[llvm] Use Module level target-abi to assign target features for codegenerated functions. (PR #100833)
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Tue Dec 17 17:53:08 PST 2024
https://github.com/hiraditya updated https://github.com/llvm/llvm-project/pull/100833
>From 2430ee2b3d02cf84e60fe16595d00c91beed6e46 Mon Sep 17 00:00:00 2001
From: AdityaK <hiraditya at msn.com>
Date: Fri, 26 Jul 2024 14:22:40 -0700
Subject: [PATCH] Use TargetABI to assign default-target features in
getDefaultSubtargetFeatures
It is currently not possible to provide any reasonable
target-features for compiler generated functions (See: #69780)
Having a target-abi will provide a way to add minimal
requirements for target-features like `+d` for RISC-V.
---
llvm/include/llvm/IR/Function.h | 2 ++
llvm/include/llvm/IR/Module.h | 3 +++
llvm/lib/IR/Function.cpp | 20 ++++++++++++++++++++
llvm/lib/IR/Module.cpp | 9 +++++++++
llvm/lib/Transforms/IPO/CrossDSOCFI.cpp | 12 +++++++++---
llvm/test/Transforms/CrossDSOCFI/riscv.ll | 19 +++++++++++++++++++
6 files changed, 62 insertions(+), 3 deletions(-)
create mode 100644 llvm/test/Transforms/CrossDSOCFI/riscv.ll
diff --git a/llvm/include/llvm/IR/Function.h b/llvm/include/llvm/IR/Function.h
index e7afcbd31420c1..77ffde6a95a9c6 100644
--- a/llvm/include/llvm/IR/Function.h
+++ b/llvm/include/llvm/IR/Function.h
@@ -190,6 +190,8 @@ class LLVM_ABI Function : public GlobalObject, public ilist_node<Function> {
static Function *Create(FunctionType *Ty, LinkageTypes Linkage,
const Twine &N, Module &M);
+ StringRef getDefaultTargetFeatures(const StringRef TargetABI);
+
/// Creates a function with some attributes recorded in llvm.module.flags
/// and the LLVMContext applied.
///
diff --git a/llvm/include/llvm/IR/Module.h b/llvm/include/llvm/IR/Module.h
index 12b50fc506516e..3368184af4103e 100644
--- a/llvm/include/llvm/IR/Module.h
+++ b/llvm/include/llvm/IR/Module.h
@@ -1065,6 +1065,9 @@ class LLVM_ABI Module {
/// Set the target variant version build SDK version metadata.
void setDarwinTargetVariantSDKVersion(VersionTuple Version);
+
+ /// Returns target-abi from MDString, null if target-abi is absent.
+ StringRef getTargetABIFromMD();
};
/// Given "llvm.used" or "llvm.compiler.used" as a global name, collect the
diff --git a/llvm/lib/IR/Function.cpp b/llvm/lib/IR/Function.cpp
index 9c5dd5aeb92e97..18ab34aa7ef952 100644
--- a/llvm/lib/IR/Function.cpp
+++ b/llvm/lib/IR/Function.cpp
@@ -48,6 +48,7 @@
#include "llvm/Support/Compiler.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/ModRef.h"
+#include "llvm/TargetParser/Triple.h"
#include <cassert>
#include <cstddef>
#include <cstdint>
@@ -387,6 +388,25 @@ Function *Function::Create(FunctionType *Ty, LinkageTypes Linkage,
return Create(Ty, Linkage, M.getDataLayout().getProgramAddressSpace(), N, &M);
}
+StringRef Function::getDefaultTargetFeatures(const StringRef TargetABI) {
+ Triple T(getParent()->getTargetTriple());
+ StringRef attr = "";
+ if (T.isRISCV64()) {
+ if (TargetABI.contains("lp64d"))
+ attr = "+d";
+ else if (TargetABI.contains("lp64f"))
+ attr = "+f";
+ else if (TargetABI.contains("lp64q"))
+ attr = "+q";
+ } else if (T.isRISCV32() && TargetABI.contains("ilp32f")) {
+ attr = "+f";
+ } else if (T.isARM() || T.isThumb()) {
+ attr = "+thumb-mode";
+ }
+
+ return attr;
+}
+
Function *Function::createWithDefaultAttr(FunctionType *Ty,
LinkageTypes Linkage,
unsigned AddrSpace, const Twine &N,
diff --git a/llvm/lib/IR/Module.cpp b/llvm/lib/IR/Module.cpp
index c7b9f8744d8d35..6cb014360eb1a4 100644
--- a/llvm/lib/IR/Module.cpp
+++ b/llvm/lib/IR/Module.cpp
@@ -915,3 +915,12 @@ VersionTuple Module::getDarwinTargetVariantSDKVersion() const {
void Module::setDarwinTargetVariantSDKVersion(VersionTuple Version) {
addSDKVersionMD(Version, *this, "darwin.target_variant.SDK Version");
}
+
+StringRef Module::getTargetABIFromMD() {
+ StringRef TargetABI = "";
+ if (auto *TargetABIMD =
+ dyn_cast_or_null<MDString>(getModuleFlag("target-abi")))
+ TargetABI = TargetABIMD->getString();
+ return TargetABI;
+}
+
diff --git a/llvm/lib/Transforms/IPO/CrossDSOCFI.cpp b/llvm/lib/Transforms/IPO/CrossDSOCFI.cpp
index 2d884078940cc0..92b9ece7484a6f 100644
--- a/llvm/lib/Transforms/IPO/CrossDSOCFI.cpp
+++ b/llvm/lib/Transforms/IPO/CrossDSOCFI.cpp
@@ -86,14 +86,20 @@ void CrossDSOCFI::buildCFICheck(Module &M) {
"__cfi_check", Type::getVoidTy(Ctx), Type::getInt64Ty(Ctx),
PointerType::getUnqual(Ctx), PointerType::getUnqual(Ctx));
Function *F = cast<Function>(C.getCallee());
+ std::string DefaultFeatures =
+ F->getContext().getDefaultTargetFeatures().str();
// Take over the existing function. The frontend emits a weak stub so that the
// linker knows about the symbol; this pass replaces the function body.
F->deleteBody();
F->setAlignment(Align(4096));
- Triple T(M.getTargetTriple());
- if (T.isARM() || T.isThumb())
- F->addFnAttr("target-features", "+thumb-mode");
+ // Set existing target-features.
+ if (!DefaultFeatures.empty())
+ F->addFnAttr("target-features", DefaultFeatures);
+
+ DefaultFeatures = F->getDefaultTargetFeatures(M.getTargetABIFromMD());
+ if (!DefaultFeatures.empty())
+ F->addFnAttr("target-features", DefaultFeatures);
auto args = F->arg_begin();
Value &CallSiteTypeId = *(args++);
diff --git a/llvm/test/Transforms/CrossDSOCFI/riscv.ll b/llvm/test/Transforms/CrossDSOCFI/riscv.ll
new file mode 100644
index 00000000000000..9427ff5e8cf0e1
--- /dev/null
+++ b/llvm/test/Transforms/CrossDSOCFI/riscv.ll
@@ -0,0 +1,19 @@
+; RUN: opt -S -passes=cross-dso-cfi < %s | FileCheck --check-prefix=RISCV64 %s
+
+target datalayout = "e-m:e-p:64:64-i64:64-i128:128-n32:64-S128"
+target triple = "riscv64-unknown-linux-gnu"
+
+define signext i8 @f() !type !0 !type !1 {
+entry:
+ ret i8 1
+}
+
+!llvm.module.flags = !{!2, !3}
+
+!0 = !{i64 0, !"_ZTSFcvE"}
+!1 = !{i64 0, i64 111}
+!2 = !{i32 4, !"Cross-DSO CFI", i32 1}
+!3 = !{i32 1, !"target-abi", !"lp64d"}
+
+; RISCV64: define void @__cfi_check({{.*}} #[[A:.*]] align 4096
+; RISCV64: attributes #[[A]] = { {{.*}}"target-features"="+d"
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