[cfe-commits] r90820 - in /cfe/trunk: lib/CodeGen/CGRecordLayoutBuilder.cpp test/CodeGenCXX/class-layout.cpp
Anders Carlsson
andersca at mac.com
Mon Dec 7 17:24:24 PST 2009
Author: andersca
Date: Mon Dec 7 19:24:23 2009
New Revision: 90820
URL: http://llvm.org/viewvc/llvm-project?rev=90820&view=rev
Log:
No need to add tail padding if the resulting LLVM struct type will have the same size as the final record size.
Modified:
cfe/trunk/lib/CodeGen/CGRecordLayoutBuilder.cpp
cfe/trunk/test/CodeGenCXX/class-layout.cpp
Modified: cfe/trunk/lib/CodeGen/CGRecordLayoutBuilder.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGRecordLayoutBuilder.cpp?rev=90820&r1=90819&r2=90820&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGRecordLayoutBuilder.cpp (original)
+++ cfe/trunk/lib/CodeGen/CGRecordLayoutBuilder.cpp Mon Dec 7 19:24:23 2009
@@ -88,8 +88,6 @@
AppendBytes(NumBytesToAppend);
- AlignmentAsLLVMStruct = std::max(AlignmentAsLLVMStruct, getTypeAlignment(Ty));
-
BitsAvailableInLastField =
NextFieldOffsetInBytes * 8 - (FieldOffset + FieldSize);
}
@@ -247,6 +245,14 @@
uint64_t RecordSizeInBytes = RecordSize / 8;
assert(NextFieldOffsetInBytes <= RecordSizeInBytes && "Size mismatch!");
+ uint64_t AlignedNextFieldOffset =
+ llvm::RoundUpToAlignment(NextFieldOffsetInBytes, AlignmentAsLLVMStruct);
+
+ if (AlignedNextFieldOffset == RecordSizeInBytes) {
+ // We don't need any padding.
+ return;
+ }
+
unsigned NumPadBytes = RecordSizeInBytes - NextFieldOffsetInBytes;
AppendBytes(NumPadBytes);
}
Modified: cfe/trunk/test/CodeGenCXX/class-layout.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCXX/class-layout.cpp?rev=90820&r1=90819&r2=90820&view=diff
==============================================================================
--- cfe/trunk/test/CodeGenCXX/class-layout.cpp (original)
+++ cfe/trunk/test/CodeGenCXX/class-layout.cpp Mon Dec 7 19:24:23 2009
@@ -1,5 +1,9 @@
-// RUN: clang-cc %s -emit-llvm -o %t
+// RUN: clang-cc %s -emit-llvm -o - | FileCheck %s
// An extra byte shoudl be allocated for an empty class.
-// RUN: grep '%.truct.A = type { i8 }' %t
+// CHECK: %struct.A = type { i8 }
struct A { } a;
+
+// No need to add tail padding here.
+// CHECK: %struct.B = type { i8*, i32 }
+struct B { void *a; int b; } b;
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