diff --git a/llvm/include/llvm/IR/StructuralHash.h b/llvm/include/llvm/IR/StructuralHash.h index 071575137ff57..514dd6f174b90 100644 --- a/llvm/include/llvm/IR/StructuralHash.h +++ b/llvm/include/llvm/IR/StructuralHash.h @@ -31,6 +31,9 @@ class Module; /// to true includes instruction and operand type information. stable_hash StructuralHash(const Function &F, bool DetailedHash = false); +/// Returns a hash of the global variable \p G. +stable_hash StructuralHash(const GlobalVariable &G); + /// Returns a hash of the module \p M by hashing all functions and global /// variables contained within. \param M The module to hash. \param DetailedHash /// Whether or not to encode additional information in the function hashes that diff --git a/llvm/lib/CodeGen/MachineStableHash.cpp b/llvm/lib/CodeGen/MachineStableHash.cpp index facda7a59e2f8..5ab589acee413 100644 --- a/llvm/lib/CodeGen/MachineStableHash.cpp +++ b/llvm/lib/CodeGen/MachineStableHash.cpp @@ -27,6 +27,8 @@ #include "llvm/CodeGen/Register.h" #include "llvm/Config/llvm-config.h" #include "llvm/IR/Constants.h" +#include "llvm/IR/GlobalVariable.h" +#include "llvm/IR/StructuralHash.h" #include "llvm/MC/MCSymbol.h" #include "llvm/Support/Alignment.h" #include "llvm/Support/ErrorHandling.h" @@ -93,13 +95,19 @@ stable_hash llvm::stableHashValue(const MachineOperand &MO) { return 0; case MachineOperand::MO_GlobalAddress: { const GlobalValue *GV = MO.getGlobal(); - if (!GV->hasName()) { - ++StableHashBailingGlobalAddress; - return 0; + stable_hash GVHash = 0; + if (auto *GVar = dyn_cast(GV)) + GVHash = StructuralHash(*GVar); + if (!GVHash) { + if (!GV->hasName()) { + ++StableHashBailingGlobalAddress; + return 0; + } + GVHash = stable_hash_name(GV->getName()); } - auto Name = GV->getName(); - return stable_hash_combine(MO.getType(), MO.getTargetFlags(), - stable_hash_name(Name), MO.getOffset()); + + return stable_hash_combine(MO.getType(), MO.getTargetFlags(), GVHash, + MO.getOffset()); } case MachineOperand::MO_TargetIndex: { diff --git a/llvm/lib/IR/StructuralHash.cpp b/llvm/lib/IR/StructuralHash.cpp index ccc534a890419..56b925626d845 100644 --- a/llvm/lib/IR/StructuralHash.cpp +++ b/llvm/lib/IR/StructuralHash.cpp @@ -46,7 +46,7 @@ class StructuralHashImpl { /// Assign a unique ID to each Value in the order they are first seen. DenseMap ValueToId; - stable_hash hashType(Type *ValueType) { + static stable_hash hashType(Type *ValueType) { SmallVector Hashes; Hashes.emplace_back(ValueType->getTypeID()); if (ValueType->isIntegerTy()) @@ -65,7 +65,7 @@ class StructuralHashImpl { } } - stable_hash hashAPInt(const APInt &I) { + static stable_hash hashAPInt(const APInt &I) { SmallVector Hashes; Hashes.emplace_back(I.getBitWidth()); auto RawVals = ArrayRef(I.getRawData(), I.getNumWords()); @@ -73,11 +73,39 @@ class StructuralHashImpl { return stable_hash_combine(Hashes); } - stable_hash hashAPFloat(const APFloat &F) { + static stable_hash hashAPFloat(const APFloat &F) { return hashAPInt(F.bitcastToAPInt()); } - stable_hash hashGlobalValue(const GlobalValue *GV) { + static stable_hash hashGlobalVariable(const GlobalVariable &GVar) { + if (!GVar.hasInitializer()) + return hashGlobalValue(&GVar); + + // Hash the contents of a string. + if (GVar.getName().starts_with(".str")) { + auto *C = GVar.getInitializer(); + if (const auto *Seq = dyn_cast(C)) + if (Seq->isString()) + return stable_hash_name(Seq->getAsString()); + } + + // Hash structural contents of Objective-C metadata in specific sections. + // This can be extended to other metadata if needed. + static constexpr const char *SectionNames[] = { + "__cfstring", "__cstring", "__objc_classrefs", + "__objc_methname", "__objc_selrefs", + }; + if (GVar.hasSection()) { + StringRef SectionName = GVar.getSection(); + for (const char *Name : SectionNames) + if (SectionName.contains(Name)) + return hashConstant(GVar.getInitializer()); + } + + return hashGlobalValue(&GVar); + } + + static stable_hash hashGlobalValue(const GlobalValue *GV) { if (!GV->hasName()) return 0; return stable_hash_name(GV->getName()); @@ -87,7 +115,7 @@ class StructuralHashImpl { // FunctionComparator::cmpConstants() in FunctionComparator.cpp, but here // we're interested in computing a hash rather than comparing two Constants. // Some of the logic is simplified, e.g, we don't expand GEPOperator. - stable_hash hashConstant(Constant *C) { + static stable_hash hashConstant(const Constant *C) { SmallVector Hashes; Type *Ty = C->getType(); @@ -98,14 +126,21 @@ class StructuralHashImpl { return stable_hash_combine(Hashes); } + if (auto *GVar = dyn_cast(C)) { + Hashes.emplace_back(hashGlobalVariable(*GVar)); + return stable_hash_combine(Hashes); + } + if (auto *G = dyn_cast(C)) { Hashes.emplace_back(hashGlobalValue(G)); return stable_hash_combine(Hashes); } if (const auto *Seq = dyn_cast(C)) { - Hashes.emplace_back(xxh3_64bits(Seq->getRawDataValues())); - return stable_hash_combine(Hashes); + if (Seq->isString()) { + Hashes.emplace_back(stable_hash_name(Seq->getAsString())); + return stable_hash_combine(Hashes); + } } switch (C->getValueID()) { @@ -266,6 +301,7 @@ class StructuralHashImpl { Hashes.emplace_back(Hash); Hashes.emplace_back(GlobalHeaderHash); Hashes.emplace_back(GV.getValueType()->getTypeID()); + Hashes.emplace_back(hashGlobalVariable(GV)); // Update the combined hash in place. Hash = stable_hash_combine(Hashes); @@ -297,6 +333,10 @@ stable_hash llvm::StructuralHash(const Function &F, bool DetailedHash) { return H.getHash(); } +stable_hash llvm::StructuralHash(const GlobalVariable &GVar) { + return StructuralHashImpl::hashGlobalVariable(GVar); +} + stable_hash llvm::StructuralHash(const Module &M, bool DetailedHash) { StructuralHashImpl H(DetailedHash); H.update(M); diff --git a/llvm/test/CodeGen/AArch64/cgdata-merge-gvar-nsconst.ll b/llvm/test/CodeGen/AArch64/cgdata-merge-gvar-nsconst.ll new file mode 100644 index 0000000000000..490a778f69e26 --- /dev/null +++ b/llvm/test/CodeGen/AArch64/cgdata-merge-gvar-nsconst.ll @@ -0,0 +1,32 @@ +; This test verifies that global variables (ns constant) are hashed based on their initial contents, +; allowing them to be merged even if they appear different due to their names. +; Now they become identical functions that can be merged without creating a parameter + +; RUN: llc -mtriple=arm64-apple-darwin -enable-global-merge-func=true -global-merging-skip-no-params=false < %s | FileCheck %s + +; CHECK: _f1.Tgm +; CHECK: _f2.Tgm + +%struct.__NSConstantString_tag = type { ptr, i32, ptr, i64 } +@__CFConstantStringClassReference = external global [0 x i32] +@.str.2 = private unnamed_addr constant [9 x i8] c"cfstring\00", section "__TEXT,__cstring,cstring_literals", align 1 +@_unnamed_cfstring_ = private global %struct.__NSConstantString_tag { ptr @__CFConstantStringClassReference, i32 1992, ptr @.str.2, i64 8 }, section "__DATA,__cfstring", align 8 + +@.str.3 = private unnamed_addr constant [9 x i8] c"cfstring\00", section "__TEXT,__cstring,cstring_literals", align 1 +@_unnamed_cfstring_.2 = private global %struct.__NSConstantString_tag { ptr @__CFConstantStringClassReference, i32 1992, ptr @.str.3, i64 8 }, section "__DATA,__cfstring", align 8 + +declare i32 @hoo(ptr noundef) + +define i32 @f1() { +entry: + %call = tail call i32 @hoo(ptr noundef nonnull @_unnamed_cfstring_) + %add = sub nsw i32 %call, 1 + ret i32 %add +} + +define i32 @f2() { +entry: + %call = tail call i32 @hoo(ptr noundef nonnull @_unnamed_cfstring_.2) + %add = sub nsw i32 %call, 1 + ret i32 %add +} diff --git a/llvm/test/CodeGen/AArch64/cgdata-merge-gvar-objc.ll b/llvm/test/CodeGen/AArch64/cgdata-merge-gvar-objc.ll new file mode 100644 index 0000000000000..0073114941501 --- /dev/null +++ b/llvm/test/CodeGen/AArch64/cgdata-merge-gvar-objc.ll @@ -0,0 +1,38 @@ +; This test verifies that global variables (objc metadata) are hashed based on their initial contents, +; allowing them to be merged even if they appear different due to their names. +; Now they become identical functions that can be merged without creating a parameter + +; RUN: llc -mtriple=arm64-apple-darwin -enable-global-merge-func=true -global-merging-skip-no-params=false < %s | FileCheck %s + +; CHECK: _f1.Tgm +; CHECK: _f2.Tgm + +%struct._class_t = type { ptr, ptr, ptr, ptr, ptr } + +@"OBJC_CLASS_$_MyClass" = external global %struct._class_t +@"OBJC_CLASSLIST_REFERENCES_$_" = internal global ptr @"OBJC_CLASS_$_MyClass", section "__DATA,__objc_classrefs,regular,no_dead_strip", align 8 +@"OBJC_CLASSLIST_REFERENCES_$_.1" = internal global ptr @"OBJC_CLASS_$_MyClass", section "__DATA,__objc_classrefs,regular,no_dead_strip", align 8 + +@OBJC_METH_VAR_NAME_ = private unnamed_addr constant [6 x i8] c"hello\00", section "__TEXT,__objc_methname,cstring_literals", align 1 +@OBJC_METH_VAR_NAME_.1 = private unnamed_addr constant [6 x i8] c"hello\00", section "__TEXT,__objc_methname,cstring_literals", align 1 + +@OBJC_SELECTOR_REFERENCES_ = internal externally_initialized global ptr @OBJC_METH_VAR_NAME_, section "__DATA,__objc_selrefs,literal_pointers,no_dead_strip", align 8 +@OBJC_SELECTOR_REFERENCES_.1 = internal externally_initialized global ptr @OBJC_METH_VAR_NAME_.1, section "__DATA,__objc_selrefs,literal_pointers,no_dead_strip", align 8 + +declare ptr @objc_msgSend(ptr, ptr, ...) + +define i32 @f1() { +entry: + %0 = load ptr, ptr @"OBJC_CLASSLIST_REFERENCES_$_", align 8 + %1 = load ptr, ptr @OBJC_SELECTOR_REFERENCES_, align 8 + %call = tail call i32 @objc_msgSend(ptr noundef %0, ptr noundef %1) + ret i32 %call +} + +define i32 @f2() { +entry: + %0 = load ptr, ptr @"OBJC_CLASSLIST_REFERENCES_$_.1", align 8 + %1 = load ptr, ptr @OBJC_SELECTOR_REFERENCES_.1, align 8 + %call = tail call i32 @objc_msgSend(ptr noundef %0, ptr noundef %1) + ret i32 %call +} diff --git a/llvm/test/CodeGen/AArch64/cgdata-merge-gvar-string.ll b/llvm/test/CodeGen/AArch64/cgdata-merge-gvar-string.ll new file mode 100644 index 0000000000000..1e67425f0b847 --- /dev/null +++ b/llvm/test/CodeGen/AArch64/cgdata-merge-gvar-string.ll @@ -0,0 +1,46 @@ +; This test verifies that global variables (string) are hashed based on their initial contents, +; allowing them to be merged even if they appear different due to their names. +; Now they become identical functions that can be merged without creating a parameter. + +; RUN: llc -mtriple=arm64-apple-darwin -enable-global-merge-func=true -global-merging-skip-no-params=false < %s | FileCheck %s + +; CHECK: _f1.Tgm +; CHECK: _f2.Tgm +; CHECK-NOT: _f3.Tgm +; CHECK-NOT: _f4.Tgm + +; The initial contents of `.str` and `.str.1` are identical, but not with those of `.str.2` and `.str.3`. +@.str = private unnamed_addr constant [6 x i8] c"hello\00", align 1 +@.str.1 = private unnamed_addr constant [6 x i8] c"hello\00", align 1 +@.str.2 = private unnamed_addr constant [6 x i8] c"diff2\00", align 1 +@.str.3 = private unnamed_addr constant [6 x i8] c"diff3\00", align 1 + +declare i32 @goo(ptr noundef) + +define i32 @f1() { +entry: + %call = tail call i32 @goo(ptr noundef nonnull @.str) + %add = add nsw i32 %call, 1 + ret i32 %add +} + +define i32 @f2() { +entry: + %call = tail call i32 @goo(ptr noundef nonnull @.str.1) + %add = add nsw i32 %call, 1 + ret i32 %add +} + +define i32 @f3() { +entry: + %call = tail call noundef i32 @goo(ptr noundef nonnull @.str.2) + %add = sub nsw i32 %call, 1 + ret i32 %add +} + +define i32 @f4() { +entry: + %call = tail call noundef i32 @goo(ptr noundef nonnull @.str.3) + %add = sub nsw i32 %call, 1 + ret i32 %add +} diff --git a/llvm/test/CodeGen/AArch64/cgdata-outline-gvar.ll b/llvm/test/CodeGen/AArch64/cgdata-outline-gvar.ll new file mode 100644 index 0000000000000..63ba1d491f9c7 --- /dev/null +++ b/llvm/test/CodeGen/AArch64/cgdata-outline-gvar.ll @@ -0,0 +1,64 @@ +; This test verifies that global variables are hashed based on their initial contents, +; allowing them to be outlined even if they appear different due to their names. + +; RUN: split-file %s %t + +; The outlined function is created locally. +; Note that `.str.3` is commonly used in both `f1()` and `f2()`. +; RUN: llc -mtriple=arm64-apple-darwin -enable-machine-outliner -codegen-data-generate -aarch64-enable-collect-loh=false \ +; RUN: %t/local-two.ll -o - | FileCheck %s --check-prefix=WRITE + +; WRITE-LABEL: _OUTLINED_FUNCTION_{{.*}}: +; WRITE: adrp x1, l_.str.3 +; WRITE-NEXT: add x1, x1, l_.str.3 +; WRITE-NEXT: mov w2 +; WRITE-NEXT: mov w3 +; WRITE-NEXT: mov w4 +; WRITE-NEXT: b + +; Create an object file and merge it into the cgdata. +; RUN: llc -mtriple=arm64-apple-darwin -enable-machine-outliner -codegen-data-generate -aarch64-enable-collect-loh=false \ +; RUN: -filetype=obj %t/local-two.ll -o %t_write_base +; RUN: llvm-cgdata --merge %t_write_base -o %t_cgdata_base + +; Read the cgdata in the machine outliner for optimistically outlining in local-one.ll. +; Note that the hash of `.str.5` in local-one.ll matches that of `.str.3` in an outlined tree in the cgdata. + +; RUN: llc -mtriple=arm64-apple-darwin -enable-machine-outliner -codegen-data-use-path=%t_cgdata_base -aarch64-enable-collect-loh=false \ +; RUN: %t/local-one.ll -o - | FileCheck %s --check-prefix=READ + +; READ-LABEL: _OUTLINED_FUNCTION_{{.*}}: +; READ: adrp x1, l_.str.5 +; READ-NEXT: add x1, x1, l_.str.5 +; READ-NEXT: mov w2 +; READ-NEXT: mov w3 +; READ-NEXT: mov w4 +; READ-NEXT: b + +;--- local-two.ll +@.str.1 = private unnamed_addr constant [3 x i8] c"f1\00", align 1 +@.str.2 = private unnamed_addr constant [3 x i8] c"f2\00", align 1 +@.str.3 = private unnamed_addr constant [6 x i8] c"hello\00", align 1 + +declare noundef i32 @goo(ptr noundef, ptr noundef, i32, i32, i32) +define i32 @f1() minsize { +entry: + %call = tail call noundef i32 @goo(ptr noundef nonnull @.str.1, ptr noundef nonnull @.str.3, i32 1, i32 2, i32 3) + ret i32 %call +} +define i32 @f2() minsize { +entry: + %call = tail call noundef i32 @goo(ptr noundef nonnull @.str.2, ptr noundef nonnull @.str.3, i32 1, i32 2, i32 3) + ret i32 %call +} + +;--- local-one.ll +@.str.4 = private unnamed_addr constant [3 x i8] c"f3\00", align 1 +@.str.5 = private unnamed_addr constant [6 x i8] c"hello\00", align 1 + +declare noundef i32 @goo(ptr noundef, ptr noundef, i32, i32, i32) +define i32 @f1() minsize { +entry: + %call = tail call noundef i32 @goo(ptr noundef nonnull @.str.4, ptr noundef nonnull @.str.5, i32 1, i32 2, i32 3) + ret i32 %call +}