diff -r 9d1c1b6af205 -r 708c0b301c7b patches/gcc/4.3.0/160-flatten-switch-stmt-00.patch --- a/patches/gcc/4.3.0/160-flatten-switch-stmt-00.patch Sun Jan 31 12:22:54 2010 +0100 +++ /dev/null Thu Jan 01 00:00:00 1970 +0000 @@ -1,76 +0,0 @@ -Original patch from gentoo: gentoo/src/patchsets/gcc/4.3.0/gentoo/18_all_904-flatten-switch-stmt-00.patch -http://gcc.gnu.org/ml/gcc-patches/2007-04/msg00927.html - -Hi, - -The attached patch makes sure that we create smaller object code for -simple switch statements. We just make sure to flatten the switch -statement into an if-else chain, basically. - -This fixes a size-regression as compared to gcc-3.4, as can be seen -below. - -2007-04-15 Bernhard Fischer <..> - - * stmt.c (expand_case): Do not create a complex binary tree when - optimizing for size but rather use the simple ordered list. - (emit_case_nodes): do not emit jumps to the default_label when - optimizing for size. - -Not regtested so far. -Comments? - -Attached is the test switch.c mentioned below. - -$ 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 -gcc-$i -DCHAIN -Os -o switch-CHAIN-$i.o -c switch.c ;done -$ 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 -gcc-$i -UCHAIN -Os -o switch-$i.o -c switch.c ;done - -$ size switch-*.o - text data bss dec hex filename - 169 0 0 169 a9 switch-2.95.o - 115 0 0 115 73 switch-3.3.o - 103 0 0 103 67 switch-3.4.o - 124 0 0 124 7c switch-4.0.o - 124 0 0 124 7c switch-4.1.o - 124 0 0 124 7c switch-4.2.orig-HEAD.o - 95 0 0 95 5f switch-4.3-HEAD.o - 124 0 0 124 7c switch-4.3.orig-HEAD.o - 166 0 0 166 a6 switch-CHAIN-2.95.o - 111 0 0 111 6f switch-CHAIN-3.3.o - 95 0 0 95 5f switch-CHAIN-3.4.o - 95 0 0 95 5f switch-CHAIN-4.0.o - 95 0 0 95 5f switch-CHAIN-4.1.o - 95 0 0 95 5f switch-CHAIN-4.2.orig-HEAD.o - 95 0 0 95 5f switch-CHAIN-4.3-HEAD.o - 95 0 0 95 5f switch-CHAIN-4.3.orig-HEAD.o - - -Content-Type: text/x-diff; charset=us-ascii -Content-Disposition: attachment; filename="gcc-4.3.gcc-flatten-switch-stmt.00.diff" - -diff -durN gcc-4.3.0.orig/gcc/stmt.c gcc-4.3.0/gcc/stmt.c ---- gcc-4.3.0.orig/gcc/stmt.c 2007-12-04 22:55:32.000000000 +0100 -+++ gcc-4.3.0/gcc/stmt.c 2008-06-10 14:44:33.000000000 +0200 -@@ -2508,7 +2508,11 @@ - use_cost_table - = (TREE_CODE (orig_type) != ENUMERAL_TYPE - && estimate_case_costs (case_list)); -- balance_case_nodes (&case_list, NULL); -+ /* When optimizing for size, we want a straight list to avoid -+ jumps as much as possible. This basically creates an if-else -+ chain. */ -+ if (!optimize_size) -+ balance_case_nodes (&case_list, NULL); - emit_case_nodes (index, case_list, default_label, index_type); - emit_jump (default_label); - } -@@ -3066,6 +3070,7 @@ - { - if (!node_has_low_bound (node, index_type)) - { -+ if (!optimize_size) /* don't jl to the .default_label. */ - emit_cmp_and_jump_insns (index, - convert_modes - (mode, imode,