Hi All,

This adds an RTL pattern for when two NARROWB instructions are being combined
with a PACK.  The second NARROWB is then transformed into a NARROWT.

For the example:

void draw_bitmap1(uint8_t* restrict pixel, uint8_t level, int n)
{
  for (int i = 0; i < (n & -16); i+=1)
    pixel[i] += (pixel[i] * level) / 0xff;
}

we generate:

        addhnb  z6.b, z0.h, z4.h
        addhnb  z5.b, z1.h, z4.h
        addhnb  z0.b, z0.h, z6.h
        addhnt  z0.b, z1.h, z5.h
        add     z0.b, z0.b, z2.b

instead of:

        addhnb  z6.b, z1.h, z4.h
        addhnb  z5.b, z0.h, z4.h
        addhnb  z1.b, z1.h, z6.h
        addhnb  z0.b, z0.h, z5.h
        uzp1    z0.b, z0.b, z1.b
        add     z0.b, z0.b, z2.b

Bootstrapped Regtested on aarch64-none-linux-gnu and no issues.

Ok for master?

Thanks,
Tamar

gcc/ChangeLog:

	* config/aarch64/aarch64-sve2.md (*aarch64_sve_pack_<sve_int_op><mode>):
	New.
	* config/aarch64/iterators.md (binary_top): New.

gcc/testsuite/ChangeLog:

	* gcc.dg/vect/vect-div-bitmask-4.c: New test.
	* gcc.target/aarch64/sve2/div-by-bitmask_2.c: New test.

--- inline copy of patch -- 
diff --git a/gcc/config/aarch64/aarch64-sve2.md b/gcc/config/aarch64/aarch64-sve2.md
index ab5dcc369481311e5bd68a1581265e1ce99b4b0f..0ee46c8b0d43467da4a6b98ad3c41e5d05d8cf38 100644
--- a/gcc/config/aarch64/aarch64-sve2.md
+++ b/gcc/config/aarch64/aarch64-sve2.md
@@ -1600,6 +1600,25 @@ (define_insn "@aarch64_sve_<sve_int_op><mode>"
   "<sve_int_op>\t%0.<Ventype>, %2.<Vetype>, %3.<Vetype>"
 )
 
+(define_insn_and_split "*aarch64_sve_pack_<sve_int_op><mode>"
+  [(set (match_operand:<VNARROW> 0 "register_operand" "=w")
+	(unspec:<VNARROW>
+	  [(match_operand:SVE_FULL_HSDI 1 "register_operand" "w")
+	   (subreg:SVE_FULL_HSDI (unspec:<VNARROW>
+	     [(match_operand:SVE_FULL_HSDI 2 "register_operand" "w")
+	      (match_operand:SVE_FULL_HSDI 3 "register_operand" "w")]
+	     SVE2_INT_BINARY_NARROWB) 0)]
+	  UNSPEC_PACK))]
+  "TARGET_SVE2"
+  "#"
+  "&& true"
+  [(const_int 0)]
+{
+  rtx tmp = lowpart_subreg (<VNARROW>mode, operands[1], <MODE>mode);
+  emit_insn (gen_aarch64_sve (<SVE2_INT_BINARY_NARROWB:binary_top>, <MODE>mode,
+			      operands[0], tmp, operands[2], operands[3]));
+})
+
 ;; -------------------------------------------------------------------------
 ;; ---- [INT] Narrowing right shifts
 ;; -------------------------------------------------------------------------
diff --git a/gcc/config/aarch64/iterators.md b/gcc/config/aarch64/iterators.md
index 0dd9dc66f7ccd78acacb759662d0cd561cd5b4ef..37d8161a33b1c399d80be82afa67613a087389d4 100644
--- a/gcc/config/aarch64/iterators.md
+++ b/gcc/config/aarch64/iterators.md
@@ -3589,6 +3589,11 @@ (define_int_attr brk_op [(UNSPEC_BRKA "a") (UNSPEC_BRKB "b")
 
 (define_int_attr sve_pred_op [(UNSPEC_PFIRST "pfirst") (UNSPEC_PNEXT "pnext")])
 
+(define_int_attr binary_top [(UNSPEC_ADDHNB "UNSPEC_ADDHNT")
+			     (UNSPEC_RADDHNB "UNSPEC_RADDHNT")
+			     (UNSPEC_RSUBHNB "UNSPEC_RSUBHNT")
+			     (UNSPEC_SUBHNB "UNSPEC_SUBHNT")])
+
 (define_int_attr sve_int_op [(UNSPEC_ADCLB "adclb")
 			     (UNSPEC_ADCLT "adclt")
 			     (UNSPEC_ADDHNB "addhnb")
diff --git a/gcc/testsuite/gcc.dg/vect/vect-div-bitmask-4.c b/gcc/testsuite/gcc.dg/vect/vect-div-bitmask-4.c
new file mode 100644
index 0000000000000000000000000000000000000000..0df08bda6fd3e33280307ea15c82dd9726897cfd
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/vect/vect-div-bitmask-4.c
@@ -0,0 +1,26 @@
+/* { dg-require-effective-target vect_int } */
+/* { dg-additional-options "-fno-vect-cost-model" { target aarch64*-*-* } } */
+
+#include <stdint.h>
+#include "tree-vect.h"
+
+#define N 50
+#define TYPE uint32_t
+
+__attribute__((noipa, noinline, optimize("O1")))
+void fun1(TYPE* restrict pixel, TYPE level, int n)
+{
+  for (int i = 0; i < n; i+=1)
+    pixel[i] += (pixel[i] * (uint64_t)level) / 0xffffffffUL;
+}
+
+__attribute__((noipa, noinline, optimize("O3")))
+void fun2(TYPE* restrict pixel, TYPE level, int n)
+{
+  for (int i = 0; i < n; i+=1)
+    pixel[i] += (pixel[i] * (uint64_t)level) / 0xffffffffUL;
+}
+
+#include "vect-div-bitmask.h"
+
+/* { dg-final { scan-tree-dump-not "vect_recog_divmod_pattern: detected" "vect" { target aarch64*-*-* } } } */
diff --git a/gcc/testsuite/gcc.target/aarch64/sve2/div-by-bitmask_2.c b/gcc/testsuite/gcc.target/aarch64/sve2/div-by-bitmask_2.c
new file mode 100644
index 0000000000000000000000000000000000000000..cddcebdf15ecaa9dc515f58cdbced36c8038db1b
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/sve2/div-by-bitmask_2.c
@@ -0,0 +1,56 @@
+/* { dg-do compile } */
+/* { dg-additional-options "-O2 -std=c99" } */
+/* { dg-final { check-function-bodies "**" "" "" { target { le } } } } */
+
+#include <stdint.h>
+
+/*
+** draw_bitmap1:
+** ...
+** 	addhnb	z6.b, z0.h, z4.h
+** 	addhnb	z5.b, z1.h, z4.h
+** 	addhnb	z0.b, z0.h, z6.h
+** 	addhnt	z0.b, z1.h, z5.h
+** ...
+*/
+void draw_bitmap1(uint8_t* restrict pixel, uint8_t level, int n)
+{
+  for (int i = 0; i < (n & -16); i+=1)
+    pixel[i] += (pixel[i] * level) / 0xff;
+}
+
+void draw_bitmap2(uint8_t* restrict pixel, uint8_t level, int n)
+{
+  for (int i = 0; i < (n & -16); i+=1)
+    pixel[i] += (pixel[i] * level) / 0xfe;
+}
+
+/*
+** draw_bitmap3:
+** ...
+** 	addhnb	z6.h, z0.s, z4.s
+** 	addhnb	z5.h, z1.s, z4.s
+** 	addhnb	z0.h, z0.s, z6.s
+** 	addhnt	z0.h, z1.s, z5.s
+** ...
+*/
+void draw_bitmap3(uint16_t* restrict pixel, uint16_t level, int n)
+{
+  for (int i = 0; i < (n & -16); i+=1)
+    pixel[i] += (pixel[i] * level) / 0xffffU;
+}
+
+/*
+** draw_bitmap4:
+** ...
+** 	addhnb	z6.s, z0.d, z4.d
+** 	addhnb	z5.s, z1.d, z4.d
+** 	addhnb	z0.s, z0.d, z6.d
+** 	addhnt	z0.s, z1.d, z5.d
+** ...
+*/
+void draw_bitmap4(uint32_t* restrict pixel, uint32_t level, int n)
+{
+  for (int i = 0; i < (n & -16); i+=1)
+    pixel[i] += (pixel[i] * (uint64_t)level) / 0xffffffffUL;
+}




--