diff options
author | Imre Kaloz <kaloz@openwrt.org> | 2008-05-31 18:45:07 +0000 |
---|---|---|
committer | Imre Kaloz <kaloz@openwrt.org> | 2008-05-31 18:45:07 +0000 |
commit | 389c1186cf53918fbf5be9db470c118394ff352c (patch) | |
tree | 08aae266715b32c53cae6a55038859212af880be /toolchain/gcc/patches/4.2.4/904-flatten-switch-stmt-00.patch | |
parent | 80219efc2d2fd0eefaebac28e50fddf723100a65 (diff) | |
download | mtk-20170518-389c1186cf53918fbf5be9db470c118394ff352c.zip mtk-20170518-389c1186cf53918fbf5be9db470c118394ff352c.tar.gz mtk-20170518-389c1186cf53918fbf5be9db470c118394ff352c.tar.bz2 |
gcc 4.2.4 support
SVN-Revision: 11310
Diffstat (limited to 'toolchain/gcc/patches/4.2.4/904-flatten-switch-stmt-00.patch')
-rw-r--r-- | toolchain/gcc/patches/4.2.4/904-flatten-switch-stmt-00.patch | 74 |
1 files changed, 74 insertions, 0 deletions
diff --git a/toolchain/gcc/patches/4.2.4/904-flatten-switch-stmt-00.patch b/toolchain/gcc/patches/4.2.4/904-flatten-switch-stmt-00.patch new file mode 100644 index 0000000..f33f8e7 --- /dev/null +++ b/toolchain/gcc/patches/4.2.4/904-flatten-switch-stmt-00.patch @@ -0,0 +1,74 @@ +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" + +Index: gcc-4.2.3/gcc/stmt.c +=================================================================== +--- gcc-4.2.3.orig/gcc/stmt.c 2007-09-01 17:28:30.000000000 +0200 ++++ gcc-4.2.3/gcc/stmt.c 2008-05-21 13:45:59.137288494 +0200 +@@ -2511,7 +2511,11 @@ + 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); + } +@@ -3069,6 +3073,7 @@ + { + 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, |