Richard,
this patch implements VRP for the 2 openacc axis internal fns I've added. We
know the position within a dimension cannot exceed that dimensions extend.
Further, if the extend is dynamic, the target backend may well know there's a
hardware-mandated maximum value.
Hence, added a new target hook to allow the backend to specify that upper bound,
and added smarts to extract_range_basic to process the two internal functions.
Incidentally, this was the bit I was working on at the cauldron, which caused me
to work on the min/max range combining.
ok for trunk?
nathan
2015-11-03 Nathan Sidwell <nat...@codesourcery.com>
* target.def (goacc.dim_limit): New hook.
* targhooks.h (default_goacc_dim_limit): Declare.
* doc/tm.texi.in (TARGET_GOACC_DIM_LIMIT): Add.
* doc/tm.texi: Rebuilt.
* omp-low.c (default_goacc_dim_limit): New.
* config/nvptx/nvptx.c (PTX_VECTOR_LENGTH, PTX_WORKER_LENGTH): New.
(nvptx_goacc_dim_limit) New.
(TARGET_GOACC_DIM_LIMIT): Override.
* tree-vrp.c: Include omp-low.h, target.h.
(extract_range_basic): Add handling for IFN_GOACC_DIM_SIZE &
IFN_GOACC_DIM_POS.
Index: gcc/targhooks.h
===================================================================
--- gcc/targhooks.h (revision 229535)
+++ gcc/targhooks.h (working copy)
@@ -110,6 +110,7 @@ extern void default_destroy_cost_data (v
/* OpenACC hooks. */
extern bool default_goacc_validate_dims (tree, int [], int);
+extern int default_goacc_dim_limit (int);
extern bool default_goacc_fork_join (gcall *, const int [], bool);
/* These are here, and not in hooks.[ch], because not all users of
Index: gcc/config/nvptx/nvptx.c
===================================================================
--- gcc/config/nvptx/nvptx.c (revision 229535)
+++ gcc/config/nvptx/nvptx.c (working copy)
@@ -3248,6 +3248,10 @@ nvptx_file_end (void)
}
}
+/* Define dimension sizes for known hardware. */
+#define PTX_VECTOR_LENGTH 32
+#define PTX_WORKER_LENGTH 32
+
/* Validate compute dimensions of an OpenACC offload or routine, fill
in non-unity defaults. FN_LEVEL indicates the level at which a
routine might spawn a loop. It is negative for non-routines. */
@@ -3264,6 +3268,25 @@ nvptx_goacc_validate_dims (tree ARG_UNUS
return changed;
}
+/* Return maximum dimension size, or zero for unbounded. */
+
+static int
+nvptx_goacc_dim_limit (int axis)
+{
+ switch (axis)
+ {
+ case GOMP_DIM_WORKER:
+ return PTX_WORKER_LENGTH;
+
+ case GOMP_DIM_VECTOR:
+ return PTX_VECTOR_LENGTH;
+
+ default:
+ break;
+ }
+ return 0;
+}
+
/* Determine whether fork & joins are needed. */
static bool
@@ -3376,6 +3399,9 @@ nvptx_goacc_fork_join (gcall *call, cons
#undef TARGET_GOACC_VALIDATE_DIMS
#define TARGET_GOACC_VALIDATE_DIMS nvptx_goacc_validate_dims
+#undef TARGET_GOACC_DIM_LIMIT
+#define TARGET_GOACC_DIM_LIMIT nvptx_goacc_dim_limit
+
#undef TARGET_GOACC_FORK_JOIN
#define TARGET_GOACC_FORK_JOIN nvptx_goacc_fork_join
Index: gcc/omp-low.c
===================================================================
--- gcc/omp-low.c (revision 229535)
+++ gcc/omp-low.c (working copy)
@@ -19380,6 +19380,18 @@ default_goacc_validate_dims (tree ARG_UN
return changed;
}
+/* Default dimension bound is unknown on accelerator and 1 on host. */
+
+int
+default_goacc_dim_limit (int ARG_UNUSED (axis))
+{
+#ifdef ACCEL_COMPILER
+ return 0;
+#else
+ return 1;
+#endif
+}
+
namespace {
const pass_data pass_data_oacc_device_lower =
Index: gcc/tree-vrp.c
===================================================================
--- gcc/tree-vrp.c (revision 229535)
+++ gcc/tree-vrp.c (working copy)
@@ -58,8 +58,8 @@ along with GCC; see the file COPYING3.
#include "tree-ssa-threadupdate.h"
#include "tree-ssa-scopedtables.h"
#include "tree-ssa-threadedge.h"
-
-
+#include "omp-low.h"
+#include "target.h"
/* Range of values that can be associated with an SSA_NAME after VRP
has executed. */
@@ -3976,7 +3976,9 @@ extract_range_basic (value_range *vr, gi
else if (is_gimple_call (stmt) && gimple_call_internal_p (stmt))
{
enum tree_code subcode = ERROR_MARK;
- switch (gimple_call_internal_fn (stmt))
+ unsigned ifn_code = gimple_call_internal_fn (stmt);
+
+ switch (ifn_code)
{
case IFN_UBSAN_CHECK_ADD:
subcode = PLUS_EXPR;
@@ -3987,6 +3989,37 @@ extract_range_basic (value_range *vr, gi
case IFN_UBSAN_CHECK_MUL:
subcode = MULT_EXPR;
break;
+ case IFN_GOACC_DIM_SIZE:
+ case IFN_GOACC_DIM_POS:
+ /* Optimizing these two internal functions helps the loop
+ optimizer eliminate outer comparisons. Size is [1,N]
+ and pos is [0,N-1]. */
+ {
+ bool is_pos = ifn_code == IFN_GOACC_DIM_POS;
+ tree attr = get_oacc_fn_attrib (current_function_decl);
+ tree arg = gimple_call_arg (stmt, 0);
+ int axis = TREE_INT_CST_LOW (arg);
+ tree dims = TREE_VALUE (attr);
+
+ for (int ix = axis; ix--;)
+ dims = TREE_CHAIN (dims);
+ int size = TREE_INT_CST_LOW (TREE_VALUE (dims));
+
+ if (!size)
+ /* If it's dynamic, the backend might know a hardware
+ limitation. */
+ size = targetm.goacc.dim_limit (axis);
+
+ if (size)
+ {
+ tree type = TREE_TYPE (gimple_call_lhs (stmt));
+
+ set_value_range (vr, VR_RANGE,
+ build_int_cst (type, is_pos ? 0 : 1),
+ build_int_cst (type, size - is_pos), NULL);
+ }
+ }
+ return;
default:
break;
}
Index: gcc/doc/tm.texi
===================================================================
--- gcc/doc/tm.texi (revision 229535)
+++ gcc/doc/tm.texi (working copy)
@@ -5777,6 +5777,11 @@ true, if changes have been made. You mu
provide dimensions larger than 1.
@end deftypefn
+@deftypefn {Target Hook} int TARGET_GOACC_DIM_LIMIT (int @var{axis})
+This hook should return the maximum size of a particular dimension,
+or zero if unbounded.
+@end deftypefn
+
@deftypefn {Target Hook} bool TARGET_GOACC_FORK_JOIN (gcall *@var{call}, const int *@var{dims}, bool @var{is_fork})
This hook can be used to convert IFN_GOACC_FORK and IFN_GOACC_JOIN
function calls to target-specific gimple, or indicate whether they
Index: gcc/doc/tm.texi.in
===================================================================
--- gcc/doc/tm.texi.in (revision 229535)
+++ gcc/doc/tm.texi.in (working copy)
@@ -4262,6 +4262,8 @@ address; but often a machine-dependent
@hook TARGET_GOACC_VALIDATE_DIMS
+@hook TARGET_GOACC_DIM_LIMIT
+
@hook TARGET_GOACC_FORK_JOIN
@node Anchored Addresses
Index: gcc/target.def
===================================================================
--- gcc/target.def (revision 229535)
+++ gcc/target.def (working copy)
@@ -1659,6 +1659,13 @@ bool, (tree decl, int *dims, int fn_leve
default_goacc_validate_dims)
DEFHOOK
+(dim_limit,
+"This hook should return the maximum size of a particular dimension,\n\
+or zero if unbounded.",
+int, (int axis),
+default_goacc_dim_limit)
+
+DEFHOOK
(fork_join,
"This hook can be used to convert IFN_GOACC_FORK and IFN_GOACC_JOIN\n\
function calls to target-specific gimple, or indicate whether they\n\
