Describe stack-id as an enum

This patch changes MIR stack-id from an integer to an enum,
and adds printing/parsing support for this in MIR files. The default
stack-id '0' is now renamed to 'default'.

This should make MIR tests that have stack objects with different stack-ids
more descriptive. It also clarifies code operating on StackID.

Reviewers: arsenm, thegameg, qcolombet

Reviewed By: arsenm

Differential Revision: https://reviews.llvm.org/D60137

llvm-svn: 363533
diff --git a/llvm/lib/CodeGen/MIRParser/MIRParser.cpp b/llvm/lib/CodeGen/MIRParser/MIRParser.cpp
index 14cf47f..e1b43fe 100644
--- a/llvm/lib/CodeGen/MIRParser/MIRParser.cpp
+++ b/llvm/lib/CodeGen/MIRParser/MIRParser.cpp
@@ -27,6 +27,7 @@
 #include "llvm/CodeGen/MachineFunction.h"
 #include "llvm/CodeGen/MachineModuleInfo.h"
 #include "llvm/CodeGen/MachineRegisterInfo.h"
+#include "llvm/CodeGen/TargetFrameLowering.h"
 #include "llvm/IR/BasicBlock.h"
 #include "llvm/IR/DebugInfo.h"
 #include "llvm/IR/DiagnosticInfo.h"
@@ -579,6 +580,7 @@
                                         const yaml::MachineFunction &YamlMF) {
   MachineFunction &MF = PFS.MF;
   MachineFrameInfo &MFI = MF.getFrameInfo();
+  const TargetFrameLowering *TFI = MF.getSubtarget().getFrameLowering();
   const Function &F = MF.getFunction();
   const yaml::MachineFrameInfo &YamlMFI = YamlMF.FrameInfo;
   MFI.setFrameAddressIsTaken(YamlMFI.IsFrameAddressTaken);
@@ -620,6 +622,10 @@
                                         Object.IsImmutable, Object.IsAliased);
     else
       ObjectIdx = MFI.CreateFixedSpillStackObject(Object.Size, Object.Offset);
+
+    if (!TFI->isSupportedStackID(Object.StackID))
+      return error(Object.ID.SourceRange.Start,
+                   Twine("StackID is not supported by target"));
     MFI.setStackID(ObjectIdx, Object.StackID);
     MFI.setObjectAlignment(ObjectIdx, Object.Alignment);
     if (!PFS.FixedStackObjectSlots.insert(std::make_pair(Object.ID.Value,
@@ -649,6 +655,9 @@
                          "' isn't defined in the function '" + F.getName() +
                          "'");
     }
+    if (!TFI->isSupportedStackID(Object.StackID))
+      return error(Object.ID.SourceRange.Start,
+                   Twine("StackID is not supported by target"));
     if (Object.Type == yaml::MachineStackObject::VariableSized)
       ObjectIdx = MFI.CreateVariableSizedObject(Object.Alignment, Alloca);
     else
diff --git a/llvm/lib/CodeGen/MIRPrinter.cpp b/llvm/lib/CodeGen/MIRPrinter.cpp
index e6f5890..f14ce57 100644
--- a/llvm/lib/CodeGen/MIRPrinter.cpp
+++ b/llvm/lib/CodeGen/MIRPrinter.cpp
@@ -35,6 +35,7 @@
 #include "llvm/CodeGen/TargetInstrInfo.h"
 #include "llvm/CodeGen/TargetRegisterInfo.h"
 #include "llvm/CodeGen/TargetSubtargetInfo.h"
+#include "llvm/CodeGen/TargetFrameLowering.h"
 #include "llvm/IR/BasicBlock.h"
 #include "llvm/IR/Constants.h"
 #include "llvm/IR/DebugInfo.h"
@@ -368,7 +369,7 @@
     YamlObject.Offset = MFI.getObjectOffset(I);
     YamlObject.Size = MFI.getObjectSize(I);
     YamlObject.Alignment = MFI.getObjectAlignment(I);
-    YamlObject.StackID = MFI.getStackID(I);
+    YamlObject.StackID = (TargetStackID::Value)MFI.getStackID(I);
     YamlObject.IsImmutable = MFI.isImmutableObjectIndex(I);
     YamlObject.IsAliased = MFI.isAliasedObjectIndex(I);
     YMF.FixedStackObjects.push_back(YamlObject);
@@ -395,7 +396,7 @@
     YamlObject.Offset = MFI.getObjectOffset(I);
     YamlObject.Size = MFI.getObjectSize(I);
     YamlObject.Alignment = MFI.getObjectAlignment(I);
-    YamlObject.StackID = MFI.getStackID(I);
+    YamlObject.StackID = (TargetStackID::Value)MFI.getStackID(I);
 
     YMF.StackObjects.push_back(YamlObject);
     StackObjectOperandMapping.insert(std::make_pair(
diff --git a/llvm/lib/CodeGen/MachineFrameInfo.cpp b/llvm/lib/CodeGen/MachineFrameInfo.cpp
index e8a3dda..989a6a7 100644
--- a/llvm/lib/CodeGen/MachineFrameInfo.cpp
+++ b/llvm/lib/CodeGen/MachineFrameInfo.cpp
@@ -143,14 +143,14 @@
 
   for (int i = getObjectIndexBegin(); i != 0; ++i) {
     // Only estimate stack size of default stack.
-    if (getStackID(i))
+    if (getStackID(i) != TargetStackID::Default)
       continue;
     int FixedOff = -getObjectOffset(i);
     if (FixedOff > Offset) Offset = FixedOff;
   }
   for (unsigned i = 0, e = getObjectIndexEnd(); i != e; ++i) {
     // Only estimate stack size of live objects on default stack.
-    if (isDeadObjectIndex(i) || getStackID(i))
+    if (isDeadObjectIndex(i) || getStackID(i) != TargetStackID::Default)
       continue;
     Offset += getObjectSize(i);
     unsigned Align = getObjectAlignment(i);
diff --git a/llvm/lib/CodeGen/PrologEpilogInserter.cpp b/llvm/lib/CodeGen/PrologEpilogInserter.cpp
index ab6814b..9495567 100644
--- a/llvm/lib/CodeGen/PrologEpilogInserter.cpp
+++ b/llvm/lib/CodeGen/PrologEpilogInserter.cpp
@@ -662,11 +662,11 @@
   // Add fixed objects.
   for (int i = MFI.getObjectIndexBegin(); i != 0; ++i)
     // StackSlot scavenging is only implemented for the default stack.
-    if (MFI.getStackID(i) == 0)
+    if (MFI.getStackID(i) == TargetStackID::Default)
       AllocatedFrameSlots.push_back(i);
   // Add callee-save objects.
   for (int i = MinCSFrameIndex; i <= (int)MaxCSFrameIndex; ++i)
-    if (MFI.getStackID(i) == 0)
+    if (MFI.getStackID(i) == TargetStackID::Default)
       AllocatedFrameSlots.push_back(i);
 
   for (int i : AllocatedFrameSlots) {
@@ -791,7 +791,8 @@
 
 #ifdef EXPENSIVE_CHECKS
   for (unsigned i = 0, e = MFI.getObjectIndexEnd(); i != e; ++i)
-    if (!MFI.isDeadObjectIndex(i) && MFI.getStackID(i) == 0)
+    if (!MFI.isDeadObjectIndex(i) &&
+        MFI.getStackID(i) == TargetStackID::Default)
       assert(MFI.getObjectAlignment(i) <= MFI.getMaxAlignment() &&
              "MaxAlignment is invalid");
 #endif
@@ -801,7 +802,8 @@
   // Adjust 'Offset' to point to the end of last fixed sized preallocated
   // object.
   for (int i = MFI.getObjectIndexBegin(); i != 0; ++i) {
-    if (MFI.getStackID(i)) // Only allocate objects on the default stack.
+    if (MFI.getStackID(i) !=
+        TargetStackID::Default) // Only allocate objects on the default stack.
       continue;
 
     int64_t FixedOff;
@@ -822,7 +824,8 @@
   // callee saved registers.
   if (StackGrowsDown) {
     for (unsigned i = MinCSFrameIndex; i <= MaxCSFrameIndex; ++i) {
-      if (MFI.getStackID(i)) // Only allocate objects on the default stack.
+      if (MFI.getStackID(i) !=
+          TargetStackID::Default) // Only allocate objects on the default stack.
         continue;
 
       // If the stack grows down, we need to add the size to find the lowest
@@ -839,7 +842,8 @@
   } else if (MaxCSFrameIndex >= MinCSFrameIndex) {
     // Be careful about underflow in comparisons agains MinCSFrameIndex.
     for (unsigned i = MaxCSFrameIndex; i != MinCSFrameIndex - 1; --i) {
-      if (MFI.getStackID(i)) // Only allocate objects on the default stack.
+      if (MFI.getStackID(i) !=
+          TargetStackID::Default) // Only allocate objects on the default stack.
         continue;
 
       if (MFI.isDeadObjectIndex(i))
@@ -932,7 +936,8 @@
       if (MFI.getStackProtectorIndex() == (int)i ||
           EHRegNodeFrameIndex == (int)i)
         continue;
-      if (MFI.getStackID(i)) // Only allocate objects on the default stack.
+      if (MFI.getStackID(i) !=
+          TargetStackID::Default) // Only allocate objects on the default stack.
         continue;
 
       switch (MFI.getObjectSSPLayout(i)) {
@@ -977,7 +982,8 @@
       continue;
     if (ProtectedObjs.count(i))
       continue;
-    if (MFI.getStackID(i)) // Only allocate objects on the default stack.
+    if (MFI.getStackID(i) !=
+        TargetStackID::Default) // Only allocate objects on the default stack.
       continue;
 
     // Add the objects that we need to allocate to our working set.