From 9c2ac5939f2f4115d7052af9aba886bd3773d28a Mon Sep 17 00:00:00 2001 From: hp Date: Mon, 22 Oct 2012 09:22:11 +0000 Subject: * stmt.c (expand_nl_goto_receiver): Remove almost-copy of expand_builtin_setjmp_receiver. (expand_label): Adjust, call expand_builtin_setjmp_receiver with NULL for the label parameter. * builtins.c (expand_builtin_setjmp_receiver): Don't clobber the frame-pointer. Adjust comments. [HAVE_builtin_setjmp_receiver]: Emit builtin_setjmp_receiver only if LABEL is non-NULL. git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@192676 138bc75d-0d04-0410-961f-82ee72b054a4 --- gcc/builtins.c | 30 +++++++++++++++++++++--------- 1 file changed, 21 insertions(+), 9 deletions(-) (limited to 'gcc/builtins.c') diff --git a/gcc/builtins.c b/gcc/builtins.c index c309566919e..6d501c47ad8 100644 --- a/gcc/builtins.c +++ b/gcc/builtins.c @@ -885,14 +885,15 @@ expand_builtin_setjmp_setup (rtx buf_addr, rtx receiver_label) } /* Construct the trailing part of a __builtin_setjmp call. This is - also called directly by the SJLJ exception handling code. */ + also called directly by the SJLJ exception handling code. + If RECEIVER_LABEL is NULL, instead contruct a nonlocal goto handler. */ void expand_builtin_setjmp_receiver (rtx receiver_label ATTRIBUTE_UNUSED) { rtx chain; - /* Clobber the FP when we get here, so we have to make sure it's + /* Mark the FP as used when we get here, so we have to make sure it's marked as used by this function. */ emit_use (hard_frame_pointer_rtx); @@ -907,17 +908,28 @@ expand_builtin_setjmp_receiver (rtx receiver_label ATTRIBUTE_UNUSED) #ifdef HAVE_nonlocal_goto if (! HAVE_nonlocal_goto) #endif - { - emit_move_insn (virtual_stack_vars_rtx, hard_frame_pointer_rtx); - /* This might change the hard frame pointer in ways that aren't - apparent to early optimization passes, so force a clobber. */ - emit_clobber (hard_frame_pointer_rtx); - } + /* First adjust our frame pointer to its actual value. It was + previously set to the start of the virtual area corresponding to + the stacked variables when we branched here and now needs to be + adjusted to the actual hardware fp value. + + Assignments to virtual registers are converted by + instantiate_virtual_regs into the corresponding assignment + to the underlying register (fp in this case) that makes + the original assignment true. + So the following insn will actually be decrementing fp by + STARTING_FRAME_OFFSET. */ + emit_move_insn (virtual_stack_vars_rtx, hard_frame_pointer_rtx); #if !HARD_FRAME_POINTER_IS_ARG_POINTER if (fixed_regs[ARG_POINTER_REGNUM]) { #ifdef ELIMINABLE_REGS + /* If the argument pointer can be eliminated in favor of the + frame pointer, we don't need to restore it. We assume here + that if such an elimination is present, it can always be used. + This is the case on all known machines; if we don't make this + assumption, we do unnecessary saving on many machines. */ size_t i; static const struct elims {const int from, to;} elim_regs[] = ELIMINABLE_REGS; @@ -938,7 +950,7 @@ expand_builtin_setjmp_receiver (rtx receiver_label ATTRIBUTE_UNUSED) #endif #ifdef HAVE_builtin_setjmp_receiver - if (HAVE_builtin_setjmp_receiver) + if (receiver_label != NULL && HAVE_builtin_setjmp_receiver) emit_insn (gen_builtin_setjmp_receiver (receiver_label)); else #endif -- cgit v1.2.1