builtin-types.def (BT_FN_VOID_PTR_VAR): New.

	* builtin-types.def (BT_FN_VOID_PTR_VAR): New.
	* builtins.def (BUILT_IN_PREFETCH): Change arguments.
	* builtins.c (expand_builtin_prefetch): Two arguments are now optional,
	with defaults for read prefetch with high degree of locality.
	* doc/extend.texi (__builtin_prefetch): Update documentation.
	* doc/md.texi (prefetch): Add documentation.

From-SVN: r47741

2 files changed, 22 insertions, 3 deletions

diff --git a/gcc/doc/extend.texi b/gcc/doc/extend.texi
index 61757f0..a6853d8 100644
--- a/gcc/doc/extend.texi
+++ b/gcc/doc/extend.texi
@@ -4442,7 +4442,7 @@ if (__builtin_expect (ptr != NULL, 1))
 when testing pointer or floating-point values.
 @end deftypefn
 
-@deftypefn {Built-in Function} void __builtin_prefetch (void *@var{addr}, int @var{rw}, int @var{locality})
+@deftypefn {Built-in Function} void __builtin_prefetch (void *@var{addr}, ...)
 This function is used to minimize cache-miss latency by moving data into
 a cache before it is accessed.
 You can insert calls to @code{__builtin_prefetch} into code for which
@@ -4452,14 +4452,17 @@ If the prefetch is done early enough before the access then the data will
 be in the cache by the time it is accessed.
 
 The value of @var{addr} is the address of the memory to prefetch.
+There are two optional arguments, @var{rw} and @var{locality}.
 The value of @var{rw} is a compile-time constant one or zero; one
-means that the prefetch is preparing for a write to the memory address.
+means that the prefetch is preparing for a write to the memory address
+and zero, the default, means that the prefetch is preparing for a read.
 The value @var{locality} must be a compile-time constant integer between
 zero and three.  A value of zero means that the data has no temporal
 locality, so it need not be left in the cache after the access.  A value
 of three means that the data has a high degree of temporal locality and
 should be left in all levels of cache possible.  Values of one and two
-mean, respectively, a low or moderate degree of temporal locality.
+mean, respectively, a low or moderate degree of temporal locality.  The
+default is three.
 
 @smallexample
 for (i = 0; i < n; i++)
diff --git a/gcc/doc/md.texi b/gcc/doc/md.texi
index f8ecb2a..23154cd 100644
--- a/gcc/doc/md.texi
+++ b/gcc/doc/md.texi
@@ -3015,6 +3015,22 @@ A typical @code{conditional_trap} pattern looks like
   "@dots{}")
 @end smallexample
 
+@cindex @code{prefetch} instruction pattern
+@item @samp{prefetch}
+
+This pattern, if defined, emits code for a non-faulting data prefetch
+instruction.  Operand 0 is the address of the memory to prefetch.  Operand 1
+is a constant 1 if the prefetch is preparing for a write to the memory
+address, or a constant 0 otherwise.  Operand 2 is the expected degree of
+temporal locality of the data and is a value between 0 and 3, inclusive; 0
+means that the data has no temporal locality, so it need not be left in the
+cache after the access; 3 means that the data has a high degree of temporal
+locality and should be left in all levels of cache possible;  1 and 2 mean,
+respectively, a low or moderate degree of temporal locality.
+
+Targets that do not support write prefetches or locality hints can ignore
+the values of operands 1 and 2.
+
 @cindex @code{cycle_display} instruction pattern
 @item @samp{cycle_display}