Hello,
This patch removes the CASE_USE_BIT_TESTS target macro. The default
value of the macro is defined in stmt.c, where the only user of the
macro is also. No target re-defines the macro.
(I wonder if the test is necessary at all. AFAICT all targets support
shifts in word_mode. The macro was originally written to test for
ashlsi3, which is _not_ supported on all targets -- but word_mode
shifts are. Oh well, another day perhaps...)
Bootstrapped and tested on powerpc64-unknown-linux-gnu. OK for trunk?
Ciao!
Steven
* stmt.c (CASE_USE_BIT_TESTS): Fold away into its only user ...
(expand_switch_using_bit_tests_p): ...here.
* doc/tm.texi.in (CASE_USE_BIT_TESTS): Remove documentation.
* doc/tm.texi (CASE_USE_BIT_TESTS): Regenerate.
Index: stmt.c
===================================================================
--- stmt.c (revision 189073)
+++ stmt.c (working copy)
@@ -1722,13 +1722,6 @@ add_case_node (struct case_node *head, tree type,
/* Maximum number of case bit tests. */
#define MAX_CASE_BIT_TESTS 3
-/* By default, enable case bit tests on targets with ashlsi3. */
-#ifndef CASE_USE_BIT_TESTS
-#define CASE_USE_BIT_TESTS (optab_handler (ashl_optab, word_mode) \
- != CODE_FOR_nothing)
-#endif
-
-
/* A case_bit_test represents a set of case nodes that may be
selected from using a bit-wise comparison. HI and LO hold
the integer to be tested against, LABEL contains the label
@@ -1888,8 +1881,10 @@ bool
expand_switch_using_bit_tests_p (tree index_expr, tree range,
unsigned int uniq, unsigned int count)
{
- return (CASE_USE_BIT_TESTS
- && ! TREE_CONSTANT (index_expr)
+ if (optab_handler (ashl_optab, word_mode) == CODE_FOR_nothing)
+ return false;
+
+ return (! TREE_CONSTANT (index_expr)
&& compare_tree_int (range, GET_MODE_BITSIZE (word_mode)) < 0
&& compare_tree_int (range, 0) > 0
&& lshift_cheap_p ()
Index: doc/tm.texi
===================================================================
--- doc/tm.texi (revision 189074)
+++ doc/tm.texi (working copy)
@@ -10306,16 +10306,6 @@ The default is four for machines with a @code{case
five otherwise. This is best for most machines.
@end deftypefn
-@defmac CASE_USE_BIT_TESTS
-Define this macro to be a C expression to indicate whether C switch
-statements may be implemented by a sequence of bit tests. This is
-advantageous on processors that can efficiently implement left shift
-of 1 by the number of bits held in a register, but inappropriate on
-targets that would require a loop. By default, this macro returns
-@code{true} if the target defines an @code{ashlsi3} pattern, and
-@code{false} otherwise.
-@end defmac
-
@defmac WORD_REGISTER_OPERATIONS
Define this macro if operations between registers with integral mode
smaller than a word are always performed on the entire register.
Index: doc/tm.texi.in
===================================================================
--- doc/tm.texi.in (revision 189074)
+++ doc/tm.texi.in (working copy)
@@ -10180,16 +10180,6 @@ The default is four for machines with a @code{case
five otherwise. This is best for most machines.
@end deftypefn
-@defmac CASE_USE_BIT_TESTS
-Define this macro to be a C expression to indicate whether C switch
-statements may be implemented by a sequence of bit tests. This is
-advantageous on processors that can efficiently implement left shift
-of 1 by the number of bits held in a register, but inappropriate on
-targets that would require a loop. By default, this macro returns
-@code{true} if the target defines an @code{ashlsi3} pattern, and
-@code{false} otherwise.
-@end defmac
-
@defmac WORD_REGISTER_OPERATIONS
Define this macro if operations between registers with integral mode
smaller than a word are always performed on the entire register.
