patches/gcc/4.3.3/160-flatten-switch-stmt-00.patch
author "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
Tue Aug 02 18:28:10 2011 +0200 (2011-08-02)
changeset 2590 b64cfb67944e
permissions -rw-r--r--
scripts/functions: svn retrieval first tries the mirror for tarballs

The svn download helper looks for the local tarballs dir to see if it
can find a pre-downloaded tarball, and if it does not find it, does
the actual fetch to upstream via svn.

In the process, it does not even try to get a tarball from the local
mirror, which can be useful if the mirror has been pre-populated
manually (or with a previously downloaded tree).

Fake a tarball get with the standard tarball-download helper, but
without specifying any upstream URL, which makes the helper directly
try the LAN mirror.

Of course, if no mirror is specified, no URL wil be available, and
the standard svn retrieval will kick in.

Reported-by: ANDY KENNEDY <ANDY.KENNEDY@adtran.com>
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
     1 Original patch from: ../4.3.2/160-flatten-switch-stmt-00.patch
     2 
     3 -= BEGIN original header =-
     4 Original patch from gentoo: gentoo/src/patchsets/gcc/4.3.1/gentoo/18_all_904-flatten-switch-stmt-00.patch
     5 http://gcc.gnu.org/ml/gcc-patches/2007-04/msg00927.html
     6 
     7 Hi,
     8 
     9 The attached patch makes sure that we create smaller object code for
    10 simple switch statements. We just make sure to flatten the switch
    11 statement into an if-else chain, basically.
    12 
    13 This fixes a size-regression as compared to gcc-3.4, as can be seen
    14 below.
    15 
    16 2007-04-15  Bernhard Fischer  <..>
    17 
    18 	* stmt.c (expand_case): Do not create a complex binary tree when
    19 	optimizing for size but rather use the simple ordered list.
    20 	(emit_case_nodes): do not emit jumps to the default_label when
    21 	optimizing for size.
    22 
    23 Not regtested so far.
    24 Comments?
    25 
    26 Attached is the test switch.c mentioned below.
    27 
    28 $ for i in 2.95 3.3 3.4 4.0 4.1 4.2.orig-HEAD 4.3.orig-HEAD 4.3-HEAD;do
    29 gcc-$i  -DCHAIN -Os -o switch-CHAIN-$i.o -c switch.c ;done
    30 $ for i in 2.95 3.3 3.4 4.0 4.1 4.2.orig-HEAD 4.3.orig-HEAD 4.3-HEAD;do
    31 gcc-$i  -UCHAIN -Os -o switch-$i.o -c switch.c ;done
    32 
    33 $ size switch-*.o
    34    text	   data	    bss	    dec	    hex	filename
    35     169	      0	      0	    169	     a9	switch-2.95.o
    36     115	      0	      0	    115	     73	switch-3.3.o
    37     103	      0	      0	    103	     67	switch-3.4.o
    38     124	      0	      0	    124	     7c	switch-4.0.o
    39     124	      0	      0	    124	     7c	switch-4.1.o
    40     124	      0	      0	    124	     7c	switch-4.2.orig-HEAD.o
    41      95	      0	      0	     95	     5f	switch-4.3-HEAD.o
    42     124	      0	      0	    124	     7c	switch-4.3.orig-HEAD.o
    43     166	      0	      0	    166	     a6	switch-CHAIN-2.95.o
    44     111	      0	      0	    111	     6f	switch-CHAIN-3.3.o
    45      95	      0	      0	     95	     5f	switch-CHAIN-3.4.o
    46      95	      0	      0	     95	     5f	switch-CHAIN-4.0.o
    47      95	      0	      0	     95	     5f	switch-CHAIN-4.1.o
    48      95	      0	      0	     95	     5f	switch-CHAIN-4.2.orig-HEAD.o
    49      95	      0	      0	     95	     5f	switch-CHAIN-4.3-HEAD.o
    50      95	      0	      0	     95	     5f	switch-CHAIN-4.3.orig-HEAD.o
    51 
    52 
    53 Content-Type: text/x-diff; charset=us-ascii
    54 Content-Disposition: attachment; filename="gcc-4.3.gcc-flatten-switch-stmt.00.diff"
    55 
    56 -= END original header =-
    57 
    58 diff -durN gcc-4.3.3.orig/gcc/stmt.c gcc-4.3.3/gcc/stmt.c
    59 --- gcc-4.3.3.orig/gcc/stmt.c	2008-05-09 20:12:13.000000000 +0200
    60 +++ gcc-4.3.3/gcc/stmt.c	2009-01-27 22:19:28.000000000 +0100
    61 @@ -2509,7 +2509,11 @@
    62  	  use_cost_table
    63  	    = (TREE_CODE (orig_type) != ENUMERAL_TYPE
    64  	       && estimate_case_costs (case_list));
    65 -	  balance_case_nodes (&case_list, NULL);
    66 +	  /* When optimizing for size, we want a straight list to avoid
    67 +	     jumps as much as possible. This basically creates an if-else
    68 +	     chain.  */
    69 +	  if (!optimize_size)
    70 +	    balance_case_nodes (&case_list, NULL);
    71  	  emit_case_nodes (index, case_list, default_label, index_type);
    72  	  emit_jump (default_label);
    73  	}
    74 @@ -3067,6 +3071,7 @@
    75  	    {
    76  	      if (!node_has_low_bound (node, index_type))
    77  		{
    78 +		  if (!optimize_size) /* don't jl to the .default_label. */
    79  		  emit_cmp_and_jump_insns (index,
    80  					   convert_modes
    81  					   (mode, imode,