From 215ccb66e6abdaed0a41582d6b8c40ffa340eea7 Mon Sep 17 00:00:00 2001
From: Felix Fietkau <nbd@openwrt.org>
Date: Sat, 10 Oct 2009 19:25:48 +0000
Subject: gcc: add llvm-gcc and llvm from trunk (does not successfully compile
 a target yet, but gets close)

SVN-Revision: 18019
---
 .../patches/llvm/904-flatten-switch-stmt-00.patch  | 72 ++++++++++++++++++++++
 1 file changed, 72 insertions(+)
 create mode 100644 toolchain/gcc/patches/llvm/904-flatten-switch-stmt-00.patch

(limited to 'toolchain/gcc/patches/llvm/904-flatten-switch-stmt-00.patch')

diff --git a/toolchain/gcc/patches/llvm/904-flatten-switch-stmt-00.patch b/toolchain/gcc/patches/llvm/904-flatten-switch-stmt-00.patch
new file mode 100644
index 0000000000..f3a6372b64
--- /dev/null
+++ b/toolchain/gcc/patches/llvm/904-flatten-switch-stmt-00.patch
@@ -0,0 +1,72 @@
+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"
+
+--- a/gcc/stmt.c
++++ b/gcc/stmt.c
+@@ -2574,7 +2574,11 @@ expand_case (tree exp)
+ 	  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);
+ 	}
+@@ -3136,6 +3140,7 @@ emit_case_nodes (rtx index, case_node_pt
+ 	    {
+ 	      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,
-- 
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