[PATCH V4] VECT: Enhance SLP of MASK_LEN_GATHER_LOAD[PR111721]
Juzhe-Zhong
juzhe.zhong@rivai.ai
Tue Oct 17 06:43:24 GMT 2023
This patch fixes this following FAILs in RISC-V regression:
FAIL: gcc.dg/vect/vect-gather-1.c -flto -ffat-lto-objects scan-tree-dump vect "Loop contains only SLP stmts"
FAIL: gcc.dg/vect/vect-gather-1.c scan-tree-dump vect "Loop contains only SLP stmts"
FAIL: gcc.dg/vect/vect-gather-3.c -flto -ffat-lto-objects scan-tree-dump vect "Loop contains only SLP stmts"
FAIL: gcc.dg/vect/vect-gather-3.c scan-tree-dump vect "Loop contains only SLP stmts"
The root cause of these FAIL is that GCC SLP failed on MASK_LEN_GATHER_LOAD.
We have 2 following situations of scalar recognized MASK_LEN_GATHER_LOAD:
1. conditional gather load: MASK_LEN_GATHER_LOAD (base, offset, scale, zero, condtional mask).
This situation we just need to leverage the current MASK_GATHER_LOAD which can achieve SLP MASK_LEN_GATHER_LOAD.
2. un-conditional gather load: MASK_LEN_GATHER_LOAD (base, offset, scale, zero, -1)
Current SLP check will failed on dummy mask -1, so we relax the check in tree-vect-slp.cc and allow it to be materialized.
Consider this following case:
void __attribute__((noipa))
f (int *restrict y, int *restrict x, int *restrict indices, int n)
{
for (int i = 0; i < n; ++i)
{
y[i * 2] = x[indices[i * 2]] + 1;
y[i * 2 + 1] = x[indices[i * 2 + 1]] + 2;
}
}
https://godbolt.org/z/WG3M3n7Mo
GCC unable to SLP using VEC_LOAD_LANES/VEC_STORE_LANES:
f:
ble a3,zero,.L5
.L3:
vsetvli a5,a3,e8,mf4,ta,ma
vsetvli zero,a5,e32,m1,ta,ma
vlseg2e32.v v6,(a2)
vsetvli a4,zero,e64,m2,ta,ma
vsext.vf2 v2,v6
vsll.vi v2,v2,2
vsetvli zero,a5,e32,m1,ta,ma
vluxei64.v v1,(a1),v2
vsetvli a4,zero,e64,m2,ta,ma
vsext.vf2 v2,v7
vsetvli zero,zero,e32,m1,ta,ma
vadd.vi v4,v1,1
vsetvli zero,zero,e64,m2,ta,ma
vsll.vi v2,v2,2
vsetvli zero,a5,e32,m1,ta,ma
vluxei64.v v2,(a1),v2
vsetvli a4,zero,e32,m1,ta,ma
slli a6,a5,3
vadd.vi v5,v2,2
sub a3,a3,a5
vsetvli zero,a5,e32,m1,ta,ma
vsseg2e32.v v4,(a0)
add a2,a2,a6
add a0,a0,a6
bne a3,zero,.L3
.L5:
ret
After this patch:
f:
ble a3,zero,.L5
li a5,1
csrr t1,vlenb
slli a5,a5,33
srli a7,t1,2
addi a5,a5,1
slli a3,a3,1
neg t3,a7
vsetvli a4,zero,e64,m1,ta,ma
vmv.v.x v4,a5
.L3:
minu a5,a3,a7
vsetvli zero,a5,e32,m1,ta,ma
vle32.v v1,0(a2)
vsetvli a4,zero,e64,m2,ta,ma
vsext.vf2 v2,v1
vsll.vi v2,v2,2
vsetvli zero,a5,e32,m1,ta,ma
vluxei64.v v2,(a1),v2
vsetvli a4,zero,e32,m1,ta,ma
mv a6,a3
vadd.vv v2,v2,v4
vsetvli zero,a5,e32,m1,ta,ma
vse32.v v2,0(a0)
add a2,a2,t1
add a0,a0,t1
add a3,a3,t3
bgtu a6,a7,.L3
.L5:
ret
Note that I found we are missing conditional mask gather_load SLP test, Append a test for it in this patch.
Tested on RISC-V and Bootstrap && Regression on X86 passed.
Ok for trunk ?
gcc/ChangeLog:
* tree-vect-slp.cc (vect_get_operand_map): Add MASK_LEN_GATHER_LOAD.
(vect_get_and_check_slp_defs): Ditto.
(vect_build_slp_tree_1): Ditto.
(vect_build_slp_tree_2): Ditto.
* tree-vect-stmts.cc (vectorizable_load): Ditto.
gcc/testsuite/ChangeLog:
* gcc.dg/vect/vect-gather-6.c: New test.
---
gcc/testsuite/gcc.dg/vect/vect-gather-6.c | 15 +++++++++++++++
gcc/tree-vect-slp.cc | 22 ++++++++++++++++++----
gcc/tree-vect-stmts.cc | 9 ++++++++-
3 files changed, 41 insertions(+), 5 deletions(-)
create mode 100644 gcc/testsuite/gcc.dg/vect/vect-gather-6.c
diff --git a/gcc/testsuite/gcc.dg/vect/vect-gather-6.c b/gcc/testsuite/gcc.dg/vect/vect-gather-6.c
new file mode 100644
index 00000000000..ff55f321854
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/vect/vect-gather-6.c
@@ -0,0 +1,15 @@
+/* { dg-do compile } */
+
+void
+f (int *restrict y, int *restrict x, int *restrict indices, int *restrict cond, int n)
+{
+ for (int i = 0; i < n; ++i)
+ {
+ if (cond[i * 2])
+ y[i * 2] = x[indices[i * 2]] + 1;
+ if (cond[i * 2 + 1])
+ y[i * 2 + 1] = x[indices[i * 2 + 1]] + 2;
+ }
+}
+
+/* { dg-final { scan-tree-dump "Loop contains only SLP stmts" vect { target vect_gather_load_ifn } } } */
diff --git a/gcc/tree-vect-slp.cc b/gcc/tree-vect-slp.cc
index af8f5031bd2..b379278446b 100644
--- a/gcc/tree-vect-slp.cc
+++ b/gcc/tree-vect-slp.cc
@@ -550,6 +550,7 @@ vect_get_operand_map (const gimple *stmt, unsigned char swap = 0)
return arg1_map;
case IFN_MASK_GATHER_LOAD:
+ case IFN_MASK_LEN_GATHER_LOAD:
return arg1_arg4_map;
case IFN_MASK_STORE:
@@ -717,8 +718,7 @@ vect_get_and_check_slp_defs (vec_info *vinfo, unsigned char swap,
{
tree type = TREE_TYPE (oprnd);
dt = dts[i];
- if ((dt == vect_constant_def
- || dt == vect_external_def)
+ if (dt == vect_external_def
&& !GET_MODE_SIZE (vinfo->vector_mode).is_constant ()
&& (TREE_CODE (type) == BOOLEAN_TYPE
|| !can_duplicate_and_interleave_p (vinfo, stmts.length (),
@@ -730,6 +730,17 @@ vect_get_and_check_slp_defs (vec_info *vinfo, unsigned char swap,
"for variable-length SLP %T\n", oprnd);
return -1;
}
+ if (dt == vect_constant_def
+ && !GET_MODE_SIZE (vinfo->vector_mode).is_constant ()
+ && !can_duplicate_and_interleave_p (vinfo, stmts.length (), type))
+ {
+ if (dump_enabled_p ())
+ dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
+ "Build SLP failed: invalid type of def "
+ "for variable-length SLP %T\n",
+ oprnd);
+ return -1;
+ }
/* For the swapping logic below force vect_reduction_def
for the reduction op in a SLP reduction group. */
@@ -1094,7 +1105,8 @@ vect_build_slp_tree_1 (vec_info *vinfo, unsigned char *swap,
if (cfn == CFN_MASK_LOAD
|| cfn == CFN_GATHER_LOAD
- || cfn == CFN_MASK_GATHER_LOAD)
+ || cfn == CFN_MASK_GATHER_LOAD
+ || cfn == CFN_MASK_LEN_GATHER_LOAD)
ldst_p = true;
else if (cfn == CFN_MASK_STORE)
{
@@ -1355,6 +1367,7 @@ vect_build_slp_tree_1 (vec_info *vinfo, unsigned char *swap,
if (DR_IS_READ (STMT_VINFO_DATA_REF (stmt_info))
&& rhs_code != CFN_GATHER_LOAD
&& rhs_code != CFN_MASK_GATHER_LOAD
+ && rhs_code != CFN_MASK_LEN_GATHER_LOAD
/* Not grouped loads are handled as externals for BB
vectorization. For loop vectorization we can handle
splats the same we handle single element interleaving. */
@@ -1855,7 +1868,8 @@ vect_build_slp_tree_2 (vec_info *vinfo, slp_tree node,
if (gcall *stmt = dyn_cast <gcall *> (stmt_info->stmt))
gcc_assert (gimple_call_internal_p (stmt, IFN_MASK_LOAD)
|| gimple_call_internal_p (stmt, IFN_GATHER_LOAD)
- || gimple_call_internal_p (stmt, IFN_MASK_GATHER_LOAD));
+ || gimple_call_internal_p (stmt, IFN_MASK_GATHER_LOAD)
+ || gimple_call_internal_p (stmt, IFN_MASK_LEN_GATHER_LOAD));
else
{
*max_nunits = this_max_nunits;
diff --git a/gcc/tree-vect-stmts.cc b/gcc/tree-vect-stmts.cc
index b3a56498595..d50eb48c0be 100644
--- a/gcc/tree-vect-stmts.cc
+++ b/gcc/tree-vect-stmts.cc
@@ -9874,12 +9874,19 @@ vectorizable_load (vec_info *vinfo,
return false;
mask_index = internal_fn_mask_index (ifn);
+ slp_tree slp_op = NULL;
if (mask_index >= 0 && slp_node)
mask_index = vect_slp_child_index_for_operand (call, mask_index);
if (mask_index >= 0
&& !vect_check_scalar_mask (vinfo, stmt_info, slp_node, mask_index,
- &mask, NULL, &mask_dt, &mask_vectype))
+ &mask, &slp_op, &mask_dt, &mask_vectype))
return false;
+ if (mask_index >= 0 && slp_node)
+ {
+ bool match_p
+ = vect_maybe_update_slp_op_vectype (slp_op, mask_vectype);
+ gcc_assert (match_p);
+ }
}
tree vectype = STMT_VINFO_VECTYPE (stmt_info);
--
2.36.3
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