[llvm-branch-commits] [cfe-branch] r102088 - in /cfe/branches/Apple/williamson: lib/CodeGen/CGRecordLayoutBuilder.cpp test/CodeGen/bitfield-2.c

[Daniel Dunbar]

Author: ddunbar
Date: Thu Apr 22 12:18:15 2010
New Revision: 102088

URL: http://llvm.org/viewvc/llvm-project?rev=102088&view=rev
Log:
IRgen: Set alignment correctly on bit-field accesses.

Modified:
    cfe/branches/Apple/williamson/lib/CodeGen/CGRecordLayoutBuilder.cpp
    cfe/branches/Apple/williamson/test/CodeGen/bitfield-2.c

Modified: cfe/branches/Apple/williamson/lib/CodeGen/CGRecordLayoutBuilder.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/branches/Apple/williamson/lib/CodeGen/CGRecordLayoutBuilder.cpp?rev=102088&r1=102087&r2=102088&view=diff
==============================================================================
--- cfe/branches/Apple/williamson/lib/CodeGen/CGRecordLayoutBuilder.cpp (original)
+++ cfe/branches/Apple/williamson/lib/CodeGen/CGRecordLayoutBuilder.cpp Thu Apr 22 12:18:15 2010
@@ -152,8 +152,9 @@
                                           uint64_t FieldOffset,
                                           uint64_t FieldSize) {
   const RecordDecl *RD = FD->getParent();
-  uint64_t ContainingTypeSizeInBits =
-    Types.getContext().getASTRecordLayout(RD).getSize();
+  const ASTRecordLayout &RL = Types.getContext().getASTRecordLayout(RD);
+  uint64_t ContainingTypeSizeInBits = RL.getSize();
+  unsigned ContainingTypeAlign = RL.getAlignment();
 
   const llvm::Type *Ty = Types.ConvertTypeForMemRecursive(FD->getType());
   uint64_t TypeSizeInBytes = Types.getTargetData().getTypeAllocSize(Ty);
@@ -223,8 +224,7 @@
     AI.FieldByteOffset = AccessStart / 8;
     AI.FieldBitStart = AccessBitsInFieldStart - AccessStart;
     AI.AccessWidth = AccessWidth;
-    // FIXME: This might be wrong!
-    AI.AccessAlignment = 0;
+    AI.AccessAlignment = llvm::MinAlign(ContainingTypeAlign, AccessStart) / 8;
     AI.TargetBitOffset = AccessedTargetBits;
     AI.TargetBitWidth = AccessBitsInFieldSize;
 

Modified: cfe/branches/Apple/williamson/test/CodeGen/bitfield-2.c
URL: http://llvm.org/viewvc/llvm-project/cfe/branches/Apple/williamson/test/CodeGen/bitfield-2.c?rev=102088&r1=102087&r2=102088&view=diff
==============================================================================
--- cfe/branches/Apple/williamson/test/CodeGen/bitfield-2.c (original)
+++ cfe/branches/Apple/williamson/test/CodeGen/bitfield-2.c Thu Apr 22 12:18:15 2010
@@ -17,9 +17,9 @@
 // CHECK-RECORD:     <CGBitFieldInfo Size:24 IsSigned:1
 // CHECK-RECORD:                     NumComponents:2 Components: [
 // CHECK-RECORD:         <AccessInfo FieldIndex:0 FieldByteOffset:0 FieldBitStart:0 AccessWidth:16
-// CHECK-RECORD:                     AccessAlignment:0 TargetBitOffset:0 TargetBitWidth:16>
+// CHECK-RECORD:                     AccessAlignment:1 TargetBitOffset:0 TargetBitWidth:16>
 // CHECK-RECORD:         <AccessInfo FieldIndex:0 FieldByteOffset:2 FieldBitStart:0 AccessWidth:8
-// CHECK-RECORD:                     AccessAlignment:0 TargetBitOffset:16 TargetBitWidth:8>
+// CHECK-RECORD:                     AccessAlignment:1 TargetBitOffset:16 TargetBitWidth:8>
 struct __attribute((packed)) s0 {
   int f0 : 24;
 };
@@ -62,14 +62,14 @@
 // CHECK-RECORD:     <CGBitFieldInfo Size:10 IsSigned:1
 // CHECK-RECORD:                     NumComponents:1 Components: [
 // CHECK-RECORD:         <AccessInfo FieldIndex:0 FieldByteOffset:0 FieldBitStart:0 AccessWidth:16
-// CHECK-RECORD:                     AccessAlignment:0 TargetBitOffset:0 TargetBitWidth:10>
+// CHECK-RECORD:                     AccessAlignment:1 TargetBitOffset:0 TargetBitWidth:10>
 // CHECK-RECORD:     ]>
 // CHECK-RECORD:     <CGBitFieldInfo Size:10 IsSigned:1
 // CHECK-RECORD:                     NumComponents:2 Components: [
 // CHECK-RECORD:         <AccessInfo FieldIndex:0 FieldByteOffset:0 FieldBitStart:10 AccessWidth:16
-// CHECK-RECORD:                     AccessAlignment:0 TargetBitOffset:0 TargetBitWidth:6>
+// CHECK-RECORD:                     AccessAlignment:1 TargetBitOffset:0 TargetBitWidth:6>
 // CHECK-RECORD:         <AccessInfo FieldIndex:0 FieldByteOffset:2 FieldBitStart:0 AccessWidth:8
-// CHECK-RECORD:                     AccessAlignment:0 TargetBitOffset:6 TargetBitWidth:4>
+// CHECK-RECORD:                     AccessAlignment:1 TargetBitOffset:6 TargetBitWidth:4>
 
 #pragma pack(push)
 #pragma pack(1)
@@ -119,7 +119,7 @@
 // CHECK-RECORD:     <CGBitFieldInfo Size:3 IsSigned:0
 // CHECK-RECORD:                     NumComponents:1 Components: [
 // CHECK-RECORD:         <AccessInfo FieldIndex:0 FieldByteOffset:0 FieldBitStart:0 AccessWidth:8
-// CHECK-RECORD:                     AccessAlignment:0 TargetBitOffset:0 TargetBitWidth:3>
+// CHECK-RECORD:                     AccessAlignment:1 TargetBitOffset:0 TargetBitWidth:3>
 
 union __attribute__((packed)) u2 {
   unsigned long long f0 : 3;
@@ -280,3 +280,33 @@
   res ^= g6.f0;
   return res;
 }
+
+/***/
+
+// Check that we compute the best alignment possible for each access.
+//
+// CHECK-RECORD: *** Dumping IRgen Record Layout
+// CHECK-RECORD: Record: struct s7
+// CHECK-RECORD: Layout: <CGRecordLayout
+// CHECK-RECORD:   LLVMType:{ i32, i32, i32, i8, [3 x i8], [4 x i8], [12 x i8] }
+// CHECK-RECORD:   ContainsPointerToDataMember:0
+// CHECK-RECORD:   BitFields:[
+// CHECK-RECORD:     <CGBitFieldInfo Size:5 IsSigned:1
+// CHECK-RECORD:                     NumComponents:1 Components: [
+// CHECK-RECORD:         <AccessInfo FieldIndex:0 FieldByteOffset:12 FieldBitStart:0 AccessWidth:32
+// CHECK-RECORD:                     AccessAlignment:4 TargetBitOffset:0 TargetBitWidth:5>
+// CHECK-RECORD:     ]>
+// CHECK-RECORD:     <CGBitFieldInfo Size:29 IsSigned:1
+// CHECK-RECORD:                     NumComponents:1 Components: [
+// CHECK-RECORD:         <AccessInfo FieldIndex:0 FieldByteOffset:16 FieldBitStart:0 AccessWidth:32
+// CHECK-RECORD:                     AccessAlignment:16 TargetBitOffset:0 TargetBitWidth:29>
+
+struct __attribute__((aligned(16))) s7 {
+  int a, b, c;
+  int f0 : 5;
+  int f1 : 29;
+};
+
+int f7_load(struct s7 *a0) {
+  return a0->f0;
+}