x86-32 long doubles are 4-byte aligned on the stack

for parameter passing (only for that, on Darwin).

llvm-svn: 45038

llvm/lib/Target/X86/X86CallingConv.td

@@ -183,7 +183,7 @@ def CC_X86_32_Common : CallingConv<[
 
   // Long doubles get slots whose size and alignment depends on the
   // subtarget.
-  CCIfType<[f80], CCAssignToStack<0, 0>>,
+  CCIfType<[f80], CCAssignToStack<16, 4>>,
 
   // The first 4 vector arguments are passed in XMM registers.
   CCIfType<[v16i8, v8i16, v4i32, v2i64, v4f32, v2f64],