Enable tail call optimization for functions that return a struct (bug 3664) and for functions that return types that need extending (e.g i1).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67934 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/llvm/Target/TargetLowering.h b/include/llvm/Target/TargetLowering.h
index 587666f..cbe4ca4 100644
--- a/include/llvm/Target/TargetLowering.h
+++ b/include/llvm/Target/TargetLowering.h
@@ -1206,18 +1206,7 @@
/// preceeds the RET node and whether the return uses the result of the node
/// or is a void return. This function can be used by the target to determine
/// eligiblity of tail call optimization.
- static bool CheckTailCallReturnConstraints(CallSDNode *TheCall, SDValue Ret) {
- unsigned NumOps = Ret.getNumOperands();
- if ((NumOps == 1 &&
- (Ret.getOperand(0) == SDValue(TheCall,1) ||
- Ret.getOperand(0) == SDValue(TheCall,0))) ||
- (NumOps > 1 &&
- Ret.getOperand(0) == SDValue(TheCall,
- TheCall->getNumValues()-1) &&
- Ret.getOperand(1) == SDValue(TheCall,0)))
- return true;
- return false;
- }
+ static bool CheckTailCallReturnConstraints(CallSDNode *TheCall, SDValue Ret);
/// GetPossiblePreceedingTailCall - Get preceeding TailCallNodeOpCode node if
/// it exists. Skip a possible ISD::TokenFactor.
diff --git a/lib/CodeGen/SelectionDAG/TargetLowering.cpp b/lib/CodeGen/SelectionDAG/TargetLowering.cpp
index a08dcb2..1efc4a6 100644
--- a/lib/CodeGen/SelectionDAG/TargetLowering.cpp
+++ b/lib/CodeGen/SelectionDAG/TargetLowering.cpp
@@ -2571,3 +2571,27 @@
DAG.getConstant(magics.s-1, getShiftAmountTy()));
}
}
+
+bool TargetLowering::CheckTailCallReturnConstraints(CallSDNode *TheCall, SDValue Ret) {
+ unsigned NumOps = Ret.getNumOperands();
+ // Struct return.
+ if(NumOps >= 5&&
+ Ret.getOperand(1).getOpcode()==ISD::MERGE_VALUES &&
+ Ret.getOperand(1).getOperand(0) == SDValue(TheCall, 0))
+ return true;
+ if ((NumOps == 1 &&
+ (Ret.getOperand(0) == SDValue(TheCall,1) ||
+ Ret.getOperand(0) == SDValue(TheCall,0))) ||
+ (NumOps == 3 &&
+ Ret.getOperand(1).getOpcode() == ISD::ANY_EXTEND &&
+ Ret.getOperand(1).getNumOperands()>0 &&
+ Ret.getOperand(1).getOperand(0).getOpcode() == ISD::TRUNCATE &&
+ Ret.getOperand(1).getOperand(0).getNumOperands()>0 &&
+ Ret.getOperand(1).getOperand(0).getOperand(0) == SDValue(TheCall, 0)) ||
+ (NumOps > 1 &&
+ Ret.getOperand(0) == SDValue(TheCall,
+ TheCall->getNumValues()-1) &&
+ Ret.getOperand(1) == SDValue(TheCall,0)))
+ return true;
+ return false;
+}
diff --git a/test/CodeGen/X86/tailcall-i1.ll b/test/CodeGen/X86/tailcall-i1.ll
new file mode 100644
index 0000000..0ec6a77
--- /dev/null
+++ b/test/CodeGen/X86/tailcall-i1.ll
@@ -0,0 +1,6 @@
+; RUN: llvm-as < %s | llc -march=x86 -tailcallopt | grep TAILCALL
+define fastcc i1 @i1test(i32, i32, i32, i32) {
+ entry:
+ %4 = tail call fastcc i1 @i1test( i32 %0, i32 %1, i32 %2, i32 %3)
+ ret i1 %4
+}
diff --git a/test/CodeGen/X86/tailcall-structret.ll b/test/CodeGen/X86/tailcall-structret.ll
new file mode 100644
index 0000000..e94d7d8
--- /dev/null
+++ b/test/CodeGen/X86/tailcall-structret.ll
@@ -0,0 +1,6 @@
+; RUN: llvm-as < %s | llc -march=x86 -tailcallopt | grep TAILCALL
+define fastcc { { i8*, i8* }*, i8*} @init({ { i8*, i8* }*, i8*}, i32) {
+entry:
+ %2 = tail call fastcc { { i8*, i8* }*, i8* } @init({ { i8*, i8*}*, i8*} %0, i32 %1)
+ ret { { i8*, i8* }*, i8*} %2
+}