diff --git a/llvm/lib/Target/AArch64/MCTargetDesc/AArch64AsmBackend.cpp b/llvm/lib/Target/AArch64/MCTargetDesc/AArch64AsmBackend.cpp
--- a/llvm/lib/Target/AArch64/MCTargetDesc/AArch64AsmBackend.cpp
+++ b/llvm/lib/Target/AArch64/MCTargetDesc/AArch64AsmBackend.cpp
@@ -27,6 +27,7 @@
 #include "llvm/MC/TargetRegistry.h"
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/MathExtras.h"
+#include "llvm/Support/Alignment.h"
 #include "llvm/TargetParser/Triple.h"
 using namespace llvm;
 
@@ -143,8 +144,8 @@
 }
 
 static unsigned AdrImmBits(unsigned Value) {
-  unsigned lo2 = Value & 0x3;
-  unsigned hi19 = (Value & 0x1ffffc) >> 2;
+  unsigned lo2 = Value & maskTrailingOnes<unsigned>(2);
+  unsigned hi19 = (Value >> 2) & maskTrailingOnes<unsigned>(19);
   return (hi19 << 5) | (lo2 << 29);
 }
 
@@ -158,66 +159,66 @@
   case AArch64::fixup_aarch64_pcrel_adr_imm21:
     if (!isInt<21>(SignedValue))
       Ctx.reportError(Fixup.getLoc(), "fixup value out of range");
-    return AdrImmBits(Value & 0x1fffffULL);
+    return AdrImmBits(Value & maskTrailingOnes<uint64_t>(21));
   case AArch64::fixup_aarch64_pcrel_adrp_imm21:
     assert(!IsResolved);
     if (TheTriple.isOSBinFormatCOFF()) {
       if (!isInt<21>(SignedValue))
         Ctx.reportError(Fixup.getLoc(), "fixup value out of range");
-      return AdrImmBits(Value & 0x1fffffULL);
+      return AdrImmBits(Value & maskTrailingOnes<uint64_t>(21));
     }
-    return AdrImmBits((Value & 0x1fffff000ULL) >> 12);
+    return AdrImmBits((Value >> 12) & maskTrailingOnes<uint64_t>(21));
   case AArch64::fixup_aarch64_ldr_pcrel_imm19:
   case AArch64::fixup_aarch64_pcrel_branch19:
     // Signed 19-bit immediate which gets multiplied by 4
     if (!isInt<21>(SignedValue))
       Ctx.reportError(Fixup.getLoc(), "fixup value out of range");
-    if (Value & 0x3)
+    if (!isAligned(Align{4}, Value))
       Ctx.reportError(Fixup.getLoc(), "fixup not sufficiently aligned");
     // Low two bits are not encoded.
-    return (Value >> 2) & 0x7ffff;
+    return (Value >> 2) & maskTrailingOnes<uint64_t>(19);
   case AArch64::fixup_aarch64_add_imm12:
   case AArch64::fixup_aarch64_ldst_imm12_scale1:
     if (TheTriple.isOSBinFormatCOFF() && !IsResolved)
-      Value &= 0xfff;
+      Value &= maskTrailingOnes<uint64_t>(12);
     // Unsigned 12-bit immediate
-    if (Value >= 0x1000)
+    if (!isUInt<12>(Value))
       Ctx.reportError(Fixup.getLoc(), "fixup value out of range");
     return Value;
   case AArch64::fixup_aarch64_ldst_imm12_scale2:
     if (TheTriple.isOSBinFormatCOFF() && !IsResolved)
-      Value &= 0xfff;
+      Value &= maskTrailingOnes<uint64_t>(12);
     // Unsigned 12-bit immediate which gets multiplied by 2
-    if (Value >= 0x2000)
+    if (!isUInt<13>(Value))
       Ctx.reportError(Fixup.getLoc(), "fixup value out of range");
-    if (Value & 0x1)
+    if (!isAligned(Align{2}, Value))
       Ctx.reportError(Fixup.getLoc(), "fixup must be 2-byte aligned");
     return Value >> 1;
   case AArch64::fixup_aarch64_ldst_imm12_scale4:
     if (TheTriple.isOSBinFormatCOFF() && !IsResolved)
-      Value &= 0xfff;
+      Value &= maskTrailingOnes<uint64_t>(12);
     // Unsigned 12-bit immediate which gets multiplied by 4
-    if (Value >= 0x4000)
+    if (!isUInt<14>(Value))
       Ctx.reportError(Fixup.getLoc(), "fixup value out of range");
-    if (Value & 0x3)
+    if (!isAligned(Align{4}, Value))
       Ctx.reportError(Fixup.getLoc(), "fixup must be 4-byte aligned");
     return Value >> 2;
   case AArch64::fixup_aarch64_ldst_imm12_scale8:
     if (TheTriple.isOSBinFormatCOFF() && !IsResolved)
-      Value &= 0xfff;
+      Value &= maskTrailingOnes<uint64_t>(12);
     // Unsigned 12-bit immediate which gets multiplied by 8
-    if (Value >= 0x8000)
+    if (!isUInt<15>(Value))
       Ctx.reportError(Fixup.getLoc(), "fixup value out of range");
-    if (Value & 0x7)
+    if (!isAligned(Align{8}, Value))
       Ctx.reportError(Fixup.getLoc(), "fixup must be 8-byte aligned");
     return Value >> 3;
   case AArch64::fixup_aarch64_ldst_imm12_scale16:
     if (TheTriple.isOSBinFormatCOFF() && !IsResolved)
-      Value &= 0xfff;
+      Value &= maskTrailingOnes<uint64_t>(12);
     // Unsigned 12-bit immediate which gets multiplied by 16
-    if (Value >= 0x10000)
+    if (!isUInt<16>(Value))
       Ctx.reportError(Fixup.getLoc(), "fixup value out of range");
-    if (Value & 0xf)
+    if (!isAligned(Align{16}, Value))
       Ctx.reportError(Fixup.getLoc(), "fixup must be 16-byte aligned");
     return Value >> 4;
   case AArch64::fixup_aarch64_movw: {
@@ -306,21 +307,21 @@
   }
   case AArch64::fixup_aarch64_pcrel_branch14:
     // Signed 16-bit immediate
-    if (SignedValue > 32767 || SignedValue < -32768)
+    if (!isInt<16>(SignedValue))
       Ctx.reportError(Fixup.getLoc(), "fixup value out of range");
     // Low two bits are not encoded (4-byte alignment assumed).
-    if (Value & 0x3)
+    if (Value != alignTo(Value, 4))
       Ctx.reportError(Fixup.getLoc(), "fixup not sufficiently aligned");
-    return (Value >> 2) & 0x3fff;
+    return (Value >> 2) & maskTrailingOnes<uint64_t>(14);
   case AArch64::fixup_aarch64_pcrel_branch26:
   case AArch64::fixup_aarch64_pcrel_call26:
     // Signed 28-bit immediate
-    if (SignedValue > 134217727 || SignedValue < -134217728)
+    if (!isInt<28>(SignedValue))
       Ctx.reportError(Fixup.getLoc(), "fixup value out of range");
     // Low two bits are not encoded (4-byte alignment assumed).
-    if (Value & 0x3)
+    if (Value != alignTo(Value, 4))
       Ctx.reportError(Fixup.getLoc(), "fixup not sufficiently aligned");
-    return (Value >> 2) & 0x3ffffff;
+    return (Value >> 2) & maskTrailingOnes<uint64_t>(26);
   case FK_Data_1:
   case FK_Data_2:
   case FK_Data_4: