[LLVM][Alignment] Introduce Alignment In MachineFrameInfo

Summary:
This is patch is part of a serie to introduce an Alignment type.
See this thread for context: http://lists.llvm.org/pipermail/llvm-dev/2019-July/133851.html
See this patch for the introduction of the type: https://reviews.llvm.org/D64790

Reviewers: jfb

Subscribers: hiraditya, dexonsmith, llvm-commits, courbet

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D65800

llvm-svn: 369531

Author: gchatelet

llvm/include/llvm/CodeGen/MachineFrameInfo.h

@@ -14,6 +14,7 @@
 #define LLVM_CODEGEN_MACHINEFRAMEINFO_H
 
 #include "llvm/ADT/SmallVector.h"
+#include "llvm/Support/Alignment.h"
 #include "llvm/Support/DataTypes.h"
 #include <cassert>
 #include <vector>
@@ -129,7 +130,7 @@ class MachineFrameInfo {
     uint64_t Size;
 
     // The required alignment of this stack slot.
-    unsigned Alignment;
+    Align Alignment;
 
     // If true, the value of the stack object is set before
     // entering the function and is not modified inside the function. By
@@ -180,17 +181,16 @@ class MachineFrameInfo {
 
     uint8_t SSPLayout;
 
-    StackObject(uint64_t Size, unsigned Alignment, int64_t SPOffset,
+    StackObject(uint64_t Size, llvm::Align Alignment, int64_t SPOffset,
                 bool IsImmutable, bool IsSpillSlot, const AllocaInst *Alloca,
                 bool IsAliased, uint8_t StackID = 0)
-      : SPOffset(SPOffset), Size(Size), Alignment(Alignment),
-        isImmutable(IsImmutable), isSpillSlot(IsSpillSlot),
-        StackID(StackID), Alloca(Alloca), isAliased(IsAliased),
-        SSPLayout(SSPLK_None) {}
+        : SPOffset(SPOffset), Size(Size), Alignment(Alignment),
+          isImmutable(IsImmutable), isSpillSlot(IsSpillSlot), StackID(StackID),
+          Alloca(Alloca), isAliased(IsAliased), SSPLayout(SSPLK_None) {}
   };
 
   /// The alignment of the stack.
-  unsigned StackAlignment;
+  Align StackAlignment;
 
   /// Can the stack be realigned. This can be false if the target does not
   /// support stack realignment, or if the user asks us not to realign the
@@ -260,7 +260,7 @@ class MachineFrameInfo {
   /// native alignment maintained by the compiler, dynamic alignment code will
   /// be needed.
   ///
-  unsigned MaxAlignment = 0;
+  Align MaxAlignment;
 
   /// Set to true if this function adjusts the stack -- e.g.,
   /// when calling another function. This is only valid during and after
@@ -304,7 +304,7 @@ class MachineFrameInfo {
 
   /// Required alignment of the local object blob, which is the strictest
   /// alignment of any object in it.
-  unsigned LocalFrameMaxAlign = 0;
+  Align LocalFrameMaxAlign;
 
   /// Whether the local object blob needs to be allocated together. If not,
   /// PEI should ignore the isPreAllocated flags on the stack objects and
@@ -338,8 +338,8 @@ class MachineFrameInfo {
 public:
   explicit MachineFrameInfo(unsigned StackAlignment, bool StackRealignable,
                             bool ForcedRealign)
-      : StackAlignment(StackAlignment), StackRealignable(StackRealignable),
-        ForcedRealign(ForcedRealign) {}
+      : StackAlignment(assumeAligned(StackAlignment)),
+        StackRealignable(StackRealignable), ForcedRealign(ForcedRealign) {}
 
   /// Return true if there are any stack objects in this function.
   bool hasStackObjects() const { return !Objects.empty(); }
@@ -419,10 +419,10 @@ class MachineFrameInfo {
 
   /// Required alignment of the local object blob,
   /// which is the strictest alignment of any object in it.
-  void setLocalFrameMaxAlign(unsigned Align) { LocalFrameMaxAlign = Align; }
+  void setLocalFrameMaxAlign(Align Align) { LocalFrameMaxAlign = Align; }
 
   /// Return the required alignment of the local object blob.
-  unsigned getLocalFrameMaxAlign() const { return LocalFrameMaxAlign; }
+  Align getLocalFrameMaxAlign() const { return LocalFrameMaxAlign; }
 
   /// Get whether the local allocation blob should be allocated together or
   /// let PEI allocate the locals in it directly.
@@ -462,14 +462,14 @@ class MachineFrameInfo {
   unsigned getObjectAlignment(int ObjectIdx) const {
     assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() &&
            "Invalid Object Idx!");
-    return Objects[ObjectIdx+NumFixedObjects].Alignment;
+    return Objects[ObjectIdx + NumFixedObjects].Alignment.value();
   }
 
   /// setObjectAlignment - Change the alignment of the specified stack object.
   void setObjectAlignment(int ObjectIdx, unsigned Align) {
     assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() &&
            "Invalid Object Idx!");
-    Objects[ObjectIdx+NumFixedObjects].Alignment = Align;
+    Objects[ObjectIdx + NumFixedObjects].Alignment = assumeAligned(Align);
 
     // Only ensure max alignment for the default stack.
     if (getStackID(ObjectIdx) == 0)
@@ -561,10 +561,14 @@ class MachineFrameInfo {
 
   /// Return the alignment in bytes that this function must be aligned to,
   /// which is greater than the default stack alignment provided by the target.
-  unsigned getMaxAlignment() const { return MaxAlignment; }
+  unsigned getMaxAlignment() const { return MaxAlignment.value(); }
 
   /// Make sure the function is at least Align bytes aligned.
-  void ensureMaxAlignment(unsigned Align);
+  void ensureMaxAlignment(llvm::Align Align);
+  /// FIXME: Remove this once transition to Align is over.
+  inline void ensureMaxAlignment(unsigned Align) {
+    ensureMaxAlignment(assumeAligned(Align));
+  }
 
   /// Return true if this function adjusts the stack -- e.g.,
   /// when calling another function. This is only valid during and after
@@ -728,12 +732,24 @@ class MachineFrameInfo {
 
   /// Create a new statically sized stack object, returning
   /// a nonnegative identifier to represent it.
-  int CreateStackObject(uint64_t Size, unsigned Alignment, bool isSpillSlot,
+  int CreateStackObject(uint64_t Size, llvm::Align Alignment, bool isSpillSlot,
                         const AllocaInst *Alloca = nullptr, uint8_t ID = 0);
+  /// FIXME: Remove this function when transition to llvm::Align is over.
+  inline int CreateStackObject(uint64_t Size, unsigned Alignment,
+                               bool isSpillSlot,
+                               const AllocaInst *Alloca = nullptr,
+                               uint8_t ID = 0) {
+    return CreateStackObject(Size, assumeAligned(Alignment), isSpillSlot,
+                             Alloca, ID);
+  }
 
   /// Create a new statically sized stack object that represents a spill slot,
   /// returning a nonnegative identifier to represent it.
-  int CreateSpillStackObject(uint64_t Size, unsigned Alignment);
+  int CreateSpillStackObject(uint64_t Size, llvm::Align Alignment);
+  /// FIXME: Remove this function when transition to llvm::Align is over.
+  inline int CreateSpillStackObject(uint64_t Size, unsigned Alignment) {
+    return CreateSpillStackObject(Size, assumeAligned(Alignment));
+  }
 
   /// Remove or mark dead a statically sized stack object.
   void RemoveStackObject(int ObjectIdx) {
@@ -744,7 +760,12 @@ class MachineFrameInfo {
   /// Notify the MachineFrameInfo object that a variable sized object has been
   /// created.  This must be created whenever a variable sized object is
   /// created, whether or not the index returned is actually used.
-  int CreateVariableSizedObject(unsigned Alignment, const AllocaInst *Alloca);
+  int CreateVariableSizedObject(llvm::Align Alignment,
+                                const AllocaInst *Alloca);
+  /// FIXME: Remove this function when transition to llvm::Align is over.
+  int CreateVariableSizedObject(unsigned Alignment, const AllocaInst *Alloca) {
+    return CreateVariableSizedObject(assumeAligned(Alignment), Alloca);
+  }
 
   /// Returns a reference to call saved info vector for the current function.
   const std::vector<CalleeSavedInfo> &getCalleeSavedInfo() const {

llvm/lib/Analysis/MemoryBuiltins.cpp

@@ -523,7 +523,7 @@ STATISTIC(ObjectVisitorLoad,
 
 APInt ObjectSizeOffsetVisitor::align(APInt Size, uint64_t Align) {
   if (Options.RoundToAlign && Align)
-    return APInt(IntTyBits, alignTo(Size.getZExtValue(), Align));
+    return APInt(IntTyBits, alignTo(Size.getZExtValue(), llvm::Align(Align)));
   return Size;
 }
 

llvm/lib/CodeGen/LocalStackSlotAllocation.cpp

@@ -261,7 +261,7 @@ void LocalStackSlotPass::calculateFrameObjectOffsets(MachineFunction &Fn) {
 
   // Remember how big this blob of stack space is
   MFI.setLocalFrameSize(Offset);
-  MFI.setLocalFrameMaxAlign(MaxAlign);
+  MFI.setLocalFrameMaxAlign(assumeAligned(MaxAlign));
 }
 
 static inline bool

llvm/lib/CodeGen/MachineFrameInfo.cpp

@@ -28,25 +28,26 @@
 
 using namespace llvm;
 
-void MachineFrameInfo::ensureMaxAlignment(unsigned Align) {
+void MachineFrameInfo::ensureMaxAlignment(llvm::Align Align) {
   if (!StackRealignable)
     assert(Align <= StackAlignment &&
            "For targets without stack realignment, Align is out of limit!");
   if (MaxAlignment < Align) MaxAlignment = Align;
 }
 
 /// Clamp the alignment if requested and emit a warning.
-static inline unsigned clampStackAlignment(bool ShouldClamp, unsigned Align,
-                                           unsigned StackAlign) {
+static inline llvm::Align clampStackAlignment(bool ShouldClamp,
+                                              llvm::Align Align,
+                                              llvm::Align StackAlign) {
   if (!ShouldClamp || Align <= StackAlign)
     return Align;
-  LLVM_DEBUG(dbgs() << "Warning: requested alignment " << Align
-                    << " exceeds the stack alignment " << StackAlign
+  LLVM_DEBUG(dbgs() << "Warning: requested alignment " << Align.value()
+                    << " exceeds the stack alignment " << StackAlign.value()
                     << " when stack realignment is off" << '\n');
   return StackAlign;
 }
 
-int MachineFrameInfo::CreateStackObject(uint64_t Size, unsigned Alignment,
+int MachineFrameInfo::CreateStackObject(uint64_t Size, llvm::Align Alignment,
                                         bool IsSpillSlot,
                                         const AllocaInst *Alloca,
                                         uint8_t StackID) {
@@ -62,15 +63,15 @@ int MachineFrameInfo::CreateStackObject(uint64_t Size, unsigned Alignment,
 }
 
 int MachineFrameInfo::CreateSpillStackObject(uint64_t Size,
-                                             unsigned Alignment) {
+                                             llvm::Align Alignment) {
   Alignment = clampStackAlignment(!StackRealignable, Alignment, StackAlignment);
   CreateStackObject(Size, Alignment, true);
   int Index = (int)Objects.size() - NumFixedObjects - 1;
   ensureMaxAlignment(Alignment);
   return Index;
 }
 
-int MachineFrameInfo::CreateVariableSizedObject(unsigned Alignment,
+int MachineFrameInfo::CreateVariableSizedObject(llvm::Align Alignment,
                                                 const AllocaInst *Alloca) {
   HasVarSizedObjects = true;
   Alignment = clampStackAlignment(!StackRealignable, Alignment, StackAlignment);
@@ -88,7 +89,8 @@ int MachineFrameInfo::CreateFixedObject(uint64_t Size, int64_t SPOffset,
   // object is 16-byte aligned. Note that unlike the non-fixed case, if the
   // stack needs realignment, we can't assume that the stack will in fact be
   // aligned.
-  unsigned Alignment = MinAlign(SPOffset, ForcedRealign ? 1 : StackAlignment);
+  llvm::Align Alignment =
+      commonAlignment(ForcedRealign ? llvm::Align() : StackAlignment, SPOffset);
   Alignment = clampStackAlignment(!StackRealignable, Alignment, StackAlignment);
   Objects.insert(Objects.begin(),
                  StackObject(Size, Alignment, SPOffset, IsImmutable,
@@ -100,7 +102,8 @@ int MachineFrameInfo::CreateFixedObject(uint64_t Size, int64_t SPOffset,
 int MachineFrameInfo::CreateFixedSpillStackObject(uint64_t Size,
                                                   int64_t SPOffset,
                                                   bool IsImmutable) {
-  unsigned Alignment = MinAlign(SPOffset, ForcedRealign ? 1 : StackAlignment);
+  llvm::Align Alignment =
+      commonAlignment(ForcedRealign ? llvm::Align() : StackAlignment, SPOffset);
   Alignment = clampStackAlignment(!StackRealignable, Alignment, StackAlignment);
   Objects.insert(Objects.begin(),
                  StackObject(Size, Alignment, SPOffset, IsImmutable,
@@ -232,7 +235,7 @@ void MachineFrameInfo::print(const MachineFunction &MF, raw_ostream &OS) const{
       OS << "variable sized";
     else
       OS << "size=" << SO.Size;
-    OS << ", align=" << SO.Alignment;
+    OS << ", align=" << SO.Alignment.value();
 
     if (i < NumFixedObjects)
       OS << ", fixed";

llvm/lib/CodeGen/PrologEpilogInserter.cpp

@@ -898,7 +898,7 @@ void PEI::calculateFrameObjectOffsets(MachineFunction &MF) {
   // frame index registers. Functions which don't want/need this optimization
   // will continue to use the existing code path.
   if (MFI.getUseLocalStackAllocationBlock()) {
-    unsigned Align = MFI.getLocalFrameMaxAlign();
+    unsigned Align = MFI.getLocalFrameMaxAlign().value();
 
     // Adjust to alignment boundary.
     Offset = alignTo(Offset, Align, Skew);

llvm/lib/Target/Hexagon/HexagonFrameLowering.cpp

@@ -1377,10 +1377,10 @@ void HexagonFrameLowering::processFunctionBeforeFrameFinalized(
   }
 
   MFI.setLocalFrameSize(LFS);
-  unsigned A = MFI.getLocalFrameMaxAlign();
+  Align A = MFI.getLocalFrameMaxAlign();
   assert(A <= 8 && "Unexpected local frame alignment");
-  if (A == 0)
-    MFI.setLocalFrameMaxAlign(8);
+  if (A == 1)
+    MFI.setLocalFrameMaxAlign(llvm::Align(8));
   MFI.setUseLocalStackAllocationBlock(true);
 
   // Set the physical aligned-stack base address register.

llvm/lib/Target/NVPTX/NVPTXPrologEpilogPass.cpp

@@ -178,7 +178,7 @@ NVPTXPrologEpilogPass::calculateFrameObjectOffsets(MachineFunction &Fn) {
   // frame index registers. Functions which don't want/need this optimization
   // will continue to use the existing code path.
   if (MFI.getUseLocalStackAllocationBlock()) {
-    unsigned Align = MFI.getLocalFrameMaxAlign();
+    unsigned Align = MFI.getLocalFrameMaxAlign().value();
 
     // Adjust to alignment boundary.
     Offset = (Offset + Align - 1) / Align * Align;