ScheduleDAGInstrs: In functions with tail calls PseudoSourceValues are not non-aliasing distinct objects
The code that builds the dependence graph assumes that two PseudoSourceValues
don't alias. In a tail calling function two FixedStackObjects might refer to the
same location. Worse 'immutable' fixed stack objects like function arguments are
not immutable and will be clobbered.
Change this so that a load from a FixedStackObject is not invariant in a tail
calling function and don't return a PseudoSourceValue for an instruction in tail
calling functions when building the dependence graph so that we handle function
arguments conservatively.
Fix for PR23459.
rdar://20740035
llvm-svn: 236916
diff --git a/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp b/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
index cbb5a32..6d2a951 100644
--- a/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
+++ b/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
@@ -2873,8 +2873,10 @@
// If we're doing a tall call, use a TC_RETURN here rather than an
// actual call instruction.
- if (IsTailCall)
+ if (IsTailCall) {
+ MF.getFrameInfo()->setHasTailCall();
return DAG.getNode(AArch64ISD::TC_RETURN, DL, NodeTys, Ops);
+ }
// Returns a chain and a flag for retval copy to use.
Chain = DAG.getNode(AArch64ISD::CALL, DL, NodeTys, Ops);
diff --git a/llvm/lib/Target/ARM/ARMISelLowering.cpp b/llvm/lib/Target/ARM/ARMISelLowering.cpp
index b1c0b85..a3743d4 100644
--- a/llvm/lib/Target/ARM/ARMISelLowering.cpp
+++ b/llvm/lib/Target/ARM/ARMISelLowering.cpp
@@ -1847,8 +1847,10 @@
Ops.push_back(InFlag);
SDVTList NodeTys = DAG.getVTList(MVT::Other, MVT::Glue);
- if (isTailCall)
+ if (isTailCall) {
+ MF.getFrameInfo()->setHasTailCall();
return DAG.getNode(ARMISD::TC_RETURN, dl, NodeTys, Ops);
+ }
// Returns a chain and a flag for retval copy to use.
Chain = DAG.getNode(CallOpc, dl, NodeTys, Ops);
diff --git a/llvm/lib/Target/Hexagon/HexagonISelLowering.cpp b/llvm/lib/Target/Hexagon/HexagonISelLowering.cpp
index 9055e7e..ed5676c 100644
--- a/llvm/lib/Target/Hexagon/HexagonISelLowering.cpp
+++ b/llvm/lib/Target/Hexagon/HexagonISelLowering.cpp
@@ -637,8 +637,10 @@
if (InFlag.getNode())
Ops.push_back(InFlag);
- if (isTailCall)
+ if (isTailCall) {
+ MF.getFrameInfo()->setHasTailCall();
return DAG.getNode(HexagonISD::TC_RETURN, dl, NodeTys, Ops);
+ }
int OpCode = doesNotReturn ? HexagonISD::CALLv3nr : HexagonISD::CALLv3;
Chain = DAG.getNode(OpCode, dl, NodeTys, Ops);
diff --git a/llvm/lib/Target/PowerPC/PPCISelLowering.cpp b/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
index c7016bc..8da10f6 100644
--- a/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
+++ b/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
@@ -4215,6 +4215,7 @@
isa<ConstantSDNode>(Callee)) &&
"Expecting an global address, external symbol, absolute value or register");
+ MF.getFrameInfo()->setHasTailCall();
return DAG.getNode(PPCISD::TC_RETURN, dl, MVT::Other, Ops);
}
diff --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp
index 7f24ab4..4563354 100644
--- a/llvm/lib/Target/X86/X86ISelLowering.cpp
+++ b/llvm/lib/Target/X86/X86ISelLowering.cpp
@@ -3135,6 +3135,7 @@
// This isn't right, although it's probably harmless on x86; liveouts
// should be computed from returns not tail calls. Consider a void
// function making a tail call to a function returning int.
+ MF.getFrameInfo()->setHasTailCall();
return DAG.getNode(X86ISD::TC_RETURN, dl, NodeTys, Ops);
}