[llvm-branch-commits] [llvm] [AArch64][PAC] Introduce AArch64::PAC pseudo instruction (PR #146488)
Anatoly Trosinenko via llvm-branch-commits
llvm-branch-commits at lists.llvm.org
Tue Jul 1 01:53:48 PDT 2025
https://github.com/atrosinenko created https://github.com/llvm/llvm-project/pull/146488
Introduce a pseudo instruction to be selected instead of a pair of
`MOVKXi` and `PAC[DI][AB]` carrying address and immediate modifiers
as separate operands. The new pseudo instruction is expanded in
AsmPrinter, so that MOVKXi is emitted immediately before `PAC[DI][AB]`.
This way, an attacker cannot control the immediate modifier used to sign
the value, even if address modifier can be substituted.
To simplify the instruction selection, select AArch64::PAC pseudo using
TableGen pattern and post-process its $AddrDisc operand by custom
inserter hook - this eliminates duplication of the logic for DAGISel
and GlobalISel. Furthermore, this improves cross-BB analysis in case of
DAGISel.
>From a7b265c78e4a5cc96cc145f136687cdcaff39999 Mon Sep 17 00:00:00 2001
From: Anatoly Trosinenko <atrosinenko at accesssoftek.com>
Date: Sat, 28 Jun 2025 10:50:46 +0300
Subject: [PATCH] [AArch64][PAC] Introduce AArch64::PAC pseudo instruction
Introduce a pseudo instruction to be selected instead of a pair of
`MOVKXi` and `PAC[DI][AB]` carrying address and immediate modifiers
as separate operands. The new pseudo instruction is expanded in
AsmPrinter, so that MOVKXi is emitted immediately before `PAC[DI][AB]`.
This way, an attacker cannot control the immediate modifier used to sign
the value, even if address modifier can be substituted.
To simplify the instruction selection, select AArch64::PAC pseudo using
TableGen pattern and post-process its $AddrDisc operand by custom
inserter hook - this eliminates duplication of the logic for DAGISel
and GlobalISel. Furthermore, this improves cross-BB analysis in case of
DAGISel.
---
llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp | 32 +++
.../Target/AArch64/AArch64ISelLowering.cpp | 74 +++++++
llvm/lib/Target/AArch64/AArch64ISelLowering.h | 7 +
llvm/lib/Target/AArch64/AArch64InstrInfo.td | 21 +-
llvm/test/CodeGen/AArch64/ptrauth-isel.ll | 205 ++++++++++++++++++
5 files changed, 338 insertions(+), 1 deletion(-)
create mode 100644 llvm/test/CodeGen/AArch64/ptrauth-isel.ll
diff --git a/llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp b/llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp
index a16c104d8bef5..40890dbe6e532 100644
--- a/llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp
+++ b/llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp
@@ -171,6 +171,9 @@ class AArch64AsmPrinter : public AsmPrinter {
// Emit the sequence for AUT or AUTPAC.
void emitPtrauthAuthResign(const MachineInstr *MI);
+ // Emit the sequence for PAC.
+ void emitPtrauthSign(const MachineInstr *MI);
+
// Emit the sequence to compute the discriminator.
//
// ScratchReg should be x16/x17.
@@ -2173,6 +2176,31 @@ void AArch64AsmPrinter::emitPtrauthAuthResign(const MachineInstr *MI) {
OutStreamer->emitLabel(EndSym);
}
+void AArch64AsmPrinter::emitPtrauthSign(const MachineInstr *MI) {
+ Register Val = MI->getOperand(1).getReg();
+ auto Key = (AArch64PACKey::ID)MI->getOperand(2).getImm();
+ uint64_t Disc = MI->getOperand(3).getImm();
+ Register AddrDisc = MI->getOperand(4).getReg();
+ bool AddrDiscKilled = MI->getOperand(4).isKill();
+
+ // Compute aut discriminator into x17
+ assert(isUInt<16>(Disc));
+ Register DiscReg = emitPtrauthDiscriminator(
+ Disc, AddrDisc, AArch64::X17, /*MayUseAddrAsScratch=*/AddrDiscKilled);
+ bool IsZeroDisc = DiscReg == AArch64::XZR;
+ unsigned Opc = getPACOpcodeForKey(Key, IsZeroDisc);
+
+ // paciza x16 ; if IsZeroDisc
+ // pacia x16, x17 ; if !IsZeroDisc
+ MCInst PACInst;
+ PACInst.setOpcode(Opc);
+ PACInst.addOperand(MCOperand::createReg(Val));
+ PACInst.addOperand(MCOperand::createReg(Val));
+ if (!IsZeroDisc)
+ PACInst.addOperand(MCOperand::createReg(DiscReg));
+ EmitToStreamer(*OutStreamer, PACInst);
+}
+
void AArch64AsmPrinter::emitPtrauthBranch(const MachineInstr *MI) {
bool IsCall = MI->getOpcode() == AArch64::BLRA;
unsigned BrTarget = MI->getOperand(0).getReg();
@@ -2867,6 +2895,10 @@ void AArch64AsmPrinter::emitInstruction(const MachineInstr *MI) {
emitPtrauthAuthResign(MI);
return;
+ case AArch64::PAC:
+ emitPtrauthSign(MI);
+ return;
+
case AArch64::LOADauthptrstatic:
LowerLOADauthptrstatic(*MI);
return;
diff --git a/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp b/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
index 1f98d69edb473..9e00905b3fec8 100644
--- a/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
+++ b/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
@@ -3071,6 +3071,75 @@ AArch64TargetLowering::EmitGetSMESaveSize(MachineInstr &MI,
return BB;
}
+// Helper function to find the instruction that defined a virtual register.
+// If unable to find such instruction, returns nullptr.
+static MachineInstr *stripVRegCopies(const MachineRegisterInfo &MRI,
+ Register Reg) {
+ while (Reg.isVirtual()) {
+ MachineInstr *DefMI = MRI.getVRegDef(Reg);
+ assert(DefMI && "Virtual register definition not found");
+ unsigned Opcode = DefMI->getOpcode();
+
+ if (Opcode == AArch64::COPY) {
+ Reg = DefMI->getOperand(1).getReg();
+ // Vreg is defined by copying from physreg.
+ if (Reg.isPhysical())
+ return DefMI;
+ continue;
+ }
+ if (Opcode == AArch64::SUBREG_TO_REG) {
+ Reg = DefMI->getOperand(2).getReg();
+ continue;
+ }
+
+ return DefMI;
+ }
+ return nullptr;
+}
+
+void AArch64TargetLowering::fixupBlendComponents(
+ MachineInstr &MI, MachineBasicBlock *BB, MachineOperand &IntDiscOp,
+ MachineOperand &AddrDiscOp, const TargetRegisterClass *AddrDiscRC) const {
+ const TargetInstrInfo *TII = Subtarget->getInstrInfo();
+ MachineRegisterInfo &MRI = MI.getMF()->getRegInfo();
+ const DebugLoc &DL = MI.getDebugLoc();
+
+ Register AddrDisc = AddrDiscOp.getReg();
+ int64_t IntDisc = IntDiscOp.getImm();
+
+ assert(IntDisc == 0 && "Blend components are already expanded");
+
+ MachineInstr *MaybeBlend = stripVRegCopies(MRI, AddrDisc);
+
+ if (MaybeBlend) {
+ // Detect blend(addr, imm) which is lowered as "MOVK addr, #imm, #48".
+ // Alternatively, recognize small immediate modifier passed via VReg.
+ if (MaybeBlend->getOpcode() == AArch64::MOVKXi &&
+ MaybeBlend->getOperand(3).getImm() == 48) {
+ AddrDisc = MaybeBlend->getOperand(1).getReg();
+ IntDisc = MaybeBlend->getOperand(2).getImm();
+ } else if (MaybeBlend->getOpcode() == AArch64::MOVi32imm &&
+ isUInt<16>(MaybeBlend->getOperand(1).getImm())) {
+ AddrDisc = AArch64::XZR;
+ IntDisc = MaybeBlend->getOperand(1).getImm();
+ }
+ }
+
+ // Normalize NoRegister operands emitted by GlobalISel.
+ if (AddrDisc == AArch64::NoRegister)
+ AddrDisc = AArch64::XZR;
+
+ // Make sure AddrDisc operand respects the register class imposed by MI.
+ if (AddrDisc != AArch64::XZR && MRI.getRegClass(AddrDisc) != AddrDiscRC) {
+ Register TmpReg = MRI.createVirtualRegister(AddrDiscRC);
+ BuildMI(*BB, MI, DL, TII->get(AArch64::COPY), TmpReg).addReg(AddrDisc);
+ AddrDisc = TmpReg;
+ }
+
+ AddrDiscOp.setReg(AddrDisc);
+ IntDiscOp.setImm(IntDisc);
+}
+
MachineBasicBlock *AArch64TargetLowering::EmitInstrWithCustomInserter(
MachineInstr &MI, MachineBasicBlock *BB) const {
@@ -3169,6 +3238,11 @@ MachineBasicBlock *AArch64TargetLowering::EmitInstrWithCustomInserter(
return EmitZTInstr(MI, BB, AArch64::ZERO_T, /*Op0IsDef=*/true);
case AArch64::MOVT_TIZ_PSEUDO:
return EmitZTInstr(MI, BB, AArch64::MOVT_TIZ, /*Op0IsDef=*/true);
+
+ case AArch64::PAC:
+ fixupBlendComponents(MI, BB, MI.getOperand(3), MI.getOperand(4),
+ &AArch64::GPR64noipRegClass);
+ return BB;
}
}
diff --git a/llvm/lib/Target/AArch64/AArch64ISelLowering.h b/llvm/lib/Target/AArch64/AArch64ISelLowering.h
index 89f90ee2b7707..3f71daa4daa91 100644
--- a/llvm/lib/Target/AArch64/AArch64ISelLowering.h
+++ b/llvm/lib/Target/AArch64/AArch64ISelLowering.h
@@ -182,6 +182,13 @@ class AArch64TargetLowering : public TargetLowering {
MachineBasicBlock *EmitGetSMESaveSize(MachineInstr &MI,
MachineBasicBlock *BB) const;
+ /// Replace (0, vreg) discriminator components with the operands of blend
+ /// or with (immediate, XZR) when possible.
+ void fixupBlendComponents(MachineInstr &MI, MachineBasicBlock *BB,
+ MachineOperand &IntDiscOp,
+ MachineOperand &AddrDiscOp,
+ const TargetRegisterClass *AddrDiscRC) const;
+
MachineBasicBlock *
EmitInstrWithCustomInserter(MachineInstr &MI,
MachineBasicBlock *MBB) const override;
diff --git a/llvm/lib/Target/AArch64/AArch64InstrInfo.td b/llvm/lib/Target/AArch64/AArch64InstrInfo.td
index 0f3f24f0853c9..98ba694551d9f 100644
--- a/llvm/lib/Target/AArch64/AArch64InstrInfo.td
+++ b/llvm/lib/Target/AArch64/AArch64InstrInfo.td
@@ -2025,7 +2025,7 @@ let Predicates = [HasPAuth] in {
def DZB : SignAuthZero<prefix_z, 0b11, !strconcat(asm, "dzb"), op>;
}
- defm PAC : SignAuth<0b000, 0b010, "pac", int_ptrauth_sign>;
+ defm PAC : SignAuth<0b000, 0b010, "pac", null_frag>;
defm AUT : SignAuth<0b001, 0b011, "aut", null_frag>;
def XPACI : ClearAuth<0, "xpaci">;
@@ -2131,6 +2131,25 @@ let Predicates = [HasPAuth] in {
let Uses = [X16];
}
+ // PAC pseudo instruction. Is AsmPrinter, it is expanded into an actual PAC*
+ // instruction immediately preceded by the discriminator computation.
+ // This enforces the expected immediate modifier is used for signing, even
+ // if an attacker is able to substitute AddrDisc.
+ def PAC : Pseudo<(outs GPR64:$SignedVal),
+ (ins GPR64:$Val, i32imm:$Key, i64imm:$Disc, GPR64noip:$AddrDisc),
+ [], "$SignedVal = $Val">, Sched<[WriteI, ReadI]> {
+ let isCodeGenOnly = 1;
+ let hasSideEffects = 0;
+ let mayStore = 0;
+ let mayLoad = 0;
+ let Size = 12;
+ let Defs = [X17];
+ let usesCustomInserter = 1;
+ }
+
+ def : Pat<(int_ptrauth_sign GPR64:$Val, timm:$Key, GPR64noip:$AddrDisc),
+ (PAC GPR64:$Val, $Key, 0, GPR64noip:$AddrDisc)>;
+
// AUT and re-PAC a value, using different keys/data.
// This directly manipulates x16/x17, which are the only registers the OS
// guarantees are safe to use for sensitive operations.
diff --git a/llvm/test/CodeGen/AArch64/ptrauth-isel.ll b/llvm/test/CodeGen/AArch64/ptrauth-isel.ll
new file mode 100644
index 0000000000000..89ce439f5b47b
--- /dev/null
+++ b/llvm/test/CodeGen/AArch64/ptrauth-isel.ll
@@ -0,0 +1,205 @@
+; NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py UTC_ARGS: --version 5
+; RUN: llc < %s -mtriple arm64e-apple-darwin -verify-machineinstrs -stop-after=finalize-isel -global-isel=0 \
+; RUN: | FileCheck %s --check-prefixes=DAGISEL
+; RUN: llc < %s -mtriple arm64e-apple-darwin -verify-machineinstrs -stop-after=finalize-isel -global-isel=1 -global-isel-abort=1 \
+; RUN: | FileCheck %s --check-prefixes=GISEL
+; RUN: llc < %s -mtriple aarch64-linux-gnu -mattr=+pauth -verify-machineinstrs -stop-after=finalize-isel -global-isel=0 \
+; RUN: | FileCheck %s --check-prefixes=DAGISEL
+; RUN: llc < %s -mtriple aarch64-linux-gnu -mattr=+pauth -verify-machineinstrs -stop-after=finalize-isel -global-isel=1 -global-isel-abort=1 \
+; RUN: | FileCheck %s --check-prefixes=GISEL
+
+; Check MIR produced by the instruction selector to validate properties that
+; cannot be reliably tested by only inspecting the final asm output.
+
+ at discvar = dso_local global i64 0
+
+; Make sure the components of blend(addr, imm) are recognized and passed to
+; PAC pseudo via separate operands to prevent substitution of the immediate
+; modifier.
+;
+; MIR output of the instruction selector is inspected, as it is hard to reliably
+; distinguish MOVKXi immediately followed by a pseudo from a standalone pseudo
+; instruction carrying address and immediate modifiers in its separate operands
+; by only observing the final asm output.
+
+define i64 @small_imm_disc(i64 %addr) {
+ ; DAGISEL-LABEL: name: small_imm_disc
+ ; DAGISEL: bb.0.entry:
+ ; DAGISEL-NEXT: liveins: $x0
+ ; DAGISEL-NEXT: {{ $}}
+ ; DAGISEL-NEXT: [[COPY:%[0-9]+]]:gpr64 = COPY $x0
+ ; DAGISEL-NEXT: [[MOVi32imm:%[0-9]+]]:gpr32 = MOVi32imm 42
+ ; DAGISEL-NEXT: [[SUBREG_TO_REG:%[0-9]+]]:gpr64noip = SUBREG_TO_REG 0, killed [[MOVi32imm]], %subreg.sub_32
+ ; DAGISEL-NEXT: [[PAC:%[0-9]+]]:gpr64 = PAC [[COPY]], 2, 42, killed $xzr, implicit-def dead $x17
+ ; DAGISEL-NEXT: $x0 = COPY [[PAC]]
+ ; DAGISEL-NEXT: RET_ReallyLR implicit $x0
+ ;
+ ; GISEL-LABEL: name: small_imm_disc
+ ; GISEL: bb.1.entry:
+ ; GISEL-NEXT: liveins: $x0
+ ; GISEL-NEXT: {{ $}}
+ ; GISEL-NEXT: [[COPY:%[0-9]+]]:gpr64 = COPY $x0
+ ; GISEL-NEXT: [[MOVi32imm:%[0-9]+]]:gpr32 = MOVi32imm 42
+ ; GISEL-NEXT: [[SUBREG_TO_REG:%[0-9]+]]:gpr64noip = SUBREG_TO_REG 0, [[MOVi32imm]], %subreg.sub_32
+ ; GISEL-NEXT: [[PAC:%[0-9]+]]:gpr64 = PAC [[COPY]], 2, 42, $xzr, implicit-def dead $x17
+ ; GISEL-NEXT: $x0 = COPY [[PAC]]
+ ; GISEL-NEXT: RET_ReallyLR implicit $x0
+entry:
+ %signed = call i64 @llvm.ptrauth.sign(i64 %addr, i32 2, i64 42)
+ ret i64 %signed
+}
+
+define i64 @large_imm_disc_wreg(i64 %addr) {
+ ; DAGISEL-LABEL: name: large_imm_disc_wreg
+ ; DAGISEL: bb.0.entry:
+ ; DAGISEL-NEXT: liveins: $x0
+ ; DAGISEL-NEXT: {{ $}}
+ ; DAGISEL-NEXT: [[COPY:%[0-9]+]]:gpr64 = COPY $x0
+ ; DAGISEL-NEXT: [[MOVi32imm:%[0-9]+]]:gpr32 = MOVi32imm 12345678
+ ; DAGISEL-NEXT: [[SUBREG_TO_REG:%[0-9]+]]:gpr64noip = SUBREG_TO_REG 0, killed [[MOVi32imm]], %subreg.sub_32
+ ; DAGISEL-NEXT: [[PAC:%[0-9]+]]:gpr64 = PAC [[COPY]], 2, 0, killed [[SUBREG_TO_REG]], implicit-def dead $x17
+ ; DAGISEL-NEXT: $x0 = COPY [[PAC]]
+ ; DAGISEL-NEXT: RET_ReallyLR implicit $x0
+ ;
+ ; GISEL-LABEL: name: large_imm_disc_wreg
+ ; GISEL: bb.1.entry:
+ ; GISEL-NEXT: liveins: $x0
+ ; GISEL-NEXT: {{ $}}
+ ; GISEL-NEXT: [[COPY:%[0-9]+]]:gpr64 = COPY $x0
+ ; GISEL-NEXT: [[MOVi32imm:%[0-9]+]]:gpr32 = MOVi32imm 12345678
+ ; GISEL-NEXT: [[SUBREG_TO_REG:%[0-9]+]]:gpr64noip = SUBREG_TO_REG 0, [[MOVi32imm]], %subreg.sub_32
+ ; GISEL-NEXT: [[PAC:%[0-9]+]]:gpr64 = PAC [[COPY]], 2, 0, [[SUBREG_TO_REG]], implicit-def dead $x17
+ ; GISEL-NEXT: $x0 = COPY [[PAC]]
+ ; GISEL-NEXT: RET_ReallyLR implicit $x0
+entry:
+ %signed = call i64 @llvm.ptrauth.sign(i64 %addr, i32 2, i64 12345678)
+ ret i64 %signed
+}
+
+define i64 @large_imm_disc_xreg(i64 %addr) {
+ ; DAGISEL-LABEL: name: large_imm_disc_xreg
+ ; DAGISEL: bb.0.entry:
+ ; DAGISEL-NEXT: liveins: $x0
+ ; DAGISEL-NEXT: {{ $}}
+ ; DAGISEL-NEXT: [[COPY:%[0-9]+]]:gpr64 = COPY $x0
+ ; DAGISEL-NEXT: [[MOVi64imm:%[0-9]+]]:gpr64noip = MOVi64imm 123456789012345
+ ; DAGISEL-NEXT: [[PAC:%[0-9]+]]:gpr64 = PAC [[COPY]], 2, 0, killed [[MOVi64imm]], implicit-def dead $x17
+ ; DAGISEL-NEXT: $x0 = COPY [[PAC]]
+ ; DAGISEL-NEXT: RET_ReallyLR implicit $x0
+ ;
+ ; GISEL-LABEL: name: large_imm_disc_xreg
+ ; GISEL: bb.1.entry:
+ ; GISEL-NEXT: liveins: $x0
+ ; GISEL-NEXT: {{ $}}
+ ; GISEL-NEXT: [[COPY:%[0-9]+]]:gpr64 = COPY $x0
+ ; GISEL-NEXT: [[MOVi64imm:%[0-9]+]]:gpr64noip = MOVi64imm 123456789012345
+ ; GISEL-NEXT: [[PAC:%[0-9]+]]:gpr64 = PAC [[COPY]], 2, 0, [[MOVi64imm]], implicit-def dead $x17
+ ; GISEL-NEXT: $x0 = COPY [[PAC]]
+ ; GISEL-NEXT: RET_ReallyLR implicit $x0
+entry:
+ %signed = call i64 @llvm.ptrauth.sign(i64 %addr, i32 2, i64 123456789012345)
+ ret i64 %signed
+}
+
+define i64 @blend_and_sign_same_bb(i64 %addr) {
+ ; DAGISEL-LABEL: name: blend_and_sign_same_bb
+ ; DAGISEL: bb.0.entry:
+ ; DAGISEL-NEXT: liveins: $x0
+ ; DAGISEL-NEXT: {{ $}}
+ ; DAGISEL-NEXT: [[COPY:%[0-9]+]]:gpr64 = COPY $x0
+ ; DAGISEL-NEXT: [[ADRP:%[0-9]+]]:gpr64common = ADRP target-flags(aarch64-page) @discvar
+ ; DAGISEL-NEXT: [[LDRXui:%[0-9]+]]:gpr64 = LDRXui killed [[ADRP]], target-flags(aarch64-pageoff, aarch64-nc) @discvar :: (dereferenceable load (s64) from @discvar)
+ ; DAGISEL-NEXT: [[MOVKXi:%[0-9]+]]:gpr64noip = MOVKXi [[LDRXui]], 42, 48
+ ; DAGISEL-NEXT: [[COPY1:%[0-9]+]]:gpr64noip = COPY [[LDRXui]]
+ ; DAGISEL-NEXT: [[PAC:%[0-9]+]]:gpr64 = PAC [[COPY]], 2, 42, killed [[COPY1]], implicit-def dead $x17
+ ; DAGISEL-NEXT: $x0 = COPY [[PAC]]
+ ; DAGISEL-NEXT: RET_ReallyLR implicit $x0
+ ;
+ ; GISEL-LABEL: name: blend_and_sign_same_bb
+ ; GISEL: bb.1.entry:
+ ; GISEL-NEXT: liveins: $x0
+ ; GISEL-NEXT: {{ $}}
+ ; GISEL-NEXT: [[COPY:%[0-9]+]]:gpr64 = COPY $x0
+ ; GISEL-NEXT: [[ADRP:%[0-9]+]]:gpr64common = ADRP target-flags(aarch64-page) @discvar
+ ; GISEL-NEXT: [[LDRXui:%[0-9]+]]:gpr64 = LDRXui [[ADRP]], target-flags(aarch64-pageoff, aarch64-nc) @discvar :: (dereferenceable load (s64) from @discvar)
+ ; GISEL-NEXT: [[MOVKXi:%[0-9]+]]:gpr64noip = MOVKXi [[LDRXui]], 42, 48
+ ; GISEL-NEXT: [[COPY1:%[0-9]+]]:gpr64noip = COPY [[LDRXui]]
+ ; GISEL-NEXT: [[PAC:%[0-9]+]]:gpr64 = PAC [[COPY]], 2, 42, [[COPY1]], implicit-def dead $x17
+ ; GISEL-NEXT: $x0 = COPY [[PAC]]
+ ; GISEL-NEXT: RET_ReallyLR implicit $x0
+entry:
+ %addrdisc = load i64, ptr @discvar
+ %disc = call i64 @llvm.ptrauth.blend(i64 %addrdisc, i64 42)
+ %signed = call i64 @llvm.ptrauth.sign(i64 %addr, i32 2, i64 %disc)
+ ret i64 %signed
+}
+
+; In the below test cases both %addrdisc and %disc are computed (i.e. they are
+; neither global addresses, nor function arguments) in a different basic block,
+; making them harder to express via ISD::PtrAuthGlobalAddress.
+
+define i64 @blend_and_sign_different_bbs(i64 %addr, i64 %cond) {
+ ; DAGISEL-LABEL: name: blend_and_sign_different_bbs
+ ; DAGISEL: bb.0.entry:
+ ; DAGISEL-NEXT: successors: %bb.1(0x50000000), %bb.2(0x30000000)
+ ; DAGISEL-NEXT: liveins: $x0, $x1
+ ; DAGISEL-NEXT: {{ $}}
+ ; DAGISEL-NEXT: [[COPY:%[0-9]+]]:gpr64 = COPY $x1
+ ; DAGISEL-NEXT: [[COPY1:%[0-9]+]]:gpr64 = COPY $x0
+ ; DAGISEL-NEXT: [[ADRP:%[0-9]+]]:gpr64common = ADRP target-flags(aarch64-page) @discvar
+ ; DAGISEL-NEXT: [[LDRXui:%[0-9]+]]:gpr64 = LDRXui killed [[ADRP]], target-flags(aarch64-pageoff, aarch64-nc) @discvar :: (dereferenceable load (s64) from @discvar)
+ ; DAGISEL-NEXT: [[MOVKXi:%[0-9]+]]:gpr64 = MOVKXi [[LDRXui]], 42, 48
+ ; DAGISEL-NEXT: [[COPY2:%[0-9]+]]:gpr64noip = COPY [[MOVKXi]]
+ ; DAGISEL-NEXT: CBZX [[COPY]], %bb.2
+ ; DAGISEL-NEXT: B %bb.1
+ ; DAGISEL-NEXT: {{ $}}
+ ; DAGISEL-NEXT: bb.1.next:
+ ; DAGISEL-NEXT: successors: %bb.2(0x80000000)
+ ; DAGISEL-NEXT: {{ $}}
+ ; DAGISEL-NEXT: [[COPY3:%[0-9]+]]:gpr64common = COPY [[COPY2]]
+ ; DAGISEL-NEXT: INLINEASM &nop, 1 /* sideeffect attdialect */, 3866633 /* reguse:GPR64common */, [[COPY3]]
+ ; DAGISEL-NEXT: {{ $}}
+ ; DAGISEL-NEXT: bb.2.exit:
+ ; DAGISEL-NEXT: [[COPY4:%[0-9]+]]:gpr64noip = COPY [[LDRXui]]
+ ; DAGISEL-NEXT: [[PAC:%[0-9]+]]:gpr64 = PAC [[COPY1]], 2, 42, [[COPY4]], implicit-def dead $x17
+ ; DAGISEL-NEXT: $x0 = COPY [[PAC]]
+ ; DAGISEL-NEXT: RET_ReallyLR implicit $x0
+ ;
+ ; GISEL-LABEL: name: blend_and_sign_different_bbs
+ ; GISEL: bb.1.entry:
+ ; GISEL-NEXT: successors: %bb.2(0x50000000), %bb.3(0x30000000)
+ ; GISEL-NEXT: liveins: $x0, $x1
+ ; GISEL-NEXT: {{ $}}
+ ; GISEL-NEXT: [[COPY:%[0-9]+]]:gpr64 = COPY $x0
+ ; GISEL-NEXT: [[COPY1:%[0-9]+]]:gpr64 = COPY $x1
+ ; GISEL-NEXT: [[ADRP:%[0-9]+]]:gpr64common = ADRP target-flags(aarch64-page) @discvar
+ ; GISEL-NEXT: [[LDRXui:%[0-9]+]]:gpr64 = LDRXui [[ADRP]], target-flags(aarch64-pageoff, aarch64-nc) @discvar :: (dereferenceable load (s64) from @discvar)
+ ; GISEL-NEXT: [[MOVKXi:%[0-9]+]]:gpr64noip = MOVKXi [[LDRXui]], 42, 48
+ ; GISEL-NEXT: CBZX [[COPY1]], %bb.3
+ ; GISEL-NEXT: B %bb.2
+ ; GISEL-NEXT: {{ $}}
+ ; GISEL-NEXT: bb.2.next:
+ ; GISEL-NEXT: successors: %bb.3(0x80000000)
+ ; GISEL-NEXT: {{ $}}
+ ; GISEL-NEXT: [[COPY2:%[0-9]+]]:gpr64common = COPY [[MOVKXi]]
+ ; GISEL-NEXT: INLINEASM &nop, 1 /* sideeffect attdialect */, 3866633 /* reguse:GPR64common */, [[COPY2]]
+ ; GISEL-NEXT: {{ $}}
+ ; GISEL-NEXT: bb.3.exit:
+ ; GISEL-NEXT: [[COPY3:%[0-9]+]]:gpr64noip = COPY [[LDRXui]]
+ ; GISEL-NEXT: [[PAC:%[0-9]+]]:gpr64 = PAC [[COPY]], 2, 42, [[COPY3]], implicit-def dead $x17
+ ; GISEL-NEXT: $x0 = COPY [[PAC]]
+ ; GISEL-NEXT: RET_ReallyLR implicit $x0
+entry:
+ %addrdisc = load i64, ptr @discvar
+ %disc = call i64 @llvm.ptrauth.blend(i64 %addrdisc, i64 42)
+ %cond.b = icmp ne i64 %cond, 0
+ br i1 %cond.b, label %next, label %exit
+
+next:
+ call void asm sideeffect "nop", "r"(i64 %disc)
+ br label %exit
+
+exit:
+ %signed = call i64 @llvm.ptrauth.sign(i64 %addr, i32 2, i64 %disc)
+ ret i64 %signed
+}
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