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[MemoryBuiltins] Add field for alignment argument [NFC]

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There are a few places where the alignment argument for AlignedAllocLike functions was previously hardcoded. This patch adds an getAllocAlignment function and a change to the MemoryBuiltin table to allow alignment arguments to be found generically.

This will shortly allow alignment inference on operator new's with align_val params and an extension to Attributor's HeapToStack.  The former will follow shortly - I split Bryce's patch for purpose of having the large change be NFC.  The later will be reviewed separately.

Differential Revision: https://reviews.llvm.org/D116851 (part 1 of 2)
This commit is contained in:
Bryce Wilson
2022-01-10 08:58:44 -08:00
committed by Philip Reames
parent b271184f07
commit fb936595fa
3 changed files with 59 additions and 46 deletions
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3
llvm/include/llvm/Analysis/MemoryBuiltins.h
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@@ -114,6 +114,9 @@ inline CallInst *isFreeCall(Value *I, const TargetLibraryInfo *TLI) {
// Properties of allocation functions
//
/// Gets the alignment argument for an aligned_alloc-like function
Value *getAllocAlignment(const CallBase *V, const TargetLibraryInfo *TLI);
/// If this allocation function initializes memory to a fixed value, return
/// said value in the requested type. Otherwise, return nullptr.
Constant *getInitialValueOfAllocation(const CallBase *Alloc,

93
llvm/lib/Analysis/MemoryBuiltins.cpp
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@@ -66,53 +66,51 @@ struct AllocFnsTy {
unsigned NumParams;
// First and Second size parameters (or -1 if unused)
int FstParam, SndParam;
// Alignment parameter for aligned_alloc and aligned new
int AlignParam;
};
// FIXME: certain users need more information. E.g., SimplifyLibCalls needs to
// know which functions are nounwind, noalias, nocapture parameters, etc.
static const std::pair<LibFunc, AllocFnsTy> AllocationFnData[] = {
{LibFunc_malloc, {MallocLike, 1, 0, -1}},
{LibFunc_vec_malloc, {MallocLike, 1, 0, -1}},
{LibFunc_valloc, {MallocLike, 1, 0, -1}},
{LibFunc_Znwj, {OpNewLike, 1, 0, -1}}, // new(unsigned int)
{LibFunc_ZnwjRKSt9nothrow_t, {MallocLike, 2, 0, -1}}, // new(unsigned int, nothrow)
{LibFunc_ZnwjSt11align_val_t, {OpNewLike, 2, 0, -1}}, // new(unsigned int, align_val_t)
{LibFunc_ZnwjSt11align_val_tRKSt9nothrow_t, // new(unsigned int, align_val_t, nothrow)
{MallocLike, 3, 0, -1}},
{LibFunc_Znwm, {OpNewLike, 1, 0, -1}}, // new(unsigned long)
{LibFunc_ZnwmRKSt9nothrow_t, {MallocLike, 2, 0, -1}}, // new(unsigned long, nothrow)
{LibFunc_ZnwmSt11align_val_t, {OpNewLike, 2, 0, -1}}, // new(unsigned long, align_val_t)
{LibFunc_ZnwmSt11align_val_tRKSt9nothrow_t, // new(unsigned long, align_val_t, nothrow)
{MallocLike, 3, 0, -1}},
{LibFunc_Znaj, {OpNewLike, 1, 0, -1}}, // new[](unsigned int)
{LibFunc_ZnajRKSt9nothrow_t, {MallocLike, 2, 0, -1}}, // new[](unsigned int, nothrow)
{LibFunc_ZnajSt11align_val_t, {OpNewLike, 2, 0, -1}}, // new[](unsigned int, align_val_t)
{LibFunc_ZnajSt11align_val_tRKSt9nothrow_t, // new[](unsigned int, align_val_t, nothrow)
{MallocLike, 3, 0, -1}},
{LibFunc_Znam, {OpNewLike, 1, 0, -1}}, // new[](unsigned long)
{LibFunc_ZnamRKSt9nothrow_t, {MallocLike, 2, 0, -1}}, // new[](unsigned long, nothrow)
{LibFunc_ZnamSt11align_val_t, {OpNewLike, 2, 0, -1}}, // new[](unsigned long, align_val_t)
{LibFunc_ZnamSt11align_val_tRKSt9nothrow_t, // new[](unsigned long, align_val_t, nothrow)
{MallocLike, 3, 0, -1}},
{LibFunc_msvc_new_int, {OpNewLike, 1, 0, -1}}, // new(unsigned int)
{LibFunc_msvc_new_int_nothrow, {MallocLike, 2, 0, -1}}, // new(unsigned int, nothrow)
{LibFunc_msvc_new_longlong, {OpNewLike, 1, 0, -1}}, // new(unsigned long long)
{LibFunc_msvc_new_longlong_nothrow, {MallocLike, 2, 0, -1}}, // new(unsigned long long, nothrow)
{LibFunc_msvc_new_array_int, {OpNewLike, 1, 0, -1}}, // new[](unsigned int)
{LibFunc_msvc_new_array_int_nothrow, {MallocLike, 2, 0, -1}}, // new[](unsigned int, nothrow)
{LibFunc_msvc_new_array_longlong, {OpNewLike, 1, 0, -1}}, // new[](unsigned long long)
{LibFunc_msvc_new_array_longlong_nothrow, {MallocLike, 2, 0, -1}}, // new[](unsigned long long, nothrow)
{LibFunc_aligned_alloc, {AlignedAllocLike, 2, 1, -1}},
{LibFunc_memalign, {AlignedAllocLike, 2, 1, -1}},
{LibFunc_calloc, {CallocLike, 2, 0, 1}},
{LibFunc_vec_calloc, {CallocLike, 2, 0, 1}},
{LibFunc_realloc, {ReallocLike, 2, 1, -1}},
{LibFunc_vec_realloc, {ReallocLike, 2, 1, -1}},
{LibFunc_reallocf, {ReallocLike, 2, 1, -1}},
{LibFunc_strdup, {StrDupLike, 1, -1, -1}},
{LibFunc_strndup, {StrDupLike, 2, 1, -1}},
{LibFunc___kmpc_alloc_shared, {MallocLike, 1, 0, -1}},
// TODO: Handle "int posix_memalign(void **, size_t, size_t)"
{LibFunc_malloc, {MallocLike, 1, 0, -1, -1}},
{LibFunc_vec_malloc, {MallocLike, 1, 0, -1, -1}},
{LibFunc_valloc, {MallocLike, 1, 0, -1, -1}},
{LibFunc_Znwj, {OpNewLike, 1, 0, -1, -1}}, // new(unsigned int)
{LibFunc_ZnwjRKSt9nothrow_t, {MallocLike, 2, 0, -1, -1}}, // new(unsigned int, nothrow)
{LibFunc_ZnwjSt11align_val_t, {OpNewLike, 2, 0, -1, -1}}, // new(unsigned int, align_val_t)
{LibFunc_ZnwjSt11align_val_tRKSt9nothrow_t, {MallocLike, 3, 0, -1, -1}}, // new(unsigned int, align_val_t, nothrow)
{LibFunc_Znwm, {OpNewLike, 1, 0, -1, -1}}, // new(unsigned long)
{LibFunc_ZnwmRKSt9nothrow_t, {MallocLike, 2, 0, -1, -1}}, // new(unsigned long, nothrow)
{LibFunc_ZnwmSt11align_val_t, {OpNewLike, 2, 0, -1, -1}}, // new(unsigned long, align_val_t)
{LibFunc_ZnwmSt11align_val_tRKSt9nothrow_t, {MallocLike, 3, 0, -1, -1}}, // new(unsigned long, align_val_t, nothrow)
{LibFunc_Znaj, {OpNewLike, 1, 0, -1, -1}}, // new[](unsigned int)
{LibFunc_ZnajRKSt9nothrow_t, {MallocLike, 2, 0, -1, -1}}, // new[](unsigned int, nothrow)
{LibFunc_ZnajSt11align_val_t, {OpNewLike, 2, 0, -1, -1}}, // new[](unsigned int, align_val_t)
{LibFunc_ZnajSt11align_val_tRKSt9nothrow_t, {MallocLike, 3, 0, -1, -1}}, // new[](unsigned int, align_val_t, nothrow)
{LibFunc_Znam, {OpNewLike, 1, 0, -1, -1}}, // new[](unsigned long)
{LibFunc_ZnamRKSt9nothrow_t, {MallocLike, 2, 0, -1, -1}}, // new[](unsigned long, nothrow)
{LibFunc_ZnamSt11align_val_t, {OpNewLike, 2, 0, -1, -1}}, // new[](unsigned long, align_val_t)
{LibFunc_ZnamSt11align_val_tRKSt9nothrow_t, {MallocLike, 3, 0, -1, -1}}, // new[](unsigned long, align_val_t, nothrow)
{LibFunc_msvc_new_int, {OpNewLike, 1, 0, -1, -1}}, // new(unsigned int)
{LibFunc_msvc_new_int_nothrow, {MallocLike, 2, 0, -1, -1}}, // new(unsigned int, nothrow)
{LibFunc_msvc_new_longlong, {OpNewLike, 1, 0, -1, -1}}, // new(unsigned long long)
{LibFunc_msvc_new_longlong_nothrow, {MallocLike, 2, 0, -1, -1}}, // new(unsigned long long, nothrow)
{LibFunc_msvc_new_array_int, {OpNewLike, 1, 0, -1, -1}}, // new[](unsigned int)
{LibFunc_msvc_new_array_int_nothrow, {MallocLike, 2, 0, -1, -1}}, // new[](unsigned int, nothrow)
{LibFunc_msvc_new_array_longlong, {OpNewLike, 1, 0, -1, -1}}, // new[](unsigned long long)
{LibFunc_msvc_new_array_longlong_nothrow, {MallocLike, 2, 0, -1, -1}}, // new[](unsigned long long, nothrow)
{LibFunc_aligned_alloc, {AlignedAllocLike, 2, 1, -1, 0}},
{LibFunc_memalign, {AlignedAllocLike, 2, 1, -1, 0}},
{LibFunc_calloc, {CallocLike, 2, 0, 1, -1}},
{LibFunc_vec_calloc, {CallocLike, 2, 0, 1, -1}},
{LibFunc_realloc, {ReallocLike, 2, 1, -1, -1}},
{LibFunc_vec_realloc, {ReallocLike, 2, 1, -1, -1}},
{LibFunc_reallocf, {ReallocLike, 2, 1, -1, -1}},
{LibFunc_strdup, {StrDupLike, 1, -1, -1, -1}},
{LibFunc_strndup, {StrDupLike, 2, 1, -1, -1}},
{LibFunc___kmpc_alloc_shared, {MallocLike, 1, 0, -1, -1}},
// TODO: Handle "int posix_memalign(void **, size_t, size_t)"
};
static const Function *getCalledFunction(const Value *V,
@@ -219,6 +217,8 @@ static Optional<AllocFnsTy> getAllocationSize(const Value *V,
Result.NumParams = Callee->getNumOperands();
Result.FstParam = Args.first;
Result.SndParam = Args.second.getValueOr(-1);
// Allocsize has no way to specify an alignment argument
Result.AlignParam = -1;
return Result;
}
@@ -255,6 +255,15 @@ bool llvm::isAlignedAllocLikeFn(
return getAllocationData(V, AlignedAllocLike, GetTLI)
.hasValue();
}
/// Gets the alignment argument for an aligned_alloc-like function
Value *llvm::getAllocAlignment(const CallBase *V,
const TargetLibraryInfo *TLI) {
const Optional<AllocFnsTy> FnData = getAllocationData(V, AnyAlloc, TLI);
if (!FnData.hasValue() || FnData->AlignParam < 0) {
return nullptr;
}
return V->getOperand(FnData->AlignParam);
}
/// Tests if a value is a call or invoke to a library function that
/// allocates zero-filled memory (such as calloc).

9
llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
View File

@@ -2590,12 +2590,13 @@ void InstCombinerImpl::annotateAnyAllocSite(CallBase &Call, const TargetLibraryI
}
// Add alignment attribute if alignment is a power of two constant.
if (!isAlignedAllocLikeFn(&Call, TLI))
Value *Alignment = getAllocAlignment(&Call, TLI);
if (!Alignment)
return;
ConstantInt *Op0C = dyn_cast<ConstantInt>(Call.getOperand(0));
if (Op0C && Op0C->getValue().ult(llvm::Value::MaximumAlignment)) {
uint64_t AlignmentVal = Op0C->getZExtValue();
ConstantInt *AlignOpC = dyn_cast<ConstantInt>(Alignment);
if (AlignOpC && AlignOpC->getValue().ult(llvm::Value::MaximumAlignment)) {
uint64_t AlignmentVal = AlignOpC->getZExtValue();
if (llvm::isPowerOf2_64(AlignmentVal)) {
Call.removeRetAttr(Attribute::Alignment);
Call.addRetAttr(Attribute::getWithAlignment(Call.getContext(),