Allow constant folding IntToPtr builtin (make it isValidInStaticInitializerOfGlobal)

Author: kubamracek

SwiftCompilerSources/Sources/SIL/GlobalVariable.swift

@@ -82,6 +82,8 @@ extension Instruction {
         return type.isBuiltinInteger || type.isBuiltinFloat
       case .PtrToInt:
         return bi.operands[0].value is StringLiteralInst
+      case .IntToPtr:
+        return bi.operands[0].value is IntegerLiteralInst
       case .StringObjectOr:
         // The first operand can be a string literal (i.e. a pointer), but the
         // second operand must be a constant. This enables creating a

lib/IRGen/GenConstant.cpp

@@ -302,6 +302,10 @@ Explosion irgen::emitConstantValue(IRGenModule &IGM, SILValue operand,
         auto *ptr = emitConstantValue(IGM, args[0]).claimNextConstant();
         return llvm::ConstantExpr::getPtrToInt(ptr, IGM.IntPtrTy);
       }
+      case BuiltinValueKind::IntToPtr: {
+        auto *num = emitConstantValue(IGM, args[0]).claimNextConstant();
+        return llvm::ConstantExpr::getIntToPtr(num, IGM.Int8PtrTy);
+      }
       case BuiltinValueKind::ZExtOrBitCast: {
         auto *val = emitConstantValue(IGM, args[0]).claimNextConstant();
         return llvm::ConstantExpr::getZExtOrBitCast(val,

test/SILOptimizer/init_static_globals.sil

@@ -66,6 +66,14 @@ sil_global private @g1_token : $Builtin.Word
 sil_global [let] @g2 : $Int32
 sil_global private @g2_token : $Builtin.Word
 
+// CHECK-LABEL: sil_global [let] @g3 : $Optional<UnsafeMutablePointer<Int>>
+sil_global [let] @g3 : $Optional<UnsafeMutablePointer<Int>>
+sil_global private @g3_token : $Builtin.Word
+
+// CHECK-LABEL: sil_global [let] @g4 : $Optional<UnsafeMutablePointer<Int>>
+sil_global [let] @g4 : $Optional<UnsafeMutablePointer<Int>>
+sil_global private @g4_token : $Builtin.Word
+
 
 // CHECK-LABEL: sil [global_init_once_fn] [ossa] @globalinit_trivialglobal_func :
 // CHECK-NOT:     alloc_global
@@ -151,3 +159,33 @@ bb0:
   return %6 : $()
 }
 
+// CHECK-LABEL: sil [global_init_once_fn] [ossa] @globalinit_enum :
+// CHECK-NOT:     alloc_global
+// CHECK-NOT:     store
+// CHECK:       } // end sil function 'globalinit_enum'
+sil [global_init_once_fn] [ossa] @globalinit_enum : $@convention(c) () -> () {
+bb0:
+  alloc_global @g3
+  %2 = global_addr @g3 : $*Optional<UnsafeMutablePointer<Int>>
+  %3 = enum $Optional<UnsafeMutablePointer<Int>>, #Optional.none!enumelt
+  store %3 to [trivial] %2 : $*Optional<UnsafeMutablePointer<Int>>
+  %5 = tuple ()
+  return %5 : $()
+}
+
+// CHECK-LABEL: sil [global_init_once_fn] [ossa] @globalinit_enum_inttoptr :
+// CHECK-NOT:     alloc_global
+// CHECK-NOT:     store
+// CHECK:       } // end sil function 'globalinit_enum_inttoptr'
+sil [global_init_once_fn] [ossa] @globalinit_enum_inttoptr : $@convention(c) () -> () {
+bb0:
+  alloc_global @g4
+  %2 = global_addr @g4 : $*Optional<UnsafeMutablePointer<Int>>
+  %4 = integer_literal $Builtin.Word, 1111638594
+  %5 = builtin "inttoptr_Word"(%4 : $Builtin.Word) : $Builtin.RawPointer
+  %6 = struct $UnsafeMutablePointer<Int> (%5 : $Builtin.RawPointer)
+  %7 = enum $Optional<UnsafeMutablePointer<Int>>, #Optional.some!enumelt, %6 : $UnsafeMutablePointer<Int>
+  store %7 to [trivial] %2 : $*Optional<UnsafeMutablePointer<Int>>
+  %10 = tuple ()
+  return %10 : $()
+}