From c6c9bc0cd895bdefcc68d72b36f3b564f4e88938 Mon Sep 17 00:00:00 2001
From: Tim Northover <tnorthover@apple.com>
Date: Thu, 9 Mar 2017 23:36:26 +0000
Subject: [PATCH] GlobalISel: support trivial inlineasm calls.

They're used for nefarious purposes by ObjC.

llvm-svn: 297422
---
 .../llvm/CodeGen/GlobalISel/IRTranslator.h    |  2 ++
 lib/CodeGen/GlobalISel/IRTranslator.cpp       | 21 ++++++++++++++++++-
 .../AArch64/GlobalISel/arm64-irtranslator.ll  |  9 ++++++++
 test/CodeGen/AArch64/GlobalISel/inline-asm.ll |  4 ++--
 4 files changed, 33 insertions(+), 3 deletions(-)

diff --git a/include/llvm/CodeGen/GlobalISel/IRTranslator.h b/include/llvm/CodeGen/GlobalISel/IRTranslator.h
index 74b0c8d63fd..174443d47a5 100644
--- a/include/llvm/CodeGen/GlobalISel/IRTranslator.h
+++ b/include/llvm/CodeGen/GlobalISel/IRTranslator.h
@@ -143,6 +143,8 @@ private:
   bool translateKnownIntrinsic(const CallInst &CI, Intrinsic::ID ID,
                                MachineIRBuilder &MIRBuilder);
 
+  bool translateInlineAsm(const CallInst &CI, MachineIRBuilder &MIRBuilder);
+
   /// Translate call instruction.
   /// \pre \p U is a call instruction.
   bool translateCall(const User &U, MachineIRBuilder &MIRBuilder);
diff --git a/lib/CodeGen/GlobalISel/IRTranslator.cpp b/lib/CodeGen/GlobalISel/IRTranslator.cpp
index e170b762ab8..b2ab3c12bc1 100644
--- a/lib/CodeGen/GlobalISel/IRTranslator.cpp
+++ b/lib/CodeGen/GlobalISel/IRTranslator.cpp
@@ -715,13 +715,32 @@ bool IRTranslator::translateKnownIntrinsic(const CallInst &CI, Intrinsic::ID ID,
   return false;
 }
 
+bool IRTranslator::translateInlineAsm(const CallInst &CI,
+                                      MachineIRBuilder &MIRBuilder) {
+  const InlineAsm &IA = cast<InlineAsm>(*CI.getCalledValue());
+  if (!IA.getConstraintString().empty())
+    return false;
+
+  unsigned ExtraInfo = 0;
+  if (IA.hasSideEffects())
+    ExtraInfo |= InlineAsm::Extra_HasSideEffects;
+  if (IA.getDialect() == InlineAsm::AD_Intel)
+    ExtraInfo |= InlineAsm::Extra_AsmDialect;
+
+  MIRBuilder.buildInstr(TargetOpcode::INLINEASM)
+    .addExternalSymbol(IA.getAsmString().c_str())
+    .addImm(ExtraInfo);
+
+  return true;
+}
+
 bool IRTranslator::translateCall(const User &U, MachineIRBuilder &MIRBuilder) {
   const CallInst &CI = cast<CallInst>(U);
   auto TII = MF->getTarget().getIntrinsicInfo();
   const Function *F = CI.getCalledFunction();
 
   if (CI.isInlineAsm())
-    return false;
+    return translateInlineAsm(CI, MIRBuilder);
 
   if (!F || !F->isIntrinsic()) {
     unsigned Res = CI.getType()->isVoidTy() ? 0 : getOrCreateVReg(CI);
diff --git a/test/CodeGen/AArch64/GlobalISel/arm64-irtranslator.ll b/test/CodeGen/AArch64/GlobalISel/arm64-irtranslator.ll
index c0cbf69a2e6..21ce631cca3 100644
--- a/test/CodeGen/AArch64/GlobalISel/arm64-irtranslator.ll
+++ b/test/CodeGen/AArch64/GlobalISel/arm64-irtranslator.ll
@@ -1262,3 +1262,12 @@ define double @test_fneg_f64(double %x) {
   %neg = fsub double -0.000000e+00, %x
   ret double %neg
 }
+
+define void @test_trivial_inlineasm() {
+; CHECK-LABEL: name: test_trivial_inlineasm
+; CHECK: INLINEASM $wibble, 1
+; CHECK: INLINEASM $wibble, 0
+  call void asm sideeffect "wibble", ""()
+  call void asm "wibble", ""()
+  ret void
+}
diff --git a/test/CodeGen/AArch64/GlobalISel/inline-asm.ll b/test/CodeGen/AArch64/GlobalISel/inline-asm.ll
index 3dc8f8cb706..8ff7c4495dc 100644
--- a/test/CodeGen/AArch64/GlobalISel/inline-asm.ll
+++ b/test/CodeGen/AArch64/GlobalISel/inline-asm.ll
@@ -2,9 +2,9 @@
 
 ; CHECK-LABEL: test_asm:
 ; CHECK: {{APP|InlineAsm Start}}
-; CHECK: mov x0, x0
+; CHECK: mov x0, {{x[0-9]+}}
 ; CHECK: {{NO_APP|InlineAsm End}}
 define void @test_asm() {
-  call void asm sideeffect "mov x0, x0", ""()
+  call void asm sideeffect "mov x0, $0", "r"(i64 42)
   ret void
 }