rs6000: Add vgnb

Add support for the vgnb instruction, which gathers every Nth bit
per vector element.

[gcc]

2020-05-11  Kelvin Nilsen  <kelvin@gcc.gnu.org>
	    Bill Schmidt  <wschmidt@linux.ibm.com>

	* config/rs6000/altivec.h (vec_gnb): New #define.
	* config/rs6000/altivec.md (UNSPEC_VGNB): New constant.
	(vgnb): New insn.
	* config/rs6000/rs6000-builtin.def (BU_FUTURE_OVERLOAD_1): New
	#define.
	(BU_FUTURE_OVERLOAD_2): Likewise.
	(BU_FUTURE_OVERLOAD_3): Likewise.
	(__builtin_altivec_gnb): New built-in function.
	(__buiiltin_vec_gnb): New overloaded built-in function.
	* config/rs6000/rs6000-call.c (altivec_overloaded_builtins):
	Define overloaded forms of __builtin_vec_gnb.
	(rs6000_expand_binop_builtin): Add error checking for 2nd argument
	of __builtin_vec_gnb.
	(builtin_function_type): Mark return value and arguments unsigned
	for FUTURE_BUILTIN_VGNB.
	* doc/extend.texi (PowerPC AltiVec Built-in Functions Available
	for a Future Architecture): Add description of vec_gnb built-in
	function.

[gcc/testsuite]

2020-05-11  Kelvin Nilsen  <kelvin@gcc.gnu.org>
	    Bill Schmidt  <wschmidt@linux.ibm.com>

	* gcc.target/powerpc/vec-gnb-0.c: New test.
	* gcc.target/powerpc/vec-gnb-1.c: New test.
	* gcc.target/powerpc/vec-gnb-10.c: New test.
	* gcc.target/powerpc/vec-gnb-2.c: New test.
	* gcc.target/powerpc/vec-gnb-3.c: New test.
	* gcc.target/powerpc/vec-gnb-4.c: New test.
	* gcc.target/powerpc/vec-gnb-5.c: New test.
	* gcc.target/powerpc/vec-gnb-6.c: New test.
	* gcc.target/powerpc/vec-gnb-7.c: New test.
	* gcc.target/powerpc/vec-gnb-8.c: New test.
	* gcc.target/powerpc/vec-gnb-9.c: New test.

1 files changed, 71 insertions, 0 deletions

diff --git a/gcc/testsuite/gcc.target/powerpc/vec-gnb-5.c b/gcc/testsuite/gcc.target/powerpc/vec-gnb-5.c
new file mode 100644
index 00000000000..1c3c3fa72c0
--- /dev/null
+++ b/gcc/testsuite/gcc.target/powerpc/vec-gnb-5.c
@@ -0,0 +1,71 @@
+/* { dg-do run } */
+/* { dg-require-effective-target powerpc_future_hw } */
+/* { dg-options "-mdejagnu-cpu=future" } */
+
+#include <altivec.h>
+
+extern void abort (void);
+
+/* This test is replicated for every different vector type since
+   vec_gnb is polymorphic.  */
+unsigned long long int
+do_vec_gnb (vector unsigned int source, int stride)
+{
+  switch (stride)
+    {
+    case 2:
+      return vec_gnb (source, 2);
+    case 3:
+      return vec_gnb (source, 3);
+    case 4:
+      return vec_gnb (source, 4);
+    case 5:
+      return vec_gnb (source, 5);
+    case 6:
+      return vec_gnb (source, 6);
+    case 7:
+      return vec_gnb (source, 7);
+
+    default:
+      /* Illegal value of stride */
+      abort ();
+      return 0;
+    }
+}
+
+int
+main (int argc, char *argv [])
+{
+  /* For result = 0xaaaa_0000_0000_0000, use:
+      stride = 2: binary 1x0x_1x0x_1x0x_... = 0x8888_8888_0000_0000, 0
+      stride = 4: binary 1xxx_0xxx_1xxx_0xxxx = 0x8080_8080_8080_8080, 0
+
+     For result = 0xaaaa_aaaa_0000_0000, use:
+      stride = 2: source = 0x8888_8888_8888_8888, 0x0 }
+      stride = 4: source = { 0x8080_8080_8080_8080, 0x8080_8080_8080_8080 }
+  */
+
+  /* The last array element appears in the left-most (first) bit
+     positions of the vector register.  */
+  vector unsigned int source_a = { 0, 0, 0, 0x88888888 };
+  vector unsigned int source_b = { 0, 0, 0x80808080, 0x80808080 };
+  vector unsigned int source_c = { 0, 0, 0x88888888, 0x88888888 };
+  vector unsigned int source_d =
+    { 0x80808080, 0x80808080, 0x80808080, 0x80808080 };
+
+  unsigned long long int results [] =
+    { 0xaaaa000000000000ull, 0xaaaa000000000000ull,
+      0xaaaaaaaa00000000ull, 0xaaaaaaaa00000000ull };
+
+  if (do_vec_gnb (source_a, 2) != results [0])
+    abort ();
+  if (do_vec_gnb (source_b, 4) != results [1])
+    abort ();
+  if (do_vec_gnb (source_c, 2) != results [2])
+    abort ();
+  if (do_vec_gnb (source_d, 4) != results [3])
+    abort ();
+
+  return 0;
+}
+