[llvm-commits] [llvm-gcc-4.2] r46958 - in /llvm-gcc-4.2/trunk/gcc: config/i386/llvm-i386-target.h llvm-types.cpp

[Dale Johannesen]

Author: johannes
Date: Mon Feb 11 12:03:06 2008
New Revision: 46958

URL: http://llvm.org/viewvc/llvm-project?rev=46958&view=rev
Log:
Choose an SSE vector-containing type for the constructed
type that represents a union, if the union contains such
a type.


Modified:
    llvm-gcc-4.2/trunk/gcc/config/i386/llvm-i386-target.h
    llvm-gcc-4.2/trunk/gcc/llvm-types.cpp

Modified: llvm-gcc-4.2/trunk/gcc/config/i386/llvm-i386-target.h
URL: http://llvm.org/viewvc/llvm-project/llvm-gcc-4.2/trunk/gcc/config/i386/llvm-i386-target.h?rev=46958&r1=46957&r2=46958&view=diff

==============================================================================
--- llvm-gcc-4.2/trunk/gcc/config/i386/llvm-i386-target.h (original)
+++ llvm-gcc-4.2/trunk/gcc/config/i386/llvm-i386-target.h Mon Feb 11 12:03:06 2008
@@ -83,6 +83,15 @@
     }                                                           \
   }
 
+/* Aggregates containing SSE vectors are aligned at 16 bytes as parameters;
+   while long double has GCC alignment of 16 bytes (correct for struct layout)
+   but is only 4 byte aligned as a parameter.  So if a union type contains an
+   SSE vector, use that as the basis for the constructed LLVM struct. */
+#define TARGET_LLVM_COMPARE_UNION_FIELDS(curType, newType, curAlign, newAlign) \
+  (newAlign==curAlign && TARGET_SSE &&                                         \
+   TheTarget->getTargetLowering()->getByValTypeAlignment(newType) >            \
+   TheTarget->getTargetLowering()->getByValTypeAlignment(curType))
+
 #ifdef LLVM_ABI_H
 extern bool llvm_x86_should_pass_aggregate_in_memory(tree, const Type *);
 

Modified: llvm-gcc-4.2/trunk/gcc/llvm-types.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm-gcc-4.2/trunk/gcc/llvm-types.cpp?rev=46958&r1=46957&r2=46958&view=diff

==============================================================================
--- llvm-gcc-4.2/trunk/gcc/llvm-types.cpp (original)
+++ llvm-gcc-4.2/trunk/gcc/llvm-types.cpp Mon Feb 11 12:03:06 2008
@@ -33,6 +33,7 @@
 #include "llvm/TypeSymbolTable.h"
 #include "llvm/Target/TargetData.h"
 #include "llvm/Target/TargetMachine.h"
+#include "llvm/Target/TargetLowering.h"
 #include "llvm/Assembly/Writer.h"
 #include "llvm/ADT/DenseMap.h"
 #include "llvm/ADT/StringExtras.h"
@@ -1137,7 +1138,7 @@
   // 'sret' functions cannot be 'readnone' or 'readonly'.
   if (ABIConverter.isStructReturn())
     RAttributes &= ~(ParamAttr::ReadNone|ParamAttr::ReadOnly);
-  
+
   // Compute whether the result needs to be zext or sext'd.
   RAttributes |= HandleArgumentExtension(TREE_TYPE(type));
 
@@ -2124,6 +2125,8 @@
 
 /// ConvertUNION - We know that 'type' is a UNION_TYPE or a QUAL_UNION_TYPE:
 /// convert it to an LLVM type.
+/// This involves creating a struct with the right size and alignment. In
+/// some cases this is target dependent.
 const Type *TypeConverter::ConvertUNION(tree type, tree orig_type) {
   if (const Type *Ty = GET_TYPE_LLVM(type)) {
     // If we already compiled this type, and if it was not a forward
@@ -2170,17 +2173,25 @@
     // Select TheTy as union type if it meets one of the following criteria
     // 1) UnionTy is 0
     // 2) TheTy alignment is more then UnionTy
-    // 3) TheTy size is greater than UnionTy size and TheTy alignment is equal to UnionTy
+    // 3) TheTy size is greater than UnionTy size and TheTy alignment is equal
+    //    to UnionTy
     // 4) TheTy size is greater then UnionTy size and TheTy is packed
+    //    FIXME there is no check for packed?
     bool useTheTy = false;
     if (UnionTy == 0)
       useTheTy = true;
     else if (Align > MaxAlign)
       useTheTy = true;
+#ifdef TARGET_LLVM_COMPARE_UNION_FIELDS
+    else
+      useTheTy = TARGET_LLVM_COMPARE_UNION_FIELDS(UnionTy, TheTy,
+                                                   Align, MaxAlign);
+#else
     else if (MaxAlign == Align && Size > MaxSize)
       useTheTy = true;
-    else if (Size > MaxSize)
+    else if (Size > MaxSize)    // FIXME really?  Seems wrong to lower alignment
       useTheTy = true;
+#endif
 
     if (useTheTy) {
       UnionTy = TheTy;