From 64573da4bf0bc7883e6d4d3debc60daf665d78b8 Mon Sep 17 00:00:00 2001 From: Arthur Eubanks Date: Tue, 19 Sep 2023 16:36:30 -0700 Subject: [PATCH] [IR] Add "Large Data Threshold" module metadata (#66797) This allows us to not have to pass -mllvm flags to set the large data threshold for (in-LLD/not-distributed) ThinLTO. Follows https://reviews.llvm.org/D52322, which did the same for the code model. Since the large data threshold is tied to the code model and we disallow mixing different code models, do the same for the large data threshold. --- llvm/include/llvm/IR/Module.h | 11 ++++++++++ llvm/lib/IR/Module.cpp | 17 +++++++++++++++ llvm/lib/LTO/LTOBackend.cpp | 5 +++++ .../test/LTO/X86/Inputs/largedatathreshold.ll | 10 +++++++++ llvm/test/LTO/X86/largedatathreshold-1.ll | 21 +++++++++++++++++++ llvm/test/LTO/X86/largedatathreshold-2.ll | 20 ++++++++++++++++++ llvm/test/LTO/X86/largedatathreshold-3.ll | 20 ++++++++++++++++++ 7 files changed, 104 insertions(+) create mode 100644 llvm/test/LTO/X86/Inputs/largedatathreshold.ll create mode 100644 llvm/test/LTO/X86/largedatathreshold-1.ll create mode 100644 llvm/test/LTO/X86/largedatathreshold-2.ll create mode 100644 llvm/test/LTO/X86/largedatathreshold-3.ll diff --git a/llvm/include/llvm/IR/Module.h b/llvm/include/llvm/IR/Module.h index 61b19409a96d..70beddddc1c1 100644 --- a/llvm/include/llvm/IR/Module.h +++ b/llvm/include/llvm/IR/Module.h @@ -922,6 +922,17 @@ public: void setCodeModel(CodeModel::Model CL); /// @} + /// @} + /// @name Utility function for querying and setting the large data threshold + /// @{ + + /// Returns the code model (tiny, small, kernel, medium or large model) + std::optional getLargeDataThreshold() const; + + /// Set the code model (tiny, small, kernel, medium or large) + void setLargeDataThreshold(uint64_t Threshold); + /// @} + /// @name Utility functions for querying and setting PGO summary /// @{ diff --git a/llvm/lib/IR/Module.cpp b/llvm/lib/IR/Module.cpp index 5861bbd1f293..dba660bbe5ba 100644 --- a/llvm/lib/IR/Module.cpp +++ b/llvm/lib/IR/Module.cpp @@ -631,6 +631,23 @@ void Module::setCodeModel(CodeModel::Model CL) { addModuleFlag(ModFlagBehavior::Error, "Code Model", CL); } +std::optional Module::getLargeDataThreshold() const { + auto *Val = + cast_or_null(getModuleFlag("Large Data Threshold")); + + if (!Val) + return std::nullopt; + + return cast(Val->getValue())->getZExtValue(); +} + +void Module::setLargeDataThreshold(uint64_t Threshold) { + // Since the large data threshold goes along with the code model, the merge + // behavior is the same. + addModuleFlag(ModFlagBehavior::Error, "Large Data Threshold", + ConstantInt::get(Type::getInt64Ty(Context), Threshold)); +} + void Module::setProfileSummary(Metadata *M, ProfileSummary::Kind Kind) { if (Kind == ProfileSummary::PSK_CSInstr) setModuleFlag(ModFlagBehavior::Error, "CSProfileSummary", M); diff --git a/llvm/lib/LTO/LTOBackend.cpp b/llvm/lib/LTO/LTOBackend.cpp index 29e288767608..ccc4276e36da 100644 --- a/llvm/lib/LTO/LTOBackend.cpp +++ b/llvm/lib/LTO/LTOBackend.cpp @@ -225,7 +225,12 @@ createTargetMachine(const Config &Conf, const Target *TheTarget, Module &M) { std::unique_ptr TM(TheTarget->createTargetMachine( TheTriple, Conf.CPU, Features.getString(), Conf.Options, RelocModel, CodeModel, Conf.CGOptLevel)); + assert(TM && "Failed to create target machine"); + + if (std::optional LargeDataThreshold = M.getLargeDataThreshold()) + TM->setLargeDataThreshold(*LargeDataThreshold); + return TM; } diff --git a/llvm/test/LTO/X86/Inputs/largedatathreshold.ll b/llvm/test/LTO/X86/Inputs/largedatathreshold.ll new file mode 100644 index 000000000000..34174deb78c0 --- /dev/null +++ b/llvm/test/LTO/X86/Inputs/largedatathreshold.ll @@ -0,0 +1,10 @@ +target triple = "x86_64-unknown-linux-gnu" +target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128" + +define void @bar() { + ret void +} +!llvm.module.flags = !{!0, !1} + +!0 = !{i32 1, !"Code Model", i32 3} +!1 = !{i32 1, !"Large Data Threshold", i32 101} diff --git a/llvm/test/LTO/X86/largedatathreshold-1.ll b/llvm/test/LTO/X86/largedatathreshold-1.ll new file mode 100644 index 000000000000..e3be5c11baaa --- /dev/null +++ b/llvm/test/LTO/X86/largedatathreshold-1.ll @@ -0,0 +1,21 @@ +; RUN: llvm-as %s -o %t.o +; RUN: llvm-lto2 run -r %t.o,_start,px %t.o -o %t.s +; RUN: llvm-objdump -d %t.s.0 | FileCheck %s + +target triple = "x86_64-unknown-linux-gnu" +target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128" + +@data = internal constant [20 x i8] zeroinitializer + +define ptr @_start() { +entry: +; CHECK-LABEL: <_start>: +; CHECK: leaq (%rip), %rax +; CHECK-NOT: movabsq + ret ptr @data +} + +!llvm.module.flags = !{!0, !1} + +!0 = !{i32 1, !"Code Model", i32 3} +!1 = !{i32 1, !"Large Data Threshold", i32 100} diff --git a/llvm/test/LTO/X86/largedatathreshold-2.ll b/llvm/test/LTO/X86/largedatathreshold-2.ll new file mode 100644 index 000000000000..103c066b744d --- /dev/null +++ b/llvm/test/LTO/X86/largedatathreshold-2.ll @@ -0,0 +1,20 @@ +; RUN: llvm-as %s -o %t.o +; RUN: llvm-lto2 run -r %t.o,_start,px %t.o -o %t.s +; RUN: llvm-objdump -d %t.s.0 | FileCheck %s + +target triple = "x86_64-unknown-linux-gnu" +target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128" + +@data = internal constant [20 x i8] zeroinitializer + +define ptr @_start() { +entry: +; CHECK-LABEL: <_start>: +; CHECK: movabsq $0x0, %rax + ret ptr @data +} + +!llvm.module.flags = !{!0, !1} + +!0 = !{i32 1, !"Code Model", i32 3} +!1 = !{i32 1, !"Large Data Threshold", i32 10} diff --git a/llvm/test/LTO/X86/largedatathreshold-3.ll b/llvm/test/LTO/X86/largedatathreshold-3.ll new file mode 100644 index 000000000000..3c0653db334d --- /dev/null +++ b/llvm/test/LTO/X86/largedatathreshold-3.ll @@ -0,0 +1,20 @@ +; RUN: llvm-as %s -o %t0.o +; RUN: llvm-as < %p/Inputs/largedatathreshold.ll > %t1.o +; RUN: not llvm-lto2 run -r %t0.o,_start,px -r %t1.o,bar,px %t0.o %t1.o -o %t2.s 2>&1 | FileCheck %s + +; CHECK: 'Large Data Threshold': IDs have conflicting values + +target triple = "x86_64-unknown-linux-gnu" +target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128" + +@data = internal constant [20 x i8] zeroinitializer + +define ptr @_start() { +entry: + ret ptr @data +} + +!llvm.module.flags = !{!0, !1} + +!0 = !{i32 1, !"Code Model", i32 3} +!1 = !{i32 1, !"Large Data Threshold", i32 100}