[llvm-commits] [llvm-gcc-4.2] r46157 - in /llvm-gcc-4.2/trunk/gcc/config/i386: llvm-i386-target.h llvm-i386.cpp

[Evan Cheng]

Author: evancheng
Date: Thu Jan 17 19:47:03 2008
New Revision: 46157

URL: http://llvm.org/viewvc/llvm-project?rev=46157&view=rev
Log:
Do not pass zero sized array, struct, or class using byval attribute. This is true on both x86-32 and x86-64.

Modified:
    llvm-gcc-4.2/trunk/gcc/config/i386/llvm-i386-target.h
    llvm-gcc-4.2/trunk/gcc/config/i386/llvm-i386.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=46157&r1=46156&r2=46157&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 Thu Jan 17 19:47:03 2008
@@ -62,10 +62,13 @@
     }                                                           \
   }
 
+extern bool llvm_x86_is_zero_sized_aggregate(tree);
 extern bool llvm_x86_64_should_pass_aggregate_in_memory(tree);
 
 #define LLVM_SHOULD_PASS_AGGREGATE_USING_BYVAL_ATTR(X)          \
-  (!TARGET_64BIT || llvm_x86_64_should_pass_aggregate_in_memory(X))
+  (!llvm_x86_is_zero_sized_aggregate(X) &&                      \
+   (!TARGET_64BIT ||                                            \
+    llvm_x86_64_should_pass_aggregate_in_memory(X)))
 
 /* LLVM LOCAL end (ENTIRE FILE!)  */
 

Modified: llvm-gcc-4.2/trunk/gcc/config/i386/llvm-i386.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm-gcc-4.2/trunk/gcc/config/i386/llvm-i386.cpp?rev=46157&r1=46156&r2=46157&view=diff

==============================================================================
--- llvm-gcc-4.2/trunk/gcc/config/i386/llvm-i386.cpp (original)
+++ llvm-gcc-4.2/trunk/gcc/config/i386/llvm-i386.cpp Thu Jan 17 19:47:03 2008
@@ -664,6 +664,15 @@
 extern "C" enum machine_mode ix86_getNaturalModeForType(tree);
 extern "C" int ix86_HowToPassArgument(enum machine_mode, tree, int, int*, int*);
 
+/* Target hook for llvm-abi.h. It returns true if the specified type is a
+   zero sized array, struct, or class. */
+bool llvm_x86_is_zero_sized_aggregate(tree type) {
+  enum machine_mode Mode = ix86_getNaturalModeForType(type);
+  HOST_WIDE_INT Bytes =
+    (Mode == BLKmode) ? int_size_in_bytes(type) : (int) GET_MODE_SIZE(Mode);
+  return Bytes == 0;
+}
+
 /* Target hook for llvm-abi.h. It returns true if an aggregate of the
    specified type should be passed in memory. This is only called for
    x86-64. */