Unify CALLSEQ_{START,END}. They take 4 parameters: the chain, two stack
adjustment fields, and an optional flag. If there is a "dynamic_stackalloc" in
the code, make sure that it's bracketed by CALLSEQ_START and CALLSEQ_END. If
not, then there is the potential for the stack to be changed while the stack's
being used by another instruction (like a call).
This can only result in tears...
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@44037 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp b/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
index 4e096d8..5264141 100644
--- a/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
+++ b/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
@@ -1142,12 +1142,20 @@
// The only option for this is to custom lower it.
Tmp3 = TLI.LowerOperation(Result.getValue(0), DAG);
assert(Tmp3.Val && "Target didn't custom lower this node!");
- assert(Tmp3.Val->getNumValues() == Result.Val->getNumValues() &&
+
+ // The number of incoming and outgoing values should match; unless the final
+ // outgoing value is a flag.
+ assert((Tmp3.Val->getNumValues() == Result.Val->getNumValues() ||
+ (Tmp3.Val->getNumValues() == Result.Val->getNumValues() + 1 &&
+ Tmp3.Val->getValueType(Tmp3.Val->getNumValues() - 1) ==
+ MVT::Flag)) &&
"Lowering call/formal_arguments produced unexpected # results!");
// Since CALL/FORMAL_ARGUMENTS nodes produce multiple values, make sure to
// remember that we legalized all of them, so it doesn't get relegalized.
for (unsigned i = 0, e = Tmp3.Val->getNumValues(); i != e; ++i) {
+ if (Tmp3.Val->getValueType(i) == MVT::Flag)
+ continue;
Tmp1 = LegalizeOp(Tmp3.getValue(i));
if (Op.ResNo == i)
Tmp2 = Tmp1;
@@ -1472,6 +1480,12 @@
assert(SPReg && "Target cannot require DYNAMIC_STACKALLOC expansion and"
" not tell us which reg is the stack pointer!");
SDOperand Chain = Tmp1.getOperand(0);
+
+ // Chain the dynamic stack allocation so that it doesn't modify the stack
+ // pointer when other instructions are using the stack.
+ Chain = DAG.getCALLSEQ_START(Chain,
+ DAG.getConstant(0, TLI.getPointerTy()));
+
SDOperand Size = Tmp2.getOperand(1);
SDOperand SP = DAG.getCopyFromReg(Chain, SPReg, VT);
Chain = SP.getValue(1);
@@ -1482,7 +1496,14 @@
SP = DAG.getNode(ISD::AND, VT, SP,
DAG.getConstant(-(uint64_t)Align, VT));
Tmp1 = DAG.getNode(ISD::SUB, VT, SP, Size); // Value
- Tmp2 = DAG.getCopyToReg(Chain, SPReg, Tmp1); // Output chain
+ Chain = DAG.getCopyToReg(Chain, SPReg, Tmp1); // Output chain
+
+ Tmp2 =
+ DAG.getCALLSEQ_END(Chain,
+ DAG.getConstant(0, TLI.getPointerTy()),
+ DAG.getConstant(0, TLI.getPointerTy()),
+ SDOperand());
+
Tmp1 = LegalizeOp(Tmp1);
Tmp2 = LegalizeOp(Tmp2);
break;