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Use Module level target-abi to assign target features for codegenerated functions. #100833

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2 changes: 2 additions & 0 deletions llvm/include/llvm/IR/Function.h
Original file line number Diff line number Diff line change
Expand Up @@ -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.
///
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3 changes: 3 additions & 0 deletions llvm/include/llvm/IR/Module.h
Original file line number Diff line number Diff line change
Expand Up @@ -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
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21 changes: 21 additions & 0 deletions llvm/lib/IR/Function.cpp
Original file line number Diff line number Diff line change
Expand Up @@ -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>
Expand Down Expand Up @@ -387,6 +388,26 @@ 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.equals_insensitive("lp64d"))
Attr = "+d";
else if (TargetABI.equals_insensitive("lp64f"))
Attr = "+f";
} else if (T.isRISCV32()) {
if (TargetABI.equals_insensitive("ilp32d"))
Attr = "+d";
else if (TargetABI.equals_insensitive("ilp32f"))
Attr = "+f";
} else if (T.isARM() || T.isThumb()) {
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Can we also get a test for the ARM cases?

Attr = "+thumb-mode";
}

return Attr;
}

Function *Function::createWithDefaultAttr(FunctionType *Ty,
LinkageTypes Linkage,
unsigned AddrSpace, const Twine &N,
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8 changes: 8 additions & 0 deletions llvm/lib/IR/Module.cpp
Original file line number Diff line number Diff line change
Expand Up @@ -915,3 +915,11 @@ 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;
}
12 changes: 9 additions & 3 deletions llvm/lib/Transforms/IPO/CrossDSOCFI.cpp
Original file line number Diff line number Diff line change
Expand Up @@ -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++);
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19 changes: 19 additions & 0 deletions llvm/test/Transforms/CrossDSOCFI/riscv.ll
Original file line number Diff line number Diff line change
@@ -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"