1//===-- AutoUpgrade.cpp - Implement auto-upgrade helper functions ---------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file implements the auto-upgrade helper functions
11//
12//===----------------------------------------------------------------------===//
13
14#include "llvm/AutoUpgrade.h"
15#include "llvm/Constants.h"
16#include "llvm/Function.h"
17#include "llvm/IRBuilder.h"
18#include "llvm/Instruction.h"
19#include "llvm/IntrinsicInst.h"
20#include "llvm/LLVMContext.h"
21#include "llvm/Module.h"
22#include "llvm/Support/CFG.h"
23#include "llvm/Support/CallSite.h"
24#include "llvm/Support/ErrorHandling.h"
25#include <cstring>
26using namespace llvm;
27
28// Upgrade the declarations of the SSE4.1 functions whose arguments have
29// changed their type from v4f32 to v2i64.
30static bool UpgradeSSE41Function(Function* F, Intrinsic::ID IID,
31                                 Function *&NewFn) {
32  // Check whether this is an old version of the function, which received
33  // v4f32 arguments.
34  Type *Arg0Type = F->getFunctionType()->getParamType(0);
35  if (Arg0Type != VectorType::get(Type::getFloatTy(F->getContext()), 4))
36    return false;
37
38  // Yes, it's old, replace it with new version.
39  F->setName(F->getName() + ".old");
40  NewFn = Intrinsic::getDeclaration(F->getParent(), IID);
41  return true;
42}
43
44static bool UpgradeIntrinsicFunction1(Function *F, Function *&NewFn) {
45  assert(F && "Illegal to upgrade a non-existent Function.");
46
47  // Quickly eliminate it, if it's not a candidate.
48  StringRef Name = F->getName();
49  if (Name.size() <= 8 || !Name.startswith("llvm."))
50    return false;
51  Name = Name.substr(5); // Strip off "llvm."
52
53  switch (Name[0]) {
54  default: break;
55  case 'a': {
56    if (Name.startswith("arm.neon.vclz")) {
57      Type* args[2] = {
58        F->arg_begin()->getType(),
59        Type::getInt1Ty(F->getContext())
60      };
61      // Can't use Intrinsic::getDeclaration here as it adds a ".i1" to
62      // the end of the name. Change name from llvm.arm.neon.vclz.* to
63      //  llvm.ctlz.*
64      FunctionType* fType = FunctionType::get(F->getReturnType(), args, false);
65      NewFn = Function::Create(fType, F->getLinkage(),
66                               "llvm.ctlz." + Name.substr(14), F->getParent());
67      return true;
68    }
69    if (Name.startswith("arm.neon.vcnt")) {
70      NewFn = Intrinsic::getDeclaration(F->getParent(), Intrinsic::ctpop,
71                                        F->arg_begin()->getType());
72      return true;
73    }
74    break;
75  }
76  case 'c': {
77    if (Name.startswith("ctlz.") && F->arg_size() == 1) {
78      F->setName(Name + ".old");
79      NewFn = Intrinsic::getDeclaration(F->getParent(), Intrinsic::ctlz,
80                                        F->arg_begin()->getType());
81      return true;
82    }
83    if (Name.startswith("cttz.") && F->arg_size() == 1) {
84      F->setName(Name + ".old");
85      NewFn = Intrinsic::getDeclaration(F->getParent(), Intrinsic::cttz,
86                                        F->arg_begin()->getType());
87      return true;
88    }
89    break;
90  }
91  case 'x': {
92    if (Name.startswith("x86.sse2.pcmpeq.") ||
93        Name.startswith("x86.sse2.pcmpgt.") ||
94        Name.startswith("x86.avx2.pcmpeq.") ||
95        Name.startswith("x86.avx2.pcmpgt.") ||
96        Name.startswith("x86.avx.vpermil.") ||
97        Name == "x86.avx.movnt.dq.256" ||
98        Name == "x86.avx.movnt.pd.256" ||
99        Name == "x86.avx.movnt.ps.256" ||
100        (Name.startswith("x86.xop.vpcom") && F->arg_size() == 2)) {
101      NewFn = 0;
102      return true;
103    }
104    // SSE4.1 ptest functions may have an old signature.
105    if (Name.startswith("x86.sse41.ptest")) {
106      if (Name == "x86.sse41.ptestc")
107        return UpgradeSSE41Function(F, Intrinsic::x86_sse41_ptestc, NewFn);
108      if (Name == "x86.sse41.ptestz")
109        return UpgradeSSE41Function(F, Intrinsic::x86_sse41_ptestz, NewFn);
110      if (Name == "x86.sse41.ptestnzc")
111        return UpgradeSSE41Function(F, Intrinsic::x86_sse41_ptestnzc, NewFn);
112    }
113    // frcz.ss/sd may need to have an argument dropped
114    if (Name.startswith("x86.xop.vfrcz.ss") && F->arg_size() == 2) {
115      F->setName(Name + ".old");
116      NewFn = Intrinsic::getDeclaration(F->getParent(),
117                                        Intrinsic::x86_xop_vfrcz_ss);
118      return true;
119    }
120    if (Name.startswith("x86.xop.vfrcz.sd") && F->arg_size() == 2) {
121      F->setName(Name + ".old");
122      NewFn = Intrinsic::getDeclaration(F->getParent(),
123                                        Intrinsic::x86_xop_vfrcz_sd);
124      return true;
125    }
126    // Fix the FMA4 intrinsics to remove the 4
127    if (Name.startswith("x86.fma4.")) {
128      F->setName("llvm.x86.fma" + Name.substr(8));
129      NewFn = F;
130      return true;
131    }
132    break;
133  }
134  }
135
136  //  This may not belong here. This function is effectively being overloaded
137  //  to both detect an intrinsic which needs upgrading, and to provide the
138  //  upgraded form of the intrinsic. We should perhaps have two separate
139  //  functions for this.
140  return false;
141}
142
143bool llvm::UpgradeIntrinsicFunction(Function *F, Function *&NewFn) {
144  NewFn = 0;
145  bool Upgraded = UpgradeIntrinsicFunction1(F, NewFn);
146
147  // Upgrade intrinsic attributes.  This does not change the function.
148  if (NewFn)
149    F = NewFn;
150  if (unsigned id = F->getIntrinsicID())
151    F->setAttributes(Intrinsic::getAttributes((Intrinsic::ID)id));
152  return Upgraded;
153}
154
155bool llvm::UpgradeGlobalVariable(GlobalVariable *GV) {
156  // Nothing to do yet.
157  return false;
158}
159
160// UpgradeIntrinsicCall - Upgrade a call to an old intrinsic to be a call the
161// upgraded intrinsic. All argument and return casting must be provided in
162// order to seamlessly integrate with existing context.
163void llvm::UpgradeIntrinsicCall(CallInst *CI, Function *NewFn) {
164  Function *F = CI->getCalledFunction();
165  LLVMContext &C = CI->getContext();
166  IRBuilder<> Builder(C);
167  Builder.SetInsertPoint(CI->getParent(), CI);
168
169  assert(F && "Intrinsic call is not direct?");
170
171  if (!NewFn) {
172    // Get the Function's name.
173    StringRef Name = F->getName();
174
175    Value *Rep;
176    // Upgrade packed integer vector compares intrinsics to compare instructions
177    if (Name.startswith("llvm.x86.sse2.pcmpeq.") ||
178        Name.startswith("llvm.x86.avx2.pcmpeq.")) {
179      Rep = Builder.CreateICmpEQ(CI->getArgOperand(0), CI->getArgOperand(1),
180                                 "pcmpeq");
181      // need to sign extend since icmp returns vector of i1
182      Rep = Builder.CreateSExt(Rep, CI->getType(), "");
183    } else if (Name.startswith("llvm.x86.sse2.pcmpgt.") ||
184               Name.startswith("llvm.x86.avx2.pcmpgt.")) {
185      Rep = Builder.CreateICmpSGT(CI->getArgOperand(0), CI->getArgOperand(1),
186                                  "pcmpgt");
187      // need to sign extend since icmp returns vector of i1
188      Rep = Builder.CreateSExt(Rep, CI->getType(), "");
189    } else if (Name == "llvm.x86.avx.movnt.dq.256" ||
190               Name == "llvm.x86.avx.movnt.ps.256" ||
191               Name == "llvm.x86.avx.movnt.pd.256") {
192      IRBuilder<> Builder(C);
193      Builder.SetInsertPoint(CI->getParent(), CI);
194
195      Module *M = F->getParent();
196      SmallVector<Value *, 1> Elts;
197      Elts.push_back(ConstantInt::get(Type::getInt32Ty(C), 1));
198      MDNode *Node = MDNode::get(C, Elts);
199
200      Value *Arg0 = CI->getArgOperand(0);
201      Value *Arg1 = CI->getArgOperand(1);
202
203      // Convert the type of the pointer to a pointer to the stored type.
204      Value *BC = Builder.CreateBitCast(Arg0,
205                                        PointerType::getUnqual(Arg1->getType()),
206                                        "cast");
207      StoreInst *SI = Builder.CreateStore(Arg1, BC);
208      SI->setMetadata(M->getMDKindID("nontemporal"), Node);
209      SI->setAlignment(16);
210
211      // Remove intrinsic.
212      CI->eraseFromParent();
213      return;
214    } else if (Name.startswith("llvm.x86.xop.vpcom")) {
215      Intrinsic::ID intID;
216      if (Name.endswith("ub"))
217        intID = Intrinsic::x86_xop_vpcomub;
218      else if (Name.endswith("uw"))
219        intID = Intrinsic::x86_xop_vpcomuw;
220      else if (Name.endswith("ud"))
221        intID = Intrinsic::x86_xop_vpcomud;
222      else if (Name.endswith("uq"))
223        intID = Intrinsic::x86_xop_vpcomuq;
224      else if (Name.endswith("b"))
225        intID = Intrinsic::x86_xop_vpcomb;
226      else if (Name.endswith("w"))
227        intID = Intrinsic::x86_xop_vpcomw;
228      else if (Name.endswith("d"))
229        intID = Intrinsic::x86_xop_vpcomd;
230      else if (Name.endswith("q"))
231        intID = Intrinsic::x86_xop_vpcomq;
232      else
233        llvm_unreachable("Unknown suffix");
234
235      Name = Name.substr(18); // strip off "llvm.x86.xop.vpcom"
236      unsigned Imm;
237      if (Name.startswith("lt"))
238        Imm = 0;
239      else if (Name.startswith("le"))
240        Imm = 1;
241      else if (Name.startswith("gt"))
242        Imm = 2;
243      else if (Name.startswith("ge"))
244        Imm = 3;
245      else if (Name.startswith("eq"))
246        Imm = 4;
247      else if (Name.startswith("ne"))
248        Imm = 5;
249      else if (Name.startswith("true"))
250        Imm = 6;
251      else if (Name.startswith("false"))
252        Imm = 7;
253      else
254        llvm_unreachable("Unknown condition");
255
256      Function *VPCOM = Intrinsic::getDeclaration(F->getParent(), intID);
257      Rep = Builder.CreateCall3(VPCOM, CI->getArgOperand(0),
258                                CI->getArgOperand(1), Builder.getInt8(Imm));
259    } else {
260      bool PD128 = false, PD256 = false, PS128 = false, PS256 = false;
261      if (Name == "llvm.x86.avx.vpermil.pd.256")
262        PD256 = true;
263      else if (Name == "llvm.x86.avx.vpermil.pd")
264        PD128 = true;
265      else if (Name == "llvm.x86.avx.vpermil.ps.256")
266        PS256 = true;
267      else if (Name == "llvm.x86.avx.vpermil.ps")
268        PS128 = true;
269
270      if (PD256 || PD128 || PS256 || PS128) {
271        Value *Op0 = CI->getArgOperand(0);
272        unsigned Imm = cast<ConstantInt>(CI->getArgOperand(1))->getZExtValue();
273        SmallVector<Constant*, 8> Idxs;
274
275        if (PD128)
276          for (unsigned i = 0; i != 2; ++i)
277            Idxs.push_back(Builder.getInt32((Imm >> i) & 0x1));
278        else if (PD256)
279          for (unsigned l = 0; l != 4; l+=2)
280            for (unsigned i = 0; i != 2; ++i)
281              Idxs.push_back(Builder.getInt32(((Imm >> (l+i)) & 0x1) + l));
282        else if (PS128)
283          for (unsigned i = 0; i != 4; ++i)
284            Idxs.push_back(Builder.getInt32((Imm >> (2 * i)) & 0x3));
285        else if (PS256)
286          for (unsigned l = 0; l != 8; l+=4)
287            for (unsigned i = 0; i != 4; ++i)
288              Idxs.push_back(Builder.getInt32(((Imm >> (2 * i)) & 0x3) + l));
289        else
290          llvm_unreachable("Unexpected function");
291
292        Rep = Builder.CreateShuffleVector(Op0, Op0, ConstantVector::get(Idxs));
293      } else {
294        llvm_unreachable("Unknown function for CallInst upgrade.");
295      }
296    }
297
298    CI->replaceAllUsesWith(Rep);
299    CI->eraseFromParent();
300    return;
301  }
302
303  std::string Name = CI->getName().str();
304  CI->setName(Name + ".old");
305
306  switch (NewFn->getIntrinsicID()) {
307  default:
308    llvm_unreachable("Unknown function for CallInst upgrade.");
309
310  case Intrinsic::ctlz:
311  case Intrinsic::cttz:
312    assert(CI->getNumArgOperands() == 1 &&
313           "Mismatch between function args and call args");
314    CI->replaceAllUsesWith(Builder.CreateCall2(NewFn, CI->getArgOperand(0),
315                                               Builder.getFalse(), Name));
316    CI->eraseFromParent();
317    return;
318
319  case Intrinsic::arm_neon_vclz: {
320    // Change name from llvm.arm.neon.vclz.* to llvm.ctlz.*
321    CI->replaceAllUsesWith(Builder.CreateCall2(NewFn, CI->getArgOperand(0),
322                                               Builder.getFalse(),
323                                               "llvm.ctlz." + Name.substr(14)));
324    CI->eraseFromParent();
325    return;
326  }
327  case Intrinsic::ctpop: {
328    CI->replaceAllUsesWith(Builder.CreateCall(NewFn, CI->getArgOperand(0)));
329    CI->eraseFromParent();
330    return;
331  }
332
333  case Intrinsic::x86_xop_vfrcz_ss:
334  case Intrinsic::x86_xop_vfrcz_sd:
335    CI->replaceAllUsesWith(Builder.CreateCall(NewFn, CI->getArgOperand(1),
336                                              Name));
337    CI->eraseFromParent();
338    return;
339
340  case Intrinsic::x86_sse41_ptestc:
341  case Intrinsic::x86_sse41_ptestz:
342  case Intrinsic::x86_sse41_ptestnzc: {
343    // The arguments for these intrinsics used to be v4f32, and changed
344    // to v2i64. This is purely a nop, since those are bitwise intrinsics.
345    // So, the only thing required is a bitcast for both arguments.
346    // First, check the arguments have the old type.
347    Value *Arg0 = CI->getArgOperand(0);
348    if (Arg0->getType() != VectorType::get(Type::getFloatTy(C), 4))
349      return;
350
351    // Old intrinsic, add bitcasts
352    Value *Arg1 = CI->getArgOperand(1);
353
354    Value *BC0 =
355      Builder.CreateBitCast(Arg0,
356                            VectorType::get(Type::getInt64Ty(C), 2),
357                            "cast");
358    Value *BC1 =
359      Builder.CreateBitCast(Arg1,
360                            VectorType::get(Type::getInt64Ty(C), 2),
361                            "cast");
362
363    CallInst* NewCall = Builder.CreateCall2(NewFn, BC0, BC1, Name);
364    CI->replaceAllUsesWith(NewCall);
365    CI->eraseFromParent();
366    return;
367  }
368  }
369}
370
371// This tests each Function to determine if it needs upgrading. When we find
372// one we are interested in, we then upgrade all calls to reflect the new
373// function.
374void llvm::UpgradeCallsToIntrinsic(Function* F) {
375  assert(F && "Illegal attempt to upgrade a non-existent intrinsic.");
376
377  // Upgrade the function and check if it is a totaly new function.
378  Function *NewFn;
379  if (UpgradeIntrinsicFunction(F, NewFn)) {
380    if (NewFn != F) {
381      // Replace all uses to the old function with the new one if necessary.
382      for (Value::use_iterator UI = F->use_begin(), UE = F->use_end();
383           UI != UE; ) {
384        if (CallInst *CI = dyn_cast<CallInst>(*UI++))
385          UpgradeIntrinsicCall(CI, NewFn);
386      }
387      // Remove old function, no longer used, from the module.
388      F->eraseFromParent();
389    }
390  }
391}
392
393