GlobalISel: support swiftself attribute

llvm-svn: 367683

8 files changed, 66 insertions, 23 deletions

diff --git a/llvm/lib/CodeGen/GlobalISel/CallLowering.cpp b/llvm/lib/CodeGen/GlobalISel/CallLowering.cpp
index 9f950131c85..17c6b84e48a 100644
--- a/llvm/lib/CodeGen/GlobalISel/CallLowering.cpp
+++ b/llvm/lib/CodeGen/GlobalISel/CallLowering.cpp
@@ -45,9 +45,6 @@ bool CallLowering::lowerCall(MachineIRBuilder &MIRBuilder, ImmutableCallSite CS,
     ArgInfo OrigArg{ArgRegs[i], Arg->getType(), ISD::ArgFlagsTy{},
                     i < NumFixedArgs};
     setArgFlags(OrigArg, i + AttributeList::FirstArgIndex, DL, CS);
-    // We don't currently support swiftself args.
-    if (OrigArg.Flags.isSwiftSelf())
-      return false;
     OrigArgs.push_back(OrigArg);
     ++i;
   }
diff --git a/llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp b/llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp
index 3dc2200d37f..8b89070cd71 100644
--- a/llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp
+++ b/llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp
@@ -2284,18 +2284,6 @@ bool IRTranslator::runOnMachineFunction(MachineFunction &CurMF) {
     }
   }
 
-  // We don't currently support translating swifterror or swiftself functions.
-  for (auto &Arg : F.args()) {
-    if (Arg.hasSwiftSelfAttr()) {
-      OptimizationRemarkMissed R("gisel-irtranslator", "GISelFailure",
-                                 F.getSubprogram(), &F.getEntryBlock());
-      R << "unable to lower arguments due to swiftself: "
-        << ore::NV("Prototype", F.getType());
-      reportTranslationError(*MF, *TPC, *ORE, R);
-      return false;
-    }
-  }
-
   if (!CLI->lowerFormalArguments(*EntryBuilder.get(), F, VRegArgs)) {
     OptimizationRemarkMissed R("gisel-irtranslator", "GISelFailure",
                                F.getSubprogram(), &F.getEntryBlock());
diff --git a/llvm/lib/Target/AArch64/AArch64CallLowering.cpp b/llvm/lib/Target/AArch64/AArch64CallLowering.cpp
index fb9b5ab7e85..c7434e5a2e4 100644
--- a/llvm/lib/Target/AArch64/AArch64CallLowering.cpp
+++ b/llvm/lib/Target/AArch64/AArch64CallLowering.cpp
@@ -110,6 +110,7 @@ struct FormalArgHandler : public IncomingArgHandler {
     : IncomingArgHandler(MIRBuilder, MRI, AssignFn) {}
 
   void markPhysRegUsed(unsigned PhysReg) override {
+    MIRBuilder.getMRI()->addLiveIn(PhysReg);
     MIRBuilder.getMBB().addLiveIn(PhysReg);
   }
 };
diff --git a/llvm/lib/Target/ARM/ARMCallLowering.cpp b/llvm/lib/Target/ARM/ARMCallLowering.cpp
index 3d22a9191b4..00f21a916c6 100644
--- a/llvm/lib/Target/ARM/ARMCallLowering.cpp
+++ b/llvm/lib/Target/ARM/ARMCallLowering.cpp
@@ -405,6 +405,7 @@ struct FormalArgHandler : public IncomingValueHandler {
       : IncomingValueHandler(MIRBuilder, MRI, AssignFn) {}
 
   void markPhysRegUsed(unsigned PhysReg) override {
+    MIRBuilder.getMRI()->addLiveIn(PhysReg);
     MIRBuilder.getMBB().addLiveIn(PhysReg);
   }
 };
diff --git a/llvm/lib/Target/Mips/MipsCallLowering.cpp b/llvm/lib/Target/Mips/MipsCallLowering.cpp
index 849f9558ac2..9b8a12e0e58 100644
--- a/llvm/lib/Target/Mips/MipsCallLowering.cpp
+++ b/llvm/lib/Target/Mips/MipsCallLowering.cpp
@@ -106,6 +106,7 @@ private:
                    Register ArgsReg, const EVT &VT) override;
 
   virtual void markPhysRegUsed(unsigned PhysReg) {
+    MIRBuilder.getMRI()->addLiveIn(PhysReg);
     MIRBuilder.getMBB().addLiveIn(PhysReg);
   }
 
diff --git a/llvm/lib/Target/X86/X86CallLowering.cpp b/llvm/lib/Target/X86/X86CallLowering.cpp
index e97a28a760c..e4079d6e415 100644
--- a/llvm/lib/Target/X86/X86CallLowering.cpp
+++ b/llvm/lib/Target/X86/X86CallLowering.cpp
@@ -301,6 +301,7 @@ struct FormalArgHandler : public IncomingValueHandler {
       : IncomingValueHandler(MIRBuilder, MRI, AssignFn) {}
 
   void markPhysRegUsed(unsigned PhysReg) override {
+    MIRBuilder.getMRI()->addLiveIn(PhysReg);
     MIRBuilder.getMBB().addLiveIn(PhysReg);
   }
 };
diff --git a/llvm/test/CodeGen/AArch64/GlobalISel/arm64-fallback.ll b/llvm/test/CodeGen/AArch64/GlobalISel/arm64-fallback.ll
index 9c27fb741da..ed45a6e95da 100644
--- a/llvm/test/CodeGen/AArch64/GlobalISel/arm64-fallback.ll
+++ b/llvm/test/CodeGen/AArch64/GlobalISel/arm64-fallback.ll
@@ -227,11 +227,3 @@ define void @nonpow2_vector_add_fewerelements() {
   store i64 %ex, i64* undef
   ret void
 }
-
-%swift_error = type {i64, i8}
-
-; FALLBACK-WITH-REPORT-ERR: remark: <unknown>:0:0: unable to lower arguments due to swiftself: void (%swift_error**)* (in function: swiftself_param)
-; FALLBACK-WITH-REPORT-ERR: warning: Instruction selection used fallback path for swiftself_param
-define void @swiftself_param(%swift_error** swiftself %error_ptr_ref) {
-  ret void
-}
diff --git a/llvm/test/CodeGen/AArch64/GlobalISel/swiftself.ll b/llvm/test/CodeGen/AArch64/GlobalISel/swiftself.ll
new file mode 100644
index 00000000000..8ed06f23383
--- /dev/null
+++ b/llvm/test/CodeGen/AArch64/GlobalISel/swiftself.ll
@@ -0,0 +1,62 @@
+; RUN: llc -verify-machineinstrs -mtriple=aarch64-apple-ios -o - %s -global-isel | FileCheck %s
+
+; Parameter with swiftself should be allocated to x20.
+; CHECK-LABEL: swiftself_param:
+; CHECK: mov x0, x20
+; CHECK-NEXT: ret
+define i8* @swiftself_param(i8* swiftself %addr0) {
+  ret i8 *%addr0
+}
+
+; Check that x20 is used to pass a swiftself argument.
+; CHECK-LABEL: call_swiftself:
+; CHECK: mov x20, x0
+; CHECK: bl {{_?}}swiftself_param
+; CHECK: ret
+define i8 *@call_swiftself(i8* %arg) {
+  %res = call i8 *@swiftself_param(i8* swiftself %arg)
+  ret i8 *%res
+}
+
+; Demonstrate that we do not need any movs when calling multiple functions
+; with swiftself argument.
+; CHECK-LABEL: swiftself_passthrough:
+; CHECK-NOT: mov{{.*}}x20
+; CHECK: bl {{_?}}swiftself_param
+; CHECK-NOT: mov{{.*}}x20
+; CHECK-NEXT: bl {{_?}}swiftself_param
+; CHECK: ret
+define void @swiftself_passthrough(i8* swiftself %addr0) {
+  call i8 *@swiftself_param(i8* swiftself %addr0)
+  call i8 *@swiftself_param(i8* swiftself %addr0)
+  ret void
+}
+
+; We can not use a tail call if the callee swiftself is not the same as the
+; caller one.
+; CHECK-LABEL: swiftself_notail:
+; CHECK: mov x20, x0
+; CHECK: bl {{_?}}swiftself_param
+; CHECK: ret
+define i8* @swiftself_notail(i8* swiftself %addr0, i8* %addr1) nounwind {
+  %res = tail call i8* @swiftself_param(i8* swiftself %addr1)
+  ret i8* %res
+}
+
+; We cannot pretend that 'x0' is alive across the thisreturn_attribute call as
+; we normally would. We marked the first parameter with swiftself which means it
+; will no longer be passed in x0.
+declare swiftcc i8* @thisreturn_attribute(i8* returned swiftself)
+; CHECK-LABEL: swiftself_nothisreturn:
+; CHECK-DAG: ldr  x20, [x20]
+; CHECK-DAG: mov [[CSREG:x[1-9].*]], x8
+; CHECK: bl {{_?}}thisreturn_attribute
+; CHECK: str x0, {{\[}}[[CSREG]]
+; CHECK: ret
+define hidden swiftcc void @swiftself_nothisreturn(i8** noalias nocapture sret, i8** noalias nocapture readonly swiftself) {
+entry:
+  %2 = load i8*, i8** %1, align 8
+  %3 = tail call swiftcc i8* @thisreturn_attribute(i8* swiftself %2)
+  store i8* %3, i8** %0, align 8
+  ret void
+}