Address comments

Author: djtodoro

llvm/lib/Target/Mips/Mips16ISelLowering.cpp

@@ -248,7 +248,7 @@ Mips16TargetLowering::EmitInstrWithCustomInserter(MachineInstr &MI,
 
 bool Mips16TargetLowering::isEligibleForTailCallOptimization(
     const CCState &CCInfo, unsigned NextStackOffset,
-    const MipsFunctionInfo &FI) const {
+    const MipsFunctionInfo &FI, bool IsMustTail) const {
   // No tail call optimization for mips16.
   return false;
 }

llvm/lib/Target/Mips/Mips16ISelLowering.h

@@ -33,7 +33,8 @@ namespace llvm {
   private:
     bool isEligibleForTailCallOptimization(
         const CCState &CCInfo, unsigned NextStackOffset,
-        const MipsFunctionInfo &FI) const override;
+        const MipsFunctionInfo &FI,
+        bool IsMustTail = false) const override;
 
     void setMips16HardFloatLibCalls();
 

llvm/lib/Target/Mips/MipsISelLowering.cpp

@@ -3408,15 +3408,18 @@ MipsTargetLowering::LowerCall(TargetLowering::CallLoweringInfo &CLI,
   // that are part of this compilation unit.
   bool InternalLinkage = false;
   bool IsMustTail = CLI.CB && CLI.CB->isMustTailCall();
-  if (IsTailCall && !IsMustTail) {
+  if (IsTailCall) {
     IsTailCall = isEligibleForTailCallOptimization(
-        CCInfo, StackSize, *MF.getInfo<MipsFunctionInfo>());
-    if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee)) {
-      InternalLinkage = G->getGlobal()->hasInternalLinkage();
-      IsTailCall &= (InternalLinkage || G->getGlobal()->hasLocalLinkage() ||
-                     G->getGlobal()->hasPrivateLinkage() ||
-                     G->getGlobal()->hasHiddenVisibility() ||
-                     G->getGlobal()->hasProtectedVisibility());
+        CCInfo, StackSize, *MF.getInfo<MipsFunctionInfo>(), IsMustTail);
+    if (IsTailCall) {
+      if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee)) {
+        InternalLinkage = G->getGlobal()->hasInternalLinkage();
+        IsTailCall &= (InternalLinkage || G->getGlobal()->hasLocalLinkage() ||
+                       G->getGlobal()->isDSOLocal() ||
+                       G->getGlobal()->hasPrivateLinkage() ||
+                       G->getGlobal()->hasHiddenVisibility() ||
+                       G->getGlobal()->hasProtectedVisibility());
+      }
     }
   }
   if (!IsTailCall && IsMustTail)

llvm/lib/Target/Mips/MipsISelLowering.h

@@ -598,7 +598,8 @@ class TargetRegisterClass;
     virtual bool
     isEligibleForTailCallOptimization(const CCState &CCInfo,
                                       unsigned NextStackOffset,
-                                      const MipsFunctionInfo &FI) const = 0;
+                                      const MipsFunctionInfo &FI,
+                                      bool IsMustTail = false) const = 0;
 
     /// copyByValArg - Copy argument registers which were used to pass a byval
     /// argument to the stack. Create a stack frame object for the byval

llvm/lib/Target/Mips/MipsSEISelLowering.cpp

@@ -1180,8 +1180,8 @@ MipsSETargetLowering::EmitInstrWithCustomInserter(MachineInstr &MI,
 
 bool MipsSETargetLowering::isEligibleForTailCallOptimization(
     const CCState &CCInfo, unsigned NextStackOffset,
-    const MipsFunctionInfo &FI) const {
-  if (!UseMipsTailCalls)
+    const MipsFunctionInfo &FI, bool IsMustTail) const {
+  if (!UseMipsTailCalls && !IsMustTail)
     return false;
 
   // Exception has to be cleared with eret.

llvm/lib/Target/Mips/MipsSEISelLowering.h

@@ -65,7 +65,8 @@ class TargetRegisterClass;
   private:
     bool isEligibleForTailCallOptimization(
         const CCState &CCInfo, unsigned NextStackOffset,
-        const MipsFunctionInfo &FI) const override;
+        const MipsFunctionInfo &FI,
+        bool IsMustTail = false) const override;
 
     void
     getOpndList(SmallVectorImpl<SDValue> &Ops,

llvm/test/CodeGen/Mips/musttail.ll

@@ -4,25 +4,10 @@
 
 ; Test musttail support for MIPS
 
-declare void @external_func()
-
-; Test basic musttail with external function
-define void @test_musttail_external() {
-; MIPS32-LABEL: test_musttail_external:
-; MIPS32:       # %bb.0:
-; MIPS32-NEXT:    j external_func
-; MIPS32-NEXT:    nop
-;
-; MIPS64-LABEL: test_musttail_external:
-; MIPS64:       # %bb.0:
-; MIPS64-NEXT:    j external_func
-; MIPS64-NEXT:    nop
-  musttail call void @external_func()
-  ret void
+define dso_local i32 @callee_args(i32 %a, i32 %b, i32 %c) {
+  ret i32 %a;
 }
 
-declare i32 @callee_args(i32 %a, i32 %b, i32 %c)
-
 define i32 @test_musttail_args(i32 %x, i32 %y, i32 %z) {
 ; MIPS32-LABEL: test_musttail_args:
 ; MIPS32:       # %bb.0: