Do not model all INLINEASM instructions as having unmodelled side effects.

Instead encode llvm IR level property "HasSideEffects" in an operand (shared
with IsAlignStack). Added MachineInstrs::hasUnmodeledSideEffects() to check
the operand when the instruction is an INLINEASM.

This allows memory instructions to be moved around INLINEASM instructions.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123044 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 15 insertions, 12 deletions

diff --git a/lib/CodeGen/SelectionDAG/InstrEmitter.cpp b/lib/CodeGen/SelectionDAG/InstrEmitter.cpp
index 977cd63..d7bf6c1 100644
--- a/lib/CodeGen/SelectionDAG/InstrEmitter.cpp
+++ b/lib/CodeGen/SelectionDAG/InstrEmitter.cpp
@@ -821,11 +821,11 @@ EmitSpecialNode(SDNode *Node, bool IsClone, bool IsCloned,
     const char *AsmStr = cast<ExternalSymbolSDNode>(AsmStrV)->getSymbol();
     MI->addOperand(MachineOperand::CreateES(AsmStr));
       
-    // Add the isAlignStack bit.
-    int64_t isAlignStack =
-      cast<ConstantSDNode>(Node->getOperand(InlineAsm::Op_IsAlignStack))->
+    // Add the HasSideEffect and isAlignStack bits.
+    int64_t ExtraInfo =
+      cast<ConstantSDNode>(Node->getOperand(InlineAsm::Op_ExtraInfo))->
                           getZExtValue();
-    MI->addOperand(MachineOperand::CreateImm(isAlignStack));
+    MI->addOperand(MachineOperand::CreateImm(ExtraInfo));
 
     // Add all of the operand registers to the instruction.
     for (unsigned i = InlineAsm::Op_FirstOperand; i != NumOps;) {
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index 2167523..2869bd8 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -5738,9 +5738,14 @@ void SelectionDAGBuilder::visitInlineAsm(ImmutableCallSite CS) {
   const MDNode *SrcLoc = CS.getInstruction()->getMetadata("srcloc");
   AsmNodeOperands.push_back(DAG.getMDNode(SrcLoc));
 
-  // Remember the AlignStack bit as operand 3.
-  AsmNodeOperands.push_back(DAG.getTargetConstant(IA->isAlignStack() ? 1 : 0,
-                                            MVT::i1));
+  // Remember the HasSideEffect and AlignStack bits as operand 3.
+  unsigned ExtraInfo = 0;
+  if (IA->hasSideEffects())
+    ExtraInfo |= InlineAsm::Extra_HasSideEffects;
+  if (IA->isAlignStack())
+    ExtraInfo |= InlineAsm::Extra_IsAlignStack;
+  AsmNodeOperands.push_back(DAG.getTargetConstant(ExtraInfo,
+                                                  TLI.getPointerTy()));
 
   // Loop over all of the inputs, copying the operand values into the
   // appropriate registers and processing the output regs.
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
index 4cc2761..279478f 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
@@ -380,10 +380,8 @@ bool SelectionDAGISel::runOnMachineFunction(MachineFunction &mf) {
              II = MBB->begin(), IE = MBB->end(); II != IE; ++II) {
         const TargetInstrDesc &TID = TM.getInstrInfo()->get(II->getOpcode());
 
-        // Operand 1 of an inline asm instruction indicates whether the asm
-        // needs stack or not.
-        if ((II->isInlineAsm() && II->getOperand(1).getImm()) ||
-            (TID.isCall() && !TID.isReturn())) {
+        if ((TID.isCall() && !TID.isReturn()) ||
+            II->isStackAligningInlineAsm()) {
           MFI->setHasCalls(true);
           goto done;
         }
@@ -1283,7 +1281,7 @@ SelectInlineAsmMemoryOperands(std::vector<SDValue> &Ops) {
   Ops.push_back(InOps[InlineAsm::Op_InputChain]); // 0
   Ops.push_back(InOps[InlineAsm::Op_AsmString]);  // 1
   Ops.push_back(InOps[InlineAsm::Op_MDNode]);     // 2, !srcloc
-  Ops.push_back(InOps[InlineAsm::Op_IsAlignStack]);  // 3
+  Ops.push_back(InOps[InlineAsm::Op_ExtraInfo]);  // 3 (SideEffect, AlignStack)
 
   unsigned i = InlineAsm::Op_FirstOperand, e = InOps.size();
   if (InOps[e-1].getValueType() == MVT::Glue)