[PATCH 6/8] new target hook: TARGET_SIMT_VF

[Alexander Monakov <amonakov at ispras dot ru>]

This patch adds a new target hook and implements it in a straightforward
manner on NVPTX to indicate that the target is running in SIMT fashion with 32
threads in a synchronous group ("warp").  For use in OpenMP transforms.

	* config/nvptx/nvptx.c (nvptx_simt_vf): New.
	(TARGET_SIMT_VF): Define.
	* doc/tm.texi: Regenerate.
	* doc/tm.texi.in: (TARGET_SIMT_VF): New hook.
	* target.def: Define it.
---
 gcc/config/nvptx/nvptx.c | 11 +++++++++++
 gcc/doc/tm.texi          |  4 ++++
 gcc/doc/tm.texi.in       |  2 ++
 gcc/target.def           | 12 ++++++++++++
 4 files changed, 29 insertions(+)

diff --git a/gcc/config/nvptx/nvptx.c b/gcc/config/nvptx/nvptx.c
index 294002e..46afae4 100644
--- a/gcc/config/nvptx/nvptx.c
+++ b/gcc/config/nvptx/nvptx.c
@@ -4430,6 +4430,14 @@ nvptx_expand_builtin (tree exp, rtx target, rtx ARG_UNUSED (subtarget),
 #define PTX_WORKER_LENGTH 32
 #define PTX_GANG_DEFAULT  32
 
+/* Implement TARGET_SIMT_VF target hook: number of threads in a warp.  */
+
+static int
+nvptx_simt_vf ()
+{
+  return PTX_VECTOR_LENGTH;
+}
+
 /* 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.  If
@@ -5195,6 +5203,9 @@ nvptx_goacc_reduction (gcall *call)
 #undef  TARGET_BUILTIN_DECL
 #define TARGET_BUILTIN_DECL nvptx_builtin_decl
 
+#undef TARGET_SIMT_VF
+#define TARGET_SIMT_VF nvptx_simt_vf
+
 #undef TARGET_GOACC_VALIDATE_DIMS
 #define TARGET_GOACC_VALIDATE_DIMS nvptx_goacc_validate_dims
 
diff --git a/gcc/doc/tm.texi b/gcc/doc/tm.texi
index b318615..93af006 100644
--- a/gcc/doc/tm.texi
+++ b/gcc/doc/tm.texi
@@ -5768,6 +5768,10 @@ usable.  In that case, the smaller the number is, the more desirable it is
 to use it.
 @end deftypefn
 
+@deftypefn {Target Hook} int TARGET_SIMT_VF (void)
+Return number of threads in SIMT thread group on the target.
+@end deftypefn
+
 @deftypefn {Target Hook} bool TARGET_GOACC_VALIDATE_DIMS (tree @var{decl}, int *@var{dims}, int @var{fn_level})
 This hook should check the launch dimensions provided for an OpenACC
 compute region, or routine.  Defaulted values are represented as -1
diff --git a/gcc/doc/tm.texi.in b/gcc/doc/tm.texi.in
index 1e8423c..ccec1b1 100644
--- a/gcc/doc/tm.texi.in
+++ b/gcc/doc/tm.texi.in
@@ -4263,6 +4263,8 @@ address;  but often a machine-dependent strategy can generate better code.
 
 @hook TARGET_SIMD_CLONE_USABLE
 
+@hook TARGET_SIMT_VF
+
 @hook TARGET_GOACC_VALIDATE_DIMS
 
 @hook TARGET_GOACC_DIM_LIMIT
diff --git a/gcc/target.def b/gcc/target.def
index a4df363..ba47e5b 100644
--- a/gcc/target.def
+++ b/gcc/target.def
@@ -1639,6 +1639,18 @@ int, (struct cgraph_node *), NULL)
 
 HOOK_VECTOR_END (simd_clone)
 
+/* Functions relating to OpenMP SIMT vectorization transform.  */
+#undef HOOK_PREFIX
+#define HOOK_PREFIX "TARGET_SIMT_"
+HOOK_VECTOR (TARGET_SIMT, simt)
+
+DEFHOOK
+(vf,
+"Return number of threads in SIMT thread group on the target.",
+int, (void), NULL)
+
+HOOK_VECTOR_END (simt)
+
 /* Functions relating to openacc.  */
 #undef HOOK_PREFIX
 #define HOOK_PREFIX "TARGET_GOACC_"
-- 
2.6.6