Hi Richi,
The attached testcase ICEs due to a couple of issues.
In the testcase you have two SLP instances that share the majority of their
definition with each other. One tree defines a COMPLEX_MUL sequence and the
other tree a COMPLEX_FMA.
The ice happens because:
1. the refcounts are wrong, in particular the FMA case doesn't correctly count
the references for the COMPLEX_MUL that it consumes.
2. when the FMA is created it incorrectly assumes it can just tear apart the MUL
node that it's consuming. This is wrong and should only be done when there is
no more uses of the node, in which case the vector only pattern is no longer
relevant.
To fix the last part the SLP only pattern reset code was moved into
vect_free_slp_tree which results in cleaner code. I also think it does belong
there since that function knows when there are no more uses of the node and so
the pattern should be unmarked, so when the the vectorizer is inspecting the BB
it doesn't find the now invalid vector only patterns.
This has the obvious problem in that, eventually after analysis is done, the
entire SLP tree is dissolved before codegen. Where we get into trouble as we
have now dissolved the patterns too...
My initial thought was to add a parameter to vect_free_slp_tree, but I know you
wouldn't like that. So I am sending this patch up as an RFC.
PS. This testcase actually shows that the codegen we get in these cases is not
optimal. Currently this won't vectorize as the compiler thinks the vector
version is too expensive.
My guess here is because the patterns now unshare the tree and it's likely
costing the setup for the vector code twice?
Even with the shared code (without patterns, so same as GCC 10, or turning off
the patterns) it won't vectorize it.
The scalar code is
mov w0, 0
ldr x4, [x1, #:lo12:.LANCHOR0]
ldrsw x2, [x3, 20]
ldr x1, [x3, 8]
lsl x2, x2, 3
ldrsw x3, [x3, 16]
ldp s3, s2, [x4]
add x5, x1, x2
ldr s0, [x1, x2]
lsl x3, x3, 3
add x4, x1, x3
fmul s1, s2, s2
fnmsub s1, s3, s3, s1
fmul s0, s2, s0
fmadd s0, s3, s2, s0
ldr s3, [x1, x3]
ldr s2, [x4, 4]
fadd s3, s3, s1
fadd s2, s0, s2
str s3, [x1, x3]
str s2, [x4, 4]
str s1, [x1, x2]
str s0, [x5, 4]
ret
and turning off the cost model we get
movi v1.2s, 0
mov w0, 0
ldr x4, [x1, #:lo12:.LANCHOR0]
ldrsw x3, [x2, 16]
ldr x1, [x2, 8]
ldrsw x2, [x2, 20]
ldr d0, [x4]
fcmla v1.2s, v0.2s, v0.2s, #0
ldr d2, [x1, x3, lsl 3]
fcmla v2.2s, v0.2s, v0.2s, #0
fcmla v2.2s, v0.2s, v0.2s, #90
str d2, [x1, x3, lsl 3]
fcmla v1.2s, v0.2s, v0.2s, #90
str d1, [x1, x2, lsl 3]
however, if the pattern matcher doesn't create the FMA node because it would
unshare the tree (which I think is a general heuristic that would work out to
better code wouldn't it?) then we would get (with the cost model enabled even)
movi v0.2s, 0
mov w0, 0
ldr x4, [x1, #:lo12:.LANCHOR0]
ldrsw x3, [x2, 16]
ldr x1, [x2, 8]
ldr d1, [x4]
fcmla v0.2s, v1.2s, v1.2s, #0
fcmla v0.2s, v1.2s, v1.2s, #90
ldrsw x2, [x2, 20]
ldr d1, [x1, x3, lsl 3]
fadd v1.2s, v1.2s, v0.2s
str d1, [x1, x3, lsl 3]
str d0, [x1, x2, lsl 3]
ret
Which is the most optimal form. So I think this should perhaps be handled in
GCC 12 if there's a way to detect when you're going to unshare a sub-tree.
Thanks,
Tamar
gcc/ChangeLog:
PR tree-optimization/99149
* tree-vect-slp-patterns.c (vect_detect_pair_op): Don't recreate the
buffer.
(vect_slp_reset_pattern): Remove.
(complex_fma_pattern::matches): Remove call to vect_slp_reset_pattern.
(complex_mul_pattern::build, complex_fma_pattern::build,
complex_fms_pattern::build): Fix ref counts.
* tree-vect-slp.c (vect_free_slp_tree): Undo SLP only pattern relevancy
when node is being deleted.
* tree-vectorizer.c (vec_info::new_stmt_vec_info): Initialize value.
gcc/testsuite/ChangeLog:
PR tree-optimization/99149
* gcc.dg/vect/pr99149.C: New test.
--- inline copy of patch --
diff --git a/gcc/testsuite/gcc.dg/vect/pr99149.C
b/gcc/testsuite/gcc.dg/vect/pr99149.C
new file mode 100755
index
0000000000000000000000000000000000000000..b12fe17e4ded148ce2bf67486e425dd65461a148
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/vect/pr99149.C
@@ -0,0 +1,25 @@
+/* { dg-do compile } */
+/* { dg-additional-options "-w -O3 -march=armv8.3-a" { target { aarch64*-*-* }
} } */
+
+class a {
+ float b;
+ float c;
+
+public:
+ a(float d, float e) : b(d), c(e) {}
+ a operator+(a d) { return a(b + d.b, c + d.c); }
+ a operator*(a d) { return a(b * b - c * c, b * c + c * d.b); }
+};
+int f, g;
+class {
+ a *h;
+ a *i;
+
+public:
+ void j() {
+ a k = h[0], l = i[g], m = k * i[f];
+ i[g] = l + m;
+ i[f] = m;
+ }
+} n;
+main() { n.j(); }
diff --git a/gcc/tree-vect-slp-patterns.c b/gcc/tree-vect-slp-patterns.c
index
f0817da9f622d22e3df2e30410d1cf610b4ffa1d..1e2769662a54229ab8e24390f97dfe206f17ab57
100644
--- a/gcc/tree-vect-slp-patterns.c
+++ b/gcc/tree-vect-slp-patterns.c
@@ -407,9 +407,8 @@ vect_detect_pair_op (slp_tree node1, slp_tree node2,
lane_permutation_t &lanes,
if (result != CMPLX_NONE && ops != NULL)
{
- ops->create (2);
- ops->quick_push (node1);
- ops->quick_push (node2);
+ ops->safe_push (node1);
+ ops->safe_push (node2);
}
return result;
}
@@ -1090,15 +1089,17 @@ complex_mul_pattern::build (vec_info *vinfo)
{
slp_tree node;
unsigned i;
+ slp_tree newnode
+ = vect_build_combine_node (this->m_ops[0], this->m_ops[1], *this->m_node);
+ SLP_TREE_REF_COUNT (this->m_ops[2])++;
+
FOR_EACH_VEC_ELT (SLP_TREE_CHILDREN (*this->m_node), i, node)
vect_free_slp_tree (node);
/* First re-arrange the children. */
SLP_TREE_CHILDREN (*this->m_node).reserve_exact (2);
SLP_TREE_CHILDREN (*this->m_node)[0] = this->m_ops[2];
- SLP_TREE_CHILDREN (*this->m_node)[1] =
- vect_build_combine_node (this->m_ops[0], this->m_ops[1], *this->m_node);
- SLP_TREE_REF_COUNT (this->m_ops[2])++;
+ SLP_TREE_CHILDREN (*this->m_node)[1] = newnode;
/* And then rewrite the node itself. */
complex_pattern::build (vinfo);
@@ -1133,18 +1134,6 @@ class complex_fma_pattern : public complex_pattern
}
};
-/* Helper function to "reset" a previously matched node and undo the changes
- made enough so that the node is treated as an irrelevant node. */
-
-static inline void
-vect_slp_reset_pattern (slp_tree node)
-{
- stmt_vec_info stmt_info = vect_orig_stmt (SLP_TREE_REPRESENTATIVE (node));
- STMT_VINFO_IN_PATTERN_P (stmt_info) = false;
- STMT_SLP_TYPE (stmt_info) = pure_slp;
- SLP_TREE_REPRESENTATIVE (node) = stmt_info;
-}
-
/* Pattern matcher for trying to match complex multiply and accumulate
and multiply and subtract patterns in SLP tree.
If the operation matches then IFN is set to the operation it matched and
@@ -1208,15 +1197,6 @@ complex_fma_pattern::matches (complex_operation_t op,
if (!vect_pattern_validate_optab (ifn, vnode))
return IFN_LAST;
- /* FMA matched ADD + CMUL. During the matching of CMUL the
- stmt that starts the pattern is marked as being in a pattern,
- namely the CMUL. When replacing this with a CFMA we have to
- unmark this statement as being in a pattern. This is because
- vect_mark_pattern_stmts will only mark the current stmt as being
- in a pattern. Later on when the scalar stmts are examined the
- old statement which is supposed to be irrelevant will point to
- CMUL unless we undo the pattern relationship here. */
- vect_slp_reset_pattern (node);
ops->truncate (0);
ops->create (3);
@@ -1259,10 +1239,17 @@ complex_fma_pattern::recognize
(slp_tree_to_load_perm_map_t *perm_cache,
void
complex_fma_pattern::build (vec_info *vinfo)
{
+ slp_tree node = SLP_TREE_CHILDREN (*this->m_node)[1];
+
SLP_TREE_CHILDREN (*this->m_node).release ();
SLP_TREE_CHILDREN (*this->m_node).create (3);
SLP_TREE_CHILDREN (*this->m_node).safe_splice (this->m_ops);
+ SLP_TREE_REF_COUNT (this->m_ops[1])++;
+ SLP_TREE_REF_COUNT (this->m_ops[2])++;
+
+ vect_free_slp_tree (node);
+
complex_pattern::build (vinfo);
}
@@ -1427,6 +1414,11 @@ complex_fms_pattern::build (vec_info *vinfo)
{
slp_tree node;
unsigned i;
+ slp_tree newnode =
+ vect_build_combine_node (this->m_ops[2], this->m_ops[3], *this->m_node);
+ SLP_TREE_REF_COUNT (this->m_ops[0])++;
+ SLP_TREE_REF_COUNT (this->m_ops[1])++;
+
FOR_EACH_VEC_ELT (SLP_TREE_CHILDREN (*this->m_node), i, node)
vect_free_slp_tree (node);
@@ -1436,10 +1428,7 @@ complex_fms_pattern::build (vec_info *vinfo)
/* First re-arrange the children. */
SLP_TREE_CHILDREN (*this->m_node).quick_push (this->m_ops[0]);
SLP_TREE_CHILDREN (*this->m_node).quick_push (this->m_ops[1]);
- SLP_TREE_CHILDREN (*this->m_node).quick_push (
- vect_build_combine_node (this->m_ops[2], this->m_ops[3], *this->m_node));
- SLP_TREE_REF_COUNT (this->m_ops[0])++;
- SLP_TREE_REF_COUNT (this->m_ops[1])++;
+ SLP_TREE_CHILDREN (*this->m_node).quick_push (newnode);
/* And then rewrite the node itself. */
complex_pattern::build (vinfo);
diff --git a/gcc/tree-vect-slp.c b/gcc/tree-vect-slp.c
index
ea8a97b01c6371791ac66de3e1dabfedee69cb67..65c2ff867ab41ea70367087dc26fb6eea1375ffb
100644
--- a/gcc/tree-vect-slp.c
+++ b/gcc/tree-vect-slp.c
@@ -146,6 +146,16 @@ vect_free_slp_tree (slp_tree node)
if (child)
vect_free_slp_tree (child);
+ /* If the node defines any SLP only patterns then those patterns are no
+ longer valid and should be removed. */
+ stmt_vec_info rep_stmt_info = SLP_TREE_REPRESENTATIVE (node);
+ if (rep_stmt_info && STMT_VINFO_SLP_VECT_ONLY_PATTERN (rep_stmt_info))
+ {
+ stmt_vec_info stmt_info = vect_orig_stmt (rep_stmt_info);
+ //STMT_VINFO_IN_PATTERN_P (stmt_info) = false;
+ //STMT_SLP_TYPE (stmt_info) = STMT_SLP_TYPE (rep_stmt_info);
+ }
+
delete node;
}
diff --git a/gcc/tree-vectorizer.c b/gcc/tree-vectorizer.c
index
5b45df3a4e00266b7530eb4da6985f0d940cb05b..63ba594f2276850a00fc372072d98326891f19e6
100644
--- a/gcc/tree-vectorizer.c
+++ b/gcc/tree-vectorizer.c
@@ -695,6 +695,7 @@ vec_info::new_stmt_vec_info (gimple *stmt)
STMT_VINFO_REDUC_FN (res) = IFN_LAST;
STMT_VINFO_REDUC_IDX (res) = -1;
STMT_VINFO_SLP_VECT_ONLY (res) = false;
+ STMT_VINFO_SLP_VECT_ONLY_PATTERN (res) = false;
STMT_VINFO_VEC_STMTS (res) = vNULL;
if (is_a <loop_vec_info> (this)
--
diff --git a/gcc/testsuite/gcc.dg/vect/pr99149.C b/gcc/testsuite/gcc.dg/vect/pr99149.C
new file mode 100755
index 0000000000000000000000000000000000000000..b12fe17e4ded148ce2bf67486e425dd65461a148
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/vect/pr99149.C
@@ -0,0 +1,25 @@
+/* { dg-do compile } */
+/* { dg-additional-options "-w -O3 -march=armv8.3-a" { target { aarch64*-*-* } } } */
+
+class a {
+ float b;
+ float c;
+
+public:
+ a(float d, float e) : b(d), c(e) {}
+ a operator+(a d) { return a(b + d.b, c + d.c); }
+ a operator*(a d) { return a(b * b - c * c, b * c + c * d.b); }
+};
+int f, g;
+class {
+ a *h;
+ a *i;
+
+public:
+ void j() {
+ a k = h[0], l = i[g], m = k * i[f];
+ i[g] = l + m;
+ i[f] = m;
+ }
+} n;
+main() { n.j(); }
diff --git a/gcc/tree-vect-slp-patterns.c b/gcc/tree-vect-slp-patterns.c
index f0817da9f622d22e3df2e30410d1cf610b4ffa1d..1e2769662a54229ab8e24390f97dfe206f17ab57 100644
--- a/gcc/tree-vect-slp-patterns.c
+++ b/gcc/tree-vect-slp-patterns.c
@@ -407,9 +407,8 @@ vect_detect_pair_op (slp_tree node1, slp_tree node2, lane_permutation_t &lanes,
if (result != CMPLX_NONE && ops != NULL)
{
- ops->create (2);
- ops->quick_push (node1);
- ops->quick_push (node2);
+ ops->safe_push (node1);
+ ops->safe_push (node2);
}
return result;
}
@@ -1090,15 +1089,17 @@ complex_mul_pattern::build (vec_info *vinfo)
{
slp_tree node;
unsigned i;
+ slp_tree newnode
+ = vect_build_combine_node (this->m_ops[0], this->m_ops[1], *this->m_node);
+ SLP_TREE_REF_COUNT (this->m_ops[2])++;
+
FOR_EACH_VEC_ELT (SLP_TREE_CHILDREN (*this->m_node), i, node)
vect_free_slp_tree (node);
/* First re-arrange the children. */
SLP_TREE_CHILDREN (*this->m_node).reserve_exact (2);
SLP_TREE_CHILDREN (*this->m_node)[0] = this->m_ops[2];
- SLP_TREE_CHILDREN (*this->m_node)[1] =
- vect_build_combine_node (this->m_ops[0], this->m_ops[1], *this->m_node);
- SLP_TREE_REF_COUNT (this->m_ops[2])++;
+ SLP_TREE_CHILDREN (*this->m_node)[1] = newnode;
/* And then rewrite the node itself. */
complex_pattern::build (vinfo);
@@ -1133,18 +1134,6 @@ class complex_fma_pattern : public complex_pattern
}
};
-/* Helper function to "reset" a previously matched node and undo the changes
- made enough so that the node is treated as an irrelevant node. */
-
-static inline void
-vect_slp_reset_pattern (slp_tree node)
-{
- stmt_vec_info stmt_info = vect_orig_stmt (SLP_TREE_REPRESENTATIVE (node));
- STMT_VINFO_IN_PATTERN_P (stmt_info) = false;
- STMT_SLP_TYPE (stmt_info) = pure_slp;
- SLP_TREE_REPRESENTATIVE (node) = stmt_info;
-}
-
/* Pattern matcher for trying to match complex multiply and accumulate
and multiply and subtract patterns in SLP tree.
If the operation matches then IFN is set to the operation it matched and
@@ -1208,15 +1197,6 @@ complex_fma_pattern::matches (complex_operation_t op,
if (!vect_pattern_validate_optab (ifn, vnode))
return IFN_LAST;
- /* FMA matched ADD + CMUL. During the matching of CMUL the
- stmt that starts the pattern is marked as being in a pattern,
- namely the CMUL. When replacing this with a CFMA we have to
- unmark this statement as being in a pattern. This is because
- vect_mark_pattern_stmts will only mark the current stmt as being
- in a pattern. Later on when the scalar stmts are examined the
- old statement which is supposed to be irrelevant will point to
- CMUL unless we undo the pattern relationship here. */
- vect_slp_reset_pattern (node);
ops->truncate (0);
ops->create (3);
@@ -1259,10 +1239,17 @@ complex_fma_pattern::recognize (slp_tree_to_load_perm_map_t *perm_cache,
void
complex_fma_pattern::build (vec_info *vinfo)
{
+ slp_tree node = SLP_TREE_CHILDREN (*this->m_node)[1];
+
SLP_TREE_CHILDREN (*this->m_node).release ();
SLP_TREE_CHILDREN (*this->m_node).create (3);
SLP_TREE_CHILDREN (*this->m_node).safe_splice (this->m_ops);
+ SLP_TREE_REF_COUNT (this->m_ops[1])++;
+ SLP_TREE_REF_COUNT (this->m_ops[2])++;
+
+ vect_free_slp_tree (node);
+
complex_pattern::build (vinfo);
}
@@ -1427,6 +1414,11 @@ complex_fms_pattern::build (vec_info *vinfo)
{
slp_tree node;
unsigned i;
+ slp_tree newnode =
+ vect_build_combine_node (this->m_ops[2], this->m_ops[3], *this->m_node);
+ SLP_TREE_REF_COUNT (this->m_ops[0])++;
+ SLP_TREE_REF_COUNT (this->m_ops[1])++;
+
FOR_EACH_VEC_ELT (SLP_TREE_CHILDREN (*this->m_node), i, node)
vect_free_slp_tree (node);
@@ -1436,10 +1428,7 @@ complex_fms_pattern::build (vec_info *vinfo)
/* First re-arrange the children. */
SLP_TREE_CHILDREN (*this->m_node).quick_push (this->m_ops[0]);
SLP_TREE_CHILDREN (*this->m_node).quick_push (this->m_ops[1]);
- SLP_TREE_CHILDREN (*this->m_node).quick_push (
- vect_build_combine_node (this->m_ops[2], this->m_ops[3], *this->m_node));
- SLP_TREE_REF_COUNT (this->m_ops[0])++;
- SLP_TREE_REF_COUNT (this->m_ops[1])++;
+ SLP_TREE_CHILDREN (*this->m_node).quick_push (newnode);
/* And then rewrite the node itself. */
complex_pattern::build (vinfo);
diff --git a/gcc/tree-vect-slp.c b/gcc/tree-vect-slp.c
index ea8a97b01c6371791ac66de3e1dabfedee69cb67..65c2ff867ab41ea70367087dc26fb6eea1375ffb 100644
--- a/gcc/tree-vect-slp.c
+++ b/gcc/tree-vect-slp.c
@@ -146,6 +146,16 @@ vect_free_slp_tree (slp_tree node)
if (child)
vect_free_slp_tree (child);
+ /* If the node defines any SLP only patterns then those patterns are no
+ longer valid and should be removed. */
+ stmt_vec_info rep_stmt_info = SLP_TREE_REPRESENTATIVE (node);
+ if (rep_stmt_info && STMT_VINFO_SLP_VECT_ONLY_PATTERN (rep_stmt_info))
+ {
+ stmt_vec_info stmt_info = vect_orig_stmt (rep_stmt_info);
+ //STMT_VINFO_IN_PATTERN_P (stmt_info) = false;
+ //STMT_SLP_TYPE (stmt_info) = STMT_SLP_TYPE (rep_stmt_info);
+ }
+
delete node;
}
diff --git a/gcc/tree-vectorizer.c b/gcc/tree-vectorizer.c
index 5b45df3a4e00266b7530eb4da6985f0d940cb05b..63ba594f2276850a00fc372072d98326891f19e6 100644
--- a/gcc/tree-vectorizer.c
+++ b/gcc/tree-vectorizer.c
@@ -695,6 +695,7 @@ vec_info::new_stmt_vec_info (gimple *stmt)
STMT_VINFO_REDUC_FN (res) = IFN_LAST;
STMT_VINFO_REDUC_IDX (res) = -1;
STMT_VINFO_SLP_VECT_ONLY (res) = false;
+ STMT_VINFO_SLP_VECT_ONLY_PATTERN (res) = false;
STMT_VINFO_VEC_STMTS (res) = vNULL;
if (is_a <loop_vec_info> (this)
