dmgreen created this revision.
dmgreen added reviewers: efriedma, echristo, hfinkel, davide.
Previously the alignment on the newly created rtti string was not set,
meaning that DataLayout::getPreferredAlignment was free to overalign
it to 16 bytes. This causes unnecessary code bloat.
https://reviews.llvm.org/D51416
Files:
lib/CodeGen/ItaniumCXXABI.cpp
test/CodeGenCXX/vtable-align.cpp
test/CodeGenCXX/vtable-linkage.cpp
Index: test/CodeGenCXX/vtable-linkage.cpp
===================================================================
--- test/CodeGenCXX/vtable-linkage.cpp
+++ test/CodeGenCXX/vtable-linkage.cpp
@@ -99,7 +99,7 @@
// C has no key function, so its vtable should have weak_odr linkage
// and hidden visibility (rdar://problem/7523229).
// CHECK-DAG: @_ZTV1C = linkonce_odr unnamed_addr constant {{.*}}, comdat,
-// CHECK-DAG: @_ZTS1C = linkonce_odr constant {{.*}}, comdat{{$}}
+// CHECK-DAG: @_ZTS1C = linkonce_odr constant {{.*}}, comdat, align 1{{$}}
// CHECK-DAG: @_ZTI1C = linkonce_odr constant {{.*}}, comdat{{$}}
// CHECK-DAG: @_ZTT1C = linkonce_odr unnamed_addr constant {{.*}}, comdat{{$}}
@@ -120,26 +120,26 @@
// defined in this translation unit, so its vtable should have
// weak_odr linkage.
// CHECK-DAG: @_ZTV1EIsE = weak_odr unnamed_addr constant {{.*}}, comdat,
-// CHECK-DAG: @_ZTS1EIsE = weak_odr constant {{.*}}, comdat{{$}}
+// CHECK-DAG: @_ZTS1EIsE = weak_odr constant {{.*}}, comdat, align 1{{$}}
// CHECK-DAG: @_ZTI1EIsE = weak_odr constant {{.*}}, comdat{{$}}
// F<short> is an explicit template instantiation without a key
// function, so its vtable should have weak_odr linkage
// CHECK-DAG: @_ZTV1FIsE = weak_odr unnamed_addr constant {{.*}}, comdat,
-// CHECK-DAG: @_ZTS1FIsE = weak_odr constant {{.*}}, comdat{{$}}
+// CHECK-DAG: @_ZTS1FIsE = weak_odr constant {{.*}}, comdat, align 1{{$}}
// CHECK-DAG: @_ZTI1FIsE = weak_odr constant {{.*}}, comdat{{$}}
// E<long> is an implicit template instantiation with a key function
// defined in this translation unit, so its vtable should have
// linkonce_odr linkage.
// CHECK-DAG: @_ZTV1EIlE = linkonce_odr unnamed_addr constant {{.*}}, comdat,
-// CHECK-DAG: @_ZTS1EIlE = linkonce_odr constant {{.*}}, comdat{{$}}
+// CHECK-DAG: @_ZTS1EIlE = linkonce_odr constant {{.*}}, comdat, align 1{{$}}
// CHECK-DAG: @_ZTI1EIlE = linkonce_odr constant {{.*}}, comdat{{$}}
// F<long> is an implicit template instantiation with no key function,
// so its vtable should have linkonce_odr linkage.
// CHECK-DAG: @_ZTV1FIlE = linkonce_odr unnamed_addr constant {{.*}}, comdat,
-// CHECK-DAG: @_ZTS1FIlE = linkonce_odr constant {{.*}}, comdat{{$}}
+// CHECK-DAG: @_ZTS1FIlE = linkonce_odr constant {{.*}}, comdat, align 1{{$}}
// CHECK-DAG: @_ZTI1FIlE = linkonce_odr constant {{.*}}, comdat{{$}}
// F<int> is an explicit template instantiation declaration without a
@@ -171,7 +171,7 @@
// F<char> is an explicit specialization without a key function, so
// its vtable should have linkonce_odr linkage.
// CHECK-DAG: @_ZTV1FIcE = linkonce_odr unnamed_addr constant {{.*}}, comdat,
-// CHECK-DAG: @_ZTS1FIcE = linkonce_odr constant {{.*}}, comdat{{$}}
+// CHECK-DAG: @_ZTS1FIcE = linkonce_odr constant {{.*}}, comdat, align 1{{$}}
// CHECK-DAG: @_ZTI1FIcE = linkonce_odr constant {{.*}}, comdat{{$}}
// CHECK-DAG: @_ZTV1GIiE = linkonce_odr unnamed_addr constant {{.*}}, comdat,
Index: test/CodeGenCXX/vtable-align.cpp
===================================================================
--- test/CodeGenCXX/vtable-align.cpp
+++ test/CodeGenCXX/vtable-align.cpp
@@ -10,5 +10,6 @@
void A::f() {}
// CHECK-32: @_ZTV1A = unnamed_addr constant { [5 x i8*] } { [5 x i8*] [i8*
null, i8* bitcast ({ i8*, i8* }* @_ZTI1A to i8*), i8* bitcast (void
(%struct.A*)* @_ZN1A1fEv to i8*), i8* bitcast (void (%struct.A*)* @_ZN1A1gEv to
i8*), i8* bitcast (void (%struct.A*)* @_ZN1A1hEv to i8*)] }, align 4
-
+// CHECK-32: @_ZTS1A = constant [3 x i8] c"1A\00", align 1
// CHECK-64: @_ZTV1A = unnamed_addr constant { [5 x i8*] } { [5 x i8*] [i8*
null, i8* bitcast ({ i8*, i8* }* @_ZTI1A to i8*), i8* bitcast (void
(%struct.A*)* @_ZN1A1fEv to i8*), i8* bitcast (void (%struct.A*)* @_ZN1A1gEv to
i8*), i8* bitcast (void (%struct.A*)* @_ZN1A1hEv to i8*)] }, align 8
+// CHECK-64: @_ZTS1A = constant [3 x i8] c"1A\00", align 1
Index: lib/CodeGen/ItaniumCXXABI.cpp
===================================================================
--- lib/CodeGen/ItaniumCXXABI.cpp
+++ lib/CodeGen/ItaniumCXXABI.cpp
@@ -2730,6 +2730,7 @@
CGM.CreateOrReplaceCXXRuntimeVariable(Name, Init->getType(), Linkage);
GV->setInitializer(Init);
+ GV->setAlignment(1); // prevent over-aligning the string
return GV;
}
Index: test/CodeGenCXX/vtable-linkage.cpp
===================================================================
--- test/CodeGenCXX/vtable-linkage.cpp
+++ test/CodeGenCXX/vtable-linkage.cpp
@@ -99,7 +99,7 @@
// C has no key function, so its vtable should have weak_odr linkage
// and hidden visibility (rdar://problem/7523229).
// CHECK-DAG: @_ZTV1C = linkonce_odr unnamed_addr constant {{.*}}, comdat,
-// CHECK-DAG: @_ZTS1C = linkonce_odr constant {{.*}}, comdat{{$}}
+// CHECK-DAG: @_ZTS1C = linkonce_odr constant {{.*}}, comdat, align 1{{$}}
// CHECK-DAG: @_ZTI1C = linkonce_odr constant {{.*}}, comdat{{$}}
// CHECK-DAG: @_ZTT1C = linkonce_odr unnamed_addr constant {{.*}}, comdat{{$}}
@@ -120,26 +120,26 @@
// defined in this translation unit, so its vtable should have
// weak_odr linkage.
// CHECK-DAG: @_ZTV1EIsE = weak_odr unnamed_addr constant {{.*}}, comdat,
-// CHECK-DAG: @_ZTS1EIsE = weak_odr constant {{.*}}, comdat{{$}}
+// CHECK-DAG: @_ZTS1EIsE = weak_odr constant {{.*}}, comdat, align 1{{$}}
// CHECK-DAG: @_ZTI1EIsE = weak_odr constant {{.*}}, comdat{{$}}
// F<short> is an explicit template instantiation without a key
// function, so its vtable should have weak_odr linkage
// CHECK-DAG: @_ZTV1FIsE = weak_odr unnamed_addr constant {{.*}}, comdat,
-// CHECK-DAG: @_ZTS1FIsE = weak_odr constant {{.*}}, comdat{{$}}
+// CHECK-DAG: @_ZTS1FIsE = weak_odr constant {{.*}}, comdat, align 1{{$}}
// CHECK-DAG: @_ZTI1FIsE = weak_odr constant {{.*}}, comdat{{$}}
// E<long> is an implicit template instantiation with a key function
// defined in this translation unit, so its vtable should have
// linkonce_odr linkage.
// CHECK-DAG: @_ZTV1EIlE = linkonce_odr unnamed_addr constant {{.*}}, comdat,
-// CHECK-DAG: @_ZTS1EIlE = linkonce_odr constant {{.*}}, comdat{{$}}
+// CHECK-DAG: @_ZTS1EIlE = linkonce_odr constant {{.*}}, comdat, align 1{{$}}
// CHECK-DAG: @_ZTI1EIlE = linkonce_odr constant {{.*}}, comdat{{$}}
// F<long> is an implicit template instantiation with no key function,
// so its vtable should have linkonce_odr linkage.
// CHECK-DAG: @_ZTV1FIlE = linkonce_odr unnamed_addr constant {{.*}}, comdat,
-// CHECK-DAG: @_ZTS1FIlE = linkonce_odr constant {{.*}}, comdat{{$}}
+// CHECK-DAG: @_ZTS1FIlE = linkonce_odr constant {{.*}}, comdat, align 1{{$}}
// CHECK-DAG: @_ZTI1FIlE = linkonce_odr constant {{.*}}, comdat{{$}}
// F<int> is an explicit template instantiation declaration without a
@@ -171,7 +171,7 @@
// F<char> is an explicit specialization without a key function, so
// its vtable should have linkonce_odr linkage.
// CHECK-DAG: @_ZTV1FIcE = linkonce_odr unnamed_addr constant {{.*}}, comdat,
-// CHECK-DAG: @_ZTS1FIcE = linkonce_odr constant {{.*}}, comdat{{$}}
+// CHECK-DAG: @_ZTS1FIcE = linkonce_odr constant {{.*}}, comdat, align 1{{$}}
// CHECK-DAG: @_ZTI1FIcE = linkonce_odr constant {{.*}}, comdat{{$}}
// CHECK-DAG: @_ZTV1GIiE = linkonce_odr unnamed_addr constant {{.*}}, comdat,
Index: test/CodeGenCXX/vtable-align.cpp
===================================================================
--- test/CodeGenCXX/vtable-align.cpp
+++ test/CodeGenCXX/vtable-align.cpp
@@ -10,5 +10,6 @@
void A::f() {}
// CHECK-32: @_ZTV1A = unnamed_addr constant { [5 x i8*] } { [5 x i8*] [i8* null, i8* bitcast ({ i8*, i8* }* @_ZTI1A to i8*), i8* bitcast (void (%struct.A*)* @_ZN1A1fEv to i8*), i8* bitcast (void (%struct.A*)* @_ZN1A1gEv to i8*), i8* bitcast (void (%struct.A*)* @_ZN1A1hEv to i8*)] }, align 4
-
+// CHECK-32: @_ZTS1A = constant [3 x i8] c"1A\00", align 1
// CHECK-64: @_ZTV1A = unnamed_addr constant { [5 x i8*] } { [5 x i8*] [i8* null, i8* bitcast ({ i8*, i8* }* @_ZTI1A to i8*), i8* bitcast (void (%struct.A*)* @_ZN1A1fEv to i8*), i8* bitcast (void (%struct.A*)* @_ZN1A1gEv to i8*), i8* bitcast (void (%struct.A*)* @_ZN1A1hEv to i8*)] }, align 8
+// CHECK-64: @_ZTS1A = constant [3 x i8] c"1A\00", align 1
Index: lib/CodeGen/ItaniumCXXABI.cpp
===================================================================
--- lib/CodeGen/ItaniumCXXABI.cpp
+++ lib/CodeGen/ItaniumCXXABI.cpp
@@ -2730,6 +2730,7 @@
CGM.CreateOrReplaceCXXRuntimeVariable(Name, Init->getType(), Linkage);
GV->setInitializer(Init);
+ GV->setAlignment(1); // prevent over-aligning the string
return GV;
}
_______________________________________________
cfe-commits mailing list
cfe-commits@lists.llvm.org
http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
