[LLVM][Alignment] Introduce Alignment In CallingConv

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

Subscribers: hiraditya, llvm-commits, courbet, jfb

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D65659

llvm-svn: 367822

3 files changed, 26 insertions, 19 deletions

diff --git a/llvm/include/llvm/CodeGen/CallingConvLower.h b/llvm/include/llvm/CodeGen/CallingConvLower.h
index aa339e1cc91..e0b05751b3b 100644
--- a/llvm/include/llvm/CodeGen/CallingConvLower.h
+++ b/llvm/include/llvm/CodeGen/CallingConvLower.h
@@ -20,6 +20,7 @@
 #include "llvm/CodeGen/TargetCallingConv.h"
 #include "llvm/IR/CallingConv.h"
 #include "llvm/MC/MCRegisterInfo.h"
+#include "llvm/Support/Alignment.h"
 
 namespace llvm {
 
@@ -197,7 +198,7 @@ private:
   LLVMContext &Context;
 
   unsigned StackOffset;
-  unsigned MaxStackArgAlign;
+  Align MaxStackArgAlign;
   SmallVector<uint32_t, 16> UsedRegs;
   SmallVector<CCValAssign, 4> PendingLocs;
   SmallVector<ISD::ArgFlagsTy, 4> PendingArgFlags;
@@ -421,8 +422,8 @@ public:
 
   /// AllocateStack - Allocate a chunk of stack space with the specified size
   /// and alignment.
-  unsigned AllocateStack(unsigned Size, unsigned Align) {
-    assert(Align && ((Align - 1) & Align) == 0); // Align is power of 2.
+  unsigned AllocateStack(unsigned Size, unsigned Alignment) {
+    const llvm::Align Align(Alignment);
     StackOffset = alignTo(StackOffset, Align);
     unsigned Result = StackOffset;
     StackOffset += Size;
@@ -431,9 +432,9 @@ public:
     return Result;
   }
 
-  void ensureMaxAlignment(unsigned Align) {
+  void ensureMaxAlignment(llvm::Align Align) {
     if (!AnalyzingMustTailForwardedRegs)
-      MF.getFrameInfo().ensureMaxAlignment(Align);
+      MF.getFrameInfo().ensureMaxAlignment(Align.value());
   }
 
   /// Version of AllocateStack with extra register to be shadowed.
diff --git a/llvm/include/llvm/CodeGen/TargetCallingConv.h b/llvm/include/llvm/CodeGen/TargetCallingConv.h
index aebeeecbe50..d25a9a24591 100644
--- a/llvm/include/llvm/CodeGen/TargetCallingConv.h
+++ b/llvm/include/llvm/CodeGen/TargetCallingConv.h
@@ -14,6 +14,7 @@
 #define LLVM_CODEGEN_TARGETCALLINGCONV_H
 
 #include "llvm/CodeGen/ValueTypes.h"
+#include "llvm/Support/Alignment.h"
 #include "llvm/Support/MachineValueType.h"
 #include "llvm/Support/MathExtras.h"
 #include <cassert>
@@ -120,15 +121,21 @@ namespace ISD {
     bool isPointer()  const { return IsPointer; }
     void setPointer() { IsPointer = 1; }
 
-    unsigned getByValAlign() const { return (1U << ByValAlign) / 2; }
+    unsigned getByValAlign() const {
+      MaybeAlign A = decodeMaybeAlign(ByValAlign);
+      return A ? A->value() : 0;
+    }
     void setByValAlign(unsigned A) {
-      ByValAlign = Log2_32(A) + 1;
+      ByValAlign = encode(llvm::Align(A));
       assert(getByValAlign() == A && "bitfield overflow");
     }
 
-    unsigned getOrigAlign() const { return (1U << OrigAlign) / 2; }
+    unsigned getOrigAlign() const {
+      MaybeAlign A = decodeMaybeAlign(OrigAlign);
+      return A ? A->value() : 0;
+    }
     void setOrigAlign(unsigned A) {
-      OrigAlign = Log2_32(A) + 1;
+      OrigAlign = encode(llvm::Align(A));
       assert(getOrigAlign() == A && "bitfield overflow");
     }
 
diff --git a/llvm/lib/CodeGen/CallingConvLower.cpp b/llvm/lib/CodeGen/CallingConvLower.cpp
index 497fcb14784..92da621fabb 100644
--- a/llvm/lib/CodeGen/CallingConvLower.cpp
+++ b/llvm/lib/CodeGen/CallingConvLower.cpp
@@ -32,7 +32,6 @@ CCState::CCState(CallingConv::ID CC, bool isVarArg, MachineFunction &mf,
       TRI(*MF.getSubtarget().getRegisterInfo()), Locs(locs), Context(C) {
   // No stack is used.
   StackOffset = 0;
-  MaxStackArgAlign = 1;
 
   clearByValRegsInfo();
   UsedRegs.resize((TRI.getNumRegs()+31)/32);
@@ -41,20 +40,20 @@ CCState::CCState(CallingConv::ID CC, bool isVarArg, MachineFunction &mf,
 /// Allocate space on the stack large enough to pass an argument by value.
 /// The size and alignment information of the argument is encoded in
 /// its parameter attribute.
-void CCState::HandleByVal(unsigned ValNo, MVT ValVT,
-                          MVT LocVT, CCValAssign::LocInfo LocInfo,
-                          int MinSize, int MinAlign,
-                          ISD::ArgFlagsTy ArgFlags) {
-  unsigned Align = ArgFlags.getByValAlign();
+void CCState::HandleByVal(unsigned ValNo, MVT ValVT, MVT LocVT,
+                          CCValAssign::LocInfo LocInfo, int MinSize,
+                          int MinAlignment, ISD::ArgFlagsTy ArgFlags) {
+  llvm::Align MinAlign(MinAlignment);
+  llvm::Align Align(ArgFlags.getByValAlign());
   unsigned Size  = ArgFlags.getByValSize();
   if (MinSize > (int)Size)
     Size = MinSize;
-  if (MinAlign > (int)Align)
+  if (MinAlign > Align)
     Align = MinAlign;
   ensureMaxAlignment(Align);
-  MF.getSubtarget().getTargetLowering()->HandleByVal(this, Size, Align);
+  MF.getSubtarget().getTargetLowering()->HandleByVal(this, Size, Align.value());
   Size = unsigned(alignTo(Size, MinAlign));
-  unsigned Offset = AllocateStack(Size, Align);
+  unsigned Offset = AllocateStack(Size, Align.value());
   addLoc(CCValAssign::getMem(ValNo, ValVT, Offset, LocVT, LocInfo));
 }
 
@@ -209,7 +208,7 @@ static bool isValueTypeInRegForCC(CallingConv::ID CC, MVT VT) {
 void CCState::getRemainingRegParmsForType(SmallVectorImpl<MCPhysReg> &Regs,
                                           MVT VT, CCAssignFn Fn) {
   unsigned SavedStackOffset = StackOffset;
-  unsigned SavedMaxStackArgAlign = MaxStackArgAlign;
+  llvm::Align SavedMaxStackArgAlign = MaxStackArgAlign;
   unsigned NumLocs = Locs.size();
 
   // Set the 'inreg' flag if it is used for this calling convention.