[Alignment][NFC] GlobalIsel Utils inferAlignFromPtrInfo

[gchatelet]

Summary

This is patch is part of a series 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

[arsenm]

llvm/include/llvm/CodeGen/GlobalISel/Utils.h

187–188

There's no real need for this as there should only be one or two uses of this

[gchatelet]

llvm/include/llvm/CodeGen/GlobalISel/Utils.h

187–188

Indeed thx there are only 6 instances.

I'll remove the function in my next patch which fixes the call sites.
FYI I prefer to proceed this way because the follow up patch is ready and fixing the call sites in this patch would be cumbersome.

llvm/include/llvm/CodeGen/GlobalISel/Utils.h

 //
 //===----------------------------------------------------------------------===//
 
 #ifndef LLVM_CODEGEN_GLOBALISEL_UTILS_H
 #define LLVM_CODEGEN_GLOBALISEL_UTILS_H
 
 #include "llvm/ADT/StringRef.h"
 #include "llvm/CodeGen/Register.h"
+#include "llvm/Support/Alignment.h"
 #include "llvm/Support/LowLevelTypeImpl.h"
 #include "llvm/Support/MachineValueType.h"
 
 namespace llvm {
 
 class AnalysisUsage;
 class MachineFunction;
 class MachineInstr;

 bool isKnownNeverNaN(Register Val, const MachineRegisterInfo &MRI,
                      bool SNaN = false);
 
 /// Returns true if \p Val can be assumed to never be a signaling NaN.
 inline bool isKnownNeverSNaN(Register Val, const MachineRegisterInfo &MRI) {
   return isKnownNeverNaN(Val, MRI, true);
 }
 
-unsigned inferAlignmentFromPtrInfo(MachineFunction &MF,
-                                   const MachinePointerInfo &MPO);
+Align inferAlignFromPtrInfo(MachineFunction &MF, const MachinePointerInfo &MPO);
+
+/// FIXME: Remove once the transition to Align is over.
+inline unsigned inferAlignmentFromPtrInfo(MachineFunction &MF,
+                                          const MachinePointerInfo &MPO) {
+  return inferAlignFromPtrInfo(MF, MPO).value();
+}
 
 /// Return the least common multiple type of \p Ty0 and \p Ty1, by changing
 /// the number of vector elements or scalar bitwidth. The intent is a
 /// G_MERGE_VALUES can be constructed from \p Ty0 elements, and unmerged into
 /// \p Ty1.
 LLT getLCMType(LLT Ty0, LLT Ty1);
 
 /// Return a type that is greatest common divisor of \p OrigTy and \p
 /// TargetTy. This will either change the number of vector elements, or
 /// bitwidth of scalars. The intent is the result type can be used as the
 /// result of a G_UNMERGE_VALUES from \p OrigTy.
 LLT getGCDType(LLT OrigTy, LLT TargetTy);
 
 } // End namespace llvm.
 #endif

llvm/lib/CodeGen/GlobalISel/Utils.cpp

if (SNaN) {
     default:
       return false;
     }
   }
 
   return false;
 }
 
-unsigned llvm::inferAlignmentFromPtrInfo(MachineFunction &MF,
-                                         const MachinePointerInfo &MPO) {
+Align llvm::inferAlignFromPtrInfo(MachineFunction &MF,
   auto PSV = MPO.V.dyn_cast<const PseudoSourceValue *>();
   if (auto FSPV = dyn_cast_or_null<FixedStackPseudoSourceValue>(PSV)) {
     MachineFrameInfo &MFI = MF.getFrameInfo();
-    return MinAlign(MFI.getObjectAlignment(FSPV->getFrameIndex()), MPO.Offset);
+    return commonAlignment(MFI.getObjectAlign(FSPV->getFrameIndex()),
+                           MPO.Offset);
   }
 
-  return 1;
+  return Align(1);
 }
 
 Optional<APInt> llvm::ConstantFoldExtOp(unsigned Opcode, const unsigned Op1,
                                         uint64_t Imm,
                                         const MachineRegisterInfo &MRI) {
   auto MaybeOp1Cst = getConstantVRegVal(Op1, MRI);
   if (MaybeOp1Cst) {
     LLT Ty = MRI.getType(Op1);