From 80b96e28e31e5f0379e2fa415c590bbe5abbf558 Mon Sep 17 00:00:00 2001
From: Serge Rogatch <srogatch@accesssoftek.com>
Date: Wed, 25 Jan 2017 20:21:49 +0000
Subject: [PATCH] [XRay][AArch64] More staging for tail call support in XRay on
 AArch64 - in LLVM

Summary:
This patch prepares more for tail call support in XRay. Until the logging part supports tail calls, this is just staging, so it seems LLVM part is mostly ready with this patch.
Related: https://reviews.llvm.org/D28948 (compiler-rt)

Reviewers: dberris, rengolin

Reviewed By: dberris

Subscribers: llvm-commits, iid_iunknown, aemerson

Differential Revision: https://reviews.llvm.org/D28947

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@293080 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Target/AArch64/AArch64InstrInfo.cpp     | 11 ++++
 lib/Target/AArch64/AArch64InstrInfo.h       |  2 +
 test/CodeGen/AArch64/xray-tail-call-sled.ll | 69 +++++++++++++++++++++
 3 files changed, 82 insertions(+)
 create mode 100644 test/CodeGen/AArch64/xray-tail-call-sled.ll

diff --git a/lib/Target/AArch64/AArch64InstrInfo.cpp b/lib/Target/AArch64/AArch64InstrInfo.cpp
index 9cdb8e961b4..8e3b7658c3e 100644
--- a/lib/Target/AArch64/AArch64InstrInfo.cpp
+++ b/lib/Target/AArch64/AArch64InstrInfo.cpp
@@ -1627,6 +1627,17 @@ bool AArch64InstrInfo::isUnscaledLdSt(MachineInstr &MI) const {
   return isUnscaledLdSt(MI.getOpcode());
 }
 
+bool AArch64InstrInfo::isTailCall(const MachineInstr &Inst) const
+{
+  switch (Inst.getOpcode()) {
+  case AArch64::TCRETURNdi:
+  case AArch64::TCRETURNri:
+    return true;
+  default:
+    return false;
+  }
+}
+
 // Is this a candidate for ld/st merging or pairing?  For example, we don't
 // touch volatiles or load/stores that have a hint to avoid pair formation.
 bool AArch64InstrInfo::isCandidateToMergeOrPair(MachineInstr &MI) const {
diff --git a/lib/Target/AArch64/AArch64InstrInfo.h b/lib/Target/AArch64/AArch64InstrInfo.h
index 5037866925d..8d9e8e3da1c 100644
--- a/lib/Target/AArch64/AArch64InstrInfo.h
+++ b/lib/Target/AArch64/AArch64InstrInfo.h
@@ -87,6 +87,8 @@ public:
   /// Return true if this is an unscaled load/store.
   bool isUnscaledLdSt(MachineInstr &MI) const;
 
+  bool isTailCall(const MachineInstr &Inst) const override;
+
   static bool isPairableLdStInst(const MachineInstr &MI) {
     switch (MI.getOpcode()) {
     default:
diff --git a/test/CodeGen/AArch64/xray-tail-call-sled.ll b/test/CodeGen/AArch64/xray-tail-call-sled.ll
new file mode 100644
index 00000000000..6ada3ce8d55
--- /dev/null
+++ b/test/CodeGen/AArch64/xray-tail-call-sled.ll
@@ -0,0 +1,69 @@
+; RUN: llc -filetype=asm -o - -mtriple=aarch64-linux-gnu < %s | FileCheck %s
+
+define i32 @callee() nounwind noinline uwtable "function-instrument"="xray-always" {
+; CHECK:       .p2align	2
+; CHECK-LABEL: .Lxray_sled_0:
+; CHECK-NEXT:  b	#32
+; CHECK-NEXT:  nop
+; CHECK-NEXT:  nop
+; CHECK-NEXT:  nop
+; CHECK-NEXT:  nop
+; CHECK-NEXT:  nop
+; CHECK-NEXT:  nop
+; CHECK-NEXT:  nop
+; CHECK-LABEL: .Ltmp0:
+  ret i32 0
+; CHECK-NEXT:  mov	w0, wzr
+; CHECK-NEXT:  .p2align	2
+; CHECK-LABEL: .Lxray_sled_1:
+; CHECK-NEXT:  b	#32
+; CHECK-NEXT:  nop
+; CHECK-NEXT:  nop
+; CHECK-NEXT:  nop
+; CHECK-NEXT:  nop
+; CHECK-NEXT:  nop
+; CHECK-NEXT:  nop
+; CHECK-NEXT:  nop
+; CHECK-LABEL: .Ltmp1:
+; CHECK-NEXT:  ret
+}
+; CHECK:       .p2align 4
+; CHECK-NEXT:  .xword .Lxray_synthetic_0
+; CHECK-NEXT:  .section xray_instr_map,{{.*}}
+; CHECK-LABEL: Lxray_synthetic_0:
+; CHECK:       .xword .Lxray_sled_0
+; CHECK:       .xword .Lxray_sled_1
+
+define i32 @caller() nounwind noinline uwtable "function-instrument"="xray-always" {
+; CHECK:       .p2align	2
+; CHECK-LABEL: .Lxray_sled_2:
+; CHECK-NEXT:  b	#32
+; CHECK-NEXT:  nop
+; CHECK-NEXT:  nop
+; CHECK-NEXT:  nop
+; CHECK-NEXT:  nop
+; CHECK-NEXT:  nop
+; CHECK-NEXT:  nop
+; CHECK-NEXT:  nop
+; CHECK-LABEL: .Ltmp2:
+; CHECK:       .p2align	2
+; CHECK-LABEL: .Lxray_sled_3:
+; CHECK-NEXT:  b	#32
+; CHECK-NEXT:  nop
+; CHECK-NEXT:  nop
+; CHECK-NEXT:  nop
+; CHECK-NEXT:  nop
+; CHECK-NEXT:  nop
+; CHECK-NEXT:  nop
+; CHECK-NEXT:  nop
+; CHECK-LABEL: .Ltmp3:
+  %retval = tail call i32 @callee()
+; CHECK:       b	callee
+  ret i32 %retval
+}
+; CHECK:       .p2align 4
+; CHECK-NEXT:  .xword .Lxray_synthetic_1
+; CHECK-NEXT:  .section xray_instr_map,{{.*}}
+; CHECK-LABEL: Lxray_synthetic_1:
+; CHECK:       .xword .Lxray_sled_2
+; CHECK:       .xword .Lxray_sled_3
-- 
2.40.0