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Matt Arsenault56066522017-02-08 17:49:52 +00001//===- LowerMemIntrinsics.cpp ----------------------------------*- C++ -*--===//
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#include "llvm/Transforms/Utils/LowerMemIntrinsics.h"
Sean Fertile9cd1cdf2017-07-07 02:00:06 +000011#include "llvm/Analysis/TargetTransformInfo.h"
Matt Arsenault56066522017-02-08 17:49:52 +000012#include "llvm/IR/IRBuilder.h"
Chandler Carruth6bda14b2017-06-06 11:49:48 +000013#include "llvm/IR/IntrinsicInst.h"
14#include "llvm/Transforms/Utils/BasicBlockUtils.h"
Matt Arsenault56066522017-02-08 17:49:52 +000015
16using namespace llvm;
17
Sean Fertile9cd1cdf2017-07-07 02:00:06 +000018static unsigned getLoopOperandSizeInBytes(Type *Type) {
19 if (VectorType *VTy = dyn_cast<VectorType>(Type)) {
20 return VTy->getBitWidth() / 8;
21 }
22
23 return Type->getPrimitiveSizeInBits() / 8;
24}
25
26void llvm::createMemCpyLoopKnownSize(Instruction *InsertBefore, Value *SrcAddr,
27 Value *DstAddr, ConstantInt *CopyLen,
28 unsigned SrcAlign, unsigned DestAlign,
29 bool SrcIsVolatile, bool DstIsVolatile,
30 const TargetTransformInfo &TTI) {
31 // No need to expand zero length copies.
32 if (CopyLen->isZero())
33 return;
34
35 BasicBlock *PreLoopBB = InsertBefore->getParent();
36 BasicBlock *PostLoopBB = nullptr;
37 Function *ParentFunc = PreLoopBB->getParent();
38 LLVMContext &Ctx = PreLoopBB->getContext();
39
40 Type *TypeOfCopyLen = CopyLen->getType();
41 Type *LoopOpType =
42 TTI.getMemcpyLoopLoweringType(Ctx, CopyLen, SrcAlign, DestAlign);
43
44 unsigned LoopOpSize = getLoopOperandSizeInBytes(LoopOpType);
45 uint64_t LoopEndCount = CopyLen->getZExtValue() / LoopOpSize;
46
47 unsigned SrcAS = cast<PointerType>(SrcAddr->getType())->getAddressSpace();
48 unsigned DstAS = cast<PointerType>(DstAddr->getType())->getAddressSpace();
49
50 if (LoopEndCount != 0) {
51 // Split
52 PostLoopBB = PreLoopBB->splitBasicBlock(InsertBefore, "memcpy-split");
53 BasicBlock *LoopBB =
54 BasicBlock::Create(Ctx, "load-store-loop", ParentFunc, PostLoopBB);
55 PreLoopBB->getTerminator()->setSuccessor(0, LoopBB);
56
57 IRBuilder<> PLBuilder(PreLoopBB->getTerminator());
58
59 // Cast the Src and Dst pointers to pointers to the loop operand type (if
60 // needed).
61 PointerType *SrcOpType = PointerType::get(LoopOpType, SrcAS);
62 PointerType *DstOpType = PointerType::get(LoopOpType, DstAS);
63 if (SrcAddr->getType() != SrcOpType) {
64 SrcAddr = PLBuilder.CreateBitCast(SrcAddr, SrcOpType);
65 }
66 if (DstAddr->getType() != DstOpType) {
67 DstAddr = PLBuilder.CreateBitCast(DstAddr, DstOpType);
68 }
69
70 IRBuilder<> LoopBuilder(LoopBB);
71 PHINode *LoopIndex = LoopBuilder.CreatePHI(TypeOfCopyLen, 2, "loop-index");
72 LoopIndex->addIncoming(ConstantInt::get(TypeOfCopyLen, 0U), PreLoopBB);
73 // Loop Body
74 Value *SrcGEP =
75 LoopBuilder.CreateInBoundsGEP(LoopOpType, SrcAddr, LoopIndex);
76 Value *Load = LoopBuilder.CreateLoad(SrcGEP, SrcIsVolatile);
77 Value *DstGEP =
78 LoopBuilder.CreateInBoundsGEP(LoopOpType, DstAddr, LoopIndex);
79 LoopBuilder.CreateStore(Load, DstGEP, DstIsVolatile);
80
81 Value *NewIndex =
82 LoopBuilder.CreateAdd(LoopIndex, ConstantInt::get(TypeOfCopyLen, 1U));
83 LoopIndex->addIncoming(NewIndex, LoopBB);
84
85 // Create the loop branch condition.
86 Constant *LoopEndCI = ConstantInt::get(TypeOfCopyLen, LoopEndCount);
87 LoopBuilder.CreateCondBr(LoopBuilder.CreateICmpULT(NewIndex, LoopEndCI),
88 LoopBB, PostLoopBB);
89 }
90
91 uint64_t BytesCopied = LoopEndCount * LoopOpSize;
92 uint64_t RemainingBytes = CopyLen->getZExtValue() - BytesCopied;
93 if (RemainingBytes) {
94 IRBuilder<> RBuilder(PostLoopBB ? PostLoopBB->getFirstNonPHI()
95 : InsertBefore);
96
97 // Update the alignment based on the copy size used in the loop body.
98 SrcAlign = std::min(SrcAlign, LoopOpSize);
99 DestAlign = std::min(DestAlign, LoopOpSize);
100
101 SmallVector<Type *, 5> RemainingOps;
102 TTI.getMemcpyLoopResidualLoweringType(RemainingOps, Ctx, RemainingBytes,
103 SrcAlign, DestAlign);
104
105 for (auto OpTy : RemainingOps) {
106 // Calaculate the new index
107 unsigned OperandSize = getLoopOperandSizeInBytes(OpTy);
108 uint64_t GepIndex = BytesCopied / OperandSize;
109 assert(GepIndex * OperandSize == BytesCopied &&
110 "Division should have no Remainder!");
111 // Cast source to operand type and load
112 PointerType *SrcPtrType = PointerType::get(OpTy, SrcAS);
113 Value *CastedSrc = SrcAddr->getType() == SrcPtrType
114 ? SrcAddr
115 : RBuilder.CreateBitCast(SrcAddr, SrcPtrType);
116 Value *SrcGEP = RBuilder.CreateInBoundsGEP(
117 OpTy, CastedSrc, ConstantInt::get(TypeOfCopyLen, GepIndex));
118 Value *Load = RBuilder.CreateLoad(SrcGEP, SrcIsVolatile);
119
120 // Cast destination to operand type and store.
121 PointerType *DstPtrType = PointerType::get(OpTy, DstAS);
122 Value *CastedDst = DstAddr->getType() == DstPtrType
123 ? DstAddr
124 : RBuilder.CreateBitCast(DstAddr, DstPtrType);
125 Value *DstGEP = RBuilder.CreateInBoundsGEP(
126 OpTy, CastedDst, ConstantInt::get(TypeOfCopyLen, GepIndex));
127 RBuilder.CreateStore(Load, DstGEP, DstIsVolatile);
128
129 BytesCopied += OperandSize;
130 }
131 }
132 assert(BytesCopied == CopyLen->getZExtValue() &&
133 "Bytes copied should match size in the call!");
134}
135
136void llvm::createMemCpyLoopUnknownSize(Instruction *InsertBefore,
137 Value *SrcAddr, Value *DstAddr,
138 Value *CopyLen, unsigned SrcAlign,
139 unsigned DestAlign, bool SrcIsVolatile,
140 bool DstIsVolatile,
141 const TargetTransformInfo &TTI) {
142 BasicBlock *PreLoopBB = InsertBefore->getParent();
143 BasicBlock *PostLoopBB =
144 PreLoopBB->splitBasicBlock(InsertBefore, "post-loop-memcpy-expansion");
145
146 Function *ParentFunc = PreLoopBB->getParent();
147 LLVMContext &Ctx = PreLoopBB->getContext();
148
149 Type *LoopOpType =
150 TTI.getMemcpyLoopLoweringType(Ctx, CopyLen, SrcAlign, DestAlign);
151 unsigned LoopOpSize = getLoopOperandSizeInBytes(LoopOpType);
152
153 IRBuilder<> PLBuilder(PreLoopBB->getTerminator());
154
155 unsigned SrcAS = cast<PointerType>(SrcAddr->getType())->getAddressSpace();
156 unsigned DstAS = cast<PointerType>(DstAddr->getType())->getAddressSpace();
157 PointerType *SrcOpType = PointerType::get(LoopOpType, SrcAS);
158 PointerType *DstOpType = PointerType::get(LoopOpType, DstAS);
159 if (SrcAddr->getType() != SrcOpType) {
160 SrcAddr = PLBuilder.CreateBitCast(SrcAddr, SrcOpType);
161 }
162 if (DstAddr->getType() != DstOpType) {
163 DstAddr = PLBuilder.CreateBitCast(DstAddr, DstOpType);
164 }
165
166 // Calculate the loop trip count, and remaining bytes to copy after the loop.
167 Type *CopyLenType = CopyLen->getType();
168 IntegerType *ILengthType = dyn_cast<IntegerType>(CopyLenType);
169 assert(ILengthType &&
170 "expected size argument to memcpy to be an integer type!");
171 ConstantInt *CILoopOpSize = ConstantInt::get(ILengthType, LoopOpSize);
172 Value *RuntimeLoopCount = PLBuilder.CreateUDiv(CopyLen, CILoopOpSize);
173 Value *RuntimeResidual = PLBuilder.CreateURem(CopyLen, CILoopOpSize);
174 Value *RuntimeBytesCopied = PLBuilder.CreateSub(CopyLen, RuntimeResidual);
175
176 BasicBlock *LoopBB =
177 BasicBlock::Create(Ctx, "loop-memcpy-expansion", ParentFunc, nullptr);
178 IRBuilder<> LoopBuilder(LoopBB);
179
180 PHINode *LoopIndex = LoopBuilder.CreatePHI(CopyLenType, 2, "loop-index");
181 LoopIndex->addIncoming(ConstantInt::get(CopyLenType, 0U), PreLoopBB);
182
183 Value *SrcGEP = LoopBuilder.CreateInBoundsGEP(LoopOpType, SrcAddr, LoopIndex);
184 Value *Load = LoopBuilder.CreateLoad(SrcGEP, SrcIsVolatile);
185 Value *DstGEP = LoopBuilder.CreateInBoundsGEP(LoopOpType, DstAddr, LoopIndex);
186 LoopBuilder.CreateStore(Load, DstGEP, DstIsVolatile);
187
188 Value *NewIndex =
189 LoopBuilder.CreateAdd(LoopIndex, ConstantInt::get(CopyLenType, 1U));
190 LoopIndex->addIncoming(NewIndex, LoopBB);
191
192 Type *Int8Type = Type::getInt8Ty(Ctx);
193 if (LoopOpType != Int8Type) {
194 // Loop body for the residual copy.
195 BasicBlock *ResLoopBB = BasicBlock::Create(Ctx, "loop-memcpy-residual",
196 PreLoopBB->getParent(), nullptr);
197 // Residual loop header.
198 BasicBlock *ResHeaderBB = BasicBlock::Create(
199 Ctx, "loop-memcpy-residual-header", PreLoopBB->getParent(), nullptr);
200
201 // Need to update the pre-loop basic block to branch to the correct place.
202 // branch to the main loop if the count is non-zero, branch to the residual
203 // loop if the copy size is smaller then 1 iteration of the main loop but
204 // non-zero and finally branch to after the residual loop if the memcpy
205 // size is zero.
206 ConstantInt *Zero = ConstantInt::get(ILengthType, 0U);
207 PLBuilder.CreateCondBr(PLBuilder.CreateICmpNE(RuntimeLoopCount, Zero),
208 LoopBB, ResHeaderBB);
209 PreLoopBB->getTerminator()->eraseFromParent();
210
211 LoopBuilder.CreateCondBr(
212 LoopBuilder.CreateICmpULT(NewIndex, RuntimeLoopCount), LoopBB,
213 ResHeaderBB);
214
215 // Determine if we need to branch to the residual loop or bypass it.
216 IRBuilder<> RHBuilder(ResHeaderBB);
217 RHBuilder.CreateCondBr(RHBuilder.CreateICmpNE(RuntimeResidual, Zero),
218 ResLoopBB, PostLoopBB);
219
220 // Copy the residual with single byte load/store loop.
221 IRBuilder<> ResBuilder(ResLoopBB);
222 PHINode *ResidualIndex =
223 ResBuilder.CreatePHI(CopyLenType, 2, "residual-loop-index");
224 ResidualIndex->addIncoming(Zero, ResHeaderBB);
225
226 Value *SrcAsInt8 =
227 ResBuilder.CreateBitCast(SrcAddr, PointerType::get(Int8Type, SrcAS));
228 Value *DstAsInt8 =
229 ResBuilder.CreateBitCast(DstAddr, PointerType::get(Int8Type, DstAS));
230 Value *FullOffset = ResBuilder.CreateAdd(RuntimeBytesCopied, ResidualIndex);
231 Value *SrcGEP =
232 ResBuilder.CreateInBoundsGEP(Int8Type, SrcAsInt8, FullOffset);
233 Value *Load = ResBuilder.CreateLoad(SrcGEP, SrcIsVolatile);
234 Value *DstGEP =
235 ResBuilder.CreateInBoundsGEP(Int8Type, DstAsInt8, FullOffset);
236 ResBuilder.CreateStore(Load, DstGEP, DstIsVolatile);
237
238 Value *ResNewIndex =
239 ResBuilder.CreateAdd(ResidualIndex, ConstantInt::get(CopyLenType, 1U));
240 ResidualIndex->addIncoming(ResNewIndex, ResLoopBB);
241
242 // Create the loop branch condition.
243 ResBuilder.CreateCondBr(
244 ResBuilder.CreateICmpULT(ResNewIndex, RuntimeResidual), ResLoopBB,
245 PostLoopBB);
246 } else {
247 // In this case the loop operand type was a byte, and there is no need for a
248 // residual loop to copy the remaining memory after the main loop.
249 // We do however need to patch up the control flow by creating the
250 // terminators for the preloop block and the memcpy loop.
251 ConstantInt *Zero = ConstantInt::get(ILengthType, 0U);
252 PLBuilder.CreateCondBr(PLBuilder.CreateICmpNE(RuntimeLoopCount, Zero),
253 LoopBB, PostLoopBB);
254 PreLoopBB->getTerminator()->eraseFromParent();
255 LoopBuilder.CreateCondBr(
256 LoopBuilder.CreateICmpULT(NewIndex, RuntimeLoopCount), LoopBB,
257 PostLoopBB);
258 }
259}
260
Matt Arsenault56066522017-02-08 17:49:52 +0000261void llvm::createMemCpyLoop(Instruction *InsertBefore,
262 Value *SrcAddr, Value *DstAddr, Value *CopyLen,
263 unsigned SrcAlign, unsigned DestAlign,
264 bool SrcIsVolatile, bool DstIsVolatile) {
265 Type *TypeOfCopyLen = CopyLen->getType();
266
267 BasicBlock *OrigBB = InsertBefore->getParent();
268 Function *F = OrigBB->getParent();
269 BasicBlock *NewBB =
270 InsertBefore->getParent()->splitBasicBlock(InsertBefore, "split");
271 BasicBlock *LoopBB = BasicBlock::Create(F->getContext(), "loadstoreloop",
272 F, NewBB);
273
Matt Arsenault56066522017-02-08 17:49:52 +0000274 IRBuilder<> Builder(OrigBB->getTerminator());
275
276 // SrcAddr and DstAddr are expected to be pointer types,
277 // so no check is made here.
278 unsigned SrcAS = cast<PointerType>(SrcAddr->getType())->getAddressSpace();
279 unsigned DstAS = cast<PointerType>(DstAddr->getType())->getAddressSpace();
280
281 // Cast pointers to (char *)
282 SrcAddr = Builder.CreateBitCast(SrcAddr, Builder.getInt8PtrTy(SrcAS));
283 DstAddr = Builder.CreateBitCast(DstAddr, Builder.getInt8PtrTy(DstAS));
284
Teresa Johnson32d95742017-07-01 03:24:10 +0000285 Builder.CreateCondBr(
286 Builder.CreateICmpEQ(ConstantInt::get(TypeOfCopyLen, 0), CopyLen), NewBB,
287 LoopBB);
288 OrigBB->getTerminator()->eraseFromParent();
289
Matt Arsenault56066522017-02-08 17:49:52 +0000290 IRBuilder<> LoopBuilder(LoopBB);
291 PHINode *LoopIndex = LoopBuilder.CreatePHI(TypeOfCopyLen, 0);
292 LoopIndex->addIncoming(ConstantInt::get(TypeOfCopyLen, 0), OrigBB);
293
294 // load from SrcAddr+LoopIndex
295 // TODO: we can leverage the align parameter of llvm.memcpy for more efficient
296 // word-sized loads and stores.
297 Value *Element =
298 LoopBuilder.CreateLoad(LoopBuilder.CreateInBoundsGEP(
299 LoopBuilder.getInt8Ty(), SrcAddr, LoopIndex),
300 SrcIsVolatile);
301 // store at DstAddr+LoopIndex
302 LoopBuilder.CreateStore(Element,
303 LoopBuilder.CreateInBoundsGEP(LoopBuilder.getInt8Ty(),
304 DstAddr, LoopIndex),
305 DstIsVolatile);
306
307 // The value for LoopIndex coming from backedge is (LoopIndex + 1)
308 Value *NewIndex =
309 LoopBuilder.CreateAdd(LoopIndex, ConstantInt::get(TypeOfCopyLen, 1));
310 LoopIndex->addIncoming(NewIndex, LoopBB);
311
312 LoopBuilder.CreateCondBr(LoopBuilder.CreateICmpULT(NewIndex, CopyLen), LoopBB,
313 NewBB);
314}
315
316// Lower memmove to IR. memmove is required to correctly copy overlapping memory
317// regions; therefore, it has to check the relative positions of the source and
318// destination pointers and choose the copy direction accordingly.
319//
320// The code below is an IR rendition of this C function:
321//
322// void* memmove(void* dst, const void* src, size_t n) {
323// unsigned char* d = dst;
324// const unsigned char* s = src;
325// if (s < d) {
326// // copy backwards
327// while (n--) {
328// d[n] = s[n];
329// }
330// } else {
331// // copy forward
332// for (size_t i = 0; i < n; ++i) {
333// d[i] = s[i];
334// }
335// }
336// return dst;
337// }
338static void createMemMoveLoop(Instruction *InsertBefore,
339 Value *SrcAddr, Value *DstAddr, Value *CopyLen,
340 unsigned SrcAlign, unsigned DestAlign,
341 bool SrcIsVolatile, bool DstIsVolatile) {
342 Type *TypeOfCopyLen = CopyLen->getType();
343 BasicBlock *OrigBB = InsertBefore->getParent();
344 Function *F = OrigBB->getParent();
345
346 // Create the a comparison of src and dst, based on which we jump to either
347 // the forward-copy part of the function (if src >= dst) or the backwards-copy
348 // part (if src < dst).
349 // SplitBlockAndInsertIfThenElse conveniently creates the basic if-then-else
350 // structure. Its block terminators (unconditional branches) are replaced by
351 // the appropriate conditional branches when the loop is built.
352 ICmpInst *PtrCompare = new ICmpInst(InsertBefore, ICmpInst::ICMP_ULT,
353 SrcAddr, DstAddr, "compare_src_dst");
354 TerminatorInst *ThenTerm, *ElseTerm;
355 SplitBlockAndInsertIfThenElse(PtrCompare, InsertBefore, &ThenTerm,
356 &ElseTerm);
357
358 // Each part of the function consists of two blocks:
359 // copy_backwards: used to skip the loop when n == 0
360 // copy_backwards_loop: the actual backwards loop BB
361 // copy_forward: used to skip the loop when n == 0
362 // copy_forward_loop: the actual forward loop BB
363 BasicBlock *CopyBackwardsBB = ThenTerm->getParent();
364 CopyBackwardsBB->setName("copy_backwards");
365 BasicBlock *CopyForwardBB = ElseTerm->getParent();
366 CopyForwardBB->setName("copy_forward");
367 BasicBlock *ExitBB = InsertBefore->getParent();
368 ExitBB->setName("memmove_done");
369
370 // Initial comparison of n == 0 that lets us skip the loops altogether. Shared
371 // between both backwards and forward copy clauses.
372 ICmpInst *CompareN =
373 new ICmpInst(OrigBB->getTerminator(), ICmpInst::ICMP_EQ, CopyLen,
374 ConstantInt::get(TypeOfCopyLen, 0), "compare_n_to_0");
375
376 // Copying backwards.
377 BasicBlock *LoopBB =
378 BasicBlock::Create(F->getContext(), "copy_backwards_loop", F, CopyForwardBB);
379 IRBuilder<> LoopBuilder(LoopBB);
380 PHINode *LoopPhi = LoopBuilder.CreatePHI(TypeOfCopyLen, 0);
381 Value *IndexPtr = LoopBuilder.CreateSub(
382 LoopPhi, ConstantInt::get(TypeOfCopyLen, 1), "index_ptr");
383 Value *Element = LoopBuilder.CreateLoad(
384 LoopBuilder.CreateInBoundsGEP(SrcAddr, IndexPtr), "element");
385 LoopBuilder.CreateStore(Element,
386 LoopBuilder.CreateInBoundsGEP(DstAddr, IndexPtr));
387 LoopBuilder.CreateCondBr(
388 LoopBuilder.CreateICmpEQ(IndexPtr, ConstantInt::get(TypeOfCopyLen, 0)),
389 ExitBB, LoopBB);
390 LoopPhi->addIncoming(IndexPtr, LoopBB);
391 LoopPhi->addIncoming(CopyLen, CopyBackwardsBB);
392 BranchInst::Create(ExitBB, LoopBB, CompareN, ThenTerm);
393 ThenTerm->eraseFromParent();
394
395 // Copying forward.
396 BasicBlock *FwdLoopBB =
397 BasicBlock::Create(F->getContext(), "copy_forward_loop", F, ExitBB);
398 IRBuilder<> FwdLoopBuilder(FwdLoopBB);
399 PHINode *FwdCopyPhi = FwdLoopBuilder.CreatePHI(TypeOfCopyLen, 0, "index_ptr");
400 Value *FwdElement = FwdLoopBuilder.CreateLoad(
401 FwdLoopBuilder.CreateInBoundsGEP(SrcAddr, FwdCopyPhi), "element");
402 FwdLoopBuilder.CreateStore(
403 FwdElement, FwdLoopBuilder.CreateInBoundsGEP(DstAddr, FwdCopyPhi));
404 Value *FwdIndexPtr = FwdLoopBuilder.CreateAdd(
405 FwdCopyPhi, ConstantInt::get(TypeOfCopyLen, 1), "index_increment");
406 FwdLoopBuilder.CreateCondBr(FwdLoopBuilder.CreateICmpEQ(FwdIndexPtr, CopyLen),
407 ExitBB, FwdLoopBB);
408 FwdCopyPhi->addIncoming(FwdIndexPtr, FwdLoopBB);
409 FwdCopyPhi->addIncoming(ConstantInt::get(TypeOfCopyLen, 0), CopyForwardBB);
410
411 BranchInst::Create(ExitBB, FwdLoopBB, CompareN, ElseTerm);
412 ElseTerm->eraseFromParent();
413}
414
415static void createMemSetLoop(Instruction *InsertBefore,
416 Value *DstAddr, Value *CopyLen, Value *SetValue,
417 unsigned Align, bool IsVolatile) {
Teresa Johnson32d95742017-07-01 03:24:10 +0000418 Type *TypeOfCopyLen = CopyLen->getType();
Matt Arsenault56066522017-02-08 17:49:52 +0000419 BasicBlock *OrigBB = InsertBefore->getParent();
420 Function *F = OrigBB->getParent();
421 BasicBlock *NewBB =
422 OrigBB->splitBasicBlock(InsertBefore, "split");
423 BasicBlock *LoopBB
424 = BasicBlock::Create(F->getContext(), "loadstoreloop", F, NewBB);
425
Matt Arsenault56066522017-02-08 17:49:52 +0000426 IRBuilder<> Builder(OrigBB->getTerminator());
427
428 // Cast pointer to the type of value getting stored
429 unsigned dstAS = cast<PointerType>(DstAddr->getType())->getAddressSpace();
430 DstAddr = Builder.CreateBitCast(DstAddr,
431 PointerType::get(SetValue->getType(), dstAS));
432
Teresa Johnson32d95742017-07-01 03:24:10 +0000433 Builder.CreateCondBr(
434 Builder.CreateICmpEQ(ConstantInt::get(TypeOfCopyLen, 0), CopyLen), NewBB,
435 LoopBB);
436 OrigBB->getTerminator()->eraseFromParent();
437
Matt Arsenault56066522017-02-08 17:49:52 +0000438 IRBuilder<> LoopBuilder(LoopBB);
Teresa Johnson32d95742017-07-01 03:24:10 +0000439 PHINode *LoopIndex = LoopBuilder.CreatePHI(TypeOfCopyLen, 0);
440 LoopIndex->addIncoming(ConstantInt::get(TypeOfCopyLen, 0), OrigBB);
Matt Arsenault56066522017-02-08 17:49:52 +0000441
442 LoopBuilder.CreateStore(
443 SetValue,
444 LoopBuilder.CreateInBoundsGEP(SetValue->getType(), DstAddr, LoopIndex),
445 IsVolatile);
446
447 Value *NewIndex =
Teresa Johnson32d95742017-07-01 03:24:10 +0000448 LoopBuilder.CreateAdd(LoopIndex, ConstantInt::get(TypeOfCopyLen, 1));
Matt Arsenault56066522017-02-08 17:49:52 +0000449 LoopIndex->addIncoming(NewIndex, LoopBB);
450
451 LoopBuilder.CreateCondBr(LoopBuilder.CreateICmpULT(NewIndex, CopyLen), LoopBB,
452 NewBB);
453}
454
Sean Fertile9cd1cdf2017-07-07 02:00:06 +0000455void llvm::expandMemCpyAsLoop(MemCpyInst *Memcpy,
456 const TargetTransformInfo &TTI) {
457 // Original implementation
458 if (!TTI.useWideIRMemcpyLoopLowering()) {
459 createMemCpyLoop(/* InsertBefore */ Memcpy,
460 /* SrcAddr */ Memcpy->getRawSource(),
461 /* DstAddr */ Memcpy->getRawDest(),
462 /* CopyLen */ Memcpy->getLength(),
463 /* SrcAlign */ Memcpy->getAlignment(),
464 /* DestAlign */ Memcpy->getAlignment(),
465 /* SrcIsVolatile */ Memcpy->isVolatile(),
466 /* DstIsVolatile */ Memcpy->isVolatile());
467 } else {
468 if (ConstantInt *CI = dyn_cast<ConstantInt>(Memcpy->getLength())) {
469 createMemCpyLoopKnownSize(/* InsertBefore */ Memcpy,
470 /* SrcAddr */ Memcpy->getRawSource(),
471 /* DstAddr */ Memcpy->getRawDest(),
472 /* CopyLen */ CI,
473 /* SrcAlign */ Memcpy->getAlignment(),
474 /* DestAlign */ Memcpy->getAlignment(),
475 /* SrcIsVolatile */ Memcpy->isVolatile(),
476 /* DstIsVolatile */ Memcpy->isVolatile(),
477 /* TargetTransformInfo */ TTI);
478 } else {
479 createMemCpyLoopUnknownSize(/* InsertBefore */ Memcpy,
480 /* SrcAddr */ Memcpy->getRawSource(),
481 /* DstAddr */ Memcpy->getRawDest(),
482 /* CopyLen */ Memcpy->getLength(),
483 /* SrcAlign */ Memcpy->getAlignment(),
484 /* DestAlign */ Memcpy->getAlignment(),
485 /* SrcIsVolatile */ Memcpy->isVolatile(),
486 /* DstIsVolatile */ Memcpy->isVolatile(),
487 /* TargetTransfomrInfo */ TTI);
488 }
489 }
Matt Arsenault56066522017-02-08 17:49:52 +0000490}
491
492void llvm::expandMemMoveAsLoop(MemMoveInst *Memmove) {
493 createMemMoveLoop(/* InsertBefore */ Memmove,
494 /* SrcAddr */ Memmove->getRawSource(),
495 /* DstAddr */ Memmove->getRawDest(),
496 /* CopyLen */ Memmove->getLength(),
497 /* SrcAlign */ Memmove->getAlignment(),
498 /* DestAlign */ Memmove->getAlignment(),
499 /* SrcIsVolatile */ Memmove->isVolatile(),
500 /* DstIsVolatile */ Memmove->isVolatile());
501}
502
503void llvm::expandMemSetAsLoop(MemSetInst *Memset) {
504 createMemSetLoop(/* InsertBefore */ Memset,
505 /* DstAddr */ Memset->getRawDest(),
506 /* CopyLen */ Memset->getLength(),
507 /* SetValue */ Memset->getValue(),
508 /* Alignment */ Memset->getAlignment(),
509 Memset->isVolatile());
510}