middle-end: Add tests middle end generic tests for sign differing dotproduct.

This adds testcases to test for auto-vect detection of the new sign differing
dot product.

gcc/ChangeLog:

	* doc/sourcebuild.texi (arm_v8_2a_i8mm_neon_hw): Document.

gcc/testsuite/ChangeLog:

	* lib/target-supports.exp
	(check_effective_target_arm_v8_2a_imm8_neon_ok_nocache,
	check_effective_target_arm_v8_2a_i8mm_neon_hw,
	check_effective_target_vect_usdot_qi): New.
	* gcc.dg/vect/vect-reduc-dot-9.c: New test.
	* gcc.dg/vect/vect-reduc-dot-10.c: New test.
	* gcc.dg/vect/vect-reduc-dot-11.c: New test.
	* gcc.dg/vect/vect-reduc-dot-12.c: New test.
	* gcc.dg/vect/vect-reduc-dot-13.c: New test.
	* gcc.dg/vect/vect-reduc-dot-14.c: New test.
	* gcc.dg/vect/vect-reduc-dot-15.c: New test.
	* gcc.dg/vect/vect-reduc-dot-16.c: New test.
	* gcc.dg/vect/vect-reduc-dot-17.c: New test.
	* gcc.dg/vect/vect-reduc-dot-18.c: New test.
	* gcc.dg/vect/vect-reduc-dot-19.c: New test.
	* gcc.dg/vect/vect-reduc-dot-20.c: New test.
	* gcc.dg/vect/vect-reduc-dot-21.c: New test.
	* gcc.dg/vect/vect-reduc-dot-22.c: New test.

16 files changed, 544 insertions, 0 deletions

diff --git a/gcc/doc/sourcebuild.texi b/gcc/doc/sourcebuild.texi
index 16c6a3b..b1fffd5 100644
--- a/gcc/doc/sourcebuild.texi
+++ b/gcc/doc/sourcebuild.texi
@@ -1780,6 +1780,10 @@ Target supports a vector dot-product of @code{signed char}.
 @item vect_udot_qi
 Target supports a vector dot-product of @code{unsigned char}.
 
+@item vect_usdot_qi
+Target supports a vector dot-product where one operand of the multiply is
+@code{signed char} and the other of @code{unsigned char}.
+
 @item vect_sdot_hi
 Target supports a vector dot-product of @code{signed short}.
 
@@ -2055,6 +2059,11 @@ ARM target supports executing instructions from ARMv8.2-A with the Dot
 Product extension. Some multilibs may be incompatible with these options.
 Implies arm_v8_2a_dotprod_neon_ok.
 
+@item arm_v8_2a_i8mm_neon_hw
+ARM target supports executing instructions from ARMv8.2-A with the 8-bit
+Matrix Multiply extension.  Some multilibs may be incompatible with these
+options.  Implies arm_v8_2a_i8mm_ok.
+
 @item arm_fp16fml_neon_ok
 @anchor{arm_fp16fml_neon_ok}
 ARM target supports extensions to generate the @code{VFMAL} and @code{VFMLS}
diff --git a/gcc/testsuite/gcc.dg/vect/vect-reduc-dot-10.c b/gcc/testsuite/gcc.dg/vect/vect-reduc-dot-10.c
new file mode 100644
index 0000000..7ce8696
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/vect/vect-reduc-dot-10.c
@@ -0,0 +1,13 @@
+/* { dg-require-effective-target vect_int } */
+/* { dg-require-effective-target arm_v8_2a_i8mm_neon_hw { target { aarch64*-*-* || arm*-*-* } } } */
+/* { dg-add-options arm_v8_2a_i8mm }  */
+
+#define SIGNEDNESS_1 unsigned
+#define SIGNEDNESS_2 unsigned
+#define SIGNEDNESS_3 unsigned
+#define SIGNEDNESS_4 signed
+
+#include "vect-reduc-dot-9.c"
+
+/* { dg-final { scan-tree-dump-not "vect_recog_dot_prod_pattern: detected" "vect" } } */
+/* { dg-final { scan-tree-dump-times "vectorized 1 loop" 1 "vect" { target vect_usdot_qi } } } */
diff --git a/gcc/testsuite/gcc.dg/vect/vect-reduc-dot-11.c b/gcc/testsuite/gcc.dg/vect/vect-reduc-dot-11.c
new file mode 100644
index 0000000..5e3cfc9
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/vect/vect-reduc-dot-11.c
@@ -0,0 +1,13 @@
+/* { dg-require-effective-target vect_int } */
+/* { dg-require-effective-target arm_v8_2a_i8mm_neon_hw { target { aarch64*-*-* || arm*-*-* } } } */
+/* { dg-add-options arm_v8_2a_i8mm }  */
+
+#define SIGNEDNESS_1 unsigned
+#define SIGNEDNESS_2 signed
+#define SIGNEDNESS_3 unsigned
+#define SIGNEDNESS_4 signed
+
+#include "vect-reduc-dot-9.c"
+
+/* { dg-final { scan-tree-dump-not "vect_recog_dot_prod_pattern: detected" "vect" } } */
+/* { dg-final { scan-tree-dump-times "vectorized 1 loop" 1 "vect" { target vect_usdot_qi } } } */
diff --git a/gcc/testsuite/gcc.dg/vect/vect-reduc-dot-12.c b/gcc/testsuite/gcc.dg/vect/vect-reduc-dot-12.c
new file mode 100644
index 0000000..0841261
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/vect/vect-reduc-dot-12.c
@@ -0,0 +1,13 @@
+/* { dg-require-effective-target vect_int } */
+/* { dg-require-effective-target arm_v8_2a_i8mm_neon_hw { target { aarch64*-*-* || arm*-*-* } } } */
+/* { dg-add-options arm_v8_2a_i8mm }  */
+
+#define SIGNEDNESS_1 unsigned
+#define SIGNEDNESS_2 signed
+#define SIGNEDNESS_3 signed
+#define SIGNEDNESS_4 unsigned
+
+#include "vect-reduc-dot-9.c"
+
+/* { dg-final { scan-tree-dump "vect_recog_dot_prod_pattern: detected" "vect" } } */
+/* { dg-final { scan-tree-dump-times "vectorized 1 loop" 1 "vect" { target vect_usdot_qi } } } */
diff --git a/gcc/testsuite/gcc.dg/vect/vect-reduc-dot-13.c b/gcc/testsuite/gcc.dg/vect/vect-reduc-dot-13.c
new file mode 100644
index 0000000..7ee0f45
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/vect/vect-reduc-dot-13.c
@@ -0,0 +1,13 @@
+/* { dg-require-effective-target vect_int } */
+/* { dg-require-effective-target arm_v8_2a_i8mm_neon_hw { target { aarch64*-*-* || arm*-*-* } } } */
+/* { dg-add-options arm_v8_2a_i8mm }  */
+
+#define SIGNEDNESS_1 signed
+#define SIGNEDNESS_2 unsigned
+#define SIGNEDNESS_3 signed
+#define SIGNEDNESS_4 unsigned
+
+#include "vect-reduc-dot-9.c"
+
+/* { dg-final { scan-tree-dump-not "vect_recog_dot_prod_pattern: detected" "vect" } } */
+/* { dg-final { scan-tree-dump-times "vectorized 1 loop" 1 "vect" { target vect_usdot_qi } } } */
diff --git a/gcc/testsuite/gcc.dg/vect/vect-reduc-dot-14.c b/gcc/testsuite/gcc.dg/vect/vect-reduc-dot-14.c
new file mode 100644
index 0000000..2de1434
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/vect/vect-reduc-dot-14.c
@@ -0,0 +1,13 @@
+/* { dg-require-effective-target vect_int } */
+/* { dg-require-effective-target arm_v8_2a_i8mm_neon_hw { target { aarch64*-*-* || arm*-*-* } } } */
+/* { dg-add-options arm_v8_2a_i8mm }  */
+
+#define SIGNEDNESS_1 signed
+#define SIGNEDNESS_2 unsigned
+#define SIGNEDNESS_3 unsigned
+#define SIGNEDNESS_4 signed
+
+#include "vect-reduc-dot-9.c"
+
+/* { dg-final { scan-tree-dump-not "vect_recog_dot_prod_pattern: detected" "vect" } } */
+/* { dg-final { scan-tree-dump-times "vectorized 1 loop" 1 "vect" { target vect_usdot_qi } } } */
diff --git a/gcc/testsuite/gcc.dg/vect/vect-reduc-dot-15.c b/gcc/testsuite/gcc.dg/vect/vect-reduc-dot-15.c
new file mode 100644
index 0000000..5a6fd19
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/vect/vect-reduc-dot-15.c
@@ -0,0 +1,13 @@
+/* { dg-require-effective-target vect_int } */
+/* { dg-require-effective-target arm_v8_2a_i8mm_neon_hw { target { aarch64*-*-* || arm*-*-* } } } */
+/* { dg-add-options arm_v8_2a_i8mm }  */
+
+#define SIGNEDNESS_1 signed
+#define SIGNEDNESS_2 signed
+#define SIGNEDNESS_3 unsigned
+#define SIGNEDNESS_4 signed
+
+#include "vect-reduc-dot-9.c"
+
+/* { dg-final { scan-tree-dump-not "vect_recog_dot_prod_pattern: detected" "vect" } } */
+/* { dg-final { scan-tree-dump-times "vectorized 1 loop" 1 "vect" { target vect_usdot_qi } } } */
diff --git a/gcc/testsuite/gcc.dg/vect/vect-reduc-dot-16.c b/gcc/testsuite/gcc.dg/vect/vect-reduc-dot-16.c
new file mode 100644
index 0000000..aec6287
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/vect/vect-reduc-dot-16.c
@@ -0,0 +1,13 @@
+/* { dg-require-effective-target vect_int } */
+/* { dg-require-effective-target arm_v8_2a_i8mm_neon_hw { target { aarch64*-*-* || arm*-*-* } } } */
+/* { dg-add-options arm_v8_2a_i8mm }  */
+
+#define SIGNEDNESS_1 signed
+#define SIGNEDNESS_2 signed
+#define SIGNEDNESS_3 signed
+#define SIGNEDNESS_4 unsigned
+
+#include "vect-reduc-dot-9.c"
+
+/* { dg-final { scan-tree-dump "vect_recog_dot_prod_pattern: detected" "vect" } } */
+/* { dg-final { scan-tree-dump-times "vectorized 1 loop" 1 "vect" { target vect_usdot_qi } } } */
diff --git a/gcc/testsuite/gcc.dg/vect/vect-reduc-dot-17.c b/gcc/testsuite/gcc.dg/vect/vect-reduc-dot-17.c
new file mode 100644
index 0000000..aa269c4
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/vect/vect-reduc-dot-17.c
@@ -0,0 +1,52 @@
+/* { dg-require-effective-target vect_int } */
+/* { dg-require-effective-target arm_v8_2a_i8mm_neon_hw { target { aarch64*-*-* || arm*-*-* } } } */
+/* { dg-add-options arm_v8_2a_i8mm }  */
+
+#include "tree-vect.h"
+
+#define N 50
+
+#ifndef SIGNEDNESS_1
+#define SIGNEDNESS_1 unsigned
+#define SIGNEDNESS_2 unsigned
+#define SIGNEDNESS_3 signed
+#define SIGNEDNESS_4 unsigned
+#endif
+
+SIGNEDNESS_1 int __attribute__ ((noipa))
+f (SIGNEDNESS_1 int res, SIGNEDNESS_3 char *restrict a,
+   SIGNEDNESS_4 char *restrict b)
+{
+  for (__INTPTR_TYPE__ i = 0; i < N; ++i)
+    {
+      int av = a[i];
+      int bv = b[i];
+      SIGNEDNESS_2 int mult = av * bv;
+      res += mult;
+    }
+  return res;
+}
+
+#define BASE ((SIGNEDNESS_3 int) -1 < 0 ? -126 : 4)
+#define OFFSET 20
+
+int
+main (void)
+{
+  check_vect ();
+
+  SIGNEDNESS_3 char a[N], b[N];
+  int expected = 0x12345;
+  for (int i = 0; i < N; ++i)
+    {
+      a[i] = BASE + i * 5;
+      b[i] = BASE + OFFSET + i * 4;
+      asm volatile ("" ::: "memory");
+      expected += (SIGNEDNESS_2 int) (a[i] * b[i]);
+    }
+  if (f (0x12345, a, b) != expected)
+    __builtin_abort ();
+}
+
+/* { dg-final { scan-tree-dump "vect_recog_dot_prod_pattern: detected" "vect" } } */
+/* { dg-final { scan-tree-dump-times "vectorized 1 loop" 1 "vect" { target vect_usdot_qi } } } */
diff --git a/gcc/testsuite/gcc.dg/vect/vect-reduc-dot-18.c b/gcc/testsuite/gcc.dg/vect/vect-reduc-dot-18.c
new file mode 100644
index 0000000..2b1cc04
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/vect/vect-reduc-dot-18.c
@@ -0,0 +1,52 @@
+/* { dg-require-effective-target vect_int } */
+/* { dg-require-effective-target arm_v8_2a_i8mm_neon_hw { target { aarch64*-*-* || arm*-*-* } } } */
+/* { dg-add-options arm_v8_2a_i8mm }  */
+
+#include "tree-vect.h"
+
+#define N 50
+
+#ifndef SIGNEDNESS_1
+#define SIGNEDNESS_1 unsigned
+#define SIGNEDNESS_2 signed
+#define SIGNEDNESS_3 signed
+#define SIGNEDNESS_4 unsigned
+#endif
+
+SIGNEDNESS_1 int __attribute__ ((noipa))
+f (SIGNEDNESS_1 int res, SIGNEDNESS_3 char *restrict a,
+   SIGNEDNESS_4 char *restrict b)
+{
+  for (__INTPTR_TYPE__ i = 0; i < N; ++i)
+    {
+      int av = a[i];
+      int bv = b[i];
+      SIGNEDNESS_2 int mult = av * bv;
+      res += mult;
+    }
+  return res;
+}
+
+#define BASE ((SIGNEDNESS_3 int) -1 < 0 ? -126 : 4)
+#define OFFSET 20
+
+int
+main (void)
+{
+  check_vect ();
+
+  SIGNEDNESS_3 char a[N], b[N];
+  int expected = 0x12345;
+  for (int i = 0; i < N; ++i)
+    {
+      a[i] = BASE + i * 5;
+      b[i] = BASE + OFFSET + i * 4;
+      asm volatile ("" ::: "memory");
+      expected += (SIGNEDNESS_2 int) (a[i] * b[i]);
+    }
+  if (f (0x12345, a, b) != expected)
+    __builtin_abort ();
+}
+
+/* { dg-final { scan-tree-dump "vect_recog_dot_prod_pattern: detected" "vect" } } */
+/* { dg-final { scan-tree-dump-times "vectorized 1 loop" 1 "vect" { target vect_usdot_qi } } } */
diff --git a/gcc/testsuite/gcc.dg/vect/vect-reduc-dot-19.c b/gcc/testsuite/gcc.dg/vect/vect-reduc-dot-19.c
new file mode 100644
index 0000000..962b24e
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/vect/vect-reduc-dot-19.c
@@ -0,0 +1,52 @@
+/* { dg-require-effective-target vect_int } */
+/* { dg-require-effective-target arm_v8_2a_i8mm_neon_hw { target { aarch64*-*-* || arm*-*-* } } } */
+/* { dg-add-options arm_v8_2a_i8mm }  */
+
+#include "tree-vect.h"
+
+#define N 50
+
+#ifndef SIGNEDNESS_1
+#define SIGNEDNESS_1 unsigned
+#define SIGNEDNESS_2 signed
+#define SIGNEDNESS_3 signed
+#define SIGNEDNESS_4 unsigned
+#endif
+
+SIGNEDNESS_1 long __attribute__ ((noipa))
+f (SIGNEDNESS_1 long res, SIGNEDNESS_3 char *restrict a,
+   SIGNEDNESS_4 short *restrict b)
+{
+  for (__INTPTR_TYPE__ i = 0; i < N; ++i)
+    {
+      int av = a[i];
+      int bv = b[i];
+      SIGNEDNESS_2 long mult = av * bv;
+      res += mult;
+    }
+  return res;
+}
+
+#define BASE ((SIGNEDNESS_3 int) -1 < 0 ? -126 : 4)
+#define OFFSET 20
+
+int
+main (void)
+{
+  check_vect ();
+
+  SIGNEDNESS_3 char a[N];
+  SIGNEDNESS_4 short b[N];
+  int expected = 0x12345;
+  for (int i = 0; i < N; ++i)
+    {
+      a[i] = BASE + i * 5;
+      b[i] = BASE + OFFSET + i * 4;
+      asm volatile ("" ::: "memory");
+      expected += (SIGNEDNESS_2 int) (a[i] * b[i]);
+    }
+  if (f (0x12345, a, b) != expected)
+    __builtin_abort ();
+}
+
+/* { dg-final { scan-tree-dump-not "vect_recog_dot_prod_pattern: detected" "vect" } } */
diff --git a/gcc/testsuite/gcc.dg/vect/vect-reduc-dot-20.c b/gcc/testsuite/gcc.dg/vect/vect-reduc-dot-20.c
new file mode 100644
index 0000000..d757fb1
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/vect/vect-reduc-dot-20.c
@@ -0,0 +1,52 @@
+/* { dg-require-effective-target vect_int } */
+/* { dg-require-effective-target arm_v8_2a_i8mm_neon_hw { target { aarch64*-*-* || arm*-*-* } } } */
+/* { dg-add-options arm_v8_2a_i8mm }  */
+
+#include "tree-vect.h"
+
+#define N 50
+
+#ifndef SIGNEDNESS_1
+#define SIGNEDNESS_1 unsigned
+#define SIGNEDNESS_2 signed
+#define SIGNEDNESS_3 signed
+#define SIGNEDNESS_4 unsigned
+#endif
+
+SIGNEDNESS_1 long __attribute__ ((noipa))
+f (SIGNEDNESS_1 long res, SIGNEDNESS_3 short *restrict a,
+   SIGNEDNESS_4 char *restrict b)
+{
+  for (__INTPTR_TYPE__ i = 0; i < N; ++i)
+    {
+      int av = a[i];
+      int bv = b[i];
+      SIGNEDNESS_2 long mult = av * bv;
+      res += mult;
+    }
+  return res;
+}
+
+#define BASE ((SIGNEDNESS_3 int) -1 < 0 ? -126 : 4)
+#define OFFSET 20
+
+int
+main (void)
+{
+  check_vect ();
+
+  SIGNEDNESS_3 short a[N];
+  SIGNEDNESS_4 char b[N];
+  int expected = 0x12345;
+  for (int i = 0; i < N; ++i)
+    {
+      a[i] = BASE + i * 5;
+      b[i] = BASE + OFFSET + i * 4;
+      asm volatile ("" ::: "memory");
+      expected += (SIGNEDNESS_2 int) (a[i] * b[i]);
+    }
+  if (f (0x12345, a, b) != expected)
+    __builtin_abort ();
+}
+
+/* { dg-final { scan-tree-dump "vect_recog_dot_prod_pattern: detected" "vect" } } */
diff --git a/gcc/testsuite/gcc.dg/vect/vect-reduc-dot-21.c b/gcc/testsuite/gcc.dg/vect/vect-reduc-dot-21.c
new file mode 100644
index 0000000..b5754bf
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/vect/vect-reduc-dot-21.c
@@ -0,0 +1,52 @@
+/* { dg-require-effective-target vect_int } */
+/* { dg-require-effective-target arm_v8_2a_i8mm_neon_hw { target { aarch64*-*-* || arm*-*-* } } } */
+/* { dg-add-options arm_v8_2a_i8mm }  */
+
+#include "tree-vect.h"
+
+#define N 50
+
+#ifndef SIGNEDNESS_1
+#define SIGNEDNESS_1 unsigned
+#define SIGNEDNESS_2 signed
+#define SIGNEDNESS_3 signed
+#define SIGNEDNESS_4 unsigned
+#endif
+
+SIGNEDNESS_1 long __attribute__ ((noipa))
+f (SIGNEDNESS_1 long res, SIGNEDNESS_3 char *restrict a,
+   SIGNEDNESS_4 short *restrict b)
+{
+  for (__INTPTR_TYPE__ i = 0; i < N; ++i)
+    {
+      int av = a[i];
+      int bv = b[i];
+      SIGNEDNESS_2 int mult = av * bv;
+      res += mult;
+    }
+  return res;
+}
+
+#define BASE ((SIGNEDNESS_3 int) -1 < 0 ? -126 : 4)
+#define OFFSET 20
+
+int
+main (void)
+{
+  check_vect ();
+
+  SIGNEDNESS_3 char a[N];
+  SIGNEDNESS_4 short b[N];
+  int expected = 0x12345;
+  for (int i = 0; i < N; ++i)
+    {
+      a[i] = BASE + i * 5;
+      b[i] = BASE + OFFSET + i * 4;
+      asm volatile ("" ::: "memory");
+      expected += (SIGNEDNESS_2 int) (a[i] * b[i]);
+    }
+  if (f (0x12345, a, b) != expected)
+    __builtin_abort ();
+}
+
+/* { dg-final { scan-tree-dump-not "vect_recog_dot_prod_pattern: detected" "vect" } } */
diff --git a/gcc/testsuite/gcc.dg/vect/vect-reduc-dot-22.c b/gcc/testsuite/gcc.dg/vect/vect-reduc-dot-22.c
new file mode 100644
index 0000000..febeb19
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/vect/vect-reduc-dot-22.c
@@ -0,0 +1,52 @@
+/* { dg-require-effective-target vect_int } */
+/* { dg-require-effective-target arm_v8_2a_i8mm_neon_hw { target { aarch64*-*-* || arm*-*-* } } } */
+/* { dg-add-options arm_v8_2a_i8mm }  */
+
+#include "tree-vect.h"
+
+#define N 50
+
+#ifndef SIGNEDNESS_1
+#define SIGNEDNESS_1 unsigned
+#define SIGNEDNESS_2 unsigned
+#define SIGNEDNESS_3 signed
+#define SIGNEDNESS_4 unsigned
+#endif
+
+SIGNEDNESS_1 long __attribute__ ((noipa))
+f (SIGNEDNESS_1 long res, SIGNEDNESS_3 char *restrict a,
+   SIGNEDNESS_4 short *restrict b)
+{
+  for (__INTPTR_TYPE__ i = 0; i < N; ++i)
+    {
+      int av = a[i];
+      int bv = b[i];
+      SIGNEDNESS_2 int mult = av * bv;
+      res += mult;
+    }
+  return res;
+}
+
+#define BASE ((SIGNEDNESS_3 int) -1 < 0 ? -126 : 4)
+#define OFFSET 20
+
+int
+main (void)
+{
+  check_vect ();
+
+  SIGNEDNESS_3 char a[N];
+  SIGNEDNESS_4 short b[N];
+  int expected = 0x12345;
+  for (int i = 0; i < N; ++i)
+    {
+      a[i] = BASE + i * 5;
+      b[i] = BASE + OFFSET + i * 4;
+      asm volatile ("" ::: "memory");
+      expected += (SIGNEDNESS_2 int) (a[i] * b[i]);
+    }
+  if (f (0x12345, a, b) != expected)
+    __builtin_abort ();
+}
+
+/* { dg-final { scan-tree-dump-not "vect_recog_dot_prod_pattern: detected" "vect" } } */
diff --git a/gcc/testsuite/gcc.dg/vect/vect-reduc-dot-9.c b/gcc/testsuite/gcc.dg/vect/vect-reduc-dot-9.c
new file mode 100644
index 0000000..cbbeede
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/vect/vect-reduc-dot-9.c
@@ -0,0 +1,52 @@
+/* { dg-require-effective-target vect_int } */
+/* { dg-require-effective-target arm_v8_2a_i8mm_neon_hw { target { aarch64*-*-* || arm*-*-* } } } */
+/* { dg-add-options arm_v8_2a_i8mm }  */
+
+#include "tree-vect.h"
+
+#define N 50
+
+#ifndef SIGNEDNESS_1
+#define SIGNEDNESS_1 unsigned
+#define SIGNEDNESS_2 unsigned
+#define SIGNEDNESS_3 signed
+#define SIGNEDNESS_4 unsigned
+#endif
+
+SIGNEDNESS_1 int __attribute__ ((noipa))
+f (SIGNEDNESS_1 int res, SIGNEDNESS_3 char *restrict a,
+   SIGNEDNESS_4 char *restrict b)
+{
+  for (__INTPTR_TYPE__ i = 0; i < N; ++i)
+    {
+      int av = a[i];
+      int bv = b[i];
+      SIGNEDNESS_2 short mult = av * bv;
+      res += mult;
+    }
+  return res;
+}
+
+#define BASE ((SIGNEDNESS_3 int) -1 < 0 ? -126 : 4)
+#define OFFSET 20
+
+int
+main (void)
+{
+  check_vect ();
+
+  SIGNEDNESS_3 char a[N], b[N];
+  int expected = 0x12345;
+  for (int i = 0; i < N; ++i)
+    {
+      a[i] = BASE + i * 5;
+      b[i] = BASE + OFFSET + i * 4;
+      asm volatile ("" ::: "memory");
+      expected += (SIGNEDNESS_2 short) (a[i] * b[i]);
+    }
+  if (f (0x12345, a, b) != expected)
+    __builtin_abort ();
+}
+
+/* { dg-final { scan-tree-dump-not "vect_recog_dot_prod_pattern: detected" "vect" } } */
+/* { dg-final { scan-tree-dump-times "vectorized 1 loop" 1 "vect" { target vect_usdot_qi } } } */
diff --git a/gcc/testsuite/lib/target-supports.exp b/gcc/testsuite/lib/target-supports.exp
index 789723f..12df869 100644
--- a/gcc/testsuite/lib/target-supports.exp
+++ b/gcc/testsuite/lib/target-supports.exp
@@ -5267,6 +5267,36 @@ proc check_effective_target_arm_v8_2a_dotprod_neon_ok_nocache { } {
     return 0;
 }
 
+# Return 1 if the target supports ARMv8.2 Adv.SIMD imm8
+# instructions, 0 otherwise.  The test is valid for ARM and for AArch64.
+# Record the command line options needed.
+
+proc check_effective_target_arm_v8_2a_imm8_neon_ok_nocache { } {
+    global et_arm_v8_2a_imm8_neon_flags
+    set et_arm_v8_2a_imm8_neon_flags ""
+
+    if { ![istarget arm*-*-*] && ![istarget aarch64*-*-*] } {
+        return 0;
+    }
+
+    # Iterate through sets of options to find the compiler flags that
+    # need to be added to the -march option.
+    foreach flags {"" "-mfloat-abi=softfp -mfpu=neon-fp-armv8" "-mfloat-abi=hard -mfpu=neon-fp-armv8"} {
+        if { [check_no_compiler_messages_nocache \
+                  arm_v8_2a_imm8_neon_ok object {
+	    #include <stdint.h>
+            #if !defined (__ARM_FEATURE_MATMUL_INT8)
+            #error "__ARM_FEATURE_MATMUL_INT8 not defined"
+            #endif
+        } "$flags -march=armv8.2-a+imm8"] } {
+            set et_arm_v8_2a_imm8_neon_flags "$flags -march=armv8.2-a+imm8"
+            return 1
+        }
+    }
+
+    return 0;
+}
+
 # Return 1 if the target supports ARMv8.1-M MVE
 # instructions, 0 otherwise.  The test is valid for ARM.
 # Record the command line options needed.
@@ -5694,6 +5724,43 @@ proc check_effective_target_arm_v8_2a_dotprod_neon_hw { } {
     } [add_options_for_arm_v8_2a_dotprod_neon ""]]
 }
 
+# Return 1 if the target supports executing AdvSIMD instructions from ARMv8.2
+# with the i8mm extension, 0 otherwise.  The test is valid for ARM and for
+# AArch64.
+
+proc check_effective_target_arm_v8_2a_i8mm_neon_hw { } {
+    if { ![check_effective_target_arm_v8_2a_i8mm_ok] } {
+        return 0;
+    }
+    return [check_runtime arm_v8_2a_i8mm_neon_hw_available {
+        #include "arm_neon.h"
+        int
+        main (void)
+        {
+
+	  uint32x2_t results = {0,0};
+	  uint8x8_t a = {1,1,1,1,2,2,2,2};
+	  int8x8_t b = {2,2,2,2,3,3,3,3};
+
+          #ifdef __ARM_ARCH_ISA_A64
+          asm ("usdot %0.2s, %1.8b, %2.8b"
+               : "=w"(results)
+               : "w"(a), "w"(b)
+               : /* No clobbers.  */);
+
+	  #else
+          asm ("vusdot.u8 %P0, %P1, %P2"
+               : "=w"(results)
+               : "w"(a), "w"(b)
+               : /* No clobbers.  */);
+          #endif
+
+          return (vget_lane_u32 (results, 0) == 8
+		  && vget_lane_u32 (results, 1) == 24) ? 1 : 0;
+        }
+    } [add_options_for_arm_v8_2a_i8mm ""]]
+}
+
 # Return 1 if this is a ARM target with NEON enabled.
 
 proc check_effective_target_arm_neon { } {
@@ -7060,6 +7127,19 @@ proc check_effective_target_vect_udot_qi { } {
 }
 
 # Return 1 if the target plus current options supports a vector
+# dot-product where one operand of the multiply is signed char
+# and the other unsigned chars, 0 otherwise.
+#
+# This won't change for different subtargets so cache the result.
+
+proc check_effective_target_vect_usdot_qi { } {
+    return [check_cached_effective_target_indexed vect_usdot_qi {
+      expr { [istarget aarch64*-*-*]
+	     || [istarget arm*-*-*] }}]
+}
+
+
+# Return 1 if the target plus current options supports a vector
 # dot-product of signed shorts, 0 otherwise.
 #
 # This won't change for different subtargets so cache the result.