Reapply [Hexagon] Use default attributes for intrinsics

The issue that caused the revert has been fixed in:
44bd807

-----

This switches Hexagon intrinsics to use the default attributes
(nosync, nofree, nocallback and willreturn). Especially willreturn
is needed to prevent optimization regressions in the future.

The only intrinsics I've excluded here are the load/store locked
intrinsics, which presumably aren't nosync.

Differential Revision: https://reviews.llvm.org/D137623

Author: nikic

llvm/include/llvm/IR/IntrinsicsHexagon.td

@@ -19,14 +19,14 @@ let TargetPrefix = "hexagon" in {
                               list<LLVMType> param_types,
                               list<IntrinsicProperty> properties>
     : ClangBuiltin<!strconcat("__builtin_", GCCIntSuffix)>,
-      Intrinsic<ret_types, param_types, properties>;
+      DefaultAttrsIntrinsic<ret_types, param_types, properties>;
 
   /// Hexagon_NonGCC_Intrinsic - Base class for bitcode convertible Hexagon
   /// intrinsics.
   class Hexagon_NonGCC_Intrinsic<list<LLVMType> ret_types,
                                  list<LLVMType> param_types,
                                  list<IntrinsicProperty> properties>
-    : Intrinsic<ret_types, param_types, properties>;
+    : DefaultAttrsIntrinsic<ret_types, param_types, properties>;
 }
 
 class Hexagon_mem_memmemsi_Intrinsic<string GCCIntSuffix>
@@ -129,19 +129,27 @@ def llvm_ptr32_ty : LLVMPointerType<llvm_i32_ty>;
 def llvm_ptr64_ty : LLVMPointerType<llvm_i64_ty>;
 
 // Mark locked loads as read/write to prevent any accidental reordering.
-def int_hexagon_L2_loadw_locked :
-Hexagon_Intrinsic<"HEXAGON_L2_loadw_locked", [llvm_i32_ty], [llvm_ptr32_ty],
-      [IntrArgMemOnly, NoCapture<ArgIndex<0>>]>;
-def int_hexagon_L4_loadd_locked :
-Hexagon_Intrinsic<"HEXAGON_L4_loadd_locked", [llvm_i64_ty], [llvm_ptr64_ty],
-      [IntrArgMemOnly, NoCapture<ArgIndex<0>>]>;
-
-def int_hexagon_S2_storew_locked :
-Hexagon_Intrinsic<"HEXAGON_S2_storew_locked", [llvm_i32_ty],
-      [llvm_ptr32_ty, llvm_i32_ty], [IntrArgMemOnly, NoCapture<ArgIndex<0>>]>;
-def int_hexagon_S4_stored_locked :
-Hexagon_Intrinsic<"HEXAGON_S4_stored_locked", [llvm_i32_ty],
-      [llvm_ptr64_ty, llvm_i64_ty], [IntrArgMemOnly, NoCapture<ArgIndex<0>>]>;
+// These don't use Hexagon_Intrinsic, because they are not nosync, and as such
+// cannot use default attributes.
+let TargetPrefix = "hexagon" in {
+  def int_hexagon_L2_loadw_locked :
+  ClangBuiltin<"__builtin_HEXAGON_L2_loadw_locked">,
+  Intrinsic<[llvm_i32_ty], [llvm_ptr32_ty],
+        [IntrArgMemOnly, NoCapture<ArgIndex<0>>]>;
+  def int_hexagon_L4_loadd_locked :
+  ClangBuiltin<"__builtin__HEXAGON_L4_loadd_locked">,
+  Intrinsic<[llvm_i64_ty], [llvm_ptr64_ty],
+        [IntrArgMemOnly, NoCapture<ArgIndex<0>>]>;
+
+  def int_hexagon_S2_storew_locked :
+  ClangBuiltin<"__builtin_HEXAGON_S2_storew_locked">,
+  Intrinsic<[llvm_i32_ty],
+        [llvm_ptr32_ty, llvm_i32_ty], [IntrArgMemOnly, NoCapture<ArgIndex<0>>]>;
+  def int_hexagon_S4_stored_locked :
+  ClangBuiltin<"__builtin_HEXAGON_S4_stored_locked">,
+  Intrinsic<[llvm_i32_ty],
+        [llvm_ptr64_ty, llvm_i64_ty], [IntrArgMemOnly, NoCapture<ArgIndex<0>>]>;
+}
 
 def int_hexagon_vmemcpy : Hexagon_Intrinsic<"hexagon_vmemcpy",
     [], [llvm_ptr_ty, llvm_ptr_ty, llvm_i32_ty],

llvm/test/CodeGen/Hexagon/circ-load-isel.ll

@@ -10,7 +10,7 @@ define void @circ2() #0 {
 entry:
   store i32 0, i32* @l, align 4
   %0 = tail call i8* @llvm.hexagon.circ.ldw(i8* undef, i8* undef, i32 150995968, i32 4)
-  unreachable
+  ret void
 }
 
 declare i8* @llvm.hexagon.circ.ldw(i8*, i8*, i32, i32) #1

llvm/test/CodeGen/Hexagon/select-vector-pred.ll

@@ -21,8 +21,8 @@ entry:
   %3 = tail call <128 x i1> @llvm.hexagon.V6.pred.scalar2.128B(i32 %.sroa.speculated.i13.i.i) #3
   %4 = tail call <128 x i1> @llvm.hexagon.V6.pred.and.128B(<128 x i1> undef, <128 x i1> %3) #3
   tail call void @llvm.hexagon.V6.vS32b.qpred.ai.128B(<128 x i1> %4, i8* nonnull undef, <32 x i32> undef) #3
-  unreachable
-                  }
+  ret void
+}
 
 attributes #0 = { nounwind writeonly }
 attributes #1 = { nounwind readnone }