xref: /llvm-project/llvm/lib/Target/AMDGPU/AMDGPULibCalls.cpp (revision ab6cd2d498b6d929469dacc923043eec90a31fd3)
1 //===- AMDGPULibCalls.cpp -------------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 /// \file
10 /// This file does AMD library function optimizations.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "AMDGPU.h"
15 #include "AMDGPULibFunc.h"
16 #include "GCNSubtarget.h"
17 #include "llvm/Analysis/AliasAnalysis.h"
18 #include "llvm/Analysis/Loads.h"
19 #include "llvm/IR/IRBuilder.h"
20 #include "llvm/IR/IntrinsicInst.h"
21 #include "llvm/IR/IntrinsicsAMDGPU.h"
22 #include "llvm/InitializePasses.h"
23 #include "llvm/Target/TargetMachine.h"
24 #include <cmath>
25 
26 #define DEBUG_TYPE "amdgpu-simplifylib"
27 
28 using namespace llvm;
29 
30 static cl::opt<bool> EnablePreLink("amdgpu-prelink",
31   cl::desc("Enable pre-link mode optimizations"),
32   cl::init(false),
33   cl::Hidden);
34 
35 static cl::list<std::string> UseNative("amdgpu-use-native",
36   cl::desc("Comma separated list of functions to replace with native, or all"),
37   cl::CommaSeparated, cl::ValueOptional,
38   cl::Hidden);
39 
40 #define MATH_PI      numbers::pi
41 #define MATH_E       numbers::e
42 #define MATH_SQRT2   numbers::sqrt2
43 #define MATH_SQRT1_2 numbers::inv_sqrt2
44 
45 namespace llvm {
46 
47 class AMDGPULibCalls {
48 private:
49 
50   typedef llvm::AMDGPULibFunc FuncInfo;
51 
52   const TargetMachine *TM;
53 
54   // -fuse-native.
55   bool AllNative = false;
56 
57   bool useNativeFunc(const StringRef F) const;
58 
59   // Return a pointer (pointer expr) to the function if function definition with
60   // "FuncName" exists. It may create a new function prototype in pre-link mode.
61   FunctionCallee getFunction(Module *M, const FuncInfo &fInfo);
62 
63   bool parseFunctionName(const StringRef &FMangledName, FuncInfo &FInfo);
64 
65   bool TDOFold(CallInst *CI, const FuncInfo &FInfo);
66 
67   /* Specialized optimizations */
68 
69   // recip (half or native)
70   bool fold_recip(CallInst *CI, IRBuilder<> &B, const FuncInfo &FInfo);
71 
72   // divide (half or native)
73   bool fold_divide(CallInst *CI, IRBuilder<> &B, const FuncInfo &FInfo);
74 
75   // pow/powr/pown
76   bool fold_pow(CallInst *CI, IRBuilder<> &B, const FuncInfo &FInfo);
77 
78   // rootn
79   bool fold_rootn(CallInst *CI, IRBuilder<> &B, const FuncInfo &FInfo);
80 
81   // fma/mad
82   bool fold_fma_mad(CallInst *CI, IRBuilder<> &B, const FuncInfo &FInfo);
83 
84   // -fuse-native for sincos
85   bool sincosUseNative(CallInst *aCI, const FuncInfo &FInfo);
86 
87   // evaluate calls if calls' arguments are constants.
88   bool evaluateScalarMathFunc(const FuncInfo &FInfo, double& Res0,
89     double& Res1, Constant *copr0, Constant *copr1, Constant *copr2);
90   bool evaluateCall(CallInst *aCI, const FuncInfo &FInfo);
91 
92   // sqrt
93   bool fold_sqrt(CallInst *CI, IRBuilder<> &B, const FuncInfo &FInfo);
94 
95   // sin/cos
96   bool fold_sincos(CallInst * CI, IRBuilder<> &B, AliasAnalysis * AA);
97 
98   // __read_pipe/__write_pipe
99   bool fold_read_write_pipe(CallInst *CI, IRBuilder<> &B,
100                             const FuncInfo &FInfo);
101 
102   // llvm.amdgcn.wavefrontsize
103   bool fold_wavefrontsize(CallInst *CI, IRBuilder<> &B);
104 
105   // Get insertion point at entry.
106   BasicBlock::iterator getEntryIns(CallInst * UI);
107   // Insert an Alloc instruction.
108   AllocaInst* insertAlloca(CallInst * UI, IRBuilder<> &B, const char *prefix);
109   // Get a scalar native builtin single argument FP function
110   FunctionCallee getNativeFunction(Module *M, const FuncInfo &FInfo);
111 
112 protected:
113   CallInst *CI;
114 
115   bool isUnsafeMath(const CallInst *CI) const;
116 
117   void replaceCall(Value *With) {
118     CI->replaceAllUsesWith(With);
119     CI->eraseFromParent();
120   }
121 
122 public:
123   AMDGPULibCalls(const TargetMachine *TM_ = nullptr) : TM(TM_) {}
124 
125   bool fold(CallInst *CI, AliasAnalysis *AA = nullptr);
126 
127   void initNativeFuncs();
128 
129   // Replace a normal math function call with that native version
130   bool useNative(CallInst *CI);
131 };
132 
133 } // end llvm namespace
134 
135 namespace {
136 
137   class AMDGPUSimplifyLibCalls : public FunctionPass {
138 
139   AMDGPULibCalls Simplifier;
140 
141   public:
142     static char ID; // Pass identification
143 
144     AMDGPUSimplifyLibCalls(const TargetMachine *TM = nullptr)
145       : FunctionPass(ID), Simplifier(TM) {
146       initializeAMDGPUSimplifyLibCallsPass(*PassRegistry::getPassRegistry());
147     }
148 
149     void getAnalysisUsage(AnalysisUsage &AU) const override {
150       AU.addRequired<AAResultsWrapperPass>();
151     }
152 
153     bool runOnFunction(Function &M) override;
154   };
155 
156   class AMDGPUUseNativeCalls : public FunctionPass {
157 
158   AMDGPULibCalls Simplifier;
159 
160   public:
161     static char ID; // Pass identification
162 
163     AMDGPUUseNativeCalls() : FunctionPass(ID) {
164       initializeAMDGPUUseNativeCallsPass(*PassRegistry::getPassRegistry());
165       Simplifier.initNativeFuncs();
166     }
167 
168     bool runOnFunction(Function &F) override;
169   };
170 
171 } // end anonymous namespace.
172 
173 char AMDGPUSimplifyLibCalls::ID = 0;
174 char AMDGPUUseNativeCalls::ID = 0;
175 
176 INITIALIZE_PASS_BEGIN(AMDGPUSimplifyLibCalls, "amdgpu-simplifylib",
177                       "Simplify well-known AMD library calls", false, false)
178 INITIALIZE_PASS_DEPENDENCY(AAResultsWrapperPass)
179 INITIALIZE_PASS_END(AMDGPUSimplifyLibCalls, "amdgpu-simplifylib",
180                     "Simplify well-known AMD library calls", false, false)
181 
182 INITIALIZE_PASS(AMDGPUUseNativeCalls, "amdgpu-usenative",
183                 "Replace builtin math calls with that native versions.",
184                 false, false)
185 
186 template <typename IRB>
187 static CallInst *CreateCallEx(IRB &B, FunctionCallee Callee, Value *Arg,
188                               const Twine &Name = "") {
189   CallInst *R = B.CreateCall(Callee, Arg, Name);
190   if (Function *F = dyn_cast<Function>(Callee.getCallee()))
191     R->setCallingConv(F->getCallingConv());
192   return R;
193 }
194 
195 template <typename IRB>
196 static CallInst *CreateCallEx2(IRB &B, FunctionCallee Callee, Value *Arg1,
197                                Value *Arg2, const Twine &Name = "") {
198   CallInst *R = B.CreateCall(Callee, {Arg1, Arg2}, Name);
199   if (Function *F = dyn_cast<Function>(Callee.getCallee()))
200     R->setCallingConv(F->getCallingConv());
201   return R;
202 }
203 
204 //  Data structures for table-driven optimizations.
205 //  FuncTbl works for both f32 and f64 functions with 1 input argument
206 
207 struct TableEntry {
208   double   result;
209   double   input;
210 };
211 
212 /* a list of {result, input} */
213 static const TableEntry tbl_acos[] = {
214   {MATH_PI / 2.0, 0.0},
215   {MATH_PI / 2.0, -0.0},
216   {0.0, 1.0},
217   {MATH_PI, -1.0}
218 };
219 static const TableEntry tbl_acosh[] = {
220   {0.0, 1.0}
221 };
222 static const TableEntry tbl_acospi[] = {
223   {0.5, 0.0},
224   {0.5, -0.0},
225   {0.0, 1.0},
226   {1.0, -1.0}
227 };
228 static const TableEntry tbl_asin[] = {
229   {0.0, 0.0},
230   {-0.0, -0.0},
231   {MATH_PI / 2.0, 1.0},
232   {-MATH_PI / 2.0, -1.0}
233 };
234 static const TableEntry tbl_asinh[] = {
235   {0.0, 0.0},
236   {-0.0, -0.0}
237 };
238 static const TableEntry tbl_asinpi[] = {
239   {0.0, 0.0},
240   {-0.0, -0.0},
241   {0.5, 1.0},
242   {-0.5, -1.0}
243 };
244 static const TableEntry tbl_atan[] = {
245   {0.0, 0.0},
246   {-0.0, -0.0},
247   {MATH_PI / 4.0, 1.0},
248   {-MATH_PI / 4.0, -1.0}
249 };
250 static const TableEntry tbl_atanh[] = {
251   {0.0, 0.0},
252   {-0.0, -0.0}
253 };
254 static const TableEntry tbl_atanpi[] = {
255   {0.0, 0.0},
256   {-0.0, -0.0},
257   {0.25, 1.0},
258   {-0.25, -1.0}
259 };
260 static const TableEntry tbl_cbrt[] = {
261   {0.0, 0.0},
262   {-0.0, -0.0},
263   {1.0, 1.0},
264   {-1.0, -1.0},
265 };
266 static const TableEntry tbl_cos[] = {
267   {1.0, 0.0},
268   {1.0, -0.0}
269 };
270 static const TableEntry tbl_cosh[] = {
271   {1.0, 0.0},
272   {1.0, -0.0}
273 };
274 static const TableEntry tbl_cospi[] = {
275   {1.0, 0.0},
276   {1.0, -0.0}
277 };
278 static const TableEntry tbl_erfc[] = {
279   {1.0, 0.0},
280   {1.0, -0.0}
281 };
282 static const TableEntry tbl_erf[] = {
283   {0.0, 0.0},
284   {-0.0, -0.0}
285 };
286 static const TableEntry tbl_exp[] = {
287   {1.0, 0.0},
288   {1.0, -0.0},
289   {MATH_E, 1.0}
290 };
291 static const TableEntry tbl_exp2[] = {
292   {1.0, 0.0},
293   {1.0, -0.0},
294   {2.0, 1.0}
295 };
296 static const TableEntry tbl_exp10[] = {
297   {1.0, 0.0},
298   {1.0, -0.0},
299   {10.0, 1.0}
300 };
301 static const TableEntry tbl_expm1[] = {
302   {0.0, 0.0},
303   {-0.0, -0.0}
304 };
305 static const TableEntry tbl_log[] = {
306   {0.0, 1.0},
307   {1.0, MATH_E}
308 };
309 static const TableEntry tbl_log2[] = {
310   {0.0, 1.0},
311   {1.0, 2.0}
312 };
313 static const TableEntry tbl_log10[] = {
314   {0.0, 1.0},
315   {1.0, 10.0}
316 };
317 static const TableEntry tbl_rsqrt[] = {
318   {1.0, 1.0},
319   {MATH_SQRT1_2, 2.0}
320 };
321 static const TableEntry tbl_sin[] = {
322   {0.0, 0.0},
323   {-0.0, -0.0}
324 };
325 static const TableEntry tbl_sinh[] = {
326   {0.0, 0.0},
327   {-0.0, -0.0}
328 };
329 static const TableEntry tbl_sinpi[] = {
330   {0.0, 0.0},
331   {-0.0, -0.0}
332 };
333 static const TableEntry tbl_sqrt[] = {
334   {0.0, 0.0},
335   {1.0, 1.0},
336   {MATH_SQRT2, 2.0}
337 };
338 static const TableEntry tbl_tan[] = {
339   {0.0, 0.0},
340   {-0.0, -0.0}
341 };
342 static const TableEntry tbl_tanh[] = {
343   {0.0, 0.0},
344   {-0.0, -0.0}
345 };
346 static const TableEntry tbl_tanpi[] = {
347   {0.0, 0.0},
348   {-0.0, -0.0}
349 };
350 static const TableEntry tbl_tgamma[] = {
351   {1.0, 1.0},
352   {1.0, 2.0},
353   {2.0, 3.0},
354   {6.0, 4.0}
355 };
356 
357 static bool HasNative(AMDGPULibFunc::EFuncId id) {
358   switch(id) {
359   case AMDGPULibFunc::EI_DIVIDE:
360   case AMDGPULibFunc::EI_COS:
361   case AMDGPULibFunc::EI_EXP:
362   case AMDGPULibFunc::EI_EXP2:
363   case AMDGPULibFunc::EI_EXP10:
364   case AMDGPULibFunc::EI_LOG:
365   case AMDGPULibFunc::EI_LOG2:
366   case AMDGPULibFunc::EI_LOG10:
367   case AMDGPULibFunc::EI_POWR:
368   case AMDGPULibFunc::EI_RECIP:
369   case AMDGPULibFunc::EI_RSQRT:
370   case AMDGPULibFunc::EI_SIN:
371   case AMDGPULibFunc::EI_SINCOS:
372   case AMDGPULibFunc::EI_SQRT:
373   case AMDGPULibFunc::EI_TAN:
374     return true;
375   default:;
376   }
377   return false;
378 }
379 
380 using TableRef = ArrayRef<TableEntry>;
381 
382 static TableRef getOptTable(AMDGPULibFunc::EFuncId id) {
383   switch(id) {
384   case AMDGPULibFunc::EI_ACOS:    return TableRef(tbl_acos);
385   case AMDGPULibFunc::EI_ACOSH:   return TableRef(tbl_acosh);
386   case AMDGPULibFunc::EI_ACOSPI:  return TableRef(tbl_acospi);
387   case AMDGPULibFunc::EI_ASIN:    return TableRef(tbl_asin);
388   case AMDGPULibFunc::EI_ASINH:   return TableRef(tbl_asinh);
389   case AMDGPULibFunc::EI_ASINPI:  return TableRef(tbl_asinpi);
390   case AMDGPULibFunc::EI_ATAN:    return TableRef(tbl_atan);
391   case AMDGPULibFunc::EI_ATANH:   return TableRef(tbl_atanh);
392   case AMDGPULibFunc::EI_ATANPI:  return TableRef(tbl_atanpi);
393   case AMDGPULibFunc::EI_CBRT:    return TableRef(tbl_cbrt);
394   case AMDGPULibFunc::EI_NCOS:
395   case AMDGPULibFunc::EI_COS:     return TableRef(tbl_cos);
396   case AMDGPULibFunc::EI_COSH:    return TableRef(tbl_cosh);
397   case AMDGPULibFunc::EI_COSPI:   return TableRef(tbl_cospi);
398   case AMDGPULibFunc::EI_ERFC:    return TableRef(tbl_erfc);
399   case AMDGPULibFunc::EI_ERF:     return TableRef(tbl_erf);
400   case AMDGPULibFunc::EI_EXP:     return TableRef(tbl_exp);
401   case AMDGPULibFunc::EI_NEXP2:
402   case AMDGPULibFunc::EI_EXP2:    return TableRef(tbl_exp2);
403   case AMDGPULibFunc::EI_EXP10:   return TableRef(tbl_exp10);
404   case AMDGPULibFunc::EI_EXPM1:   return TableRef(tbl_expm1);
405   case AMDGPULibFunc::EI_LOG:     return TableRef(tbl_log);
406   case AMDGPULibFunc::EI_NLOG2:
407   case AMDGPULibFunc::EI_LOG2:    return TableRef(tbl_log2);
408   case AMDGPULibFunc::EI_LOG10:   return TableRef(tbl_log10);
409   case AMDGPULibFunc::EI_NRSQRT:
410   case AMDGPULibFunc::EI_RSQRT:   return TableRef(tbl_rsqrt);
411   case AMDGPULibFunc::EI_NSIN:
412   case AMDGPULibFunc::EI_SIN:     return TableRef(tbl_sin);
413   case AMDGPULibFunc::EI_SINH:    return TableRef(tbl_sinh);
414   case AMDGPULibFunc::EI_SINPI:   return TableRef(tbl_sinpi);
415   case AMDGPULibFunc::EI_NSQRT:
416   case AMDGPULibFunc::EI_SQRT:    return TableRef(tbl_sqrt);
417   case AMDGPULibFunc::EI_TAN:     return TableRef(tbl_tan);
418   case AMDGPULibFunc::EI_TANH:    return TableRef(tbl_tanh);
419   case AMDGPULibFunc::EI_TANPI:   return TableRef(tbl_tanpi);
420   case AMDGPULibFunc::EI_TGAMMA:  return TableRef(tbl_tgamma);
421   default:;
422   }
423   return TableRef();
424 }
425 
426 static inline int getVecSize(const AMDGPULibFunc& FInfo) {
427   return FInfo.getLeads()[0].VectorSize;
428 }
429 
430 static inline AMDGPULibFunc::EType getArgType(const AMDGPULibFunc& FInfo) {
431   return (AMDGPULibFunc::EType)FInfo.getLeads()[0].ArgType;
432 }
433 
434 FunctionCallee AMDGPULibCalls::getFunction(Module *M, const FuncInfo &fInfo) {
435   // If we are doing PreLinkOpt, the function is external. So it is safe to
436   // use getOrInsertFunction() at this stage.
437 
438   return EnablePreLink ? AMDGPULibFunc::getOrInsertFunction(M, fInfo)
439                        : AMDGPULibFunc::getFunction(M, fInfo);
440 }
441 
442 bool AMDGPULibCalls::parseFunctionName(const StringRef &FMangledName,
443                                        FuncInfo &FInfo) {
444   return AMDGPULibFunc::parse(FMangledName, FInfo);
445 }
446 
447 bool AMDGPULibCalls::isUnsafeMath(const CallInst *CI) const {
448   if (auto Op = dyn_cast<FPMathOperator>(CI))
449     if (Op->isFast())
450       return true;
451   const Function *F = CI->getParent()->getParent();
452   Attribute Attr = F->getFnAttribute("unsafe-fp-math");
453   return Attr.getValueAsBool();
454 }
455 
456 bool AMDGPULibCalls::useNativeFunc(const StringRef F) const {
457   return AllNative || llvm::is_contained(UseNative, F);
458 }
459 
460 void AMDGPULibCalls::initNativeFuncs() {
461   AllNative = useNativeFunc("all") ||
462               (UseNative.getNumOccurrences() && UseNative.size() == 1 &&
463                UseNative.begin()->empty());
464 }
465 
466 bool AMDGPULibCalls::sincosUseNative(CallInst *aCI, const FuncInfo &FInfo) {
467   bool native_sin = useNativeFunc("sin");
468   bool native_cos = useNativeFunc("cos");
469 
470   if (native_sin && native_cos) {
471     Module *M = aCI->getModule();
472     Value *opr0 = aCI->getArgOperand(0);
473 
474     AMDGPULibFunc nf;
475     nf.getLeads()[0].ArgType = FInfo.getLeads()[0].ArgType;
476     nf.getLeads()[0].VectorSize = FInfo.getLeads()[0].VectorSize;
477 
478     nf.setPrefix(AMDGPULibFunc::NATIVE);
479     nf.setId(AMDGPULibFunc::EI_SIN);
480     FunctionCallee sinExpr = getFunction(M, nf);
481 
482     nf.setPrefix(AMDGPULibFunc::NATIVE);
483     nf.setId(AMDGPULibFunc::EI_COS);
484     FunctionCallee cosExpr = getFunction(M, nf);
485     if (sinExpr && cosExpr) {
486       Value *sinval = CallInst::Create(sinExpr, opr0, "splitsin", aCI);
487       Value *cosval = CallInst::Create(cosExpr, opr0, "splitcos", aCI);
488       new StoreInst(cosval, aCI->getArgOperand(1), aCI);
489 
490       DEBUG_WITH_TYPE("usenative", dbgs() << "<useNative> replace " << *aCI
491                                           << " with native version of sin/cos");
492 
493       replaceCall(sinval);
494       return true;
495     }
496   }
497   return false;
498 }
499 
500 bool AMDGPULibCalls::useNative(CallInst *aCI) {
501   CI = aCI;
502   Function *Callee = aCI->getCalledFunction();
503   if (!Callee)
504     return false;
505 
506   FuncInfo FInfo;
507   if (!parseFunctionName(Callee->getName(), FInfo) || !FInfo.isMangled() ||
508       FInfo.getPrefix() != AMDGPULibFunc::NOPFX ||
509       getArgType(FInfo) == AMDGPULibFunc::F64 || !HasNative(FInfo.getId()) ||
510       !(AllNative || useNativeFunc(FInfo.getName()))) {
511     return false;
512   }
513 
514   if (FInfo.getId() == AMDGPULibFunc::EI_SINCOS)
515     return sincosUseNative(aCI, FInfo);
516 
517   FInfo.setPrefix(AMDGPULibFunc::NATIVE);
518   FunctionCallee F = getFunction(aCI->getModule(), FInfo);
519   if (!F)
520     return false;
521 
522   aCI->setCalledFunction(F);
523   DEBUG_WITH_TYPE("usenative", dbgs() << "<useNative> replace " << *aCI
524                                       << " with native version");
525   return true;
526 }
527 
528 // Clang emits call of __read_pipe_2 or __read_pipe_4 for OpenCL read_pipe
529 // builtin, with appended type size and alignment arguments, where 2 or 4
530 // indicates the original number of arguments. The library has optimized version
531 // of __read_pipe_2/__read_pipe_4 when the type size and alignment has the same
532 // power of 2 value. This function transforms __read_pipe_2 to __read_pipe_2_N
533 // for such cases where N is the size in bytes of the type (N = 1, 2, 4, 8, ...,
534 // 128). The same for __read_pipe_4, write_pipe_2, and write_pipe_4.
535 bool AMDGPULibCalls::fold_read_write_pipe(CallInst *CI, IRBuilder<> &B,
536                                           const FuncInfo &FInfo) {
537   auto *Callee = CI->getCalledFunction();
538   if (!Callee->isDeclaration())
539     return false;
540 
541   assert(Callee->hasName() && "Invalid read_pipe/write_pipe function");
542   auto *M = Callee->getParent();
543   std::string Name = std::string(Callee->getName());
544   auto NumArg = CI->arg_size();
545   if (NumArg != 4 && NumArg != 6)
546     return false;
547   auto *PacketSize = CI->getArgOperand(NumArg - 2);
548   auto *PacketAlign = CI->getArgOperand(NumArg - 1);
549   if (!isa<ConstantInt>(PacketSize) || !isa<ConstantInt>(PacketAlign))
550     return false;
551   unsigned Size = cast<ConstantInt>(PacketSize)->getZExtValue();
552   Align Alignment = cast<ConstantInt>(PacketAlign)->getAlignValue();
553   if (Alignment != Size)
554     return false;
555 
556   unsigned PtrArgLoc = CI->arg_size() - 3;
557   Value *PtrArg = CI->getArgOperand(PtrArgLoc);
558   Type *PtrTy = PtrArg->getType();
559 
560   SmallVector<llvm::Type *, 6> ArgTys;
561   for (unsigned I = 0; I != PtrArgLoc; ++I)
562     ArgTys.push_back(CI->getArgOperand(I)->getType());
563   ArgTys.push_back(PtrTy);
564 
565   Name = Name + "_" + std::to_string(Size);
566   auto *FTy = FunctionType::get(Callee->getReturnType(),
567                                 ArrayRef<Type *>(ArgTys), false);
568   AMDGPULibFunc NewLibFunc(Name, FTy);
569   FunctionCallee F = AMDGPULibFunc::getOrInsertFunction(M, NewLibFunc);
570   if (!F)
571     return false;
572 
573   auto *BCast = B.CreatePointerCast(PtrArg, PtrTy);
574   SmallVector<Value *, 6> Args;
575   for (unsigned I = 0; I != PtrArgLoc; ++I)
576     Args.push_back(CI->getArgOperand(I));
577   Args.push_back(BCast);
578 
579   auto *NCI = B.CreateCall(F, Args);
580   NCI->setAttributes(CI->getAttributes());
581   CI->replaceAllUsesWith(NCI);
582   CI->dropAllReferences();
583   CI->eraseFromParent();
584 
585   return true;
586 }
587 
588 // This function returns false if no change; return true otherwise.
589 bool AMDGPULibCalls::fold(CallInst *CI, AliasAnalysis *AA) {
590   this->CI = CI;
591   Function *Callee = CI->getCalledFunction();
592   // Ignore indirect calls.
593   if (!Callee)
594     return false;
595 
596   IRBuilder<> B(CI);
597   switch (Callee->getIntrinsicID()) {
598   case Intrinsic::not_intrinsic:
599     break;
600   case Intrinsic::amdgcn_wavefrontsize:
601     return !EnablePreLink && fold_wavefrontsize(CI, B);
602   default:
603     return false;
604   }
605 
606   FuncInfo FInfo;
607   if (!parseFunctionName(Callee->getName(), FInfo))
608     return false;
609 
610   // Further check the number of arguments to see if they match.
611   if (CI->arg_size() != FInfo.getNumArgs())
612     return false;
613 
614   LLVM_DEBUG(dbgs() << "AMDIC: try folding " << *CI << '\n');
615 
616   if (TDOFold(CI, FInfo))
617     return true;
618 
619   // Under unsafe-math, evaluate calls if possible.
620   // According to Brian Sumner, we can do this for all f32 function calls
621   // using host's double function calls.
622   if (isUnsafeMath(CI) && evaluateCall(CI, FInfo))
623     return true;
624 
625   // Copy fast flags from the original call.
626   if (const FPMathOperator *FPOp = dyn_cast<const FPMathOperator>(CI))
627     B.setFastMathFlags(FPOp->getFastMathFlags());
628 
629   // Specialized optimizations for each function call
630   switch (FInfo.getId()) {
631   case AMDGPULibFunc::EI_RECIP:
632     // skip vector function
633     assert ((FInfo.getPrefix() == AMDGPULibFunc::NATIVE ||
634              FInfo.getPrefix() == AMDGPULibFunc::HALF) &&
635             "recip must be an either native or half function");
636     return (getVecSize(FInfo) != 1) ? false : fold_recip(CI, B, FInfo);
637 
638   case AMDGPULibFunc::EI_DIVIDE:
639     // skip vector function
640     assert ((FInfo.getPrefix() == AMDGPULibFunc::NATIVE ||
641              FInfo.getPrefix() == AMDGPULibFunc::HALF) &&
642             "divide must be an either native or half function");
643     return (getVecSize(FInfo) != 1) ? false : fold_divide(CI, B, FInfo);
644 
645   case AMDGPULibFunc::EI_POW:
646   case AMDGPULibFunc::EI_POWR:
647   case AMDGPULibFunc::EI_POWN:
648     return fold_pow(CI, B, FInfo);
649 
650   case AMDGPULibFunc::EI_ROOTN:
651     // skip vector function
652     return (getVecSize(FInfo) != 1) ? false : fold_rootn(CI, B, FInfo);
653 
654   case AMDGPULibFunc::EI_FMA:
655   case AMDGPULibFunc::EI_MAD:
656   case AMDGPULibFunc::EI_NFMA:
657     // skip vector function
658     return (getVecSize(FInfo) != 1) ? false : fold_fma_mad(CI, B, FInfo);
659 
660   case AMDGPULibFunc::EI_SQRT:
661     return isUnsafeMath(CI) && fold_sqrt(CI, B, FInfo);
662   case AMDGPULibFunc::EI_COS:
663   case AMDGPULibFunc::EI_SIN:
664     if ((getArgType(FInfo) == AMDGPULibFunc::F32 ||
665          getArgType(FInfo) == AMDGPULibFunc::F64)
666         && (FInfo.getPrefix() == AMDGPULibFunc::NOPFX))
667       return fold_sincos(CI, B, AA);
668 
669     break;
670   case AMDGPULibFunc::EI_READ_PIPE_2:
671   case AMDGPULibFunc::EI_READ_PIPE_4:
672   case AMDGPULibFunc::EI_WRITE_PIPE_2:
673   case AMDGPULibFunc::EI_WRITE_PIPE_4:
674     return fold_read_write_pipe(CI, B, FInfo);
675 
676   default:
677     break;
678   }
679 
680   return false;
681 }
682 
683 bool AMDGPULibCalls::TDOFold(CallInst *CI, const FuncInfo &FInfo) {
684   // Table-Driven optimization
685   const TableRef tr = getOptTable(FInfo.getId());
686   if (tr.empty())
687     return false;
688 
689   int const sz = (int)tr.size();
690   Value *opr0 = CI->getArgOperand(0);
691 
692   if (getVecSize(FInfo) > 1) {
693     if (ConstantDataVector *CV = dyn_cast<ConstantDataVector>(opr0)) {
694       SmallVector<double, 0> DVal;
695       for (int eltNo = 0; eltNo < getVecSize(FInfo); ++eltNo) {
696         ConstantFP *eltval = dyn_cast<ConstantFP>(
697                                CV->getElementAsConstant((unsigned)eltNo));
698         assert(eltval && "Non-FP arguments in math function!");
699         bool found = false;
700         for (int i=0; i < sz; ++i) {
701           if (eltval->isExactlyValue(tr[i].input)) {
702             DVal.push_back(tr[i].result);
703             found = true;
704             break;
705           }
706         }
707         if (!found) {
708           // This vector constants not handled yet.
709           return false;
710         }
711       }
712       LLVMContext &context = CI->getParent()->getParent()->getContext();
713       Constant *nval;
714       if (getArgType(FInfo) == AMDGPULibFunc::F32) {
715         SmallVector<float, 0> FVal;
716         for (unsigned i = 0; i < DVal.size(); ++i) {
717           FVal.push_back((float)DVal[i]);
718         }
719         ArrayRef<float> tmp(FVal);
720         nval = ConstantDataVector::get(context, tmp);
721       } else { // F64
722         ArrayRef<double> tmp(DVal);
723         nval = ConstantDataVector::get(context, tmp);
724       }
725       LLVM_DEBUG(errs() << "AMDIC: " << *CI << " ---> " << *nval << "\n");
726       replaceCall(nval);
727       return true;
728     }
729   } else {
730     // Scalar version
731     if (ConstantFP *CF = dyn_cast<ConstantFP>(opr0)) {
732       for (int i = 0; i < sz; ++i) {
733         if (CF->isExactlyValue(tr[i].input)) {
734           Value *nval = ConstantFP::get(CF->getType(), tr[i].result);
735           LLVM_DEBUG(errs() << "AMDIC: " << *CI << " ---> " << *nval << "\n");
736           replaceCall(nval);
737           return true;
738         }
739       }
740     }
741   }
742 
743   return false;
744 }
745 
746 //  [native_]half_recip(c) ==> 1.0/c
747 bool AMDGPULibCalls::fold_recip(CallInst *CI, IRBuilder<> &B,
748                                 const FuncInfo &FInfo) {
749   Value *opr0 = CI->getArgOperand(0);
750   if (ConstantFP *CF = dyn_cast<ConstantFP>(opr0)) {
751     // Just create a normal div. Later, InstCombine will be able
752     // to compute the divide into a constant (avoid check float infinity
753     // or subnormal at this point).
754     Value *nval = B.CreateFDiv(ConstantFP::get(CF->getType(), 1.0),
755                                opr0,
756                                "recip2div");
757     LLVM_DEBUG(errs() << "AMDIC: " << *CI << " ---> " << *nval << "\n");
758     replaceCall(nval);
759     return true;
760   }
761   return false;
762 }
763 
764 //  [native_]half_divide(x, c) ==> x/c
765 bool AMDGPULibCalls::fold_divide(CallInst *CI, IRBuilder<> &B,
766                                  const FuncInfo &FInfo) {
767   Value *opr0 = CI->getArgOperand(0);
768   Value *opr1 = CI->getArgOperand(1);
769   ConstantFP *CF0 = dyn_cast<ConstantFP>(opr0);
770   ConstantFP *CF1 = dyn_cast<ConstantFP>(opr1);
771 
772   if ((CF0 && CF1) ||  // both are constants
773       (CF1 && (getArgType(FInfo) == AMDGPULibFunc::F32)))
774       // CF1 is constant && f32 divide
775   {
776     Value *nval1 = B.CreateFDiv(ConstantFP::get(opr1->getType(), 1.0),
777                                 opr1, "__div2recip");
778     Value *nval  = B.CreateFMul(opr0, nval1, "__div2mul");
779     replaceCall(nval);
780     return true;
781   }
782   return false;
783 }
784 
785 namespace llvm {
786 static double log2(double V) {
787 #if _XOPEN_SOURCE >= 600 || defined(_ISOC99_SOURCE) || _POSIX_C_SOURCE >= 200112L
788   return ::log2(V);
789 #else
790   return log(V) / numbers::ln2;
791 #endif
792 }
793 }
794 
795 bool AMDGPULibCalls::fold_pow(CallInst *CI, IRBuilder<> &B,
796                               const FuncInfo &FInfo) {
797   assert((FInfo.getId() == AMDGPULibFunc::EI_POW ||
798           FInfo.getId() == AMDGPULibFunc::EI_POWR ||
799           FInfo.getId() == AMDGPULibFunc::EI_POWN) &&
800          "fold_pow: encounter a wrong function call");
801 
802   Value *opr0, *opr1;
803   ConstantFP *CF;
804   ConstantInt *CINT;
805   ConstantAggregateZero *CZero;
806   Type *eltType;
807 
808   opr0 = CI->getArgOperand(0);
809   opr1 = CI->getArgOperand(1);
810   CZero = dyn_cast<ConstantAggregateZero>(opr1);
811   if (getVecSize(FInfo) == 1) {
812     eltType = opr0->getType();
813     CF = dyn_cast<ConstantFP>(opr1);
814     CINT = dyn_cast<ConstantInt>(opr1);
815   } else {
816     VectorType *VTy = dyn_cast<VectorType>(opr0->getType());
817     assert(VTy && "Oprand of vector function should be of vectortype");
818     eltType = VTy->getElementType();
819     ConstantDataVector *CDV = dyn_cast<ConstantDataVector>(opr1);
820 
821     // Now, only Handle vector const whose elements have the same value.
822     CF = CDV ? dyn_cast_or_null<ConstantFP>(CDV->getSplatValue()) : nullptr;
823     CINT = CDV ? dyn_cast_or_null<ConstantInt>(CDV->getSplatValue()) : nullptr;
824   }
825 
826   // No unsafe math , no constant argument, do nothing
827   if (!isUnsafeMath(CI) && !CF && !CINT && !CZero)
828     return false;
829 
830   // 0x1111111 means that we don't do anything for this call.
831   int ci_opr1 = (CINT ? (int)CINT->getSExtValue() : 0x1111111);
832 
833   if ((CF && CF->isZero()) || (CINT && ci_opr1 == 0) || CZero) {
834     //  pow/powr/pown(x, 0) == 1
835     LLVM_DEBUG(errs() << "AMDIC: " << *CI << " ---> 1\n");
836     Constant *cnval = ConstantFP::get(eltType, 1.0);
837     if (getVecSize(FInfo) > 1) {
838       cnval = ConstantDataVector::getSplat(getVecSize(FInfo), cnval);
839     }
840     replaceCall(cnval);
841     return true;
842   }
843   if ((CF && CF->isExactlyValue(1.0)) || (CINT && ci_opr1 == 1)) {
844     // pow/powr/pown(x, 1.0) = x
845     LLVM_DEBUG(errs() << "AMDIC: " << *CI << " ---> " << *opr0 << "\n");
846     replaceCall(opr0);
847     return true;
848   }
849   if ((CF && CF->isExactlyValue(2.0)) || (CINT && ci_opr1 == 2)) {
850     // pow/powr/pown(x, 2.0) = x*x
851     LLVM_DEBUG(errs() << "AMDIC: " << *CI << " ---> " << *opr0 << " * " << *opr0
852                       << "\n");
853     Value *nval = B.CreateFMul(opr0, opr0, "__pow2");
854     replaceCall(nval);
855     return true;
856   }
857   if ((CF && CF->isExactlyValue(-1.0)) || (CINT && ci_opr1 == -1)) {
858     // pow/powr/pown(x, -1.0) = 1.0/x
859     LLVM_DEBUG(errs() << "AMDIC: " << *CI << " ---> 1 / " << *opr0 << "\n");
860     Constant *cnval = ConstantFP::get(eltType, 1.0);
861     if (getVecSize(FInfo) > 1) {
862       cnval = ConstantDataVector::getSplat(getVecSize(FInfo), cnval);
863     }
864     Value *nval = B.CreateFDiv(cnval, opr0, "__powrecip");
865     replaceCall(nval);
866     return true;
867   }
868 
869   Module *M = CI->getModule();
870   if (CF && (CF->isExactlyValue(0.5) || CF->isExactlyValue(-0.5))) {
871     // pow[r](x, [-]0.5) = sqrt(x)
872     bool issqrt = CF->isExactlyValue(0.5);
873     if (FunctionCallee FPExpr =
874             getFunction(M, AMDGPULibFunc(issqrt ? AMDGPULibFunc::EI_SQRT
875                                                 : AMDGPULibFunc::EI_RSQRT,
876                                          FInfo))) {
877       LLVM_DEBUG(errs() << "AMDIC: " << *CI << " ---> "
878                         << FInfo.getName().c_str() << "(" << *opr0 << ")\n");
879       Value *nval = CreateCallEx(B,FPExpr, opr0, issqrt ? "__pow2sqrt"
880                                                         : "__pow2rsqrt");
881       replaceCall(nval);
882       return true;
883     }
884   }
885 
886   if (!isUnsafeMath(CI))
887     return false;
888 
889   // Unsafe Math optimization
890 
891   // Remember that ci_opr1 is set if opr1 is integral
892   if (CF) {
893     double dval = (getArgType(FInfo) == AMDGPULibFunc::F32)
894                     ? (double)CF->getValueAPF().convertToFloat()
895                     : CF->getValueAPF().convertToDouble();
896     int ival = (int)dval;
897     if ((double)ival == dval) {
898       ci_opr1 = ival;
899     } else
900       ci_opr1 = 0x11111111;
901   }
902 
903   // pow/powr/pown(x, c) = [1/](x*x*..x); where
904   //   trunc(c) == c && the number of x == c && |c| <= 12
905   unsigned abs_opr1 = (ci_opr1 < 0) ? -ci_opr1 : ci_opr1;
906   if (abs_opr1 <= 12) {
907     Constant *cnval;
908     Value *nval;
909     if (abs_opr1 == 0) {
910       cnval = ConstantFP::get(eltType, 1.0);
911       if (getVecSize(FInfo) > 1) {
912         cnval = ConstantDataVector::getSplat(getVecSize(FInfo), cnval);
913       }
914       nval = cnval;
915     } else {
916       Value *valx2 = nullptr;
917       nval = nullptr;
918       while (abs_opr1 > 0) {
919         valx2 = valx2 ? B.CreateFMul(valx2, valx2, "__powx2") : opr0;
920         if (abs_opr1 & 1) {
921           nval = nval ? B.CreateFMul(nval, valx2, "__powprod") : valx2;
922         }
923         abs_opr1 >>= 1;
924       }
925     }
926 
927     if (ci_opr1 < 0) {
928       cnval = ConstantFP::get(eltType, 1.0);
929       if (getVecSize(FInfo) > 1) {
930         cnval = ConstantDataVector::getSplat(getVecSize(FInfo), cnval);
931       }
932       nval = B.CreateFDiv(cnval, nval, "__1powprod");
933     }
934     LLVM_DEBUG(errs() << "AMDIC: " << *CI << " ---> "
935                       << ((ci_opr1 < 0) ? "1/prod(" : "prod(") << *opr0
936                       << ")\n");
937     replaceCall(nval);
938     return true;
939   }
940 
941   // powr ---> exp2(y * log2(x))
942   // pown/pow ---> powr(fabs(x), y) | (x & ((int)y << 31))
943   FunctionCallee ExpExpr =
944       getFunction(M, AMDGPULibFunc(AMDGPULibFunc::EI_EXP2, FInfo));
945   if (!ExpExpr)
946     return false;
947 
948   bool needlog = false;
949   bool needabs = false;
950   bool needcopysign = false;
951   Constant *cnval = nullptr;
952   if (getVecSize(FInfo) == 1) {
953     CF = dyn_cast<ConstantFP>(opr0);
954 
955     if (CF) {
956       double V = (getArgType(FInfo) == AMDGPULibFunc::F32)
957                    ? (double)CF->getValueAPF().convertToFloat()
958                    : CF->getValueAPF().convertToDouble();
959 
960       V = log2(std::abs(V));
961       cnval = ConstantFP::get(eltType, V);
962       needcopysign = (FInfo.getId() != AMDGPULibFunc::EI_POWR) &&
963                      CF->isNegative();
964     } else {
965       needlog = true;
966       needcopysign = needabs = FInfo.getId() != AMDGPULibFunc::EI_POWR &&
967                                (!CF || CF->isNegative());
968     }
969   } else {
970     ConstantDataVector *CDV = dyn_cast<ConstantDataVector>(opr0);
971 
972     if (!CDV) {
973       needlog = true;
974       needcopysign = needabs = FInfo.getId() != AMDGPULibFunc::EI_POWR;
975     } else {
976       assert ((int)CDV->getNumElements() == getVecSize(FInfo) &&
977               "Wrong vector size detected");
978 
979       SmallVector<double, 0> DVal;
980       for (int i=0; i < getVecSize(FInfo); ++i) {
981         double V = (getArgType(FInfo) == AMDGPULibFunc::F32)
982                      ? (double)CDV->getElementAsFloat(i)
983                      : CDV->getElementAsDouble(i);
984         if (V < 0.0) needcopysign = true;
985         V = log2(std::abs(V));
986         DVal.push_back(V);
987       }
988       if (getArgType(FInfo) == AMDGPULibFunc::F32) {
989         SmallVector<float, 0> FVal;
990         for (unsigned i=0; i < DVal.size(); ++i) {
991           FVal.push_back((float)DVal[i]);
992         }
993         ArrayRef<float> tmp(FVal);
994         cnval = ConstantDataVector::get(M->getContext(), tmp);
995       } else {
996         ArrayRef<double> tmp(DVal);
997         cnval = ConstantDataVector::get(M->getContext(), tmp);
998       }
999     }
1000   }
1001 
1002   if (needcopysign && (FInfo.getId() == AMDGPULibFunc::EI_POW)) {
1003     // We cannot handle corner cases for a general pow() function, give up
1004     // unless y is a constant integral value. Then proceed as if it were pown.
1005     if (getVecSize(FInfo) == 1) {
1006       if (const ConstantFP *CF = dyn_cast<ConstantFP>(opr1)) {
1007         double y = (getArgType(FInfo) == AMDGPULibFunc::F32)
1008                    ? (double)CF->getValueAPF().convertToFloat()
1009                    : CF->getValueAPF().convertToDouble();
1010         if (y != (double)(int64_t)y)
1011           return false;
1012       } else
1013         return false;
1014     } else {
1015       if (const ConstantDataVector *CDV = dyn_cast<ConstantDataVector>(opr1)) {
1016         for (int i=0; i < getVecSize(FInfo); ++i) {
1017           double y = (getArgType(FInfo) == AMDGPULibFunc::F32)
1018                      ? (double)CDV->getElementAsFloat(i)
1019                      : CDV->getElementAsDouble(i);
1020           if (y != (double)(int64_t)y)
1021             return false;
1022         }
1023       } else
1024         return false;
1025     }
1026   }
1027 
1028   Value *nval;
1029   if (needabs) {
1030     FunctionCallee AbsExpr =
1031         getFunction(M, AMDGPULibFunc(AMDGPULibFunc::EI_FABS, FInfo));
1032     if (!AbsExpr)
1033       return false;
1034     nval = CreateCallEx(B, AbsExpr, opr0, "__fabs");
1035   } else {
1036     nval = cnval ? cnval : opr0;
1037   }
1038   if (needlog) {
1039     FunctionCallee LogExpr =
1040         getFunction(M, AMDGPULibFunc(AMDGPULibFunc::EI_LOG2, FInfo));
1041     if (!LogExpr)
1042       return false;
1043     nval = CreateCallEx(B,LogExpr, nval, "__log2");
1044   }
1045 
1046   if (FInfo.getId() == AMDGPULibFunc::EI_POWN) {
1047     // convert int(32) to fp(f32 or f64)
1048     opr1 = B.CreateSIToFP(opr1, nval->getType(), "pownI2F");
1049   }
1050   nval = B.CreateFMul(opr1, nval, "__ylogx");
1051   nval = CreateCallEx(B,ExpExpr, nval, "__exp2");
1052 
1053   if (needcopysign) {
1054     Value *opr_n;
1055     Type* rTy = opr0->getType();
1056     Type* nTyS = eltType->isDoubleTy() ? B.getInt64Ty() : B.getInt32Ty();
1057     Type *nTy = nTyS;
1058     if (const auto *vTy = dyn_cast<FixedVectorType>(rTy))
1059       nTy = FixedVectorType::get(nTyS, vTy);
1060     unsigned size = nTy->getScalarSizeInBits();
1061     opr_n = CI->getArgOperand(1);
1062     if (opr_n->getType()->isIntegerTy())
1063       opr_n = B.CreateZExtOrBitCast(opr_n, nTy, "__ytou");
1064     else
1065       opr_n = B.CreateFPToSI(opr1, nTy, "__ytou");
1066 
1067     Value *sign = B.CreateShl(opr_n, size-1, "__yeven");
1068     sign = B.CreateAnd(B.CreateBitCast(opr0, nTy), sign, "__pow_sign");
1069     nval = B.CreateOr(B.CreateBitCast(nval, nTy), sign);
1070     nval = B.CreateBitCast(nval, opr0->getType());
1071   }
1072 
1073   LLVM_DEBUG(errs() << "AMDIC: " << *CI << " ---> "
1074                     << "exp2(" << *opr1 << " * log2(" << *opr0 << "))\n");
1075   replaceCall(nval);
1076 
1077   return true;
1078 }
1079 
1080 bool AMDGPULibCalls::fold_rootn(CallInst *CI, IRBuilder<> &B,
1081                                 const FuncInfo &FInfo) {
1082   Value *opr0 = CI->getArgOperand(0);
1083   Value *opr1 = CI->getArgOperand(1);
1084 
1085   ConstantInt *CINT = dyn_cast<ConstantInt>(opr1);
1086   if (!CINT) {
1087     return false;
1088   }
1089   int ci_opr1 = (int)CINT->getSExtValue();
1090   if (ci_opr1 == 1) {  // rootn(x, 1) = x
1091     LLVM_DEBUG(errs() << "AMDIC: " << *CI << " ---> " << *opr0 << "\n");
1092     replaceCall(opr0);
1093     return true;
1094   }
1095   if (ci_opr1 == 2) {  // rootn(x, 2) = sqrt(x)
1096     Module *M = CI->getModule();
1097     if (FunctionCallee FPExpr =
1098             getFunction(M, AMDGPULibFunc(AMDGPULibFunc::EI_SQRT, FInfo))) {
1099       LLVM_DEBUG(errs() << "AMDIC: " << *CI << " ---> sqrt(" << *opr0 << ")\n");
1100       Value *nval = CreateCallEx(B,FPExpr, opr0, "__rootn2sqrt");
1101       replaceCall(nval);
1102       return true;
1103     }
1104   } else if (ci_opr1 == 3) { // rootn(x, 3) = cbrt(x)
1105     Module *M = CI->getModule();
1106     if (FunctionCallee FPExpr =
1107             getFunction(M, AMDGPULibFunc(AMDGPULibFunc::EI_CBRT, FInfo))) {
1108       LLVM_DEBUG(errs() << "AMDIC: " << *CI << " ---> cbrt(" << *opr0 << ")\n");
1109       Value *nval = CreateCallEx(B,FPExpr, opr0, "__rootn2cbrt");
1110       replaceCall(nval);
1111       return true;
1112     }
1113   } else if (ci_opr1 == -1) { // rootn(x, -1) = 1.0/x
1114     LLVM_DEBUG(errs() << "AMDIC: " << *CI << " ---> 1.0 / " << *opr0 << "\n");
1115     Value *nval = B.CreateFDiv(ConstantFP::get(opr0->getType(), 1.0),
1116                                opr0,
1117                                "__rootn2div");
1118     replaceCall(nval);
1119     return true;
1120   } else if (ci_opr1 == -2) {  // rootn(x, -2) = rsqrt(x)
1121     Module *M = CI->getModule();
1122     if (FunctionCallee FPExpr =
1123             getFunction(M, AMDGPULibFunc(AMDGPULibFunc::EI_RSQRT, FInfo))) {
1124       LLVM_DEBUG(errs() << "AMDIC: " << *CI << " ---> rsqrt(" << *opr0
1125                         << ")\n");
1126       Value *nval = CreateCallEx(B,FPExpr, opr0, "__rootn2rsqrt");
1127       replaceCall(nval);
1128       return true;
1129     }
1130   }
1131   return false;
1132 }
1133 
1134 bool AMDGPULibCalls::fold_fma_mad(CallInst *CI, IRBuilder<> &B,
1135                                   const FuncInfo &FInfo) {
1136   Value *opr0 = CI->getArgOperand(0);
1137   Value *opr1 = CI->getArgOperand(1);
1138   Value *opr2 = CI->getArgOperand(2);
1139 
1140   ConstantFP *CF0 = dyn_cast<ConstantFP>(opr0);
1141   ConstantFP *CF1 = dyn_cast<ConstantFP>(opr1);
1142   if ((CF0 && CF0->isZero()) || (CF1 && CF1->isZero())) {
1143     // fma/mad(a, b, c) = c if a=0 || b=0
1144     LLVM_DEBUG(errs() << "AMDIC: " << *CI << " ---> " << *opr2 << "\n");
1145     replaceCall(opr2);
1146     return true;
1147   }
1148   if (CF0 && CF0->isExactlyValue(1.0f)) {
1149     // fma/mad(a, b, c) = b+c if a=1
1150     LLVM_DEBUG(errs() << "AMDIC: " << *CI << " ---> " << *opr1 << " + " << *opr2
1151                       << "\n");
1152     Value *nval = B.CreateFAdd(opr1, opr2, "fmaadd");
1153     replaceCall(nval);
1154     return true;
1155   }
1156   if (CF1 && CF1->isExactlyValue(1.0f)) {
1157     // fma/mad(a, b, c) = a+c if b=1
1158     LLVM_DEBUG(errs() << "AMDIC: " << *CI << " ---> " << *opr0 << " + " << *opr2
1159                       << "\n");
1160     Value *nval = B.CreateFAdd(opr0, opr2, "fmaadd");
1161     replaceCall(nval);
1162     return true;
1163   }
1164   if (ConstantFP *CF = dyn_cast<ConstantFP>(opr2)) {
1165     if (CF->isZero()) {
1166       // fma/mad(a, b, c) = a*b if c=0
1167       LLVM_DEBUG(errs() << "AMDIC: " << *CI << " ---> " << *opr0 << " * "
1168                         << *opr1 << "\n");
1169       Value *nval = B.CreateFMul(opr0, opr1, "fmamul");
1170       replaceCall(nval);
1171       return true;
1172     }
1173   }
1174 
1175   return false;
1176 }
1177 
1178 // Get a scalar native builtin single argument FP function
1179 FunctionCallee AMDGPULibCalls::getNativeFunction(Module *M,
1180                                                  const FuncInfo &FInfo) {
1181   if (getArgType(FInfo) == AMDGPULibFunc::F64 || !HasNative(FInfo.getId()))
1182     return nullptr;
1183   FuncInfo nf = FInfo;
1184   nf.setPrefix(AMDGPULibFunc::NATIVE);
1185   return getFunction(M, nf);
1186 }
1187 
1188 // fold sqrt -> native_sqrt (x)
1189 bool AMDGPULibCalls::fold_sqrt(CallInst *CI, IRBuilder<> &B,
1190                                const FuncInfo &FInfo) {
1191   if (getArgType(FInfo) == AMDGPULibFunc::F32 && (getVecSize(FInfo) == 1) &&
1192       (FInfo.getPrefix() != AMDGPULibFunc::NATIVE)) {
1193     if (FunctionCallee FPExpr = getNativeFunction(
1194             CI->getModule(), AMDGPULibFunc(AMDGPULibFunc::EI_SQRT, FInfo))) {
1195       Value *opr0 = CI->getArgOperand(0);
1196       LLVM_DEBUG(errs() << "AMDIC: " << *CI << " ---> "
1197                         << "sqrt(" << *opr0 << ")\n");
1198       Value *nval = CreateCallEx(B,FPExpr, opr0, "__sqrt");
1199       replaceCall(nval);
1200       return true;
1201     }
1202   }
1203   return false;
1204 }
1205 
1206 // fold sin, cos -> sincos.
1207 bool AMDGPULibCalls::fold_sincos(CallInst *CI, IRBuilder<> &B,
1208                                  AliasAnalysis *AA) {
1209   AMDGPULibFunc fInfo;
1210   if (!AMDGPULibFunc::parse(CI->getCalledFunction()->getName(), fInfo))
1211     return false;
1212 
1213   assert(fInfo.getId() == AMDGPULibFunc::EI_SIN ||
1214          fInfo.getId() == AMDGPULibFunc::EI_COS);
1215   bool const isSin = fInfo.getId() == AMDGPULibFunc::EI_SIN;
1216 
1217   Value *CArgVal = CI->getArgOperand(0);
1218   BasicBlock * const CBB = CI->getParent();
1219 
1220   int const MaxScan = 30;
1221   bool Changed = false;
1222 
1223   { // fold in load value.
1224     LoadInst *LI = dyn_cast<LoadInst>(CArgVal);
1225     if (LI && LI->getParent() == CBB) {
1226       BasicBlock::iterator BBI = LI->getIterator();
1227       Value *AvailableVal = FindAvailableLoadedValue(LI, CBB, BBI, MaxScan, AA);
1228       if (AvailableVal) {
1229         Changed = true;
1230         CArgVal->replaceAllUsesWith(AvailableVal);
1231         if (CArgVal->getNumUses() == 0)
1232           LI->eraseFromParent();
1233         CArgVal = CI->getArgOperand(0);
1234       }
1235     }
1236   }
1237 
1238   Module *M = CI->getModule();
1239   fInfo.setId(isSin ? AMDGPULibFunc::EI_COS : AMDGPULibFunc::EI_SIN);
1240   std::string const PairName = fInfo.mangle();
1241 
1242   CallInst *UI = nullptr;
1243   for (User* U : CArgVal->users()) {
1244     CallInst *XI = dyn_cast_or_null<CallInst>(U);
1245     if (!XI || XI == CI || XI->getParent() != CBB)
1246       continue;
1247 
1248     Function *UCallee = XI->getCalledFunction();
1249     if (!UCallee || !UCallee->getName().equals(PairName))
1250       continue;
1251 
1252     BasicBlock::iterator BBI = CI->getIterator();
1253     if (BBI == CI->getParent()->begin())
1254       break;
1255     --BBI;
1256     for (int I = MaxScan; I > 0 && BBI != CBB->begin(); --BBI, --I) {
1257       if (cast<Instruction>(BBI) == XI) {
1258         UI = XI;
1259         break;
1260       }
1261     }
1262     if (UI) break;
1263   }
1264 
1265   if (!UI)
1266     return Changed;
1267 
1268   // Merge the sin and cos.
1269 
1270   // for OpenCL 2.0 we have only generic implementation of sincos
1271   // function.
1272   AMDGPULibFunc nf(AMDGPULibFunc::EI_SINCOS, fInfo);
1273   nf.getLeads()[0].PtrKind = AMDGPULibFunc::getEPtrKindFromAddrSpace(AMDGPUAS::FLAT_ADDRESS);
1274   FunctionCallee Fsincos = getFunction(M, nf);
1275   if (!Fsincos)
1276     return Changed;
1277 
1278   BasicBlock::iterator ItOld = B.GetInsertPoint();
1279   AllocaInst *Alloc = insertAlloca(UI, B, "__sincos_");
1280   B.SetInsertPoint(UI);
1281 
1282   Value *P = Alloc;
1283   Type *PTy = Fsincos.getFunctionType()->getParamType(1);
1284   // The allocaInst allocates the memory in private address space. This need
1285   // to be bitcasted to point to the address space of cos pointer type.
1286   // In OpenCL 2.0 this is generic, while in 1.2 that is private.
1287   if (PTy->getPointerAddressSpace() != AMDGPUAS::PRIVATE_ADDRESS)
1288     P = B.CreateAddrSpaceCast(Alloc, PTy);
1289   CallInst *Call = CreateCallEx2(B, Fsincos, UI->getArgOperand(0), P);
1290 
1291   LLVM_DEBUG(errs() << "AMDIC: fold_sincos (" << *CI << ", " << *UI << ") with "
1292                     << *Call << "\n");
1293 
1294   if (!isSin) { // CI->cos, UI->sin
1295     B.SetInsertPoint(&*ItOld);
1296     UI->replaceAllUsesWith(&*Call);
1297     Instruction *Reload = B.CreateLoad(Alloc->getAllocatedType(), Alloc);
1298     CI->replaceAllUsesWith(Reload);
1299     UI->eraseFromParent();
1300     CI->eraseFromParent();
1301   } else { // CI->sin, UI->cos
1302     Instruction *Reload = B.CreateLoad(Alloc->getAllocatedType(), Alloc);
1303     UI->replaceAllUsesWith(Reload);
1304     CI->replaceAllUsesWith(Call);
1305     UI->eraseFromParent();
1306     CI->eraseFromParent();
1307   }
1308   return true;
1309 }
1310 
1311 bool AMDGPULibCalls::fold_wavefrontsize(CallInst *CI, IRBuilder<> &B) {
1312   if (!TM)
1313     return false;
1314 
1315   StringRef CPU = TM->getTargetCPU();
1316   StringRef Features = TM->getTargetFeatureString();
1317   if ((CPU.empty() || CPU.equals_insensitive("generic")) &&
1318       (Features.empty() || !Features.contains_insensitive("wavefrontsize")))
1319     return false;
1320 
1321   Function *F = CI->getParent()->getParent();
1322   const GCNSubtarget &ST = TM->getSubtarget<GCNSubtarget>(*F);
1323   unsigned N = ST.getWavefrontSize();
1324 
1325   LLVM_DEBUG(errs() << "AMDIC: fold_wavefrontsize (" << *CI << ") with "
1326                << N << "\n");
1327 
1328   CI->replaceAllUsesWith(ConstantInt::get(B.getInt32Ty(), N));
1329   CI->eraseFromParent();
1330   return true;
1331 }
1332 
1333 // Get insertion point at entry.
1334 BasicBlock::iterator AMDGPULibCalls::getEntryIns(CallInst * UI) {
1335   Function * Func = UI->getParent()->getParent();
1336   BasicBlock * BB = &Func->getEntryBlock();
1337   assert(BB && "Entry block not found!");
1338   BasicBlock::iterator ItNew = BB->begin();
1339   return ItNew;
1340 }
1341 
1342 // Insert a AllocsInst at the beginning of function entry block.
1343 AllocaInst* AMDGPULibCalls::insertAlloca(CallInst *UI, IRBuilder<> &B,
1344                                          const char *prefix) {
1345   BasicBlock::iterator ItNew = getEntryIns(UI);
1346   Function *UCallee = UI->getCalledFunction();
1347   Type *RetType = UCallee->getReturnType();
1348   B.SetInsertPoint(&*ItNew);
1349   AllocaInst *Alloc =
1350       B.CreateAlloca(RetType, nullptr, std::string(prefix) + UI->getName());
1351   Alloc->setAlignment(
1352       Align(UCallee->getParent()->getDataLayout().getTypeAllocSize(RetType)));
1353   return Alloc;
1354 }
1355 
1356 bool AMDGPULibCalls::evaluateScalarMathFunc(const FuncInfo &FInfo,
1357                                             double& Res0, double& Res1,
1358                                             Constant *copr0, Constant *copr1,
1359                                             Constant *copr2) {
1360   // By default, opr0/opr1/opr3 holds values of float/double type.
1361   // If they are not float/double, each function has to its
1362   // operand separately.
1363   double opr0=0.0, opr1=0.0, opr2=0.0;
1364   ConstantFP *fpopr0 = dyn_cast_or_null<ConstantFP>(copr0);
1365   ConstantFP *fpopr1 = dyn_cast_or_null<ConstantFP>(copr1);
1366   ConstantFP *fpopr2 = dyn_cast_or_null<ConstantFP>(copr2);
1367   if (fpopr0) {
1368     opr0 = (getArgType(FInfo) == AMDGPULibFunc::F64)
1369              ? fpopr0->getValueAPF().convertToDouble()
1370              : (double)fpopr0->getValueAPF().convertToFloat();
1371   }
1372 
1373   if (fpopr1) {
1374     opr1 = (getArgType(FInfo) == AMDGPULibFunc::F64)
1375              ? fpopr1->getValueAPF().convertToDouble()
1376              : (double)fpopr1->getValueAPF().convertToFloat();
1377   }
1378 
1379   if (fpopr2) {
1380     opr2 = (getArgType(FInfo) == AMDGPULibFunc::F64)
1381              ? fpopr2->getValueAPF().convertToDouble()
1382              : (double)fpopr2->getValueAPF().convertToFloat();
1383   }
1384 
1385   switch (FInfo.getId()) {
1386   default : return false;
1387 
1388   case AMDGPULibFunc::EI_ACOS:
1389     Res0 = acos(opr0);
1390     return true;
1391 
1392   case AMDGPULibFunc::EI_ACOSH:
1393     // acosh(x) == log(x + sqrt(x*x - 1))
1394     Res0 = log(opr0 + sqrt(opr0*opr0 - 1.0));
1395     return true;
1396 
1397   case AMDGPULibFunc::EI_ACOSPI:
1398     Res0 = acos(opr0) / MATH_PI;
1399     return true;
1400 
1401   case AMDGPULibFunc::EI_ASIN:
1402     Res0 = asin(opr0);
1403     return true;
1404 
1405   case AMDGPULibFunc::EI_ASINH:
1406     // asinh(x) == log(x + sqrt(x*x + 1))
1407     Res0 = log(opr0 + sqrt(opr0*opr0 + 1.0));
1408     return true;
1409 
1410   case AMDGPULibFunc::EI_ASINPI:
1411     Res0 = asin(opr0) / MATH_PI;
1412     return true;
1413 
1414   case AMDGPULibFunc::EI_ATAN:
1415     Res0 = atan(opr0);
1416     return true;
1417 
1418   case AMDGPULibFunc::EI_ATANH:
1419     // atanh(x) == (log(x+1) - log(x-1))/2;
1420     Res0 = (log(opr0 + 1.0) - log(opr0 - 1.0))/2.0;
1421     return true;
1422 
1423   case AMDGPULibFunc::EI_ATANPI:
1424     Res0 = atan(opr0) / MATH_PI;
1425     return true;
1426 
1427   case AMDGPULibFunc::EI_CBRT:
1428     Res0 = (opr0 < 0.0) ? -pow(-opr0, 1.0/3.0) : pow(opr0, 1.0/3.0);
1429     return true;
1430 
1431   case AMDGPULibFunc::EI_COS:
1432     Res0 = cos(opr0);
1433     return true;
1434 
1435   case AMDGPULibFunc::EI_COSH:
1436     Res0 = cosh(opr0);
1437     return true;
1438 
1439   case AMDGPULibFunc::EI_COSPI:
1440     Res0 = cos(MATH_PI * opr0);
1441     return true;
1442 
1443   case AMDGPULibFunc::EI_EXP:
1444     Res0 = exp(opr0);
1445     return true;
1446 
1447   case AMDGPULibFunc::EI_EXP2:
1448     Res0 = pow(2.0, opr0);
1449     return true;
1450 
1451   case AMDGPULibFunc::EI_EXP10:
1452     Res0 = pow(10.0, opr0);
1453     return true;
1454 
1455   case AMDGPULibFunc::EI_EXPM1:
1456     Res0 = exp(opr0) - 1.0;
1457     return true;
1458 
1459   case AMDGPULibFunc::EI_LOG:
1460     Res0 = log(opr0);
1461     return true;
1462 
1463   case AMDGPULibFunc::EI_LOG2:
1464     Res0 = log(opr0) / log(2.0);
1465     return true;
1466 
1467   case AMDGPULibFunc::EI_LOG10:
1468     Res0 = log(opr0) / log(10.0);
1469     return true;
1470 
1471   case AMDGPULibFunc::EI_RSQRT:
1472     Res0 = 1.0 / sqrt(opr0);
1473     return true;
1474 
1475   case AMDGPULibFunc::EI_SIN:
1476     Res0 = sin(opr0);
1477     return true;
1478 
1479   case AMDGPULibFunc::EI_SINH:
1480     Res0 = sinh(opr0);
1481     return true;
1482 
1483   case AMDGPULibFunc::EI_SINPI:
1484     Res0 = sin(MATH_PI * opr0);
1485     return true;
1486 
1487   case AMDGPULibFunc::EI_SQRT:
1488     Res0 = sqrt(opr0);
1489     return true;
1490 
1491   case AMDGPULibFunc::EI_TAN:
1492     Res0 = tan(opr0);
1493     return true;
1494 
1495   case AMDGPULibFunc::EI_TANH:
1496     Res0 = tanh(opr0);
1497     return true;
1498 
1499   case AMDGPULibFunc::EI_TANPI:
1500     Res0 = tan(MATH_PI * opr0);
1501     return true;
1502 
1503   case AMDGPULibFunc::EI_RECIP:
1504     Res0 = 1.0 / opr0;
1505     return true;
1506 
1507   // two-arg functions
1508   case AMDGPULibFunc::EI_DIVIDE:
1509     Res0 = opr0 / opr1;
1510     return true;
1511 
1512   case AMDGPULibFunc::EI_POW:
1513   case AMDGPULibFunc::EI_POWR:
1514     Res0 = pow(opr0, opr1);
1515     return true;
1516 
1517   case AMDGPULibFunc::EI_POWN: {
1518     if (ConstantInt *iopr1 = dyn_cast_or_null<ConstantInt>(copr1)) {
1519       double val = (double)iopr1->getSExtValue();
1520       Res0 = pow(opr0, val);
1521       return true;
1522     }
1523     return false;
1524   }
1525 
1526   case AMDGPULibFunc::EI_ROOTN: {
1527     if (ConstantInt *iopr1 = dyn_cast_or_null<ConstantInt>(copr1)) {
1528       double val = (double)iopr1->getSExtValue();
1529       Res0 = pow(opr0, 1.0 / val);
1530       return true;
1531     }
1532     return false;
1533   }
1534 
1535   // with ptr arg
1536   case AMDGPULibFunc::EI_SINCOS:
1537     Res0 = sin(opr0);
1538     Res1 = cos(opr0);
1539     return true;
1540 
1541   // three-arg functions
1542   case AMDGPULibFunc::EI_FMA:
1543   case AMDGPULibFunc::EI_MAD:
1544     Res0 = opr0 * opr1 + opr2;
1545     return true;
1546   }
1547 
1548   return false;
1549 }
1550 
1551 bool AMDGPULibCalls::evaluateCall(CallInst *aCI, const FuncInfo &FInfo) {
1552   int numArgs = (int)aCI->arg_size();
1553   if (numArgs > 3)
1554     return false;
1555 
1556   Constant *copr0 = nullptr;
1557   Constant *copr1 = nullptr;
1558   Constant *copr2 = nullptr;
1559   if (numArgs > 0) {
1560     if ((copr0 = dyn_cast<Constant>(aCI->getArgOperand(0))) == nullptr)
1561       return false;
1562   }
1563 
1564   if (numArgs > 1) {
1565     if ((copr1 = dyn_cast<Constant>(aCI->getArgOperand(1))) == nullptr) {
1566       if (FInfo.getId() != AMDGPULibFunc::EI_SINCOS)
1567         return false;
1568     }
1569   }
1570 
1571   if (numArgs > 2) {
1572     if ((copr2 = dyn_cast<Constant>(aCI->getArgOperand(2))) == nullptr)
1573       return false;
1574   }
1575 
1576   // At this point, all arguments to aCI are constants.
1577 
1578   // max vector size is 16, and sincos will generate two results.
1579   double DVal0[16], DVal1[16];
1580   int FuncVecSize = getVecSize(FInfo);
1581   bool hasTwoResults = (FInfo.getId() == AMDGPULibFunc::EI_SINCOS);
1582   if (FuncVecSize == 1) {
1583     if (!evaluateScalarMathFunc(FInfo, DVal0[0],
1584                                 DVal1[0], copr0, copr1, copr2)) {
1585       return false;
1586     }
1587   } else {
1588     ConstantDataVector *CDV0 = dyn_cast_or_null<ConstantDataVector>(copr0);
1589     ConstantDataVector *CDV1 = dyn_cast_or_null<ConstantDataVector>(copr1);
1590     ConstantDataVector *CDV2 = dyn_cast_or_null<ConstantDataVector>(copr2);
1591     for (int i = 0; i < FuncVecSize; ++i) {
1592       Constant *celt0 = CDV0 ? CDV0->getElementAsConstant(i) : nullptr;
1593       Constant *celt1 = CDV1 ? CDV1->getElementAsConstant(i) : nullptr;
1594       Constant *celt2 = CDV2 ? CDV2->getElementAsConstant(i) : nullptr;
1595       if (!evaluateScalarMathFunc(FInfo, DVal0[i],
1596                                   DVal1[i], celt0, celt1, celt2)) {
1597         return false;
1598       }
1599     }
1600   }
1601 
1602   LLVMContext &context = CI->getParent()->getParent()->getContext();
1603   Constant *nval0, *nval1;
1604   if (FuncVecSize == 1) {
1605     nval0 = ConstantFP::get(CI->getType(), DVal0[0]);
1606     if (hasTwoResults)
1607       nval1 = ConstantFP::get(CI->getType(), DVal1[0]);
1608   } else {
1609     if (getArgType(FInfo) == AMDGPULibFunc::F32) {
1610       SmallVector <float, 0> FVal0, FVal1;
1611       for (int i = 0; i < FuncVecSize; ++i)
1612         FVal0.push_back((float)DVal0[i]);
1613       ArrayRef<float> tmp0(FVal0);
1614       nval0 = ConstantDataVector::get(context, tmp0);
1615       if (hasTwoResults) {
1616         for (int i = 0; i < FuncVecSize; ++i)
1617           FVal1.push_back((float)DVal1[i]);
1618         ArrayRef<float> tmp1(FVal1);
1619         nval1 = ConstantDataVector::get(context, tmp1);
1620       }
1621     } else {
1622       ArrayRef<double> tmp0(DVal0);
1623       nval0 = ConstantDataVector::get(context, tmp0);
1624       if (hasTwoResults) {
1625         ArrayRef<double> tmp1(DVal1);
1626         nval1 = ConstantDataVector::get(context, tmp1);
1627       }
1628     }
1629   }
1630 
1631   if (hasTwoResults) {
1632     // sincos
1633     assert(FInfo.getId() == AMDGPULibFunc::EI_SINCOS &&
1634            "math function with ptr arg not supported yet");
1635     new StoreInst(nval1, aCI->getArgOperand(1), aCI);
1636   }
1637 
1638   replaceCall(nval0);
1639   return true;
1640 }
1641 
1642 // Public interface to the Simplify LibCalls pass.
1643 FunctionPass *llvm::createAMDGPUSimplifyLibCallsPass(const TargetMachine *TM) {
1644   return new AMDGPUSimplifyLibCalls(TM);
1645 }
1646 
1647 FunctionPass *llvm::createAMDGPUUseNativeCallsPass() {
1648   return new AMDGPUUseNativeCalls();
1649 }
1650 
1651 bool AMDGPUSimplifyLibCalls::runOnFunction(Function &F) {
1652   if (skipFunction(F))
1653     return false;
1654 
1655   bool Changed = false;
1656   auto AA = &getAnalysis<AAResultsWrapperPass>().getAAResults();
1657 
1658   LLVM_DEBUG(dbgs() << "AMDIC: process function ";
1659              F.printAsOperand(dbgs(), false, F.getParent()); dbgs() << '\n';);
1660 
1661   for (auto &BB : F) {
1662     for (BasicBlock::iterator I = BB.begin(), E = BB.end(); I != E; ) {
1663       // Ignore non-calls.
1664       CallInst *CI = dyn_cast<CallInst>(I);
1665       ++I;
1666       if (CI) {
1667         if (Simplifier.fold(CI, AA))
1668           Changed = true;
1669       }
1670     }
1671   }
1672   return Changed;
1673 }
1674 
1675 PreservedAnalyses AMDGPUSimplifyLibCallsPass::run(Function &F,
1676                                                   FunctionAnalysisManager &AM) {
1677   AMDGPULibCalls Simplifier(&TM);
1678   Simplifier.initNativeFuncs();
1679 
1680   bool Changed = false;
1681   auto AA = &AM.getResult<AAManager>(F);
1682 
1683   LLVM_DEBUG(dbgs() << "AMDIC: process function ";
1684              F.printAsOperand(dbgs(), false, F.getParent()); dbgs() << '\n';);
1685 
1686   for (auto &BB : F) {
1687     for (BasicBlock::iterator I = BB.begin(), E = BB.end(); I != E;) {
1688       // Ignore non-calls.
1689       CallInst *CI = dyn_cast<CallInst>(I);
1690       ++I;
1691 
1692       if (CI) {
1693         if (Simplifier.fold(CI, AA))
1694           Changed = true;
1695       }
1696     }
1697   }
1698   return Changed ? PreservedAnalyses::none() : PreservedAnalyses::all();
1699 }
1700 
1701 bool AMDGPUUseNativeCalls::runOnFunction(Function &F) {
1702   if (skipFunction(F) || UseNative.empty())
1703     return false;
1704 
1705   bool Changed = false;
1706   for (auto &BB : F) {
1707     for (BasicBlock::iterator I = BB.begin(), E = BB.end(); I != E; ) {
1708       // Ignore non-calls.
1709       CallInst *CI = dyn_cast<CallInst>(I);
1710       ++I;
1711       if (CI && Simplifier.useNative(CI))
1712         Changed = true;
1713     }
1714   }
1715   return Changed;
1716 }
1717 
1718 PreservedAnalyses AMDGPUUseNativeCallsPass::run(Function &F,
1719                                                 FunctionAnalysisManager &AM) {
1720   if (UseNative.empty())
1721     return PreservedAnalyses::all();
1722 
1723   AMDGPULibCalls Simplifier;
1724   Simplifier.initNativeFuncs();
1725 
1726   bool Changed = false;
1727   for (auto &BB : F) {
1728     for (BasicBlock::iterator I = BB.begin(), E = BB.end(); I != E;) {
1729       // Ignore non-calls.
1730       CallInst *CI = dyn_cast<CallInst>(I);
1731       ++I;
1732       if (CI && Simplifier.useNative(CI))
1733         Changed = true;
1734     }
1735   }
1736   return Changed ? PreservedAnalyses::none() : PreservedAnalyses::all();
1737 }
1738