OpenE2K/gcc
2
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

re PR target/43920 (Choosing conditional execution over conditional branches for code size in some cases.)

Browse Source 
2011-04-05  Tom de Vries  <tom@codesourcery.com>

	PR target/43920
	* function.c (emit_use_return_register_into_block): New function.
	(thread_prologue_and_epilogue_insns): Use
	emit_use_return_register_into_block.

From-SVN: r171977
This commit is contained in:
Tom de Vries 2011-04-05 10:12:14 +00:00 committed by Tom de Vries
parent 2a562b0ab3
commit 4c029f40bd
2 changed files with 32 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

7
gcc/ChangeLog
View File

@ -1,3 +1,10 @@
2011-04-05 Tom de Vries <tom@codesourcery.com>
PR target/43920
* function.c (emit_use_return_register_into_block): New function.
(thread_prologue_and_epilogue_insns): Use
emit_use_return_register_into_block.
2011-04-05 Tom de Vries <tom@codesourcery.com>
PR target/43920

25
gcc/function.c
View File

@ -5262,6 +5262,19 @@ prologue_epilogue_contains (const_rtx insn)
return 0;
}
/* Insert use of return register before the end of BB. */
static void
emit_use_return_register_into_block (basic_block bb)
{
rtx seq;
start_sequence ();
use_return_register ();
seq = get_insns ();
end_sequence ();
emit_insn_before (seq, BB_END (bb));
}
#ifdef HAVE_return
/* Insert gen_return at the end of block BB. This also means updating
block_for_insn appropriately. */
@ -5416,6 +5429,15 @@ thread_prologue_and_epilogue_insns (void)
with a simple return instruction. */
if (simplejump_p (jump))
{
/* The use of the return register might be present in the exit
fallthru block. Either:
- removing the use is safe, and we should remove the use in
the exit fallthru block, or
- removing the use is not safe, and we should add it here.
For now, we conservatively choose the latter. Either of the
2 helps in crossjumping. */
emit_use_return_register_into_block (bb);
emit_return_into_block (bb);
delete_insn (jump);
}
@ -5430,6 +5452,9 @@ thread_prologue_and_epilogue_insns (void)
continue;
}
/* See comment in simple_jump_p case above. */
emit_use_return_register_into_block (bb);
/* If this block has only one successor, it both jumps
and falls through to the fallthru block, so we can't
delete the edge. */