[XRay] Fix tail call sleds for AArch64

Author: sebastiankreutzer

llvm/lib/CodeGen/XRayInstrumentation.cpp

@@ -296,8 +296,9 @@ bool XRayInstrumentation::run(MachineFunction &MF) {
     case Triple::ArchType::riscv64: {
       // For the architectures which don't have a single return instruction
       InstrumentationOptions op;
-      // RISC-V supports patching tail calls.
-      op.HandleTailcall = MF.getTarget().getTargetTriple().isRISCV();
+      // AArch64 and RISC-V support patching tail calls.
+      op.HandleTailcall = MF.getTarget().getTargetTriple().isAArch64() ||
+                          MF.getTarget().getTargetTriple().isRISCV() ;
       op.HandleAllReturns = true;
       prependRetWithPatchableExit(MF, TII, op);
       break;

llvm/lib/Target/AArch64/AArch64InstrInfo.cpp

@@ -163,6 +163,7 @@ unsigned AArch64InstrInfo::getInstSizeInBytes(const MachineInstr &MI) const {
         F.getFnAttributeAsParsedInteger("patchable-function-entry", 9) * 4;
     break;
   case TargetOpcode::PATCHABLE_FUNCTION_EXIT:
+  case TargetOpcode::PATCHABLE_TAIL_CALL:
   case TargetOpcode::PATCHABLE_TYPED_EVENT_CALL:
     // An XRay sled can be 4 bytes of alignment plus a 32-byte block.
     NumBytes = 36;

llvm/test/CodeGen/AArch64/xray-tail-call-sled.ll

@@ -21,8 +21,12 @@ define i32 @callee() nounwind noinline uwtable "function-instrument"="xray-alway
 ; CHECK-LINUX-LABEL: .Lxray_sleds_start0:
 ; CHECK-LINUX-NEXT:  [[TMP:.Ltmp[0-9]+]]:
 ; CHECK-LINUX:         .xword .Lxray_sled_0-[[TMP]]
+; CHECK-LINUX:         .xword
+; CHECK-LINUX-NEXT:    .byte   0x00
 ; CHECK-LINUX:       [[TMP:.Ltmp[0-9]+]]:
 ; CHECK-LINUX-NEXT:    .xword .Lxray_sled_1-[[TMP]]
+; CHECK-LINUX:         .xword
+; CHECK-LINUX-NEXT:    .byte   0x01
 ; CHECK-LINUX-LABEL: Lxray_sleds_end0:
 ; CHECK-LINUX-LABEL: .section xray_fn_idx,"ao",@progbits,callee{{$}}
 ; CHECK-LINUX:         .xword .Lxray_sleds_start0
@@ -32,8 +36,12 @@ define i32 @callee() nounwind noinline uwtable "function-instrument"="xray-alway
 ; CHECK-MACOS-LABEL: lxray_sleds_start0:
 ; CHECK-MACOS-NEXT:  [[TMP:Ltmp[0-9]+]]:
 ; CHECK-MACOS:         .quad Lxray_sled_0-[[TMP]]
+; CHECK-MACOS-NEXT:    .quad
+; CHECK-MACOS-NEXT:    .byte   0x00
 ; CHECK-MACOS:       [[TMP:Ltmp[0-9]+]]:
 ; CHECK-MACOS-NEXT:    .quad Lxray_sled_1-[[TMP]]
+; CHECK-MACOS-NEXT:    .quad
+; CHECK-MACOS-NEXT:    .byte   0x01
 ; CHECK-MACOS-LABEL: Lxray_sleds_end0:
 ; CHECK-MACOS-LABEL: .section __DATA,xray_fn_idx,regular,live_support{{$}}
 ; CHECK-MACOS:       [[IDX:lxray_fn_idx[0-9]+]]:
@@ -60,7 +68,11 @@ define i32 @caller() nounwind noinline uwtable "function-instrument"="xray-alway
 ; CHECK-LINUX-LABEL: .section xray_instr_map,"ao",@progbits,caller{{$}}
 ; CHECK-LINUX-LABEL: Lxray_sleds_start1:
 ; CHECK-LINUX:         .xword .Lxray_sled_2
+; CHECK-LINUX-NEXT:    .xword
+; CHECK-LINUX-NEXT:    .byte   0x00
 ; CHECK-LINUX:         .xword .Lxray_sled_3
+; CHECK-LINUX-NEXT:    .xword
+; CHECK-LINUX-NEXT:    .byte   0x02
 ; CHECK-LINUX-LABEL: Lxray_sleds_end1:
 ; CHECK-LINUX-LABEL: .section xray_fn_idx,"ao",@progbits,caller{{$}}
 ; CHECK-LINUX:       [[IDX:\.Lxray_fn_idx[0-9]+]]:
@@ -70,7 +82,11 @@ define i32 @caller() nounwind noinline uwtable "function-instrument"="xray-alway
 ; CHECK-MACOS-LABEL: .section __DATA,xray_instr_map,regular,live_support{{$}}
 ; CHECK-MACOS-LABEL: lxray_sleds_start1:
 ; CHECK-MACOS:         .quad Lxray_sled_2
+; CHECK-MACOS-NEXT:    .quad
+; CHECK-MACOS-NEXT:    .byte   0x00
 ; CHECK-MACOS:         .quad Lxray_sled_3
+; CHECK-MACOS-NEXT:    .quad
+; CHECK-MACOS-NEXT:    .byte   0x02
 ; CHECK-MACOS-LABEL: Lxray_sleds_end1:
 ; CHECK-MACOS-LABEL: .section __DATA,xray_fn_idx,regular,live_support{{$}}
 ; CHECK-MACOS:       [[IDX:lxray_fn_idx[0-9]+]]: