Reland "Fix miscompile of MS inline assembly with stack realignment"

This re-lands commit r196876, which was reverted in r196879.

The tests have been fixed to pass on platforms with a stack alignment
larger than 4.

Update to clang side tests will land shortly.

llvm-svn: 196939

2 files changed, 15 insertions, 5 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index c63a88b9d77..fc25d7281ac 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -851,12 +851,20 @@ void RegsForValue::AddInlineAsmOperands(unsigned Code, bool HasMatching,
   SDValue Res = DAG.getTargetConstant(Flag, MVT::i32);
   Ops.push_back(Res);
 
+  unsigned SP = TLI.getStackPointerRegisterToSaveRestore();
   for (unsigned Value = 0, Reg = 0, e = ValueVTs.size(); Value != e; ++Value) {
     unsigned NumRegs = TLI.getNumRegisters(*DAG.getContext(), ValueVTs[Value]);
     MVT RegisterVT = RegVTs[Value];
     for (unsigned i = 0; i != NumRegs; ++i) {
       assert(Reg < Regs.size() && "Mismatch in # registers expected");
-      Ops.push_back(DAG.getRegister(Regs[Reg++], RegisterVT));
+      unsigned TheReg = Regs[Reg++];
+      Ops.push_back(DAG.getRegister(TheReg, RegisterVT));
+
+      // Notice if we clobbered the stack pointer.  Yes, inline asm can do this.
+      if (TheReg == SP && Code == InlineAsm::Kind_Clobber) {
+        MachineFrameInfo *MFI = DAG.getMachineFunction().getFrameInfo();
+        MFI->setHasInlineAsmWithSPAdjust(true);
+      }
     }
   }
 }
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
index 6c335d96c73..506b7380515 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
@@ -428,7 +428,9 @@ bool SelectionDAGISel::runOnMachineFunction(MachineFunction &mf) {
 
   SDB->init(GFI, *AA, LibInfo);
 
-  MF->setHasMSInlineAsm(false);
+  MF->setHasInlineAsm(false);
+  MF->getFrameInfo()->setHasInlineAsmWithSPAdjust(false);
+
   SelectAllBasicBlocks(Fn);
 
   // If the first basic block in the function has live ins that need to be
@@ -512,7 +514,7 @@ bool SelectionDAGISel::runOnMachineFunction(MachineFunction &mf) {
   for (MachineFunction::const_iterator I = MF->begin(), E = MF->end(); I != E;
        ++I) {
 
-    if (MFI->hasCalls() && MF->hasMSInlineAsm())
+    if (MFI->hasCalls() && MF->hasInlineAsm())
       break;
 
     const MachineBasicBlock *MBB = I;
@@ -523,8 +525,8 @@ bool SelectionDAGISel::runOnMachineFunction(MachineFunction &mf) {
           II->isStackAligningInlineAsm()) {
         MFI->setHasCalls(true);
       }
-      if (II->isMSInlineAsm()) {
-        MF->setHasMSInlineAsm(true);
+      if (II->isInlineAsm()) {
+        MF->setHasInlineAsm(true);
       }
     }
   }