[ubsan] Don't check alignment if the alignment is 1

If a pointer is 1-byte aligned, there's no use in checking its
alignment. Somewhat surprisingly, ubsan can spend a significant amount
of time doing just that!

This loosely depends on D30283.

Testing: check-clang, check-ubsan, and a stage2 ubsan build.

Differential Revision: https://reviews.llvm.org/D30285

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@300371 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 18 insertions, 2 deletions

diff --git a/test/CodeGenCXX/ubsan-type-checks.cpp b/test/CodeGenCXX/ubsan-type-checks.cpp
index 150b2fc40c..786d049dfb 100644
--- a/test/CodeGenCXX/ubsan-type-checks.cpp
+++ b/test/CodeGenCXX/ubsan-type-checks.cpp
@@ -5,8 +5,7 @@
 struct A {
   // COMMON-LABEL: define linkonce_odr void @_ZN1A10do_nothingEv
   void do_nothing() {
-    // ALIGN: ptrtoint %struct.A* %{{.*}} to i64, !nosanitize
-    // ALIGN: and i64 %{{.*}}, 0, !nosanitize
+    // ALIGN-NOT: ptrtoint %struct.A* %{{.*}} to i64, !nosanitize
  
     // NULL: icmp ne %struct.A* %{{.*}}, null, !nosanitize
  
@@ -14,7 +13,24 @@ struct A {
   }
 };
 
+struct B {
+  int x;
+
+  // COMMON-LABEL: define linkonce_odr void @_ZN1B10do_nothingEv
+  void do_nothing() {
+    // ALIGN: ptrtoint %struct.B* %{{.*}} to i64, !nosanitize
+    // ALIGN: and i64 %{{.*}}, 3, !nosanitize
+
+    // NULL: icmp ne %struct.B* %{{.*}}, null, !nosanitize
+
+    // OBJSIZE-NOT: call i64 @llvm.objectsize
+  }
+};
+
 void force_irgen() {
   A a;
   a.do_nothing();
+
+  B b;
+  b.do_nothing();
 }