On 10/5/18 07:07, Tom de Vries wrote:
> On 6/29/18 8:19 PM, Cesar Philippidis wrote:
>> The attached patch includes the nvptx and GCC ME reductions enhancements.
>>
>> Is this patch OK for trunk? It bootstrapped / regression tested cleanly
>> for x86_64 with nvptx offloading.
>>
>
> These need fixing:
> ...
> === ERROR type #5: trailing whitespace (4 error(s)) ===
> gcc/config/nvptx/nvptx.c:5139:0:██
> gcc/config/nvptx/nvptx.c:5660:8: do█
> gcc/config/nvptx/nvptx.c:5702:0:██
> gcc/config/nvptx/nvptx.c:5726:0:██
> ...
Sorry. The attached patch fixes that.
> Otherwise, nvptx part LGTM.
Tomorrow's my last day at Mentor, so either Thomas or Julian will need
to commit it once the other patches get approved.
Thanks,
Cesar
gcc/
* config/nvptx/nvptx.c (nvptx_propagate_unified): New.
(nvptx_split_blocks): Call it for cond_uni insn.
(nvptx_expand_cond_uni): New.
(enum nvptx_builtins): Add NVPTX_BUILTIN_COND_UNI.
(nvptx_init_builtins): Initialize it.
(nvptx_expand_builtin):
(nvptx_generate_vector_shuffle): Change integral SHIFT operand to
tree BITS operand.
(nvptx_vector_reduction): New.
(nvptx_adjust_reduction_type): New.
(nvptx_goacc_reduction_setup): Use it to adjust the type of ref_to_res.
(nvptx_goacc_reduction_init): Don't update LHS if it doesn't exist.
(nvptx_goacc_reduction_fini): Call nvptx_vector_reduction for vector.
Use it to adjust the type of ref_to_res.
(nvptx_goacc_reduction_teardown):
* config/nvptx/nvptx.md (cond_uni): New pattern.
diff --git a/gcc/config/nvptx/nvptx.c b/gcc/config/nvptx/nvptx.c
index 9903a273863..acb490a9a90 100644
--- a/gcc/config/nvptx/nvptx.c
+++ b/gcc/config/nvptx/nvptx.c
@@ -2863,6 +2863,52 @@ nvptx_reorg_uniform_simt ()
}
}
+/* UNIFIED is a cond_uni insn. Find the branch insn it affects, and
+ mark that as unified. We expect to be in a single block. */
+
+static void
+nvptx_propagate_unified (rtx_insn *unified)
+{
+ rtx_insn *probe = unified;
+ rtx cond_reg = SET_DEST (PATTERN (unified));
+ rtx pat = NULL_RTX;
+
+ /* Find the comparison. (We could skip this and simply scan to he
+ blocks' terminating branch, if we didn't care for self
+ checking.) */
+ for (;;)
+ {
+ probe = next_real_insn (probe);
+ if (!probe)
+ break;
+ pat = PATTERN (probe);
+
+ if (GET_CODE (pat) == SET
+ && GET_RTX_CLASS (GET_CODE (SET_SRC (pat))) == RTX_COMPARE
+ && XEXP (SET_SRC (pat), 0) == cond_reg)
+ break;
+ gcc_assert (NONJUMP_INSN_P (probe));
+ }
+ gcc_assert (pat);
+ rtx pred_reg = SET_DEST (pat);
+
+ /* Find the branch. */
+ do
+ probe = NEXT_INSN (probe);
+ while (!JUMP_P (probe));
+
+ pat = PATTERN (probe);
+ rtx itec = XEXP (SET_SRC (pat), 0);
+ gcc_assert (XEXP (itec, 0) == pred_reg);
+
+ /* Mark the branch's condition as unified. */
+ rtx unspec = gen_rtx_UNSPEC (BImode, gen_rtvec (1, pred_reg),
+ UNSPEC_BR_UNIFIED);
+ bool ok = validate_change (probe, &XEXP (itec, 0), unspec, false);
+
+ gcc_assert (ok);
+}
+
/* Loop structure of the function. The entire function is described as
a NULL loop. */
@@ -2964,6 +3010,9 @@ nvptx_split_blocks (bb_insn_map_t *map)
continue;
switch (recog_memoized (insn))
{
+ case CODE_FOR_cond_uni:
+ nvptx_propagate_unified (insn);
+ /* FALLTHROUGH */
default:
seen_insn = true;
continue;
@@ -5083,6 +5132,21 @@ nvptx_expand_cmp_swap (tree exp, rtx target,
return target;
}
+/* Expander for the compare unified builtin. */
+
+static rtx
+nvptx_expand_cond_uni (tree exp, rtx target, machine_mode mode, int ignore)
+{
+ if (ignore)
+ return target;
+
+ rtx src = expand_expr (CALL_EXPR_ARG (exp, 0),
+ NULL_RTX, mode, EXPAND_NORMAL);
+
+ emit_insn (gen_cond_uni (target, src));
+
+ return target;
+}
/* Codes for all the NVPTX builtins. */
enum nvptx_builtins
@@ -5092,6 +5156,7 @@ enum nvptx_builtins
NVPTX_BUILTIN_WORKER_ADDR,
NVPTX_BUILTIN_CMP_SWAP,
NVPTX_BUILTIN_CMP_SWAPLL,
+ NVPTX_BUILTIN_COND_UNI,
NVPTX_BUILTIN_MAX
};
@@ -5129,6 +5194,7 @@ nvptx_init_builtins (void)
(PTRVOID, ST, UINT, UINT, NULL_TREE));
DEF (CMP_SWAP, "cmp_swap", (UINT, PTRVOID, UINT, UINT, NULL_TREE));
DEF (CMP_SWAPLL, "cmp_swapll", (LLUINT, PTRVOID, LLUINT, LLUINT, NULL_TREE));
+ DEF (COND_UNI, "cond_uni", (integer_type_node, integer_type_node, NULL_TREE));
#undef DEF
#undef ST
@@ -5161,6 +5227,9 @@ nvptx_expand_builtin (tree exp, rtx target, rtx ARG_UNUSED (subtarget),
case NVPTX_BUILTIN_CMP_SWAPLL:
return nvptx_expand_cmp_swap (exp, target, mode, ignore);
+ case NVPTX_BUILTIN_COND_UNI:
+ return nvptx_expand_cond_uni (exp, target, mode, ignore);
+
default: gcc_unreachable ();
}
}
@@ -5284,7 +5353,7 @@ nvptx_get_worker_red_addr (tree type, tree offset)
static void
nvptx_generate_vector_shuffle (location_t loc,
- tree dest_var, tree var, unsigned shift,
+ tree dest_var, tree var, tree bits,
gimple_seq *seq)
{
unsigned fn = NVPTX_BUILTIN_SHUFFLE;
@@ -5307,7 +5376,6 @@ nvptx_generate_vector_shuffle (location_t loc,
}
tree call = nvptx_builtin_decl (fn, true);
- tree bits = build_int_cst (unsigned_type_node, shift);
tree kind = build_int_cst (unsigned_type_node, SHUFFLE_DOWN);
tree expr;
@@ -5583,6 +5651,126 @@ nvptx_reduction_update (location_t loc, gimple_stmt_iterator *gsi,
return nvptx_lockfull_update (loc, gsi, ptr, var, op);
}
+/* Emit a vector-level reduction loop. OLD_VAR is the incoming
+ variable to reduce (valid in each vector), OP is the reduction
+ operator. Return the reduced value (an SSA var).
+
+ The code we generate looks like:
+ unsigned old_shift = DIM_SIZE(VECTOR);
+ do
+ {
+ shift = PHI (old_shift, new_shift);
+ var = PHI (old_var, new_var);
+ new_shift = shift >> 1;
+ other_var = VSHUFFLE (var, new_shift);
+ new_var = var OP other_var;
+ cond_var = builtin_cond_uni (new_shift);
+ }
+ while (cond_var > 1);
+
+ The builtin_cond_ini expands to a cond_uni instruction, which is
+ processed in nvpts_split_blocks to mark the loop's terminating
+ branch instruction. */
+
+static tree
+nvptx_vector_reduction (location_t loc, gimple_stmt_iterator *gsi,
+ tree old_var, tree_code op)
+{
+ tree var_type = TREE_TYPE (old_var);
+
+ /* Emit old_shift = DIM_SIZE(VECTOR) */
+ tree old_shift = make_ssa_name (integer_type_node);
+ tree dim = build_int_cst (integer_type_node, GOMP_DIM_VECTOR);
+ gcall *call = gimple_build_call_internal (IFN_GOACC_DIM_SIZE, 1, dim);
+ gimple_set_lhs (call, old_shift);
+ gimple_set_location (call, loc);
+ gsi_insert_before (gsi, call, GSI_SAME_STMT);
+
+ /* Split the block just after the init stmts. */
+ basic_block pre_bb = gsi_bb (*gsi);
+ edge pre_edge = split_block (pre_bb, call);
+ basic_block loop_bb = pre_edge->dest;
+ pre_bb = pre_edge->src;
+ /* Reset the iterator. */
+ *gsi = gsi_for_stmt (gsi_stmt (*gsi));
+
+ tree shift = make_ssa_name (integer_type_node);
+ tree new_shift = make_ssa_name (integer_type_node);
+ tree var = make_ssa_name (var_type);
+ tree other_var = make_ssa_name (var_type);
+ tree new_var = make_ssa_name (var_type);
+
+ /* Build and insert the loop body. */
+ gimple_seq loop_seq = NULL;
+
+ /* new_shift = shift >> 1 */
+ tree shift_expr = fold_build2 (RSHIFT_EXPR, integer_type_node,
+ shift, integer_one_node);
+ gimplify_assign (new_shift, shift_expr, &loop_seq);
+
+ /* other_var = shuffle (var, shift) */
+ nvptx_generate_vector_shuffle (loc, other_var, var, new_shift, &loop_seq);
+ /* new_var = var OP other_var */
+ tree red_expr = fold_build2 (op, var_type, var, other_var);
+ gimplify_assign (new_var, red_expr, &loop_seq);
+
+ /* Mark the iterator variable as unified. */
+ tree cond_var = make_ssa_name (integer_type_node);
+ tree uni_fn = nvptx_builtin_decl (NVPTX_BUILTIN_COND_UNI, true);
+ tree uni_expr = build_call_expr_loc (loc, uni_fn, 1, new_shift);
+ gimplify_assign (cond_var, uni_expr, &loop_seq);
+
+ gcond *cond = gimple_build_cond (LE_EXPR, cond_var, integer_one_node,
+ NULL_TREE, NULL_TREE);
+ gimple_seq_add_stmt (&loop_seq, cond);
+
+ gsi_insert_seq_before (gsi, loop_seq, GSI_SAME_STMT);
+
+ /* Split the block just after the loop stmts. */
+ edge post_edge = split_block (loop_bb, cond);
+ basic_block post_bb = post_edge->dest;
+ loop_bb = post_edge->src;
+ *gsi = gsi_for_stmt (gsi_stmt (*gsi));
+
+ /* Create the loop. */
+ post_edge->flags ^= EDGE_TRUE_VALUE | EDGE_FALLTHRU;
+ edge loop_edge = make_edge (loop_bb, loop_bb, EDGE_FALSE_VALUE);
+ set_immediate_dominator (CDI_DOMINATORS, loop_bb, pre_bb);
+ set_immediate_dominator (CDI_DOMINATORS, post_bb, loop_bb);
+
+ gphi *shift_phi = create_phi_node (shift, loop_bb);
+ add_phi_arg (shift_phi, old_shift, pre_edge, loc);
+ add_phi_arg (shift_phi, new_shift, loop_edge, loc);
+
+ gphi *var_phi = create_phi_node (var, loop_bb);
+ add_phi_arg (var_phi, old_var, pre_edge, loc);
+ add_phi_arg (var_phi, new_var, loop_edge, loc);
+
+ loop *loop = alloc_loop ();
+ loop->header = loop_bb;
+ loop->latch = loop_bb;
+ add_loop (loop, loop_bb->loop_father);
+
+ return new_var;
+}
+
+/* Dummy reduction vars that have GOMP_MAP_FIRSTPRIVATE_POINTER data
+ mappings gets retyped to (void *). Adjust the type of VAR to TYPE
+ as appropriate. */
+
+static tree
+nvptx_adjust_reduction_type (tree var, tree type, gimple_seq *seq)
+{
+ if (TREE_TYPE (TREE_TYPE (var)) == type)
+ return var;
+
+ tree ptype = build_pointer_type (type);
+ tree t = make_ssa_name (ptype);
+ tree expr = fold_build1 (NOP_EXPR, ptype, var);
+ gimple_seq_add_stmt (seq, gimple_build_assign (t, expr));
+ return t;
+}
+
/* NVPTX implementation of GOACC_REDUCTION_SETUP. */
static void
@@ -5602,7 +5790,11 @@ nvptx_goacc_reduction_setup (gcall *call)
tree ref_to_res = gimple_call_arg (call, 1);
if (!integer_zerop (ref_to_res))
- var = build_simple_mem_ref (ref_to_res);
+ {
+ ref_to_res = nvptx_adjust_reduction_type (ref_to_res, TREE_TYPE (var),
+ &seq);
+ var = build_simple_mem_ref (ref_to_res);
+ }
}
if (level == GOMP_DIM_WORKER)
@@ -5702,7 +5894,11 @@ nvptx_goacc_reduction_init (gcall *call)
init = var;
}
- gimplify_assign (lhs, init, &seq);
+ /* The LHS may be NULL if a reduction variable on a parallel
+ construct is initialized to some constant inside the parallel
+ region. */
+ if (lhs)
+ gimplify_assign (lhs, init, &seq);
}
pop_gimplify_context (NULL);
@@ -5727,22 +5923,7 @@ nvptx_goacc_reduction_fini (gcall *call)
push_gimplify_context (true);
if (level == GOMP_DIM_VECTOR)
- {
- /* Emit binary shuffle tree. TODO. Emit this as an actual loop,
- but that requires a method of emitting a unified jump at the
- gimple level. */
- for (int shfl = PTX_VECTOR_LENGTH / 2; shfl > 0; shfl = shfl >> 1)
- {
- tree other_var = make_ssa_name (TREE_TYPE (var));
- nvptx_generate_vector_shuffle (gimple_location (call),
- other_var, var, shfl, &seq);
-
- r = make_ssa_name (TREE_TYPE (var));
- gimplify_assign (r, fold_build2 (op, TREE_TYPE (var),
- var, other_var), &seq);
- var = r;
- }
- }
+ r = nvptx_vector_reduction (gimple_location (call), &gsi, var, op);
else
{
tree accum = NULL_TREE;
@@ -5760,7 +5941,11 @@ nvptx_goacc_reduction_fini (gcall *call)
else if (integer_zerop (ref_to_res))
r = var;
else
- accum = ref_to_res;
+ {
+ ref_to_res = nvptx_adjust_reduction_type (ref_to_res, TREE_TYPE (var),
+ &seq);
+ accum = ref_to_res;
+ }
if (accum)
{
@@ -5809,7 +5994,11 @@ nvptx_goacc_reduction_teardown (gcall *call)
tree ref_to_res = gimple_call_arg (call, 1);
if (!integer_zerop (ref_to_res))
- gimplify_assign (build_simple_mem_ref (ref_to_res), var, &seq);
+ {
+ ref_to_res = nvptx_adjust_reduction_type (ref_to_res, TREE_TYPE (var),
+ &seq);
+ gimplify_assign (build_simple_mem_ref (ref_to_res), var, &seq);
+ }
}
if (lhs)
diff --git a/gcc/config/nvptx/nvptx.md b/gcc/config/nvptx/nvptx.md
index ca00b1d8073..4f7d8ea0e68 100644
--- a/gcc/config/nvptx/nvptx.md
+++ b/gcc/config/nvptx/nvptx.md
@@ -600,6 +600,13 @@
"%J0\\tbra.uni\\t%l1;"
[(set_attr "predicable" "false")])
+(define_insn "cond_uni"
+ [(set (match_operand:SI 0 "nvptx_register_operand" "=R")
+ (unspec:SI [(match_operand:SI 1 "nvptx_nonmemory_operand" "R")]
+ UNSPEC_BR_UNIFIED))]
+ ""
+ "%.\\tmov%t0\\t%0, %1; // unified")
+
(define_expand "cbranch<mode>4"
[(set (pc)
(if_then_else (match_operator 0 "nvptx_comparison_operator"
