Hi all,
I noticed we don't document the clrsb<mode>2 optab but it does exist.
The proposed description is based on the clrsb RTL code documentation in
rtl.texi.
While we're at it, clean up the wording for some other cases in the file
which refer to an argument 'x' when they mean to refer to operand 1.
They were probably copied over from rtl.texi which does use 'x'.
Ok for trunk?
2014-07-16 Kyrylo Tkachov <kyrylo.tkac...@arm.com>
* doc/md.texi (clrsb): Document.
(clz): Change reference to x into operand 1.
(ctz): Likewise.
(popcount): Likewise.
(parity): Likewise.commit 8f0f09fbf6e8ee8136d4977f9819ee1997f82963
Author: Kyrylo Tkachov <kyrylo.tkac...@arm.com>
Date: Tue Jul 15 17:41:29 2014 +0100
[DOC] Document clrsb optab
diff --git a/gcc/doc/md.texi b/gcc/doc/md.texi
index fde67d7..268f625 100644
--- a/gcc/doc/md.texi
+++ b/gcc/doc/md.texi
@@ -5316,10 +5316,17 @@ generating the instruction.
The @code{ffs} built-in function of C always uses the mode which
corresponds to the C data type @code{int}.
+@cindex @code{clrsb@var{m}2} instruction pattern
+@item @samp{clrsb@var{m}2}
+Store into operand 0 the number of redundant sign bits in operand 1, starting
+at the most significant bit position.
+This is one less than the number of leading sign bits (either 0 or 1),
+with no special cases.
+
@cindex @code{clz@var{m}2} instruction pattern
@item @samp{clz@var{m}2}
-Store into operand 0 the number of leading 0-bits in @var{x}, starting
-at the most significant bit position. If @var{x} is 0, the
+Store into operand 0 the number of leading 0-bits in operand 1, starting
+at the most significant bit position. If operand 1 is 0, the
@code{CLZ_DEFINED_VALUE_AT_ZERO} (@pxref{Misc}) macro defines if
the result is undefined or has a useful value.
@var{m} is the mode of operand 0; operand 1's mode is
@@ -5328,8 +5335,8 @@ operand to that mode before generating the instruction.
@cindex @code{ctz@var{m}2} instruction pattern
@item @samp{ctz@var{m}2}
-Store into operand 0 the number of trailing 0-bits in @var{x}, starting
-at the least significant bit position. If @var{x} is 0, the
+Store into operand 0 the number of trailing 0-bits in operand 1, starting
+at the least significant bit position. If operand 1 is 0, the
@code{CTZ_DEFINED_VALUE_AT_ZERO} (@pxref{Misc}) macro defines if
the result is undefined or has a useful value.
@var{m} is the mode of operand 0; operand 1's mode is
@@ -5338,15 +5345,15 @@ operand to that mode before generating the instruction.
@cindex @code{popcount@var{m}2} instruction pattern
@item @samp{popcount@var{m}2}
-Store into operand 0 the number of 1-bits in @var{x}. @var{m} is the
+Store into operand 0 the number of 1-bits in operand 1. @var{m} is the
mode of operand 0; operand 1's mode is specified by the instruction
pattern, and the compiler will convert the operand to that mode before
generating the instruction.
@cindex @code{parity@var{m}2} instruction pattern
@item @samp{parity@var{m}2}
-Store into operand 0 the parity of @var{x}, i.e.@: the number of 1-bits
-in @var{x} modulo 2. @var{m} is the mode of operand 0; operand 1's mode
+Store into operand 0 the parity of operand 1, i.e.@: the number of 1-bits
+in operand 1 modulo 2. @var{m} is the mode of operand 0; operand 1's mode
is specified by the instruction pattern, and the compiler will convert
the operand to that mode before generating the instruction.
