[ARM64EC 5/?] Fix names of __chkstk and __security_check_cookie.

[efriedma]

Summary

Part of initial Arm64EC patchset.

Arm64EC code needs to use functions with a different name, to avoid using the x64 versions.

[DavidSpickett]

Matches https://docs.microsoft.com/en-us/windows/uwp/porting/arm64ec-abi#stack-checkers, LGTM.

[DavidSpickett]

(subject to discussion on what the final triple is but just a find/replace here)

[bcl5980]

llvm/lib/Target/AArch64/AArch64Subtarget.h

359

Do we need to use #__chkstk_arm64ec here?

[efriedma]

llvm/lib/Target/AArch64/AArch64Subtarget.h

359

Probably? I'm still not entirely sure how that interacts with the hybmp table.

[efriedma]

Rebased

[DavidSpickett]

LGTM

[bcl5980]

llvm/lib/Target/AArch64/AArch64Subtarget.h

359

main_clang.obj : error LNK2019: unresolved external symbol __chkstk_arm64ec referenced in function $iexit_thunk$cdecl$i8$varargs (EC Symbol)

It looks we do need add # here. This is the link error when I try to link a variadic function. It will disappear after I add #.

[efriedma]

llvm/lib/Target/AArch64/AArch64Subtarget.h

359

Hmm, okay... does this specifically apply to __chkstk_arm64ec and __security_check_cookie_arm64ec, or have you noticed link errors for anything else? (Trying to confirm if there's some general mangling rule we're missing, or these functions are just weird.)

[bcl5980]

llvm/lib/Target/AArch64/AArch64Subtarget.h

359

No other link errors for this case.
For now, I haven't found any other case similar to this.
But I haven't tested too many cases because my local code still has many issues.

llvm/lib/Target/AArch64/AArch64FrameLowering.cpp

if (NeedsWinCFI) {
             .setMIFlag(MachineInstr::FrameSetup);
       }
     } else {
       BuildMI(MBB, MBBI, DL, TII->get(AArch64::MOVi64imm), AArch64::X15)
           .addImm(NumWords)
           .setMIFlags(MachineInstr::FrameSetup);
     }
 
+    const char* ChkStk = Subtarget.getChkStkName();
     switch (MF.getTarget().getCodeModel()) {
     case CodeModel::Tiny:
     case CodeModel::Small:
     case CodeModel::Medium:
     case CodeModel::Kernel:
       BuildMI(MBB, MBBI, DL, TII->get(AArch64::BL))
-          .addExternalSymbol("__chkstk")
+          .addExternalSymbol(ChkStk)
           .addReg(AArch64::X15, RegState::Implicit)
           .addReg(AArch64::X16, RegState::Implicit | RegState::Define | RegState::Dead)
           .addReg(AArch64::X17, RegState::Implicit | RegState::Define | RegState::Dead)
           .addReg(AArch64::NZCV, RegState::Implicit | RegState::Define | RegState::Dead)
           .setMIFlags(MachineInstr::FrameSetup);
       if (NeedsWinCFI) {
         HasWinCFI = true;
         BuildMI(MBB, MBBI, DL, TII->get(AArch64::SEH_Nop))
             .setMIFlag(MachineInstr::FrameSetup);
       }
       break;
     case CodeModel::Large:
       BuildMI(MBB, MBBI, DL, TII->get(AArch64::MOVaddrEXT))
           .addReg(AArch64::X16, RegState::Define)
-          .addExternalSymbol("__chkstk")
-          .addExternalSymbol("__chkstk")
+          .addExternalSymbol(ChkStk)
+          .addExternalSymbol(ChkStk)
           .setMIFlags(MachineInstr::FrameSetup);
       if (NeedsWinCFI) {
         HasWinCFI = true;
         BuildMI(MBB, MBBI, DL, TII->get(AArch64::SEH_Nop))
             .setMIFlag(MachineInstr::FrameSetup);
       }
 
       BuildMI(MBB, MBBI, DL, TII->get(getBLRCallOpcode(MF)))

llvm/lib/Target/AArch64/AArch64ISelLowering.cpp

return DAG.getAtomic(ISD::ATOMIC_LOAD_CLR, dl, AN->getMemoryVT(),
                        Op.getOperand(0), Op.getOperand(1), RHS,
                        AN->getMemOperand());
 }
 
 SDValue AArch64TargetLowering::LowerWindowsDYNAMIC_STACKALLOC(
     SDValue Op, SDValue Chain, SDValue &Size, SelectionDAG &DAG) const {
   SDLoc dl(Op);
   EVT PtrVT = getPointerTy(DAG.getDataLayout());
-  SDValue Callee = DAG.getTargetExternalSymbol("__chkstk", PtrVT, 0);
+  SDValue Callee = DAG.getTargetExternalSymbol(Subtarget->getChkStkName(),
+                                               PtrVT, 0);
 
   const AArch64RegisterInfo *TRI = Subtarget->getRegisterInfo();
   const uint32_t *Mask = TRI->getWindowsStackProbePreservedMask();
   if (Subtarget->hasCustomCallingConv())
     TRI->UpdateCustomCallPreservedMask(DAG.getMachineFunction(), &Mask);
 
   Size = DAG.getNode(ISD::SRL, dl, MVT::i64, Size,
                      DAG.getConstant(4, dl, MVT::i64));
void AArch64TargetLowering::insertSSPDeclarations(Module &M) const {
   // MSVC CRT provides functionalities for stack protection.
   if (Subtarget->getTargetTriple().isWindowsMSVCEnvironment()) {
     // MSVC CRT has a global variable holding security cookie.
     M.getOrInsertGlobal("__security_cookie",
                         Type::getInt8PtrTy(M.getContext()));
 
     // MSVC CRT has a function to validate security cookie.
     FunctionCallee SecurityCheckCookie = M.getOrInsertFunction(
-        "__security_check_cookie", Type::getVoidTy(M.getContext()),
-        Type::getInt8PtrTy(M.getContext()));
+        Subtarget->getSecurityCheckCookieName(),
+        Type::getVoidTy(M.getContext()), Type::getInt8PtrTy(M.getContext()));
     if (Function *F = dyn_cast<Function>(SecurityCheckCookie.getCallee())) {
       F->setCallingConv(CallingConv::Win64);
       F->addParamAttr(0, Attribute::AttrKind::InReg);
     }
     return;
   }
   TargetLowering::insertSSPDeclarations(M);
 }
 
 Value *AArch64TargetLowering::getSDagStackGuard(const Module &M) const {
   // MSVC CRT has a global variable holding security cookie.
   if (Subtarget->getTargetTriple().isWindowsMSVCEnvironment())
     return M.getGlobalVariable("__security_cookie");
   return TargetLowering::getSDagStackGuard(M);
 }
 
 Function *AArch64TargetLowering::getSSPStackGuardCheck(const Module &M) const {
   // MSVC CRT has a function to validate security cookie.
   if (Subtarget->getTargetTriple().isWindowsMSVCEnvironment())
-    return M.getFunction("__security_check_cookie");
+    return M.getFunction(Subtarget->getSecurityCheckCookieName());
   return TargetLowering::getSSPStackGuardCheck(M);
 }
 
 Value *
 AArch64TargetLowering::getSafeStackPointerLocation(IRBuilderBase &IRB) const {
   // Android provides a fixed TLS slot for the SafeStack pointer. See the
   // definition of TLS_SLOT_SAFESTACK in
   // https://android.googlesource.com/platform/bionic/+/master/libc/private/bionic_tls.h

llvm/lib/Target/AArch64/AArch64Subtarget.h

#include "AArch64GenSubtargetInfo.inc"
   }
 
   bool useSVEForFixedLengthVectors() const {
     // Prefer NEON unless larger SVE registers are available.
     return hasSVE() && getMinSVEVectorSizeInBits() >= 256;
   }
 
   unsigned getVScaleForTuning() const { return VScaleForTuning; }
+
+  const char* getChkStkName() const {
+    if (isWindowsArm64EC())
+      return "__chkstk_arm64ec";
+    return "__chkstk";
+  }
+
+  const char* getSecurityCheckCookieName() const {
+    if (isWindowsArm64EC())
+      return "__security_check_cookie_arm64ec";
+    return "__security_check_cookie";
+  }
+
 };
 } // End llvm namespace
 
 #endif

llvm/test/CodeGen/AArch64/stack-protector-target.ll

 ; Test target-specific stack cookie location.
 ; RUN: llc -mtriple=aarch64-linux-android < %s -o - | FileCheck --check-prefix=ANDROID-AARCH64 %s
 ; RUN: llc -mtriple=aarch64-fuchsia < %s -o - | FileCheck --check-prefixes=FUCHSIA-AARCH64-COMMON,FUCHSIA-AARCH64-USER %s
 ; RUN: llc -mtriple=aarch64-fuchsia -mattr=+tpidr-el1 < %s -o - | FileCheck --check-prefixes=FUCHSIA-AARCH64-COMMON,FUCHSIA-AARCH64-KERNEL %s
 ; RUN: llc -mtriple=aarch64-windows < %s -o - | FileCheck --check-prefix=WINDOWS-AARCH64 %s
+; RUN: llc -mtriple=arm64ec-windows-msvc < %s -o - | FileCheck --check-prefix=WINDOWS-ARM64EC %s
 
 define void @_Z1fv() sspreq {
 entry:
   %x = alloca i32, align 4
   %0 = bitcast i32* %x to i8*
   call void @_Z7CapturePi(i32* nonnull %x)
   ret void
 }

 ; FUCHSIA-AARCH64-COMMON: cmp [[C]], [[D]]
 
 ; WINDOWS-AARCH64: adrp x8, __security_cookie
 ; WINDOWS-AARCH64: ldr x8, [x8, :lo12:__security_cookie]
 ; WINDOWS-AARCH64: str x8, [sp, #8]
 ; WINDOWS-AARCH64: bl  _Z7CapturePi
 ; WINDOWS-AARCH64: ldr x0, [sp, #8]
 ; WINDOWS-AARCH64: bl  __security_check_cookie
+
+; WINDOWS-ARM64EC: adrp x8, __security_cookie
+; WINDOWS-ARM64EC: ldr x8, [x8, :lo12:__security_cookie]
+; WINDOWS-ARM64EC: str x8, [sp, #8]
+; WINDOWS-ARM64EC: bl  _Z7CapturePi
+; WINDOWS-ARM64EC: ldr x0, [sp, #8]
+; WINDOWS-ARM64EC: bl  __security_check_cookie_arm64ec

llvm/test/CodeGen/AArch64/win-alloca.ll

 ; RUN: llc -mtriple aarch64-windows -verify-machineinstrs -filetype asm -o - %s | FileCheck %s -check-prefixes=CHECK,CHECK-OPT
 ; RUN: llc -mtriple aarch64-windows -verify-machineinstrs -filetype asm -o - %s -O0 | FileCheck %s
+; RUN: llc -mtriple arm64ec-windows-msvc -verify-machineinstrs -filetype asm -o - %s | FileCheck -check-prefix=CHECK-ARM64EC %s
 
 define void @func(i64 %a) {
 entry:
   %0 = alloca i8, i64 %a, align 16
   call void @func2(i8* nonnull %0)
   ret void
 }
 
 declare void @func2(i8*)
 
 ; The -O0 version here ends up much less elegant, so just check the
 ; details of the optimized form, but check that -O0 at least emits the
 ; call to __chkstk.
 
 ; CHECK: add [[REG1:x[0-9]+]], x0, #15
 ; CHECK-OPT: lsr x15, [[REG1]], #4
 ; CHECK: bl __chkstk
 ; CHECK-OPT: sub [[REG3:x[0-9]+]], sp, x15, lsl #4
 ; CHECK-OPT: mov sp, [[REG3]]
 ; CHECK: bl func2
+; CHECK-ARM64EC: bl __chkstk_arm64ec