[AllocToken] Refactor stateless token calculation into Support #163633
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Created using spr 1.3.8-beta.1
Created using spr 1.3.8-beta.1 [skip ci]
This was referenced Oct 15, 2025
|
@llvm/pr-subscribers-llvm-transforms Author: Marco Elver (melver) ChangesRefactor the stateless (hash-based) token calculation logic out of the This helps with making the token calculation logic available to other parts of The This change is part of the following series:
Full diff: https://github.com/llvm/llvm-project/pull/163633.diff 5 Files Affected:
diff --git a/llvm/include/llvm/Support/AllocToken.h b/llvm/include/llvm/Support/AllocToken.h
new file mode 100644
index 0000000000000..6617b7d1f7668
--- /dev/null
+++ b/llvm/include/llvm/Support/AllocToken.h
@@ -0,0 +1,58 @@
+//===- llvm/Support/AllocToken.h - Allocation Token Calculation -----*- C++ -*//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// Definition of AllocToken modes and shared calculation of stateless token IDs.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_SUPPORT_ALLOCTOKEN_H
+#define LLVM_SUPPORT_ALLOCTOKEN_H
+
+#include "llvm/ADT/SmallString.h"
+#include <cstdint>
+#include <optional>
+
+namespace llvm {
+
+/// Modes for generating allocation token IDs.
+enum class AllocTokenMode {
+ /// Incrementally increasing token ID.
+ Increment,
+
+ /// Simple mode that returns a statically-assigned random token ID.
+ Random,
+
+ /// Token ID based on allocated type hash.
+ TypeHash,
+
+ /// Token ID based on allocated type hash, where the top half ID-space is
+ /// reserved for types that contain pointers and the bottom half for types
+ /// that do not contain pointers.
+ TypeHashPointerSplit,
+};
+
+/// Metadata about an allocation used to generate a token ID.
+struct AllocTokenMetadata {
+ SmallString<64> TypeName;
+ bool ContainsPointer;
+};
+
+/// Calculates stable allocation token ID. Returns std::nullopt for stateful
+/// modes that are only available in the AllocToken pass.
+///
+/// \param Mode The token generation mode.
+/// \param Metadata The metadata about the allocation.
+/// \param MaxTokens The maximum number of tokens (must not be 0)
+/// \return The calculated allocation token ID, or std::nullopt.
+std::optional<uint64_t> getAllocTokenHash(AllocTokenMode Mode,
+ const AllocTokenMetadata &Metadata,
+ uint64_t MaxTokens);
+
+} // end namespace llvm
+
+#endif // LLVM_SUPPORT_ALLOCTOKEN_H
diff --git a/llvm/lib/Support/AllocToken.cpp b/llvm/lib/Support/AllocToken.cpp
new file mode 100644
index 0000000000000..6c6f80ac4997c
--- /dev/null
+++ b/llvm/lib/Support/AllocToken.cpp
@@ -0,0 +1,46 @@
+//===- AllocToken.cpp - Allocation Token Calculation ----------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// Definition of AllocToken modes and shared calculation of stateless token IDs.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Support/AllocToken.h"
+#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/SipHash.h"
+
+namespace llvm {
+std::optional<uint64_t> getAllocTokenHash(AllocTokenMode Mode,
+ const AllocTokenMetadata &Metadata,
+ uint64_t MaxTokens) {
+ assert(MaxTokens && "Must provide concrete max tokens");
+
+ switch (Mode) {
+ case AllocTokenMode::Increment:
+ case AllocTokenMode::Random:
+ // Stateful modes cannot be implemented as a pure function.
+ return std::nullopt;
+
+ case AllocTokenMode::TypeHash: {
+ return getStableSipHash(Metadata.TypeName) % MaxTokens;
+ }
+
+ case AllocTokenMode::TypeHashPointerSplit: {
+ if (MaxTokens == 1)
+ return 0;
+ const uint64_t HalfTokens = MaxTokens / 2;
+ uint64_t Hash = getStableSipHash(Metadata.TypeName) % HalfTokens;
+ if (Metadata.ContainsPointer)
+ Hash += HalfTokens;
+ return Hash;
+ }
+ }
+
+ llvm_unreachable("");
+}
+} // namespace llvm
diff --git a/llvm/lib/Support/CMakeLists.txt b/llvm/lib/Support/CMakeLists.txt
index 42b21b5e62029..671a5fe941cef 100644
--- a/llvm/lib/Support/CMakeLists.txt
+++ b/llvm/lib/Support/CMakeLists.txt
@@ -149,6 +149,7 @@ add_llvm_component_library(LLVMSupport
AArch64BuildAttributes.cpp
ARMAttributeParser.cpp
ARMWinEH.cpp
+ AllocToken.cpp
Allocator.cpp
AutoConvert.cpp
Base64.cpp
diff --git a/llvm/lib/Transforms/Instrumentation/AllocToken.cpp b/llvm/lib/Transforms/Instrumentation/AllocToken.cpp
index be7cad1f8f38e..7c488ec96120e 100644
--- a/llvm/lib/Transforms/Instrumentation/AllocToken.cpp
+++ b/llvm/lib/Transforms/Instrumentation/AllocToken.cpp
@@ -36,6 +36,7 @@
#include "llvm/IR/Module.h"
#include "llvm/IR/PassManager.h"
#include "llvm/IR/Type.h"
+#include "llvm/Support/AllocToken.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Compiler.h"
@@ -54,29 +55,12 @@
#include <variant>
using namespace llvm;
+using TokenMode = AllocTokenMode;
#define DEBUG_TYPE "alloc-token"
namespace {
-//===--- Constants --------------------------------------------------------===//
-
-enum class TokenMode : unsigned {
- /// Incrementally increasing token ID.
- Increment = 0,
-
- /// Simple mode that returns a statically-assigned random token ID.
- Random = 1,
-
- /// Token ID based on allocated type hash.
- TypeHash = 2,
-
- /// Token ID based on allocated type hash, where the top half ID-space is
- /// reserved for types that contain pointers and the bottom half for types
- /// that do not contain pointers.
- TypeHashPointerSplit = 3,
-};
-
//===--- Command-line options ---------------------------------------------===//
cl::opt<TokenMode> ClMode(
@@ -217,22 +201,20 @@ class TypeHashMode : public ModeBase {
using ModeBase::ModeBase;
uint64_t operator()(const CallBase &CB, OptimizationRemarkEmitter &ORE) {
- const auto [N, H] = getHash(CB, ORE);
- return N ? boundedToken(H) : H;
- }
-protected:
- std::pair<MDNode *, uint64_t> getHash(const CallBase &CB,
- OptimizationRemarkEmitter &ORE) {
if (MDNode *N = getAllocTokenMetadata(CB)) {
MDString *S = cast<MDString>(N->getOperand(0));
- return {N, getStableSipHash(S->getString())};
+ AllocTokenMetadata Metadata{S->getString(), containsPointer(N)};
+ if (auto Token =
+ getAllocTokenHash(TokenMode::TypeHash, Metadata, MaxTokens))
+ return *Token;
}
// Fallback.
remarkNoMetadata(CB, ORE);
- return {nullptr, ClFallbackToken};
+ return ClFallbackToken;
}
+protected:
/// Remark that there was no precise type information.
static void remarkNoMetadata(const CallBase &CB,
OptimizationRemarkEmitter &ORE) {
@@ -253,20 +235,18 @@ class TypeHashPointerSplitMode : public TypeHashMode {
using TypeHashMode::TypeHashMode;
uint64_t operator()(const CallBase &CB, OptimizationRemarkEmitter &ORE) {
- if (MaxTokens == 1)
- return 0;
- const uint64_t HalfTokens = MaxTokens / 2;
- const auto [N, H] = getHash(CB, ORE);
- if (!N) {
- // Pick the fallback token (ClFallbackToken), which by default is 0,
- // meaning it'll fall into the pointer-less bucket. Override by setting
- // -alloc-token-fallback if that is the wrong choice.
- return H;
+ if (MDNode *N = getAllocTokenMetadata(CB)) {
+ MDString *S = cast<MDString>(N->getOperand(0));
+ AllocTokenMetadata Metadata{S->getString(), containsPointer(N)};
+ if (auto Token = getAllocTokenHash(TokenMode::TypeHashPointerSplit,
+ Metadata, MaxTokens))
+ return *Token;
}
- uint64_t Hash = H % HalfTokens; // base hash
- if (containsPointer(N))
- Hash += HalfTokens;
- return Hash;
+ // Pick the fallback token (ClFallbackToken), which by default is 0, meaning
+ // it'll fall into the pointer-less bucket. Override by setting
+ // -alloc-token-fallback if that is the wrong choice.
+ remarkNoMetadata(CB, ORE);
+ return ClFallbackToken;
}
};
diff --git a/llvm/utils/gn/secondary/llvm/lib/Support/BUILD.gn b/llvm/utils/gn/secondary/llvm/lib/Support/BUILD.gn
index 38ba4661daacc..df9ddf91f2c49 100644
--- a/llvm/utils/gn/secondary/llvm/lib/Support/BUILD.gn
+++ b/llvm/utils/gn/secondary/llvm/lib/Support/BUILD.gn
@@ -45,6 +45,7 @@ static_library("Support") {
"ARMAttributeParser.cpp",
"ARMBuildAttributes.cpp",
"ARMWinEH.cpp",
+ "AllocToken.cpp",
"Allocator.cpp",
"AutoConvert.cpp",
"BalancedPartitioning.cpp",
|
|
@llvm/pr-subscribers-llvm-support Author: Marco Elver (melver) ChangesRefactor the stateless (hash-based) token calculation logic out of the This helps with making the token calculation logic available to other parts of The This change is part of the following series:
Full diff: https://github.com/llvm/llvm-project/pull/163633.diff 5 Files Affected:
diff --git a/llvm/include/llvm/Support/AllocToken.h b/llvm/include/llvm/Support/AllocToken.h
new file mode 100644
index 0000000000000..6617b7d1f7668
--- /dev/null
+++ b/llvm/include/llvm/Support/AllocToken.h
@@ -0,0 +1,58 @@
+//===- llvm/Support/AllocToken.h - Allocation Token Calculation -----*- C++ -*//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// Definition of AllocToken modes and shared calculation of stateless token IDs.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_SUPPORT_ALLOCTOKEN_H
+#define LLVM_SUPPORT_ALLOCTOKEN_H
+
+#include "llvm/ADT/SmallString.h"
+#include <cstdint>
+#include <optional>
+
+namespace llvm {
+
+/// Modes for generating allocation token IDs.
+enum class AllocTokenMode {
+ /// Incrementally increasing token ID.
+ Increment,
+
+ /// Simple mode that returns a statically-assigned random token ID.
+ Random,
+
+ /// Token ID based on allocated type hash.
+ TypeHash,
+
+ /// Token ID based on allocated type hash, where the top half ID-space is
+ /// reserved for types that contain pointers and the bottom half for types
+ /// that do not contain pointers.
+ TypeHashPointerSplit,
+};
+
+/// Metadata about an allocation used to generate a token ID.
+struct AllocTokenMetadata {
+ SmallString<64> TypeName;
+ bool ContainsPointer;
+};
+
+/// Calculates stable allocation token ID. Returns std::nullopt for stateful
+/// modes that are only available in the AllocToken pass.
+///
+/// \param Mode The token generation mode.
+/// \param Metadata The metadata about the allocation.
+/// \param MaxTokens The maximum number of tokens (must not be 0)
+/// \return The calculated allocation token ID, or std::nullopt.
+std::optional<uint64_t> getAllocTokenHash(AllocTokenMode Mode,
+ const AllocTokenMetadata &Metadata,
+ uint64_t MaxTokens);
+
+} // end namespace llvm
+
+#endif // LLVM_SUPPORT_ALLOCTOKEN_H
diff --git a/llvm/lib/Support/AllocToken.cpp b/llvm/lib/Support/AllocToken.cpp
new file mode 100644
index 0000000000000..6c6f80ac4997c
--- /dev/null
+++ b/llvm/lib/Support/AllocToken.cpp
@@ -0,0 +1,46 @@
+//===- AllocToken.cpp - Allocation Token Calculation ----------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// Definition of AllocToken modes and shared calculation of stateless token IDs.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Support/AllocToken.h"
+#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/SipHash.h"
+
+namespace llvm {
+std::optional<uint64_t> getAllocTokenHash(AllocTokenMode Mode,
+ const AllocTokenMetadata &Metadata,
+ uint64_t MaxTokens) {
+ assert(MaxTokens && "Must provide concrete max tokens");
+
+ switch (Mode) {
+ case AllocTokenMode::Increment:
+ case AllocTokenMode::Random:
+ // Stateful modes cannot be implemented as a pure function.
+ return std::nullopt;
+
+ case AllocTokenMode::TypeHash: {
+ return getStableSipHash(Metadata.TypeName) % MaxTokens;
+ }
+
+ case AllocTokenMode::TypeHashPointerSplit: {
+ if (MaxTokens == 1)
+ return 0;
+ const uint64_t HalfTokens = MaxTokens / 2;
+ uint64_t Hash = getStableSipHash(Metadata.TypeName) % HalfTokens;
+ if (Metadata.ContainsPointer)
+ Hash += HalfTokens;
+ return Hash;
+ }
+ }
+
+ llvm_unreachable("");
+}
+} // namespace llvm
diff --git a/llvm/lib/Support/CMakeLists.txt b/llvm/lib/Support/CMakeLists.txt
index 42b21b5e62029..671a5fe941cef 100644
--- a/llvm/lib/Support/CMakeLists.txt
+++ b/llvm/lib/Support/CMakeLists.txt
@@ -149,6 +149,7 @@ add_llvm_component_library(LLVMSupport
AArch64BuildAttributes.cpp
ARMAttributeParser.cpp
ARMWinEH.cpp
+ AllocToken.cpp
Allocator.cpp
AutoConvert.cpp
Base64.cpp
diff --git a/llvm/lib/Transforms/Instrumentation/AllocToken.cpp b/llvm/lib/Transforms/Instrumentation/AllocToken.cpp
index be7cad1f8f38e..7c488ec96120e 100644
--- a/llvm/lib/Transforms/Instrumentation/AllocToken.cpp
+++ b/llvm/lib/Transforms/Instrumentation/AllocToken.cpp
@@ -36,6 +36,7 @@
#include "llvm/IR/Module.h"
#include "llvm/IR/PassManager.h"
#include "llvm/IR/Type.h"
+#include "llvm/Support/AllocToken.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Compiler.h"
@@ -54,29 +55,12 @@
#include <variant>
using namespace llvm;
+using TokenMode = AllocTokenMode;
#define DEBUG_TYPE "alloc-token"
namespace {
-//===--- Constants --------------------------------------------------------===//
-
-enum class TokenMode : unsigned {
- /// Incrementally increasing token ID.
- Increment = 0,
-
- /// Simple mode that returns a statically-assigned random token ID.
- Random = 1,
-
- /// Token ID based on allocated type hash.
- TypeHash = 2,
-
- /// Token ID based on allocated type hash, where the top half ID-space is
- /// reserved for types that contain pointers and the bottom half for types
- /// that do not contain pointers.
- TypeHashPointerSplit = 3,
-};
-
//===--- Command-line options ---------------------------------------------===//
cl::opt<TokenMode> ClMode(
@@ -217,22 +201,20 @@ class TypeHashMode : public ModeBase {
using ModeBase::ModeBase;
uint64_t operator()(const CallBase &CB, OptimizationRemarkEmitter &ORE) {
- const auto [N, H] = getHash(CB, ORE);
- return N ? boundedToken(H) : H;
- }
-protected:
- std::pair<MDNode *, uint64_t> getHash(const CallBase &CB,
- OptimizationRemarkEmitter &ORE) {
if (MDNode *N = getAllocTokenMetadata(CB)) {
MDString *S = cast<MDString>(N->getOperand(0));
- return {N, getStableSipHash(S->getString())};
+ AllocTokenMetadata Metadata{S->getString(), containsPointer(N)};
+ if (auto Token =
+ getAllocTokenHash(TokenMode::TypeHash, Metadata, MaxTokens))
+ return *Token;
}
// Fallback.
remarkNoMetadata(CB, ORE);
- return {nullptr, ClFallbackToken};
+ return ClFallbackToken;
}
+protected:
/// Remark that there was no precise type information.
static void remarkNoMetadata(const CallBase &CB,
OptimizationRemarkEmitter &ORE) {
@@ -253,20 +235,18 @@ class TypeHashPointerSplitMode : public TypeHashMode {
using TypeHashMode::TypeHashMode;
uint64_t operator()(const CallBase &CB, OptimizationRemarkEmitter &ORE) {
- if (MaxTokens == 1)
- return 0;
- const uint64_t HalfTokens = MaxTokens / 2;
- const auto [N, H] = getHash(CB, ORE);
- if (!N) {
- // Pick the fallback token (ClFallbackToken), which by default is 0,
- // meaning it'll fall into the pointer-less bucket. Override by setting
- // -alloc-token-fallback if that is the wrong choice.
- return H;
+ if (MDNode *N = getAllocTokenMetadata(CB)) {
+ MDString *S = cast<MDString>(N->getOperand(0));
+ AllocTokenMetadata Metadata{S->getString(), containsPointer(N)};
+ if (auto Token = getAllocTokenHash(TokenMode::TypeHashPointerSplit,
+ Metadata, MaxTokens))
+ return *Token;
}
- uint64_t Hash = H % HalfTokens; // base hash
- if (containsPointer(N))
- Hash += HalfTokens;
- return Hash;
+ // Pick the fallback token (ClFallbackToken), which by default is 0, meaning
+ // it'll fall into the pointer-less bucket. Override by setting
+ // -alloc-token-fallback if that is the wrong choice.
+ remarkNoMetadata(CB, ORE);
+ return ClFallbackToken;
}
};
diff --git a/llvm/utils/gn/secondary/llvm/lib/Support/BUILD.gn b/llvm/utils/gn/secondary/llvm/lib/Support/BUILD.gn
index 38ba4661daacc..df9ddf91f2c49 100644
--- a/llvm/utils/gn/secondary/llvm/lib/Support/BUILD.gn
+++ b/llvm/utils/gn/secondary/llvm/lib/Support/BUILD.gn
@@ -45,6 +45,7 @@ static_library("Support") {
"ARMAttributeParser.cpp",
"ARMBuildAttributes.cpp",
"ARMWinEH.cpp",
+ "AllocToken.cpp",
"Allocator.cpp",
"AutoConvert.cpp",
"BalancedPartitioning.cpp",
|
fmayer
reviewed
Oct 16, 2025
vitalybuka
approved these changes
Oct 17, 2025
Created using spr 1.3.8-beta.1 [skip ci]
Created using spr 1.3.8-beta.1
fmayer
reviewed
Oct 17, 2025
Created using spr 1.3.8-beta.1 [skip ci]
Created using spr 1.3.8-beta.1
melver
changed the base branch from
users/melver/spr/main.alloctoken-refactor-stateless-token-calculation-into-support
to
main
melver
deleted the
users/melver/spr/alloctoken-refactor-stateless-token-calculation-into-support
branch
|
LLVM Buildbot has detected a new failure on builder Full details are available at: https://lab.llvm.org/buildbot/#/builders/10/builds/15897 Here is the relevant piece of the build log for the reference |
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Refactor the stateless (hash-based) token calculation logic out of the
AllocTokenpass and intollvm/Support/AllocToken.h.This helps with making the token calculation logic available to other parts of
the codebase, which will be necessary for frontend implementation of
__builtin_infer_alloc_tokento perform constexpr evaluation.The
AllocTokenModeenum and a newAllocTokenMetadatastruct are moved intoa shared header. The
getAllocTokenHash()function now provides the source oftruth for calculating token IDs for
TypeHashandTypeHashPointerSplitmodes.
This change is part of the following series: