From 65e71cd6353d3b269d6fa13a48f4cc87edcb184a Mon Sep 17 00:00:00 2001 From: Eric Botcazou Date: Wed, 13 Oct 2004 14:09:05 +0000 Subject: [PATCH] Fix incomplete commit. From-SVN: r88986 --- gcc/doc/tm.texi | 31 ++++++++++++++++--------------- 1 file changed, 16 insertions(+), 15 deletions(-) diff --git a/gcc/doc/tm.texi b/gcc/doc/tm.texi index 8ca2a9a4dc5b..dbdb614cf46d 100644 --- a/gcc/doc/tm.texi +++ b/gcc/doc/tm.texi @@ -4374,7 +4374,7 @@ You need not define this macro if you did not define @code{DELAY_SLOTS_FOR_EPILOGUE}. @end defmac -@deftypefn {Target Hook} void TARGET_ASM_OUTPUT_MI_THUNK (FILE *@var{file}, tree @var{thunk_fndecl}, HOST_WIDE_INT @var{delta}, tree @var{function}) +@deftypefn {Target Hook} void TARGET_ASM_OUTPUT_MI_THUNK (FILE *@var{file}, tree @var{thunk_fndecl}, HOST_WIDE_INT @var{delta}, HOST_WIDE_INT @var{vcall_offset}, tree @var{function}) A function that outputs the assembler code for a thunk function, used to implement C++ virtual function calls with multiple inheritance. The thunk acts as a wrapper around a virtual function, @@ -4388,7 +4388,15 @@ in C++. This is the incoming argument @emph{before} the function prologue, e.g.@: @samp{%o0} on a sparc. The addition must preserve the values of all other incoming arguments. -After the addition, emit code to jump to @var{function}, which is a +Then, if @var{vcall_offset} is nonzero, an additional adjustment should be +made after adding @code{delta}. In particular, if @var{p} is the +adjusted pointer, the following adjustment should be made: + +@smallexample +p += (*((ptrdiff_t **)p))[vcall_offset/sizeof(ptrdiff_t)] +@end smallexample + +After the additions, emit code to jump to @var{function}, which is a @code{FUNCTION_DECL}. This is a direct pure jump, not a call, and does not touch the return address. Hence returning from @var{FUNCTION} will return to whoever called the current @samp{thunk}. @@ -4408,19 +4416,12 @@ front end will generate a less efficient heavyweight thunk that calls not support varargs. @end deftypefn -@deftypefn {Target Hook} void TARGET_ASM_OUTPUT_MI_VCALL_THUNK (FILE *@var{file}, tree @var{thunk_fndecl}, HOST_WIDE_INT @var{delta}, int @var{vcall_offset}, tree @var{function}) -A function like @code{TARGET_ASM_OUTPUT_MI_THUNK}, except that if -@var{vcall_offset} is nonzero, an additional adjustment should be made -after adding @code{delta}. In particular, if @var{p} is the -adjusted pointer, the following adjustment should be made: - -@smallexample -p += (*((ptrdiff_t **)p))[vcall_offset/sizeof(ptrdiff_t)] -@end smallexample - -@noindent -If this function is defined, it will always be used in place of -@code{TARGET_ASM_OUTPUT_MI_THUNK}. +@deftypefn {Target Hook} bool TARGET_ASM_CAN_OUTPUT_MI_THUNK (tree @var{thunk_fndecl}, HOST_WIDE_INT @var{delta}, HOST_WIDE_INT @var{vcall_offset}, tree @var{function}) +A function that returns true if TARGET_ASM_OUTPUT_MI_THUNK would be able +to output the assembler code for the thunk function specified by the +arguments it is passed, and false otherwise. In the latter case, the +generic approach will be used by the C++ front end, with the limitations +previously exposed. @end deftypefn @node Profiling