s390: Use vpdi and verllg in vec_reve.

Swapping the two elements of a V2DImode or V2DFmode vector can be done
with vpdi instead of using the generic way of loading a permutation mask
from the literal pool and vperm.

Analogous to the V2DI/V2DF case reversing the elements of a four-element
vector can be done by first swapping the elements of the first
doubleword as well the ones of the second one and subsequently rotate
the doublewords by 32 bits.

gcc/ChangeLog:

	PR target/100869
	* config/s390/vector.md (@vpdi4_2<mode>): New pattern.
	(rotl<mode>3_di): New pattern.
	* config/s390/vx-builtins.md: Use vpdi and verll for reversing
	elements.

gcc/testsuite/ChangeLog:

	* gcc.target/s390/zvector/vec-reve-int-long.c: New test.

3 files changed, 100 insertions, 0 deletions

diff --git a/gcc/config/s390/vector.md b/gcc/config/s390/vector.md
index 6247298..b6a3da6 100644
--- a/gcc/config/s390/vector.md
+++ b/gcc/config/s390/vector.md
@@ -797,6 +797,17 @@
   "vpdi\t%v0,%v1,%v2,4"
   [(set_attr "op_type" "VRR")])
 
+; Second DW of op1 and first DW of op2 (when interpreted as 2-element vector).
+(define_insn "@vpdi4_2<mode>"
+  [(set (match_operand:V_HW_4   0 "register_operand" "=v")
+	(vec_select:V_HW_4
+	 (vec_concat:<vec_2x_nelts>
+	  (match_operand:V_HW_4 1 "register_operand"  "v")
+	  (match_operand:V_HW_4 2 "register_operand"  "v"))
+	 (parallel [(const_int 2) (const_int 3) (const_int 4) (const_int 5)])))]
+  "TARGET_VX"
+  "vpdi\t%v0,%v1,%v2,4"
+  [(set_attr "op_type" "VRR")])
 
 (define_insn "*vmrhb"
   [(set (match_operand:V16QI                     0 "register_operand" "=v")
@@ -1255,6 +1266,23 @@
   "<vec_shifts_mnem><bhfgq>\t%v0,%v1,%Y2"
   [(set_attr "op_type" "VRS")])
 
+; verllg for V4SI/V4SF.  This swaps the first and the second two
+; elements of a vector and is only valid in that context.
+(define_expand "rotl<mode>3_di"
+ [
+ (set (match_dup 2)
+  (subreg:V2DI (match_operand:V_HW_4 1) 0))
+ (set (match_dup 3)
+  (rotate:V2DI
+   (match_dup 2)
+   (const_int 32)))
+ (set (match_operand:V_HW_4 0)
+  (subreg:V_HW_4 (match_dup 3) 0))]
+ "TARGET_VX"
+ {
+  operands[2] = gen_reg_rtx (V2DImode);
+  operands[3] = gen_reg_rtx (V2DImode);
+ })
 
 ; Shift each element by corresponding vector element
 
diff --git a/gcc/config/s390/vx-builtins.md b/gcc/config/s390/vx-builtins.md
index 98ee08b..69ce00b 100644
--- a/gcc/config/s390/vx-builtins.md
+++ b/gcc/config/s390/vx-builtins.md
@@ -2181,6 +2181,47 @@
    vster<bhfgq>\t%v1,%v0"
   [(set_attr "op_type" "*,VRX,VRX")])
 
+; Swapping v2df/v2di can be done via vpdi on z13 and z14.
+(define_split
+  [(set (match_operand:V_HW_2                 0 "register_operand" "")
+	(unspec:V_HW_2 [(match_operand:V_HW_2 1 "register_operand" "")]
+		       UNSPEC_VEC_ELTSWAP))]
+  "TARGET_VX && can_create_pseudo_p ()"
+  [(set (match_operand:V_HW_2     0 "register_operand" "=v")
+	(vec_select:V_HW_2
+	 (vec_concat:<vec_2x_nelts>
+	  (match_operand:V_HW_2 1 "register_operand"  "v")
+	  (match_dup 1))
+	 (parallel [(const_int 1) (const_int 2)])))]
+)
+
+
+; Swapping v4df/v4si can be done via vpdi and rot.
+(define_split
+  [(set (match_operand:V_HW_4                 0 "register_operand" "")
+	(unspec:V_HW_4 [(match_operand:V_HW_4 1 "register_operand" "")]
+		       UNSPEC_VEC_ELTSWAP))]
+  "TARGET_VX && can_create_pseudo_p ()"
+  [(set (match_dup 2)
+	(vec_select:V_HW_4
+	 (vec_concat:<vec_2x_nelts>
+	  (match_dup 1)
+	  (match_dup 1))
+	 (parallel [(const_int 2) (const_int 3) (const_int 4) (const_int 5)])))
+ (set (match_dup 3)
+  (subreg:V2DI (match_dup 2) 0))
+ (set (match_dup 4)
+  (rotate:V2DI
+   (match_dup 3)
+   (const_int 32)))
+ (set (match_operand:V_HW_4 0)
+  (subreg:V_HW_4 (match_dup 4) 0))]
+{
+  operands[2] = gen_reg_rtx (<MODE>mode);
+  operands[3] = gen_reg_rtx (V2DImode);
+  operands[4] = gen_reg_rtx (V2DImode);
+})
+
 ; z15 has instructions for doing element reversal from mem to reg
 ; or the other way around.  For reg to reg or on pre z15 machines
 ; we have to emulate it with vector permute.
diff --git a/gcc/testsuite/gcc.target/s390/zvector/vec-reve-int-long.c b/gcc/testsuite/gcc.target/s390/zvector/vec-reve-int-long.c
new file mode 100644
index 0000000..dff3a94
--- /dev/null
+++ b/gcc/testsuite/gcc.target/s390/zvector/vec-reve-int-long.c
@@ -0,0 +1,31 @@
+/* Test that we use vpdi in order to reverse vectors
+   with two elements instead of creating a literal-pool entry
+   and permuting with vperm.  */
+/* { dg-do compile { target { s390*-*-* } } } */
+/* { dg-options "-O2 -march=z14 -mzarch -mzvector -fno-unroll-loops" } */
+
+/* { dg-final { scan-assembler-times "vpdi\t" 4 } } */
+/* { dg-final { scan-assembler-times "verllg\t" 2 } } */
+/* { dg-final { scan-assembler-times "vperm" 0 } } */
+
+#include <vecintrin.h>
+
+vector double reved (vector double a)
+{
+   return vec_reve (a);
+}
+
+vector long long revel (vector long long a)
+{
+   return vec_reve (a);
+}
+
+vector float revef (vector float a)
+{
+   return vec_reve (a);
+}
+
+vector int revei (vector int a)
+{
+   return vec_reve (a);
+}