From ed23352379c83f0d30fbaa1770af4dd8d06a50c6 Mon Sep 17 00:00:00 2001
From: Jessica Paquette <jpaquette@apple.com>
Date: Tue, 2 Apr 2019 22:46:31 +0000
Subject: [PATCH] [GlobalISel] Add IRTranslator support for llvm.stacksave and
 llvm.stackrestore

Also update arm64-irtranslator.ll.

Differential Revision: https://reviews.llvm.org/D60140

llvm-svn: 357538
---
 llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp       | 28 ++++++++++++++++++++++
 .../AArch64/GlobalISel/arm64-irtranslator.ll       | 12 ++++++++++
 2 files changed, 40 insertions(+)

diff --git a/llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp b/llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp
index 8528636..f60f784 100644
--- a/llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp
+++ b/llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp
@@ -1046,6 +1046,34 @@ bool IRTranslator::translateKnownIntrinsic(const CallInst &CI, Intrinsic::ID ID,
                                   PtrTy.getSizeInBits() / 8, 8));
     return true;
   }
+  case Intrinsic::stacksave: {
+    // Save the stack pointer to the location provided by the intrinsic.
+    unsigned Reg = getOrCreateVReg(CI);
+    unsigned StackPtr = MF->getSubtarget()
+                            .getTargetLowering()
+                            ->getStackPointerRegisterToSaveRestore();
+
+    // If the target doesn't specify a stack pointer, then fall back.
+    if (!StackPtr)
+      return false;
+
+    MIRBuilder.buildCopy(Reg, StackPtr);
+    return true;
+  }
+  case Intrinsic::stackrestore: {
+    // Restore the stack pointer from the location provided by the intrinsic.
+    unsigned Reg = getOrCreateVReg(*CI.getArgOperand(0));
+    unsigned StackPtr = MF->getSubtarget()
+                            .getTargetLowering()
+                            ->getStackPointerRegisterToSaveRestore();
+
+    // If the target doesn't specify a stack pointer, then fall back.
+    if (!StackPtr)
+      return false;
+
+    MIRBuilder.buildCopy(StackPtr, Reg);
+    return true;
+  }
   case Intrinsic::cttz:
   case Intrinsic::ctlz: {
     ConstantInt *Cst = cast<ConstantInt>(CI.getArgOperand(1));
diff --git a/llvm/test/CodeGen/AArch64/GlobalISel/arm64-irtranslator.ll b/llvm/test/CodeGen/AArch64/GlobalISel/arm64-irtranslator.ll
index 2e02ec0..376b2ad8 100644
--- a/llvm/test/CodeGen/AArch64/GlobalISel/arm64-irtranslator.ll
+++ b/llvm/test/CodeGen/AArch64/GlobalISel/arm64-irtranslator.ll
@@ -2359,3 +2359,15 @@ define void @test_i1_arg_zext(void (i1)* %f) {
   call void %f(i1 true)
   ret void
 }
+
+declare i8* @llvm.stacksave()
+declare void @llvm.stackrestore(i8*)
+define void @test_stacksaverestore() {
+  ; CHECK-LABEL: name: test_stacksaverestore
+  ; CHECK: [[SAVE:%[0-9]+]]:_(p0) = COPY $sp
+  ; CHECK-NEXT: $sp = COPY [[SAVE]](p0)
+  ; CHECK-NEXT: RET_ReallyLR
+  %sp = call i8* @llvm.stacksave()
+  call void @llvm.stackrestore(i8* %sp)
+  ret void
+}
-- 
2.7.4