patches/gcc/4.4.0/190-flatten-switch-stmt-00.patch
author "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
Sun Sep 12 23:51:25 2010 +0200 (2010-09-12)
changeset 2123 ff2181adbd28
permissions -rw-r--r--
cc/gcc: disable complibs if not selected

Force gcc to not link with some companion libraries when
there are not needed (because selected-out).

There is no option to tell gcc *not* to build the Graphite and/or
LTO stuff. They *will* be built if gcc finds the suitable companion
libraries. If we do not provide them, but the host has them, then
gcc *will* find them, and link with them.

Consider the following:
- host has suitable PPL and CLooG (eg. Debian Squeeze)
- user wants to build gcc>=4.4
- user de-selects GRAPHITE
- gcc will find the hosts PPL and CLooG, and will use them
- the user moves the toolchain to an older host that does
not have them (eg. Debian Lenny)
- the toolchain fails, when it was properly setup not to

So, explicitly tell gcc *not* to use unneeded companion libs.

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
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diff -durN gcc-4.4.0.orig/gcc/stmt.c gcc-4.4.0/gcc/stmt.c
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--- gcc-4.4.0.orig/gcc/stmt.c	2009-02-27 20:49:42.000000000 +0100
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+++ gcc-4.4.0/gcc/stmt.c	2009-05-27 21:38:21.000000000 +0200
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@@ -2376,7 +2376,11 @@
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 	  use_cost_table
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 	    = (TREE_CODE (orig_type) != ENUMERAL_TYPE
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 	       && estimate_case_costs (case_list));
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-	  balance_case_nodes (&case_list, NULL);
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+	  /* When optimizing for size, we want a straight list to avoid
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+	     jumps as much as possible. This basically creates an if-else
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+	     chain.  */
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+	  if (!optimize_size)
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+	    balance_case_nodes (&case_list, NULL);
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 	  emit_case_nodes (index, case_list, default_label, index_type);
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 	  if (default_label)
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 	    emit_jump (default_label);
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@@ -2942,6 +2946,7 @@
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 	    {
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 	      if (!node_has_low_bound (node, index_type))
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 		{
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+		  if (!optimize_size) /* don't jl to the .default_label. */
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 		  emit_cmp_and_jump_insns (index,
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 					   convert_modes
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 					   (mode, imode,