[IR] Allow increasing the alignment of dso-local globals.

I think this is the actual important property; the previous visibility
check was an approximation.

Differential Revision: https://reviews.llvm.org/D53852



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@345790 91177308-0d34-0410-b5e6-96231b3b80d8

lib/IR/Globals.cpp

@@ -252,7 +252,7 @@ bool GlobalValue::canIncreaseAlignment() const {
   // Conservatively assume ELF if there's no parent pointer.
   bool isELF =
       (!Parent || Triple(Parent->getTargetTriple()).isOSBinFormatELF());
-  if (isELF && hasDefaultVisibility() && !hasLocalLinkage())
+  if (isELF && !isDSOLocal())
     return false;
 
   return true;

test/CodeGen/ARM/memfunc.ll

@@ -388,6 +388,7 @@ entry:
 @arr7 = external global [7 x i8], align 1
 @arr8 = internal global [128 x i8] undef
 @arr9 = weak_odr global [128 x i8] undef
+@arr10 = dso_local global [8 x i8] c"\01\02\03\04\05\06\07\08", align 1
 define void @f9(i8* %dest, i32 %n) "no-frame-pointer-elim"="true" {
 entry:
   call void @llvm.memcpy.p0i8.p0i8.i32(i8* %dest, i8* getelementptr inbounds ([7 x i8], [7 x i8]* @arr1, i32 0, i32 0), i32 %n, i1 false)
@@ -399,7 +400,7 @@ entry:
   call void @llvm.memcpy.p0i8.p0i8.i32(i8* %dest, i8* getelementptr inbounds ([7 x i8], [7 x i8]* @arr7, i32 0, i32 0), i32 %n, i1 false)
   call void @llvm.memcpy.p0i8.p0i8.i32(i8* %dest, i8* getelementptr inbounds ([128 x i8], [128 x i8]* @arr8, i32 0, i32 0), i32 %n, i1 false)
   call void @llvm.memcpy.p0i8.p0i8.i32(i8* %dest, i8* getelementptr inbounds ([128 x i8], [128 x i8]* @arr9, i32 0, i32 0), i32 %n, i1 false)
-
+  call void @llvm.memcpy.p0i8.p0i8.i32(i8* %dest, i8* getelementptr inbounds ([8 x i8], [8 x i8]* @arr10, i32 0, i32 0), i32 %n, i1 false)
   unreachable
 }
 
@@ -427,6 +428,11 @@ entry:
 ; CHECK-GNUEABI: arr8,128,16
 ; CHECK: .p2align 4
 ; CHECK: arr9:
+; CHECK-IOS: .p2align 3
+; CHECK-DARWIN: .p2align 2
+; CHECK-EABI: .p2align 2
+; CHECK-GNUEABI: .p2align 2
+; CHECK: arr10:
 
 ; CHECK-NOT: arr7: