Author: erichkeane Date: Wed Aug 30 14:17:40 2017 New Revision: 312173 URL: http://llvm.org/viewvc/llvm-project?rev=312173&view=rev Log: [CodeGen][x86_64] Enable 'force_align_arg_pointer' attribute at x86_64
This attribute is useful in OS development when we jump from 32 to 64 bit code and expect that 64bit function forces correct stack alignment. Related discussion: http://lists.llvm.org/pipermail/cfe-dev/2017-June/054358.html Patch By: anatol.pomozov (anatol.pomo...@gmail.com) Differential Revision:https://reviews.llvm.org/D36272 Modified: cfe/trunk/include/clang/Basic/Attr.td cfe/trunk/lib/CodeGen/TargetInfo.cpp cfe/trunk/test/CodeGen/function-attributes.c Modified: cfe/trunk/include/clang/Basic/Attr.td URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Basic/Attr.td?rev=312173&r1=312172&r2=312173&view=diff ============================================================================== --- cfe/trunk/include/clang/Basic/Attr.td (original) +++ cfe/trunk/include/clang/Basic/Attr.td Wed Aug 30 14:17:40 2017 @@ -2042,7 +2042,7 @@ def AnyX86NoCallerSavedRegisters : Inher let Documentation = [AnyX86NoCallerSavedRegistersDocs]; } -def X86ForceAlignArgPointer : InheritableAttr, TargetSpecificAttr<TargetX86> { +def X86ForceAlignArgPointer : InheritableAttr, TargetSpecificAttr<TargetAnyX86> { let Spellings = [GNU<"force_align_arg_pointer">]; // Technically, this appertains to a FunctionDecl, but the target-specific // code silently allows anything function-like (such as typedefs or function Modified: cfe/trunk/lib/CodeGen/TargetInfo.cpp URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/TargetInfo.cpp?rev=312173&r1=312172&r2=312173&view=diff ============================================================================== --- cfe/trunk/lib/CodeGen/TargetInfo.cpp (original) +++ cfe/trunk/lib/CodeGen/TargetInfo.cpp Wed Aug 30 14:17:40 2017 @@ -2297,6 +2297,15 @@ public: if (!IsForDefinition) return; if (const FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(D)) { + if (FD->hasAttr<X86ForceAlignArgPointerAttr>()) { + // Get the LLVM function. + auto *Fn = cast<llvm::Function>(GV); + + // Now add the 'alignstack' attribute with a value of 16. + llvm::AttrBuilder B; + B.addStackAlignmentAttr(16); + Fn->addAttributes(llvm::AttributeList::FunctionIndex, B); + } if (FD->hasAttr<AnyX86InterruptAttr>()) { llvm::Function *Fn = cast<llvm::Function>(GV); Fn->setCallingConv(llvm::CallingConv::X86_INTR); @@ -2425,6 +2434,15 @@ void WinX86_64TargetCodeGenInfo::setTarg if (!IsForDefinition) return; if (const FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(D)) { + if (FD->hasAttr<X86ForceAlignArgPointerAttr>()) { + // Get the LLVM function. + auto *Fn = cast<llvm::Function>(GV); + + // Now add the 'alignstack' attribute with a value of 16. + llvm::AttrBuilder B; + B.addStackAlignmentAttr(16); + Fn->addAttributes(llvm::AttributeList::FunctionIndex, B); + } if (FD->hasAttr<AnyX86InterruptAttr>()) { llvm::Function *Fn = cast<llvm::Function>(GV); Fn->setCallingConv(llvm::CallingConv::X86_INTR); Modified: cfe/trunk/test/CodeGen/function-attributes.c URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGen/function-attributes.c?rev=312173&r1=312172&r2=312173&view=diff ============================================================================== --- cfe/trunk/test/CodeGen/function-attributes.c (original) +++ cfe/trunk/test/CodeGen/function-attributes.c Wed Aug 30 14:17:40 2017 @@ -1,5 +1,6 @@ // RUN: %clang_cc1 -triple i386-unknown-unknown -emit-llvm -disable-llvm-passes -Os -o - %s | FileCheck %s // RUN: %clang_cc1 -triple i386-unknown-unknown -emit-llvm -disable-llvm-passes -Os -std=c99 -o - %s | FileCheck %s +// RUN: %clang_cc1 -triple x86_64-unknown-unknown -emit-llvm -disable-llvm-passes -Os -std=c99 -o - %s | FileCheck %s // CHECK: define signext i8 @f0(i32 %x) [[NUW:#[0-9]+]] // CHECK: define zeroext i8 @f1(i32 %x) [[NUW]] // CHECK: define void @f2(i8 signext %x) [[NUW]] _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
