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* [gcc r12-2550] vect: Fix wrong check in vect_recog_mulhs_pattern [PR101596]
@ 2021-07-28 3:40 Kewen Lin
0 siblings, 0 replies; only message in thread
From: Kewen Lin @ 2021-07-28 3:40 UTC (permalink / raw)
To: gcc-cvs
https://gcc.gnu.org/g:89b3c97eed75c1e7c492bc727e0016003c5809cc
commit r12-2550-g89b3c97eed75c1e7c492bc727e0016003c5809cc
Author: Kewen Lin <linkw@linux.ibm.com>
Date: Tue Jul 27 22:04:22 2021 -0500
vect: Fix wrong check in vect_recog_mulhs_pattern [PR101596]
As PR101596 showed, vect_recog_mulhs_pattern uses target_precision to
check the scale_term is expected or not, it could be wrong when the
precision of the actual used new_type larger than target_precision as
shown by the example.
This patch is to use precision of new_type instead of target_precision
for the scale_term matching check.
Bootstrapped & regtested on powerpc64le-linux-gnu P10,
powerpc64-linux-gnu P8, x86_64-redhat-linux and aarch64-linux-gnu.
gcc/ChangeLog:
PR tree-optimization/101596
* tree-vect-patterns.c (vect_recog_mulhs_pattern): Fix wrong check
by using new_type's precision instead.
gcc/testsuite/ChangeLog:
PR tree-optimization/101596
* gcc.target/powerpc/pr101596-1.c: New test.
* gcc.target/powerpc/pr101596-2.c: Likewise.
* gcc.target/powerpc/pr101596-3.c: Likewise.
Diff:
---
gcc/testsuite/gcc.target/powerpc/pr101596-1.c | 30 +++++++++++++
gcc/testsuite/gcc.target/powerpc/pr101596-2.c | 30 +++++++++++++
gcc/testsuite/gcc.target/powerpc/pr101596-3.c | 58 ++++++++++++++++++++++++
gcc/tree-vect-patterns.c | 63 +++++++++++++++------------
4 files changed, 154 insertions(+), 27 deletions(-)
diff --git a/gcc/testsuite/gcc.target/powerpc/pr101596-1.c b/gcc/testsuite/gcc.target/powerpc/pr101596-1.c
new file mode 100644
index 00000000000..ed09e5f96ed
--- /dev/null
+++ b/gcc/testsuite/gcc.target/powerpc/pr101596-1.c
@@ -0,0 +1,30 @@
+/* { dg-require-effective-target power10_ok } */
+/* { dg-options "-mdejagnu-cpu=power10 -O2 -ftree-vectorize -fno-vect-cost-model -fdump-tree-vect-details" } */
+
+/* Check vect_recog_mulhs_pattern can't be detected with shift count 48. */
+
+#define N 128
+
+typedef signed long long sLL;
+typedef unsigned long long uLL;
+
+signed int si_a[N], si_b[N];
+unsigned int ui_a[N], ui_b[N];
+signed short sh_c[N];
+unsigned short uh_c[N];
+
+void
+test1 ()
+{
+ for (int i = 0; i < N; i++)
+ sh_c[i] = ((sLL) si_a[i] * (sLL) si_b[i]) >> 48;
+}
+
+void
+test2 ()
+{
+ for (int i = 0; i < N; i++)
+ uh_c[i] = ((uLL) ui_a[i] * (uLL) ui_b[i]) >> 48;
+}
+
+/* { dg-final { scan-tree-dump-not "vect_recog_mulhs_pattern: detected" "vect" } } */
diff --git a/gcc/testsuite/gcc.target/powerpc/pr101596-2.c b/gcc/testsuite/gcc.target/powerpc/pr101596-2.c
new file mode 100644
index 00000000000..5caa7ce4189
--- /dev/null
+++ b/gcc/testsuite/gcc.target/powerpc/pr101596-2.c
@@ -0,0 +1,30 @@
+/* { dg-require-effective-target power10_ok } */
+/* { dg-options "-mdejagnu-cpu=power10 -O2 -ftree-vectorize -fno-vect-cost-model -fdump-tree-vect-details" } */
+
+/* Check vect_recog_mulhs_pattern can be detected with shift count 32. */
+
+#define N 128
+
+typedef signed long long sLL;
+typedef unsigned long long uLL;
+
+signed int si_a[N], si_b[N];
+unsigned int ui_a[N], ui_b[N];
+signed short sh_c[N];
+unsigned short uh_c[N];
+
+void
+test1 ()
+{
+ for (int i = 0; i < N; i++)
+ sh_c[i] = ((sLL) si_a[i] * (sLL) si_b[i]) >> 32;
+}
+
+void
+test2 ()
+{
+ for (int i = 0; i < N; i++)
+ uh_c[i] = ((uLL) ui_a[i] * (uLL) ui_b[i]) >> 32;
+}
+
+/* { dg-final { scan-tree-dump-times "vect_recog_mulhs_pattern: detected" 2 "vect" } } */
diff --git a/gcc/testsuite/gcc.target/powerpc/pr101596-3.c b/gcc/testsuite/gcc.target/powerpc/pr101596-3.c
new file mode 100644
index 00000000000..4b92661412d
--- /dev/null
+++ b/gcc/testsuite/gcc.target/powerpc/pr101596-3.c
@@ -0,0 +1,58 @@
+/* { dg-do run } */
+/* { dg-require-effective-target power10_hw } */
+/* { dg-options "-mdejagnu-cpu=power10 -O2 -ftree-vectorize -fno-vect-cost-model" } */
+
+/* Verify the execution goes well with shift count either 32 or 48. */
+
+#define N 128
+
+typedef signed int si;
+typedef signed short sh;
+typedef signed long long sll;
+typedef unsigned int ui;
+typedef unsigned short uh;
+typedef unsigned long long ull;
+
+si si_a[N], si_b[N];
+ui ui_a[N], ui_b[N];
+sh sh_c[N];
+uh uh_c[N];
+
+#define TEST(NTYPE, TYPE, WTYPE, CNT) \
+ void __attribute__ ((noipa)) test_##TYPE##CNT () \
+ { \
+ for (int i = 0; i < N; i++) \
+ NTYPE##_c[i] = ((WTYPE) TYPE##_a[i] * (WTYPE) TYPE##_b[i]) >> CNT; \
+ } \
+ \
+ void __attribute__ ((noipa, optimize ("O1"))) check_##TYPE##CNT () \
+ { \
+ test_##TYPE##CNT (); \
+ for (int i = 0; i < N; i++) \
+ { \
+ NTYPE exp = ((WTYPE) TYPE##_a[i] * (WTYPE) TYPE##_b[i]) >> CNT; \
+ if (NTYPE##_c[i] != exp) \
+ __builtin_abort (); \
+ } \
+ }
+
+TEST (sh, si, sll, 32)
+TEST (sh, si, sll, 48)
+TEST (uh, ui, ull, 32)
+TEST (uh, ui, ull, 48)
+
+int
+main ()
+{
+
+ for (int i = 0; i < N; i++)
+ {
+ ui_a[i] = si_a[i] = 0x12345678ULL + 0x1000ULL * (i * 3 - 1);
+ ui_b[i] = si_b[i] = 0x87654321ULL - 0x500000ULL * (i * 5 + 1);
+ }
+
+ check_si32 ();
+ check_si48 ();
+ check_ui32 ();
+ check_ui48 ();
+}
diff --git a/gcc/tree-vect-patterns.c b/gcc/tree-vect-patterns.c
index 70bb751865b..743fd3f5414 100644
--- a/gcc/tree-vect-patterns.c
+++ b/gcc/tree-vect-patterns.c
@@ -1986,7 +1986,7 @@ vect_recog_mulhs_pattern (vec_info *vinfo,
stmt_vec_info mulh_stmt_info;
tree scale_term;
- internal_fn ifn;
+ bool rounding_p = false;
/* Check for the presence of the rounding term. */
if (gimple_assign_rhs_code (rshift_input_stmt) == PLUS_EXPR)
@@ -2035,37 +2035,18 @@ vect_recog_mulhs_pattern (vec_info *vinfo,
/* Get the scaling term. */
scale_term = gimple_assign_rhs2 (plus_input_stmt);
- /* Check that the scaling factor is correct. */
- if (TREE_CODE (scale_term) != INTEGER_CST)
- return NULL;
-
- /* Check pattern 2). */
- if (wi::to_widest (scale_term) + target_precision + 2
- != TYPE_PRECISION (lhs_type))
- return NULL;
-
- ifn = IFN_MULHRS;
+ rounding_p = true;
}
else
{
mulh_stmt_info = rshift_input_stmt_info;
scale_term = gimple_assign_rhs2 (last_stmt);
- /* Check that the scaling factor is correct. */
- if (TREE_CODE (scale_term) != INTEGER_CST)
- return NULL;
-
- /* Check for pattern 1). */
- if (wi::to_widest (scale_term) + target_precision + 1
- == TYPE_PRECISION (lhs_type))
- ifn = IFN_MULHS;
- /* Check for pattern 3). */
- else if (wi::to_widest (scale_term) + target_precision
- == TYPE_PRECISION (lhs_type))
- ifn = IFN_MULH;
- else
- return NULL;
}
+ /* Check that the scaling factor is constant. */
+ if (TREE_CODE (scale_term) != INTEGER_CST)
+ return NULL;
+
/* Check whether the scaling input term can be seen as two widened
inputs multiplied together. */
vect_unpromoted_value unprom_mult[2];
@@ -2076,13 +2057,41 @@ vect_recog_mulhs_pattern (vec_info *vinfo,
if (nops != 2)
return NULL;
- vect_pattern_detected ("vect_recog_mulhs_pattern", last_stmt);
-
/* Adjust output precision. */
if (TYPE_PRECISION (new_type) < target_precision)
new_type = build_nonstandard_integer_type
(target_precision, TYPE_UNSIGNED (new_type));
+ unsigned mult_precision = TYPE_PRECISION (new_type);
+ internal_fn ifn;
+ /* Check that the scaling factor is expected. Instead of
+ target_precision, we should use the one that we actually
+ use for internal function. */
+ if (rounding_p)
+ {
+ /* Check pattern 2). */
+ if (wi::to_widest (scale_term) + mult_precision + 2
+ != TYPE_PRECISION (lhs_type))
+ return NULL;
+
+ ifn = IFN_MULHRS;
+ }
+ else
+ {
+ /* Check for pattern 1). */
+ if (wi::to_widest (scale_term) + mult_precision + 1
+ == TYPE_PRECISION (lhs_type))
+ ifn = IFN_MULHS;
+ /* Check for pattern 3). */
+ else if (wi::to_widest (scale_term) + mult_precision
+ == TYPE_PRECISION (lhs_type))
+ ifn = IFN_MULH;
+ else
+ return NULL;
+ }
+
+ vect_pattern_detected ("vect_recog_mulhs_pattern", last_stmt);
+
/* Check for target support. */
tree new_vectype = get_vectype_for_scalar_type (vinfo, new_type);
if (!new_vectype
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