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tm.texi (STORE_FLAG_VALUE): Do not refer to sCC patterns. 

2010-05-25  Paolo Bonzini  <bonzini@gnu.org>

	* doc/tm.texi (STORE_FLAG_VALUE): Do not refer to sCC patterns.
	* doc/md.texi (cstoreXX4): Update for cond-optab changes.

From-SVN: r159814
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Paolo Bonzini 2010-05-25 09:22:41 +00:00 committed by Paolo Bonzini
parent 6597fd0bc6
commit ac5eda130d
3 changed files with 30 additions and 17 deletions
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7
gcc/ChangeLog
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@ -1,4 +1,9 @@
2010-05-09 Paolo Bonzini <bonzini@gnu.org>
2010-05-25 Paolo Bonzini <bonzini@gnu.org>
* doc/tm.texi (STORE_FLAG_VALUE): Do not refer to sCC patterns.
* doc/md.texi (cstoreXX4): Update for cond-optab changes.
2010-05-25 Paolo Bonzini <bonzini@gnu.org>
PR target/43610
* optabs.c (prepare_float_lib_cmp): Allow reversing the comparison

32
gcc/doc/md.texi
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@ -4705,20 +4705,28 @@ else must be negative. Otherwise the instruction is not suitable and
you should omit it from the machine description. You describe to the
compiler exactly which value is stored by defining the macro
@code{STORE_FLAG_VALUE} (@pxref{Misc}). If a description cannot be
found that can be used for all the @samp{s@var{cond}} patterns, you
should omit those operations from the machine description.
found that can be used for all the possible comparison operators, you
should pick one and use a @code{define_expand} to map all results
onto the one you chose.
These operations may fail, but should do so only in relatively
uncommon cases; if they would fail for common cases involving
integer comparisons, it is best to omit these patterns.
These operations may @code{FAIL}, but should do so only in relatively
uncommon cases; if they would @code{FAIL} for common cases involving
integer comparisons, it is best to restrict the predicates to not
allow these operands. Likewise if a given comparison operator will
always fail, independent of the operands (for floating-point modes, the
@code{ordered_comparison_operator} predicate is often useful in this case).
If these operations are omitted, the compiler will usually generate code
that copies the constant one to the target and branches around an
assignment of zero to the target. If this code is more efficient than
the potential instructions used for the @samp{cstore@var{mode}4} pattern
followed by those required to convert the result into a 1 or a zero in
@code{SImode}, you should omit the @samp{cstore@var{mode}4} operations from
the machine description.
If this pattern is omitted, the compiler will generate a conditional
branch---for example, it may copy a constant one to the target and branching
around an assignment of zero to the target---or a libcall. If the predicate
for operand 1 only rejects some operators, it will also try reordering the
operands and/or inverting the result value (e.g.@: by an exclusive OR).
These possibilities could be cheaper or equivalent to the instructions
used for the @samp{cstore@var{mode}4} pattern followed by those required
to convert a positive result from @code{STORE_FLAG_VALUE} to 1; in this
case, you can and should make operand 1's predicate reject some operators
in the @samp{cstore@var{mode}4} pattern, or remove the pattern altogether
from the machine description.
@cindex @code{cbranch@var{mode}4} instruction pattern
@item @samp{cbranch@var{mode}4}

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gcc/doc/tm.texi
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@ -10264,8 +10264,8 @@ In order to enforce the representation of @code{mode},
@defmac STORE_FLAG_VALUE
A C expression describing the value returned by a comparison operator
with an integral mode and stored by a store-flag instruction
(@samp{s@var{cond}}) when the condition is true. This description must
apply to @emph{all} the @samp{s@var{cond}} patterns and all the
(@samp{cstore@var{mode}4}) when the condition is true. This description must
apply to @emph{all} the @samp{cstore@var{mode}4} patterns and all the
comparison operators whose results have a @code{MODE_INT} mode.
A value of 1 or @minus{}1 means that the instruction implementing the
@ -10274,7 +10274,7 @@ and 0 when the comparison is false. Otherwise, the value indicates
which bits of the result are guaranteed to be 1 when the comparison is
true. This value is interpreted in the mode of the comparison
operation, which is given by the mode of the first operand in the
@samp{s@var{cond}} pattern. Either the low bit or the sign bit of
@samp{cstore@var{mode}4} pattern. Either the low bit or the sign bit of
@code{STORE_FLAG_VALUE} be on. Presently, only those bits are used by
the compiler.
@ -10347,7 +10347,7 @@ those cases, e.g., one matching
Some machines can also perform @code{and} or @code{plus} operations on
condition code values with less instructions than the corresponding
@samp{s@var{cond}} insn followed by @code{and} or @code{plus}. On those
@samp{cstore@var{mode}4} insn followed by @code{and} or @code{plus}. On those
machines, define the appropriate patterns. Use the names @code{incscc}
and @code{decscc}, respectively, for the patterns which perform
@code{plus} or @code{minus} operations on condition code values. See