Add tests

Author: zoecarver

lib/SILOptimizer/IPO/GlobalOpt.cpp

@@ -1088,6 +1088,7 @@ bool SILGlobalOpt::run() {
     optimizeGlobalAccess(Init.first, Init.second);
   }
 
+  SmallVector<SILGlobalVariable *, 8> addrGlobals;
   for (auto &addrPair : GlobalAddrMap) {
     // Don't optimize functions that are marked with the opt.never attribute.
     bool shouldOptimize = true;
@@ -1100,20 +1101,30 @@ bool SILGlobalOpt::run() {
     if (!shouldOptimize)
       continue;
 
-    HasChanged |= tryRemoveGlobalAddr(addrPair.first);
+    addrGlobals.push_back(addrPair.first);
+  }
+  
+  for (auto *global : addrGlobals) {
+    HasChanged |= tryRemoveGlobalAddr(global);
   }
 
+  SmallVector<std::pair<SILGlobalVariable *, AllocGlobalInst *>, 12> globalAllocPairs;
   for (auto &alloc : AllocGlobalStore) {
     if (!alloc.second->getFunction()->shouldOptimize())
       continue;
-    HasChanged |= tryRemoveGlobalAlloc(alloc.first, alloc.second);
+    globalAllocPairs.push_back(std::make_pair(alloc.first, alloc.second));
+  }
+  
+  for (auto &allocPair : globalAllocPairs) {
+    HasChanged |= tryRemoveGlobalAlloc(allocPair.first, allocPair.second);
   }
 
   // Copy the globals so we don't get issues with modifying while iterating.
   SmallVector<SILGlobalVariable *, 12> globals;
   for (auto &global : Module->getSILGlobals()) {
     globals.push_back(&global);
   }
+  
   for (auto *global : globals) {
     HasChanged |= tryRemoveUnusedGlobal(global);
   }

test/SILOptimizer/remove_unused_global_vars.swift

@@ -1,4 +1,14 @@
-// RUN: %target-swift-frontend -O -emit-sil %s | %FileCheck %s
+// RUN: %target-swift-frontend -primary-file %s -O -module-name=test -emit-sil | %FileCheck %s
+
+@_optimize(none) public func make_test(_ x: Int) -> Int {
+  return x
+}
+
+struct Foo {
+  let x : Int
+  let y : Int
+  func both() -> Int { x + y }
+}
 
 // CHECK-NOT: sil_global private [let] {{.*}}unused1{{.*}}
 private let unused1 = 0
@@ -9,6 +19,14 @@ private let used1 = 0
 // CHECK: sil_global private @${{.*}}used2{{.*}} : $Int
 private var used2 = 0
 
+// non-constant / non-trivial values
+// CHECK-NOT: sil_global private {{.*}}unused7{{.*}}
+private let unused7 = make_test(42)
+// CHECK-NOT: sil_global private {{.*}}unused8{{.*}}
+private let unused8 = Foo(x: 1, y: 1)
+// CHECK-NOT: sil_global private {{.*}}unused9{{.*}}
+private let unused9 = Foo(x: 1, y: 1).both()
+
 // CHECK: sil_global [let] @${{.*}}unused3{{.*}} : $Int
 public let unused3 = 0
 // CHECK: sil_global @${{.*}}unused4{{.*}} : $Int

test/SILOptimizer/remove_unused_global_vars_wmo.swift

@@ -0,0 +1,27 @@
+// RUN: %target-swift-frontend -O -wmo -emit-sil %s | %FileCheck %s
+
+// CHECK-NOT: sil_global private [let] {{.*}}unused1{{.*}}
+private let unused1 = 0
+// CHECK-NOT: sil_global private {{.*}}unused2{{.*}}
+private var unused2 = 42
+// CHECK: sil_global private [let] @${{.*}}used1{{.*}} : $Int
+private let used1 = 0
+// CHECK: sil_global private @${{.*}}used2{{.*}} : $Int
+private var used2 = 0
+
+// CHECK: sil_global [let] @${{.*}}unused3{{.*}} : $Int
+public let unused3 = 0
+// CHECK: sil_global @${{.*}}unused4{{.*}} : $Int
+public var unused4 = 0
+
+// CHECK-NOT: sil_global hidden [let] @${{.*}}unused5{{.*}} : $Int
+let unused5 = 0
+// CHECK-NOT: sil_global hidden @${{.*}}unused6{{.*}} : $Int
+var unused6 = 0
+
+// CHECK-LABEL: sil [Onone] @${{.*}}test{{.*}}
+@_optimize(none) public func test(x: Int) -> Int {
+  // CHECK: %{{[0-9]+}} = global_addr @${{.*}}used2{{.*}}
+  // CHECK: %{{[0-9]+}} = global_addr @${{.*}}used1{{.*}}
+  return used1 + used2 + x
+}