unused color for a single
389 for (unsigned c = Start; c < End; c++)
390 if (!IsColorUsedArr[c])
398 } // End llvm namespace