diff mbox

[ARM] Use vector wide add for mixed-mode adds

Message ID 5671FB8A.4000004@linaro.org
State Superseded
Headers show

Commit Message

Michael Collison Dec. 17, 2015, 12:02 a.m. UTC
Kyrill,

I have attached a patch that address your comments. The only change I 
would ask you to re-consider renaming is the function 'bool 
aarch32_simd_check_vect_par_cnst_half'. This function was copied from 
the aarch64 port and I thought it as important to match the naming for 
maintenance purposes. I did rename the function to 'bool 
arm_simd_check_vect_par_cnst_half_p'. I changed 'aarch32' to 'arm' and 
added '_p' per you suggestions. Is this okay?

I implemented all your other change suggestions.

2015-12-16  Michael Collison  <michael.collison@linaro.org>

     * config/arm/neon.md (widen_<us>sum<mode>): New patterns where
     mode is VQI to improve mixed mode vectorization.
     * config/arm/neon.md (vec_sel_widen_ssum_lo<VQI:mode><VW:mode>3): New
     define_insn to match low half of signed vaddw.
     * config/arm/neon.md (vec_sel_widen_ssum_hi<VQI:mode><VW:mode>3): New
     define_insn to match high half of signed vaddw.
     * config/arm/neon.md (vec_sel_widen_usum_lo<VQI:mode><VW:mode>3): New
     define_insn to match low half of unsigned vaddw.
     * config/arm/neon.md (vec_sel_widen_usum_hi<VQI:mode><VW:mode>3): New
     define_insn to match high half of unsigned vaddw.
     * config/arm/arm.c (arm_simd_vect_par_cnst_half): New function.
     (arm_simd_check_vect_par_cnst_half_p): Likewise.
     * config/arm/arm-protos.h (arm_simd_vect_par_cnst_half): Prototype
     for new function.
     (arm_simd_check_vect_par_cnst_half_p): Likewise.
     * config/arm/predicates.md (vect_par_constant_high): Support
     big endian and simplify by calling
     arm_simd_check_vect_par_cnst_half
     (vect_par_constant_low): Likewise.
     * testsuite/gcc.target/arm/neon-vaddws16.c: New test.
     * testsuite/gcc.target/arm/neon-vaddws32.c: New test.
     * testsuite/gcc.target/arm/neon-vaddwu16.c: New test.
     * testsuite/gcc.target/arm/neon-vaddwu32.c: New test.
     * testsuite/gcc.target/arm/neon-vaddwu8.c: New test.
     * testsuite/lib/target-supports.exp
     (check_effective_target_vect_widen_sum_hi_to_si_pattern): Indicate
     that arm neon support vector widen sum of HImode TO SImode.

On 12/10/2015 08:09 AM, Kyrill Tkachov wrote:
> Hi Michael,

>

> A few comments while I look deeper into this patch...

>

> On 30/11/15 01:18, Michael Collison wrote:

>>

>> This is a modified version of my previous patch that supports vector 

>> wide add. I added support for vaddw on big endian when generating the 

>> parallel operand for the vector select.

>>

>> There are four failing test cases on arm big endian with similar 

>> code. They are:

>>

>> gcc.dg/vect/vect-outer-4f.c -flto -ffat-lto-objects execution test

>> gcc.dg/vect/vect-outer-4g.c -flto -ffat-lto-objects execution test

>> gcc.dg/vect/vect-outer-4k.c -flto -ffat-lto-objects execution test

>> gcc.dg/vect/vect-outer-4l.c -flto -ffat-lto-objects execution test

>>

>>

>> The failures occur without my patch and are related to a bug with 

>> vector loads using VUZP operations.

>>

>> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68532

>>

>> Validated on arm-none-eabi, arm-none-linux-gnueabi, 

>> arm-none-linux-gnueabihf, and armeb-none-linux-gnueabihf.

>>

>> 2015-11-29  Michael Collison <michael.collison@linaro.org>

>>

>>     * config/arm/neon.md (widen_<us>sum<mode>): New patterns where

>>     mode is VQI to improve mixed mode vectorization.

>>     * config/arm/neon.md (vec_sel_widen_ssum_lo<VQI:mode><VW:mode>3): 

>> New

>>     define_insn to match low half of signed vaddw.

>>     * config/arm/neon.md (vec_sel_widen_ssum_hi<VQI:mode><VW:mode>3): 

>> New

>>     define_insn to match high half of signed vaddw.

>>     * config/arm/neon.md (vec_sel_widen_usum_lo<VQI:mode><VW:mode>3): 

>> New

>>     define_insn to match low half of unsigned vaddw.

>>     * config/arm/neon.md (vec_sel_widen_usum_hi<VQI:mode><VW:mode>3): 

>> New

>>     define_insn to match high half of unsigned vaddw.

>>     * config/arm/arm.c (aarch32_simd_vect_par_cnst_half): New function.

>>     (aarch32_simd_check_vect_par_cnst_half): Likewise.

>>     * config/arm/arm-protos.h (aarch32_simd_vect_par_cnst_half): 

>> Prototype

>>     for new function.

>>     (aarch32_simd_check_vect_par_cnst_half): Likewise.

>>     * config/arm/predicates.md (vect_par_constant_high): Support

>>     big endian and simplify by calling

>>     aarch32_simd_check_vect_par_cnst_half

>>     (vect_par_constant_low): Likewise.

>>     * testsuite/gcc.target/arm/neon-vaddws16.c: New test.

>>     * testsuite/gcc.target/arm/neon-vaddws32.c: New test.

>>     * testsuite/gcc.target/arm/neon-vaddwu16.c: New test.

>>     * testsuite/gcc.target/arm/neon-vaddwu32.c: New test.

>>     * testsuite/gcc.target/arm/neon-vaddwu8.c: New test.

>>     * testsuite/lib/target-supports.exp

>>     (check_effective_target_vect_widen_sum_hi_to_si_pattern): Indicate

>>     that arm neon support vector widen sum of HImode TO SImode.

>>

>> Okay for trunk?

>>

>

> --- a/gcc/config/arm/arm-protos.h

> +++ b/gcc/config/arm/arm-protos.h

> @@ -50,7 +50,9 @@ extern tree arm_builtin_decl (unsigned code, bool 

> initialize_p

>                    ATTRIBUTE_UNUSED);

>  extern void arm_init_builtins (void);

>  extern void arm_atomic_assign_expand_fenv (tree *hold, tree *clear, 

> tree *update);

> -

> +extern rtx aarch32_simd_vect_par_cnst_half (machine_mode mode, bool 

> high);

> +extern bool aarch32_simd_check_vect_par_cnst_half (rtx op, 

> machine_mode mode,

> +                           bool high);

>

>

> Please use arm instead of aarch32 in the name to be consistent with 

> the rest of the

> backend. Also, for functions that return a bool without side-effects 

> it's preferable

> to finish their name with '_p'. So for the second one I'd drop the 

> 'check' and call

> it something like "arm_vector_of_lane_nums_p ", is that a more 

> descriptive name?

>

> +/* Check OP for validity as a PARALLEL RTX vector with elements

> +   numbering the lanes of either the high (HIGH == TRUE) or low lanes,

> +   from the perspective of the architecture.  See the diagram above

> +   aarch64_simd_vect_par_cnst_half for more details.  */

> +

>

> aarch64?

>

> --- a/gcc/config/arm/neon.md

> +++ b/gcc/config/arm/neon.md

> @@ -1174,6 +1174,51 @@

>

>  ;; Widening operations

>

> +(define_expand "widen_ssum<mode>3"

> +  [(set (match_operand:<V_double_width> 0 "s_register_operand" "")

> +    (plus:<V_double_width> (sign_extend:<V_double_width> 

> (match_operand:VQI 1 "s_register_operand" ""))

> +                   (match_operand:<V_double_width> 2 

> "s_register_operand" "")))]

> +  "TARGET_NEON"

> +  {

> +    machine_mode mode = GET_MODE (operands[1]);

> +    rtx p1, p2;

> +

> +    p1  = aarch32_simd_vect_par_cnst_half (mode, false);

> +    p2  = aarch32_simd_vect_par_cnst_half (mode, true);

> +

> +    if (operands[0] != operands[2])

> +      emit_move_insn (operands[0], operands[2]);

> +

> +    emit_insn (gen_vec_sel_widen_ssum_lo<mode><V_half>3 (operands[0], 

> operands[1], p1, operands[0]));

> +    emit_insn (gen_vec_sel_widen_ssum_hi<mode><V_half>3 (operands[0], 

> operands[1], p2, operands[0]));

> +    DONE;

> +  }

>

> Please format these properly to avoid long lines.

> Thanks,

> Kyrill

>

>


-- 
Michael Collison
Linaro Toolchain Working Group
michael.collison@linaro.org
diff mbox

Patch

diff --git a/gcc/config/arm/arm-protos.h b/gcc/config/arm/arm-protos.h
index f9b1276..8629e24 100644
--- a/gcc/config/arm/arm-protos.h
+++ b/gcc/config/arm/arm-protos.h
@@ -50,7 +50,9 @@  extern tree arm_builtin_decl (unsigned code, bool initialize_p
 			      ATTRIBUTE_UNUSED);
 extern void arm_init_builtins (void);
 extern void arm_atomic_assign_expand_fenv (tree *hold, tree *clear, tree *update);
-
+extern rtx arm_simd_vect_par_cnst_half (machine_mode mode, bool high);
+extern bool arm_simd_check_vect_par_cnst_half_p (rtx op, machine_mode mode,
+						 bool high);
 #ifdef RTX_CODE
 extern bool arm_vector_mode_supported_p (machine_mode);
 extern bool arm_small_register_classes_for_mode_p (machine_mode);
diff --git a/gcc/config/arm/arm.c b/gcc/config/arm/arm.c
index 61e2aa2..4b85342 100644
--- a/gcc/config/arm/arm.c
+++ b/gcc/config/arm/arm.c
@@ -30111,4 +30111,80 @@  arm_sched_fusion_priority (rtx_insn *insn, int max_pri,
   *pri = tmp;
   return;
 }
+
+/* Construct and return a PARALLEL RTX vector with elements numbering the
+   lanes of either the high (HIGH == TRUE) or low (HIGH == FALSE) half of
+   the vector - from the perspective of the architecture.  This does not
+   line up with GCC's perspective on lane numbers, so we end up with
+   different masks depending on our target endian-ness.  The diagram
+   below may help.  We must draw the distinction when building masks
+   which select one half of the vector.  An instruction selecting
+   architectural low-lanes for a big-endian target, must be described using
+   a mask selecting GCC high-lanes.
+
+                 Big-Endian             Little-Endian
+
+GCC             0   1   2   3           3   2   1   0
+              | x | x | x | x |       | x | x | x | x |
+Architecture    3   2   1   0           3   2   1   0
+
+Low Mask:         { 2, 3 }                { 0, 1 }
+High Mask:        { 0, 1 }                { 2, 3 }
+*/
+
+rtx
+arm_simd_vect_par_cnst_half (machine_mode mode, bool high)
+{
+  int nunits = GET_MODE_NUNITS (mode);
+  rtvec v = rtvec_alloc (nunits / 2);
+  int high_base = nunits / 2;
+  int low_base = 0;
+  int base;
+  rtx t1;
+  int i;
+
+  if (BYTES_BIG_ENDIAN)
+    base = high ? low_base : high_base;
+  else
+    base = high ? high_base : low_base;
+
+  for (i = 0; i < nunits / 2; i++)
+    RTVEC_ELT (v, i) = GEN_INT (base + i);
+
+  t1 = gen_rtx_PARALLEL (mode, v);
+  return t1;
+}
+
+/* Check OP for validity as a PARALLEL RTX vector with elements
+   numbering the lanes of either the high (HIGH == TRUE) or low lanes,
+   from the perspective of the architecture.  See the diagram above
+   arm_simd_vect_par_cnst_half_p for more details.  */
+
+bool
+arm_simd_check_vect_par_cnst_half_p (rtx op, machine_mode mode,
+				       bool high)
+{
+  rtx ideal = arm_simd_vect_par_cnst_half (mode, high);
+  HOST_WIDE_INT count_op = XVECLEN (op, 0);
+  HOST_WIDE_INT count_ideal = XVECLEN (ideal, 0);
+  int i = 0;
+
+  if (!VECTOR_MODE_P (mode))
+    return false;
+
+  if (count_op != count_ideal)
+    return false;
+
+  for (i = 0; i < count_ideal; i++)
+    {
+      rtx elt_op = XVECEXP (op, 0, i);
+      rtx elt_ideal = XVECEXP (ideal, 0, i);
+
+      if (!CONST_INT_P (elt_op)
+	  || INTVAL (elt_ideal) != INTVAL (elt_op))
+	return false;
+    }
+  return true;
+}
+
 #include "gt-arm.h"
diff --git a/gcc/config/arm/neon.md b/gcc/config/arm/neon.md
index e5a2b0f..bdb94db 100644
--- a/gcc/config/arm/neon.md
+++ b/gcc/config/arm/neon.md
@@ -1174,6 +1174,57 @@ 
 
 ;; Widening operations
 
+(define_expand "widen_ssum<mode>3"
+  [(set (match_operand:<V_double_width> 0 "s_register_operand" "")
+	(plus:<V_double_width> (sign_extend:<V_double_width> (match_operand:VQI 1 "s_register_operand" ""))
+			       (match_operand:<V_double_width> 2 "s_register_operand" "")))]
+  "TARGET_NEON"
+  {
+    machine_mode mode = GET_MODE (operands[1]);
+    rtx p1, p2;
+ 
+    p1  = arm_simd_vect_par_cnst_half (mode, false);
+    p2  = arm_simd_vect_par_cnst_half (mode, true);
+
+    if (operands[0] != operands[2])
+      emit_move_insn (operands[0], operands[2]);
+
+    emit_insn (gen_vec_sel_widen_ssum_lo<mode><V_half>3 (operands[0], 
+							 operands[1], 
+							 p1, 
+							 operands[0]));
+    emit_insn (gen_vec_sel_widen_ssum_hi<mode><V_half>3 (operands[0], 
+							 operands[1], 
+							 p2, 
+							 operands[0]));
+    DONE;
+  }
+)
+
+(define_insn "vec_sel_widen_ssum_lo<VQI:mode><VW:mode>3"
+  [(set (match_operand:<VW:V_widen> 0 "s_register_operand" "=w")
+	(plus:<VW:V_widen> (sign_extend:<VW:V_widen> (vec_select:VW (match_operand:VQI 1 "s_register_operand" "%w")
+						   (match_operand:VQI 2 "vect_par_constant_low" "")))
+		        (match_operand:<VW:V_widen> 3 "s_register_operand" "0")))]
+  "TARGET_NEON"
+{
+  return BYTES_BIG_ENDIAN ?  "vaddw.<V_s_elem>\t%q0, %q3, %f1" :
+    "vaddw.<V_s_elem>\t%q0, %q3, %e1";
+}
+  [(set_attr "type" "neon_add_widen")])
+
+(define_insn "vec_sel_widen_ssum_hi<VQI:mode><VW:mode>3"
+  [(set (match_operand:<VW:V_widen> 0 "s_register_operand" "=w")
+	(plus:<VW:V_widen> (sign_extend:<VW:V_widen> (vec_select:VW (match_operand:VQI 1 "s_register_operand" "%w")
+						   (match_operand:VQI 2 "vect_par_constant_high" "")))
+		        (match_operand:<VW:V_widen> 3 "s_register_operand" "0")))]
+  "TARGET_NEON"
+{
+  return BYTES_BIG_ENDIAN ?  "vaddw.<V_s_elem>\t%q0, %q3, %e1" :
+    "vaddw.<V_s_elem>\t%q0, %q3, %f1";
+}
+  [(set_attr "type" "neon_add_widen")])
+
 (define_insn "widen_ssum<mode>3"
   [(set (match_operand:<V_widen> 0 "s_register_operand" "=w")
 	(plus:<V_widen> (sign_extend:<V_widen>
@@ -1184,6 +1235,57 @@ 
   [(set_attr "type" "neon_add_widen")]
 )
 
+(define_expand "widen_usum<mode>3"
+  [(set (match_operand:<V_double_width> 0 "s_register_operand" "")
+	(plus:<V_double_width> (zero_extend:<V_double_width> (match_operand:VQI 1 "s_register_operand" ""))
+			       (match_operand:<V_double_width> 2 "s_register_operand" "")))]
+  "TARGET_NEON"
+  {
+    machine_mode mode = GET_MODE (operands[1]);
+    rtx p1, p2;
+ 
+    p1  = arm_simd_vect_par_cnst_half (mode, false);
+    p2  = arm_simd_vect_par_cnst_half (mode, true);
+
+    if (operands[0] != operands[2])
+      emit_move_insn (operands[0], operands[2]);
+
+    emit_insn (gen_vec_sel_widen_usum_lo<mode><V_half>3 (operands[0], 
+							 operands[1], 
+							 p1, 
+							 operands[0]));
+    emit_insn (gen_vec_sel_widen_usum_hi<mode><V_half>3 (operands[0], 
+							 operands[1], 
+							 p2, 
+							 operands[0]));
+    DONE;
+  }
+)
+
+(define_insn "vec_sel_widen_usum_lo<VQI:mode><VW:mode>3"
+  [(set (match_operand:<VW:V_widen> 0 "s_register_operand" "=w")
+	(plus:<VW:V_widen> (zero_extend:<VW:V_widen> (vec_select:VW (match_operand:VQI 1 "s_register_operand" "%w")
+						   (match_operand:VQI 2 "vect_par_constant_low" "")))
+		        (match_operand:<VW:V_widen> 3 "s_register_operand" "0")))]
+  "TARGET_NEON"
+{
+  return BYTES_BIG_ENDIAN ?  "vaddw.<V_u_elem>\t%q0, %q3, %f1" :
+    "vaddw.<V_u_elem>\t%q0, %q3, %e1";
+}
+  [(set_attr "type" "neon_add_widen")])
+
+(define_insn "vec_sel_widen_usum_hi<VQI:mode><VW:mode>3"
+  [(set (match_operand:<VW:V_widen> 0 "s_register_operand" "=w")
+	(plus:<VW:V_widen> (zero_extend:<VW:V_widen> (vec_select:VW (match_operand:VQI 1 "s_register_operand" "%w")
+						   (match_operand:VQI 2 "vect_par_constant_high" "")))
+		        (match_operand:<VW:V_widen> 3 "s_register_operand" "0")))]
+  "TARGET_NEON"
+{
+ return BYTES_BIG_ENDIAN ?  "vaddw.<V_u_elem>\t%q0, %q3, %e1" :
+    "vaddw.<V_u_elem>\t%q0, %q3, %f1";
+}
+  [(set_attr "type" "neon_add_widen")])
+
 (define_insn "widen_usum<mode>3"
   [(set (match_operand:<V_widen> 0 "s_register_operand" "=w")
 	(plus:<V_widen> (zero_extend:<V_widen>
@@ -5331,7 +5433,7 @@  if (BYTES_BIG_ENDIAN)
  [(set (match_operand:<V_unpack> 0 "register_operand" "=w")
        (mult:<V_unpack> (SE:<V_unpack> (vec_select:<V_HALF>
 			   (match_operand:VU 1 "register_operand" "w") 
-                           (match_operand:VU 2 "vect_par_constant_low" "")))
+					(match_operand:VU 2 "vect_par_constant_low" "")))
  		        (SE:<V_unpack> (vec_select:<V_HALF>
                            (match_operand:VU 3 "register_operand" "w") 
                            (match_dup 2)))))]
diff --git a/gcc/config/arm/predicates.md b/gcc/config/arm/predicates.md
index 48e4ba8..372230a 100644
--- a/gcc/config/arm/predicates.md
+++ b/gcc/config/arm/predicates.md
@@ -605,59 +605,13 @@ 
 (define_special_predicate "vect_par_constant_high" 
   (match_code "parallel")
 {
-  HOST_WIDE_INT count = XVECLEN (op, 0);
-  int i;
-  int base = GET_MODE_NUNITS (mode);
-
-  if ((count < 1)
-      || (count != base/2))
-    return false;
-    
-  if (!VECTOR_MODE_P (mode))
-    return false;
-
-  for (i = 0; i < count; i++)
-   {
-     rtx elt = XVECEXP (op, 0, i);
-     int val;
-
-     if (!CONST_INT_P (elt))
-       return false;
-
-     val = INTVAL (elt);
-     if (val != (base/2) + i)
-       return false;
-   }
-  return true; 
+  return arm_simd_check_vect_par_cnst_half_p (op, mode, true);
 })
 
 (define_special_predicate "vect_par_constant_low"
   (match_code "parallel")
 {
-  HOST_WIDE_INT count = XVECLEN (op, 0);
-  int i;
-  int base = GET_MODE_NUNITS (mode);
-
-  if ((count < 1)
-      || (count != base/2))
-    return false;
-    
-  if (!VECTOR_MODE_P (mode))
-    return false;
-
-  for (i = 0; i < count; i++)
-   {
-     rtx elt = XVECEXP (op, 0, i);
-     int val;
-
-     if (!CONST_INT_P (elt))
-       return false;
-
-     val = INTVAL (elt);
-     if (val != i)
-       return false;
-   } 
-  return true; 
+  return arm_simd_check_vect_par_cnst_half_p (op, mode, false);
 })
 
 (define_predicate "const_double_vcvt_power_of_two_reciprocal"
diff --git a/gcc/testsuite/gcc.target/arm/neon-vaddws16.c b/gcc/testsuite/gcc.target/arm/neon-vaddws16.c
new file mode 100644
index 0000000..96c657e
--- /dev/null
+++ b/gcc/testsuite/gcc.target/arm/neon-vaddws16.c
@@ -0,0 +1,18 @@ 
+/* { dg-do compile } */
+/* { dg-require-effective-target arm_neon_hw } */
+/* { dg-add-options arm_neon_ok } */
+/* { dg-options "-O3" } */
+
+
+int 
+t6(int len, void * dummy, short * __restrict x)
+{
+  len = len & ~31;
+  int result = 0;
+  __asm volatile ("");
+  for (int i = 0; i < len; i++)
+    result += x[i];
+  return result;
+}
+
+/* { dg-final { scan-assembler "vaddw\.s16" } } */
diff --git a/gcc/testsuite/gcc.target/arm/neon-vaddws32.c b/gcc/testsuite/gcc.target/arm/neon-vaddws32.c
new file mode 100644
index 0000000..1bfdc13
--- /dev/null
+++ b/gcc/testsuite/gcc.target/arm/neon-vaddws32.c
@@ -0,0 +1,17 @@ 
+/* { dg-do compile } */
+/* { dg-require-effective-target arm_neon_hw } */
+/* { dg-add-options arm_neon_ok } */
+/* { dg-options "-O3" } */
+
+int 
+t6(int len, void * dummy, int * __restrict x)
+{
+  len = len & ~31;
+  long long result = 0;
+  __asm volatile ("");
+  for (int i = 0; i < len; i++)
+    result += x[i];
+  return result;
+}
+
+/* { dg-final { scan-assembler "vaddw\.s32" } } */
diff --git a/gcc/testsuite/gcc.target/arm/neon-vaddwu16.c b/gcc/testsuite/gcc.target/arm/neon-vaddwu16.c
new file mode 100644
index 0000000..98f8768
--- /dev/null
+++ b/gcc/testsuite/gcc.target/arm/neon-vaddwu16.c
@@ -0,0 +1,18 @@ 
+/* { dg-do compile } */
+/* { dg-require-effective-target arm_neon_hw } */
+/* { dg-add-options arm_neon_ok } */
+/* { dg-options "-O3" } */
+
+
+int 
+t6(int len, void * dummy, unsigned short * __restrict x)
+{
+  len = len & ~31;
+  unsigned int result = 0;
+  __asm volatile ("");
+  for (int i = 0; i < len; i++)
+    result += x[i];
+  return result;
+}
+
+/* { dg-final { scan-assembler "vaddw.u16" } } */
diff --git a/gcc/testsuite/gcc.target/arm/neon-vaddwu32.c b/gcc/testsuite/gcc.target/arm/neon-vaddwu32.c
new file mode 100644
index 0000000..4a72a39
--- /dev/null
+++ b/gcc/testsuite/gcc.target/arm/neon-vaddwu32.c
@@ -0,0 +1,17 @@ 
+/* { dg-do compile } */
+/* { dg-require-effective-target arm_neon_hw } */
+/* { dg-add-options arm_neon_ok } */
+/* { dg-options "-O3" } */
+
+int 
+t6(int len, void * dummy, unsigned int * __restrict x)
+{
+  len = len & ~31;
+  unsigned long long result = 0;
+  __asm volatile ("");
+  for (int i = 0; i < len; i++)
+    result += x[i];
+  return result;
+}
+
+/* { dg-final { scan-assembler "vaddw\.u32" } } */
diff --git a/gcc/testsuite/gcc.target/arm/neon-vaddwu8.c b/gcc/testsuite/gcc.target/arm/neon-vaddwu8.c
new file mode 100644
index 0000000..9c9c68a
--- /dev/null
+++ b/gcc/testsuite/gcc.target/arm/neon-vaddwu8.c
@@ -0,0 +1,18 @@ 
+/* { dg-do compile } */
+/* { dg-require-effective-target arm_neon_hw } */
+/* { dg-add-options arm_neon_ok } */
+/* { dg-options "-O3" } */
+
+
+int 
+t6(int len, void * dummy, char * __restrict x)
+{
+  len = len & ~31;
+  unsigned short result = 0;
+  __asm volatile ("");
+  for (int i = 0; i < len; i++)
+    result += x[i];
+  return result;
+}
+
+/* { dg-final { scan-assembler "vaddw\.u8" } } */
diff --git a/gcc/testsuite/lib/target-supports.exp b/gcc/testsuite/lib/target-supports.exp
index b543519..4deca1f 100644
--- a/gcc/testsuite/lib/target-supports.exp
+++ b/gcc/testsuite/lib/target-supports.exp
@@ -3943,6 +3943,7 @@  proc check_effective_target_vect_widen_sum_hi_to_si_pattern { } {
     } else {
         set et_vect_widen_sum_hi_to_si_pattern_saved 0
         if { [istarget powerpc*-*-*]
+	     || [check_effective_target_arm_neon_ok]
              || [istarget ia64-*-*] } {
             set et_vect_widen_sum_hi_to_si_pattern_saved 1
         }
-- 
1.9.1