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Emit getelementptr inbounds nuw flag where possible #4936

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Emit getelementptr inbounds nuw flag where possible #4936

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47f7457
Emit getelementptr nuw for p++
kubo39 May 18, 2025
a235955
Emit getelementptr nuw for IndexExp in static array with const exp
kubo39 May 18, 2025
396a763
Emit getelementptr nuw for SliceExp for static array with const lower
kubo39 May 19, 2025
af8bd2f
Style fix
kubo39 May 19, 2025
ade13eb
Emit getelementptr nuw for adding offset to pointer
kubo39 May 19, 2025
712e5de
Emit getelementptr nuw for Struct field
kubo39 May 20, 2025
581e0a8
remove getelement nuw flag from pointer arithmetic; too aggresive
kubo39 May 20, 2025
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14 changes: 12 additions & 2 deletions gen/llvmhelpers.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -1860,7 +1860,12 @@ DLValue *DtoIndexAggregate(LLValue *src, AggregateDeclaration *ad,
LLType * ty = nullptr;
if (!isFieldIdx) {
// apply byte-wise offset from object start
ptr = DtoGEP1(getI8Type(), ptr, off);
ptr = DtoGEP1(getI8Type(), ptr, off
#if LDC_LLVM_VER >= 2000
, "", nullptr
, llvm::GEPNoWrapFlags::inBounds() | llvm::GEPNoWrapFlags::noUnsignedWrap()
#endif
);
ty = DtoType(vd->type);
} else {
if (ad->structsize == 0) { // can happen for extern(C) structs
Expand All @@ -1874,7 +1879,12 @@ DLValue *DtoIndexAggregate(LLValue *src, AggregateDeclaration *ad,
} else {
st = irTypeAggr->getLLType();
}
ptr = DtoGEP(st, ptr, 0, off);
ptr = DtoGEP(st, ptr, 0, off
#if LDC_LLVM_VER >= 2000
, "", nullptr
, llvm::GEPNoWrapFlags::inBounds() | llvm::GEPNoWrapFlags::noUnsignedWrap()
#endif
);
ty = isaStruct(st)->getElementType(off);
}
}
Expand Down
23 changes: 20 additions & 3 deletions gen/toir.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -1190,7 +1190,16 @@ class ToElemVisitor : public Visitor {
}
LLType *elt = DtoMemType(e1type->nextOf());
LLType *arrty = llvm::ArrayType::get(elt, e1type->isTypeSArray()->dim->isIntegerExp()->getInteger());
arrptr = DtoGEP(arrty, DtoLVal(l), DtoConstUint(0), DtoRVal(r));
#if LDC_LLVM_VER >= 2000
llvm::GEPNoWrapFlags nw = llvm::GEPNoWrapFlags::inBounds();
if (e->indexIsInBounds)
nw |= llvm::GEPNoWrapFlags::noUnsignedWrap();
#endif
arrptr = DtoGEP(arrty, DtoLVal(l), DtoConstUint(0), DtoRVal(r)
#if LDC_LLVM_VER >= 2000
, "", nullptr, nw
#endif
);
} else if (e1type->ty == TY::Tarray) {
if (p->emitArrayBoundsChecks() && !e->indexIsInBounds) {
DtoIndexBoundsCheck(e->loc, l, r);
Expand Down Expand Up @@ -1284,8 +1293,16 @@ class ToElemVisitor : public Visitor {
}

// offset by lower
eptr = DtoGEP1(DtoMemType(etype->nextOf()), getBasePointer(), vlo, "lowerbound");

#if LDC_LLVM_VER >= 2000
llvm::GEPNoWrapFlags nw = llvm::GEPNoWrapFlags::inBounds();
if (!needCheckUpper && !needCheckLower)
nw |= llvm::GEPNoWrapFlags::noUnsignedWrap();
#endif
eptr = DtoGEP1(DtoMemType(etype->nextOf()), getBasePointer(), vlo, "lowerbound"
#if LDC_LLVM_VER >= 2000
, nullptr, nw
#endif
);
// adjust length
elen = p->ir->CreateSub(vup, vlo);
}
Expand Down
87 changes: 72 additions & 15 deletions gen/tollvm.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -357,46 +357,103 @@ LLIntegerType *DtoSize_t() {
namespace {
llvm::GetElementPtrInst *DtoGEP(LLType *pointeeTy, LLValue *ptr,
llvm::ArrayRef<LLValue *> indices,
const char *name, llvm::BasicBlock *bb) {
const char *name, llvm::BasicBlock *bb
#if LDC_LLVM_VER >= 2000
, llvm::GEPNoWrapFlags nw
#endif
) {
auto gep = llvm::GetElementPtrInst::Create(pointeeTy, ptr, indices, name,
bb ? bb : gIR->scopebb());
#if LDC_LLVM_VER >= 2000
gep->setNoWrapFlags(nw);
#else
gep->setIsInBounds(true);
#endif
return gep;
}
}

LLValue *DtoGEP1(LLType *pointeeTy, LLValue *ptr, LLValue *i0, const char *name,
llvm::BasicBlock *bb) {
return DtoGEP(pointeeTy, ptr, i0, name, bb);
llvm::BasicBlock *bb
#if LDC_LLVM_VER >= 2000
, llvm::GEPNoWrapFlags nw
#endif
) {
return DtoGEP(pointeeTy, ptr, i0, name, bb
#if LDC_LLVM_VER >= 2000
, nw
#endif
);
}

LLValue *DtoGEP(LLType *pointeeTy, LLValue *ptr, LLValue *i0, LLValue *i1,
const char *name, llvm::BasicBlock *bb) {
const char *name, llvm::BasicBlock *bb
#if LDC_LLVM_VER >= 2000
, llvm::GEPNoWrapFlags nw
#endif
) {
LLValue *indices[] = {i0, i1};
return DtoGEP(pointeeTy, ptr, indices, name, bb);
return DtoGEP(pointeeTy, ptr, indices, name, bb
#if LDC_LLVM_VER >= 2000
, nw
#endif
);
}

LLValue *DtoGEP1(LLType *pointeeTy, LLValue *ptr, unsigned i0, const char *name,
llvm::BasicBlock *bb) {
return DtoGEP(pointeeTy, ptr, DtoConstUint(i0), name, bb);
llvm::BasicBlock *bb
#if LDC_LLVM_VER >= 2000
, llvm::GEPNoWrapFlags nw
#endif
) {
return DtoGEP(pointeeTy, ptr, DtoConstUint(i0), name, bb
#if LDC_LLVM_VER >= 2000
, nw
#endif
);
}

LLValue *DtoGEP(LLType *pointeeTy, LLValue *ptr, unsigned i0, unsigned i1,
const char *name, llvm::BasicBlock *bb) {
const char *name, llvm::BasicBlock *bb
#if LDC_LLVM_VER >= 2000
, llvm::GEPNoWrapFlags nw
#endif
) {
LLValue *indices[] = {DtoConstUint(i0), DtoConstUint(i1)};
return DtoGEP(pointeeTy, ptr, indices, name, bb);
return DtoGEP(pointeeTy, ptr, indices, name, bb
#if LDC_LLVM_VER >= 2000
, nw
#endif
);
}

LLConstant *DtoGEP(LLType *pointeeTy, LLConstant *ptr, unsigned i0,
unsigned i1) {
unsigned i1
#if LDC_LLVM_VER >= 2000
, llvm::GEPNoWrapFlags nw
#endif
) {
LLValue *indices[] = {DtoConstUint(i0), DtoConstUint(i1)};
return llvm::ConstantExpr::getGetElementPtr(pointeeTy, ptr, indices,
/* InBounds = */ true);
#if LDC_LLVM_VER >= 2000
nw
#else
/* InBounds = */ true
#endif
);
}

LLValue *DtoGEP1i64(LLType *pointeeTy, LLValue *ptr, uint64_t i0, const char *name,
llvm::BasicBlock *bb) {
return DtoGEP(pointeeTy, ptr, DtoConstUlong(i0), name, bb);
llvm::BasicBlock *bb
#if LDC_LLVM_VER >= 2000
, llvm::GEPNoWrapFlags nw
#endif
) {
return DtoGEP(pointeeTy, ptr, DtoConstUlong(i0), name, bb
#if LDC_LLVM_VER >= 2000
, nw
#endif
);
}

////////////////////////////////////////////////////////////////////////////////
Expand Down Expand Up @@ -701,7 +758,7 @@ LLGlobalVariable *makeGlobal(LLStringRef name, LLType* type, LLStringRef section

if (!section.empty())
var->setSection(section);

return var;
}

Expand Down Expand Up @@ -737,7 +794,7 @@ LLGlobalVariable *makeGlobalWithBytes(LLStringRef name, LLConstantList packedCon
0u,
externInit
);

return var;
}

Expand Down
36 changes: 30 additions & 6 deletions gen/tollvm.h
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Original file line number Diff line number Diff line change
Expand Up @@ -77,19 +77,43 @@ LLStructType *DtoModuleReferenceType();

// getelementptr helpers
LLValue *DtoGEP1(LLType *pointeeTy, LLValue *ptr, LLValue *i0,
const char *name = "", llvm::BasicBlock *bb = nullptr);
const char *name = "", llvm::BasicBlock *bb = nullptr
#if LDC_LLVM_VER >= 2000
, llvm::GEPNoWrapFlags nw = llvm::GEPNoWrapFlags::inBounds()
#endif
);
LLValue *DtoGEP(LLType *pointeeTy, LLValue *ptr, LLValue *i0, LLValue *i1,
const char *name = "", llvm::BasicBlock *bb = nullptr);
const char *name = "", llvm::BasicBlock *bb = nullptr
#if LDC_LLVM_VER >= 2000
, llvm::GEPNoWrapFlags nw = llvm::GEPNoWrapFlags::inBounds()
#endif
);

LLValue *DtoGEP1(LLType *pointeeTy, LLValue *ptr, unsigned i0,
const char *name = "", llvm::BasicBlock *bb = nullptr);
const char *name = "", llvm::BasicBlock *bb = nullptr
#if LDC_LLVM_VER >= 2000
, llvm::GEPNoWrapFlags nw = llvm::GEPNoWrapFlags::inBounds()
#endif
);
LLValue *DtoGEP(LLType *pointeeTy, LLValue *ptr, unsigned i0, unsigned i1,
const char *name = "", llvm::BasicBlock *bb = nullptr);
const char *name = "", llvm::BasicBlock *bb = nullptr
#if LDC_LLVM_VER >= 2000
, llvm::GEPNoWrapFlags nw = llvm::GEPNoWrapFlags::inBounds()
#endif
);
LLConstant *DtoGEP(LLType *pointeeTy, LLConstant *ptr, unsigned i0,
unsigned i1);
unsigned i1
#if LDC_LLVM_VER >= 2000
, llvm::GEPNoWrapFlags nw = llvm::GEPNoWrapFlags::inBounds()
#endif
);

LLValue *DtoGEP1i64(LLType *pointeeTy, LLValue *ptr, uint64_t i0,
const char *name = "", llvm::BasicBlock *bb = nullptr);
const char *name = "", llvm::BasicBlock *bb = nullptr
#if LDC_LLVM_VER >= 2000
, llvm::GEPNoWrapFlags nw = llvm::GEPNoWrapFlags::inBounds()
#endif
);

// to constant helpers
LLConstantInt *DtoConstSize_t(uint64_t);
Expand Down
6 changes: 3 additions & 3 deletions tests/codegen/inbounds.d
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Original file line number Diff line number Diff line change
Expand Up @@ -9,7 +9,7 @@ extern(C): // Avoid name mangling
// IndexExp in static array with const exp
// CHECK-LABEL: @foo1
int foo1(int[3] a) {
// CHECK: getelementptr inbounds [3 x i32]
// CHECK: getelementptr inbounds{{( nuw)?}} [3 x i32]
return a[1];
}

Expand Down Expand Up @@ -58,7 +58,7 @@ int foo7(int* p, int i) {
// Struct field
// CHECK-LABEL: @foo8
float foo8(S s) {
// CHECK: getelementptr inbounds
// CHECK: getelementptr inbounds{{( nuw)?}}
return s.y;
}

Expand All @@ -79,7 +79,7 @@ int foo10(int[] a, int i) {
// SliceExp for static array with const lower bound
// CHECK-LABEL: @foo11
int[] foo11(ref int[3] a) {
// CHECK: getelementptr inbounds i32, ptr
// CHECK: getelementptr inbounds{{( nuw)?}} i32, ptr
return a[1 .. $];
}

Expand Down
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