[opt] Remove trivially dead instructions in mandatory combine.

Failing tests that do not test mandatory combine are updated to skip
the mandatory combine pass. Othere tests are updated to use otherwise
removed values.

Author: zoecarver

lib/SILOptimizer/Mandatory/MandatoryCombine.cpp

@@ -156,6 +156,7 @@ void MandatoryCombiner::addReachableCodeToWorklist(SILFunction &function) {
       ++iterator;
 
       if (isInstructionTriviallyDead(instruction)) {
+        instModCallbacks.deleteInst(instruction);
         continue;
       }
 

test/AutoDiff/SIL/differentiability_witness_function_inst.sil

@@ -13,7 +13,7 @@
 
 // IRGen test.
 
-// RUN: %target-swift-frontend -emit-ir %s | %FileCheck %s --check-prefix=IRGEN --check-prefix %target-cpu
+// RUN: %target-swift-frontend -emit-ir -Xllvm -sil-disable-pass=MandatoryCombine %s | %FileCheck %s --check-prefix=IRGEN --check-prefix %target-cpu
 // NOTE: `%target-cpu`-specific FileCheck lines exist because lowered function types in LLVM IR differ between architectures.
 
 // NOTE(SR-12090): `shell` is required only to run `sed` as a SR-12090 workaround.

test/ClangImporter/macro_literals.swift

@@ -1,4 +1,4 @@
-// RUN: %target-swift-frontend(mock-sdk: %clang-importer-sdk) -Xllvm -sil-print-debuginfo -emit-sil %s | %FileCheck %s
+// RUN: %target-swift-frontend(mock-sdk: %clang-importer-sdk) -Xllvm -sil-print-debuginfo -Xllvm -sil-disable-pass=MandatoryCombine -emit-sil %s | %FileCheck %s
 
 import macros
 

test/Constraints/keypath_dynamic_member_lookup.swift

@@ -39,17 +39,20 @@ var bottomRight = Point(x: 10, y: 10)
 var lens = Lens(Rectangle(topLeft: topLeft,
                           bottomRight: bottomRight))
 
+// A dummy user of variables.
+func user<T>(_ _: T) {}
+
 // CHECK: function_ref @$s29keypath_dynamic_member_lookup4LensV0B6MemberACyqd__Gs15WritableKeyPathCyxqd__G_tcluig
 // CHECK-NEXT: apply %45<Rectangle, Point>({{.*}})
 // CHECK: function_ref @$s29keypath_dynamic_member_lookup4LensV0B6MemberACyqd__Gs7KeyPathCyxqd__G_tcluig
 // CHECK-NEXT: apply %54<Point, Int>({{.*}})
-_ = lens.topLeft.x
+user(lens.topLeft.x)
 
-// CHECK: function_ref @$s29keypath_dynamic_member_lookup4LensV0B6MemberACyqd__Gs15WritableKeyPathCyxqd__G_tcluig
-// CHECK-NEXT: apply %69<Rectangle, Point>({{.*}})
-// CHECK: function_ref @$s29keypath_dynamic_member_lookup4LensV0B6MemberACyqd__Gs15WritableKeyPathCyxqd__G_tcluig
-// CHECK-NEXT: apply %76<Point, Int>({{.*}})
-_ = lens.topLeft.y
+// CHECK: [[LOOKUP_REF1:%.*]] = function_ref @$s29keypath_dynamic_member_lookup4LensV0B6MemberACyqd__Gs15WritableKeyPathCyxqd__G_tcluig
+// CHECK-NEXT: apply [[LOOKUP_REF1]]<Rectangle, Point>({{.*}})
+// CHECK: [[LOOKUP_REF2:%.*]] = function_ref @$s29keypath_dynamic_member_lookup4LensV0B6MemberACyqd__Gs15WritableKeyPathCyxqd__G_tcluig
+// CHECK-NEXT: apply [[LOOKUP_REF2]]<Point, Int>({{.*}})
+user(lens.topLeft.y)
 
 lens.topLeft = Lens(Point(x: 1, y: 2)) // Ok
 lens.bottomRight.y = Lens(12)          // Ok
@@ -238,7 +241,7 @@ func test_recursive_dynamic_lookup(_ lens: Lens<Lens<Point>>) {
   // CHECK: [[FIRST_OBJ:%.*]] = struct_extract {{.*}} : $Lens<Lens<Point>>, #Lens.obj
   // CHECK-NEXT: [[SECOND_OBJ:%.*]] = struct_extract [[FIRST_OBJ]] : $Lens<Point>, #Lens.obj
   // CHECK-NEXT: struct_extract [[SECOND_OBJ]] : $Point, #Point.y
-  _ = lens.obj.obj.y
+  user(lens.obj.obj.y)
   // CHECK: keypath $KeyPath<Point, Int>, (root $Point; stored_property #Point.x : $Int)
   // CHECK-NEXT: keypath $KeyPath<Lens<Point>, Lens<Int>>, (root $Lens<Point>; gettable_property $Lens<Int>,  id @$s29keypath_dynamic_member_lookup4LensV0B6MemberACyqd__Gs7KeyPathCyxqd__G_tcluig : {{.*}})
   // CHECK-NEXT: keypath $KeyPath<Lens<Lens<Point>>, Lens<Lens<Int>>>, (root $Lens<Lens<Point>>; gettable_property $Lens<Lens<Int>>,  id @$s29keypath_dynamic_member_lookup4LensV0B6MemberACyqd__Gs7KeyPathCyxqd__G_tcluig : {{.*}})

test/IRGen/access_markers.sil

@@ -33,6 +33,9 @@ bb0(%0 : $A):
   // CHECK-NEXT: getelementptr inbounds %Ts5Int64V, %Ts5Int64V* [[PROPERTY]], i32 0, i32 0
   // CHECK-NEXT: load i64, i64*
   %4 = load %3 : $*Int64
+  // Use %4 so it's not optimized away.
+  // CHECK-NEXT: store
+  store %4 to undef : $*Int64
 
   // CHECK-NEXT: call void @swift_endAccess([[BUFFER]]* [[SCRATCH1]])
   // CHECK-NEXT: [[T0:%.*]] = bitcast [[BUFFER]]* [[SCRATCH1]] to i8*
@@ -48,6 +51,9 @@ bb0(%0 : $A):
   // CHECK-NEXT: getelementptr inbounds %Ts5Int64V, %Ts5Int64V* [[PROPERTY]], i32 0, i32 0
   // CHECK-NEXT: load i64, i64*
   %7 = load %6 : $*Int64
+  // Use %7 so it's not optimized away.
+  // CHECK-NEXT: store
+  store %7 to undef : $*Int64
 
   // CHECK-NEXT: call void @swift_endAccess([[BUFFER]]* [[SCRATCH2]])
   // CHECK-NEXT: [[T0:%.*]] = bitcast [[BUFFER]]* [[SCRATCH2]] to i8*

test/IRGen/dynamic_self.sil

@@ -1,4 +1,4 @@
-// RUN: %target-swift-frontend -emit-ir %s | %FileCheck %s
+// RUN: %target-swift-frontend -Xllvm -sil-disable-pass=MandatoryCombine -emit-ir %s | %FileCheck %s
 
 // REQUIRES: CPU=i386 || CPU=x86_64
 

test/IRGen/enum.sil

@@ -254,6 +254,8 @@ entry(%u : $*Singleton):
   switch_enum_addr %u : $*Singleton, case #Singleton.value!enumelt: dest
 dest:
   %u2 = unchecked_take_enum_data_addr %u : $*Singleton, #Singleton.value!enumelt
+  // Use u2 so it's not optimized away.
+  copy_addr %u2 to undef : $*(Builtin.Int64, Builtin.Int64)
   %x = tuple ()
   return %x : $()
 }
@@ -979,6 +981,7 @@ entry(%u : $*SinglePayloadSpareBit):
 // CHECK-64:   [[DATA_ADDR:%.*]] = bitcast %T4enum21SinglePayloadSpareBitO* %0 to i63*
 x_dest:
   %u2 = unchecked_take_enum_data_addr %u : $*SinglePayloadSpareBit, #SinglePayloadSpareBit.x!enumelt
+  copy_addr %u2 to undef : $*Builtin.Int63
   %a = function_ref @a : $@convention(thin) () -> ()
   apply %a() : $@convention(thin) () -> ()
   br end
@@ -1489,14 +1492,20 @@ entry(%u : $*MultiPayloadNoSpareBits):
 
 x_dest:
   %x = unchecked_take_enum_data_addr %u : $*MultiPayloadNoSpareBits, #MultiPayloadNoSpareBits.x!enumelt
+  // Dummy use of %x so it's not optimized away.
+  copy_addr %x to undef : $*Builtin.Int64
   br end
 
 y_dest:
   %y = unchecked_take_enum_data_addr %u : $*MultiPayloadNoSpareBits, #MultiPayloadNoSpareBits.y!enumelt
+  // Dummy use of %y so it's not optimized away.
+  copy_addr %y to undef : $*Builtin.Int32
   br end
 
 z_dest:
   %z = unchecked_take_enum_data_addr %u : $*MultiPayloadNoSpareBits, #MultiPayloadNoSpareBits.z!enumelt
+  // Dummy use of %z so it's not optimized away.
+  copy_addr %z to undef : $*Builtin.Int63
   br end
 
 a_dest:
@@ -1742,14 +1751,20 @@ entry(%u : $*MultiPayloadOneSpareBit):
 
 x_dest:
   %x = unchecked_take_enum_data_addr %u : $*MultiPayloadOneSpareBit, #MultiPayloadOneSpareBit.x!enumelt
+  // Dummy use of %x so it's not optimized away.
+  copy_addr %x to undef : $*Builtin.Int62
   br end
 
 y_dest:
   %y = unchecked_take_enum_data_addr %u : $*MultiPayloadOneSpareBit, #MultiPayloadOneSpareBit.y!enumelt
+  // Dummy use of %y so it's not optimized away.
+  copy_addr %y to undef : $*Builtin.Int63
   br end
 
 z_dest:
   %z = unchecked_take_enum_data_addr %u : $*MultiPayloadOneSpareBit, #MultiPayloadOneSpareBit.z!enumelt
+  // Dummy use of %z so it's not optimized away.
+  copy_addr %z to undef : $*Builtin.Int61
   br end
 
 a_dest:
@@ -2441,6 +2456,8 @@ entry(%0 : $*DynamicSingleton<T>):
 
 dest:
   %1 = unchecked_take_enum_data_addr %0 : $*DynamicSingleton<T>, #DynamicSingleton.value!enumelt
+  // Dummy use of %1 so it's not optimized away.
+  copy_addr %1 to undef : $*T
   %v = tuple ()
   return %v : $()
 }
@@ -2521,6 +2538,8 @@ entry(%x : $Int32):
   // CHECK-64: [[INT_SHR:%.*]] = lshr i64 [[INT_SHL]], 32
   // CHECK-64: [[INT:%.*]] = trunc i64 [[INT_SHR]] to i32
   %e = unchecked_enum_data %d : $Optional<(Optional<()>, Int32)>, #Optional.some!enumelt
+  // Use %e so it's not optimized away.
+  store %e to undef : $*(Optional<()>, Int32)
   return %d : $Optional<(Optional<()>, Int32)>
 }
 

test/IRGen/enum_dynamic_multi_payload.sil

@@ -285,8 +285,12 @@ sil @dynamic_project : $@convention(thin) <T> () -> @out EitherOr<T, Builtin.Int
 entry(%e : $*EitherOr<T, Builtin.Int64>):
   // CHECK: bitcast [[EITHER_OR]]* %0 to %swift.opaque*
   %l = unchecked_take_enum_data_addr %e : $*EitherOr<T, Builtin.Int64>, #EitherOr.Left!enumelt
+  // Dummy use of %l so that it's not optimized away.
+  copy_addr %l to undef : $*T
   // CHECK: bitcast [[EITHER_OR]]* %0 to i64*
   %r = unchecked_take_enum_data_addr %e : $*EitherOr<T, Builtin.Int64>, #EitherOr.Right!enumelt
+  // Dummy use of %r so that it's not optimized away.
+  copy_addr %r to undef : $*Builtin.Int64
 
   return undef : $()
 }

test/IRGen/enum_future.sil

@@ -258,6 +258,7 @@ entry(%u : $*Singleton):
   switch_enum_addr %u : $*Singleton, case #Singleton.value!enumelt: dest
 dest:
   %u2 = unchecked_take_enum_data_addr %u : $*Singleton, #Singleton.value!enumelt
+  copy_addr %u2 to undef : $*(Builtin.Int64, Builtin.Int64)
   %x = tuple ()
   return %x : $()
 }
@@ -983,6 +984,7 @@ entry(%u : $*SinglePayloadSpareBit):
 // CHECK-64:   [[DATA_ADDR:%.*]] = bitcast %T11enum_future21SinglePayloadSpareBitO* %0 to i63*
 x_dest:
   %u2 = unchecked_take_enum_data_addr %u : $*SinglePayloadSpareBit, #SinglePayloadSpareBit.x!enumelt
+  copy_addr %u2 to undef : $*Builtin.Int63
   %a = function_ref @a : $@convention(thin) () -> ()
   apply %a() : $@convention(thin) () -> ()
   br end
@@ -1493,14 +1495,20 @@ entry(%u : $*MultiPayloadNoSpareBits):
 
 x_dest:
   %x = unchecked_take_enum_data_addr %u : $*MultiPayloadNoSpareBits, #MultiPayloadNoSpareBits.x!enumelt
+  // Use %x so it's not optimized away.
+  copy_addr %x to undef : $*Builtin.Int64
   br end
 
 y_dest:
   %y = unchecked_take_enum_data_addr %u : $*MultiPayloadNoSpareBits, #MultiPayloadNoSpareBits.y!enumelt
+  // Use %y so it's not optimized away.
+  copy_addr %y to undef : $*Builtin.Int32
   br end
 
 z_dest:
   %z = unchecked_take_enum_data_addr %u : $*MultiPayloadNoSpareBits, #MultiPayloadNoSpareBits.z!enumelt
+  // Use %z so it's not optimized away.
+  copy_addr %z to undef : $*Builtin.Int63
   br end
 
 a_dest:
@@ -1746,14 +1754,20 @@ entry(%u : $*MultiPayloadOneSpareBit):
 
 x_dest:
   %x = unchecked_take_enum_data_addr %u : $*MultiPayloadOneSpareBit, #MultiPayloadOneSpareBit.x!enumelt
+  // Use %x so it's not optimized away.
+  copy_addr %x to undef : $*Builtin.Int62
   br end
 
 y_dest:
   %y = unchecked_take_enum_data_addr %u : $*MultiPayloadOneSpareBit, #MultiPayloadOneSpareBit.y!enumelt
+  // Use %y so it's not optimized away.
+  copy_addr %y to undef : $*Builtin.Int63
   br end
 
 z_dest:
   %z = unchecked_take_enum_data_addr %u : $*MultiPayloadOneSpareBit, #MultiPayloadOneSpareBit.z!enumelt
+  // Use %z so it's not optimized away.
+  copy_addr %z to undef : $*Builtin.Int61
   br end
 
 a_dest:
@@ -2445,6 +2459,8 @@ entry(%0 : $*DynamicSingleton<T>):
 
 dest:
   %1 = unchecked_take_enum_data_addr %0 : $*DynamicSingleton<T>, #DynamicSingleton.value!enumelt
+  // Use %1 so it's not optimized away.
+  copy_addr %1 to undef : $*T
   %v = tuple ()
   return %v : $()
 }
@@ -2525,6 +2541,8 @@ entry(%x : $Int32):
   // CHECK-64: [[INT_SHR:%.*]] = lshr i64 [[INT_SHL]], 32
   // CHECK-64: [[INT:%.*]] = trunc i64 [[INT_SHR]] to i32
   %e = unchecked_enum_data %d : $Optional<(Optional<()>, Int32)>, #Optional.some!enumelt
+  // Use %e so it's not optimized away.
+  store %e to undef : $*(Optional<()>, Int32)
   return %d : $Optional<(Optional<()>, Int32)>
 }
 

test/IRGen/existentials.sil

@@ -73,12 +73,16 @@ entry(%w : $*@sil_weak CP?, %a : $CP?):
   // CHECK: [[SRC_WITNESS_ADDR:%.*]] = getelementptr inbounds { %swift.weak, i8** }, { %swift.weak, i8** }* %0, i32 0, i32 1
   // CHECK: [[DEST_WITNESS:%.*]] = load i8**, i8*** [[SRC_WITNESS_ADDR]]
   %b = load_weak [take] %w : $*@sil_weak CP?
+  // Use %b so it isn't removed.
+  store_weak %b to undef : $*@sil_weak CP?
 
   // CHECK: [[SRC_REF_ADDR:%.*]] = getelementptr inbounds { %swift.weak, i8** }, { %swift.weak, i8** }* %0, i32 0, i32 0
   // CHECK: [[DEST_REF:%.*]] = call %swift.refcounted* @swift_weakLoadStrong(%swift.weak* [[SRC_REF_ADDR]])
   // CHECK: [[SRC_WITNESS_ADDR:%.*]] = getelementptr inbounds { %swift.weak, i8** }, { %swift.weak, i8** }* %0, i32 0, i32 1
   // CHECK: [[DEST_WITNESS:%.*]] = load i8**, i8*** [[SRC_WITNESS_ADDR]]
   %c = load_weak        %w : $*@sil_weak CP?
+  // Use %c so it isn't removed.
+  store_weak %c to undef : $*@sil_weak CP?
 
   // CHECK: call { %swift.weak, i8** }* @"$s12existentials2CP_pSgXwWOb"({ %swift.weak, i8** }* %0, { %swift.weak, i8** }* [[V]])
   copy_addr [take] %w to [initialization] %v : $*@sil_weak CP?