Add gen_(const_)vec_duplicate helpers

This patch adds helper functions for generating constant and
non-constant vector duplicates.  These routines help with SVE because
it is then easier to use:

   (const:M (vec_duplicate:M X))

for a broadcast of X, even if the number of elements in M isn't known
at compile time.  It also makes it easier for general rtx code to treat
constant and non-constant duplicates in the same way.

In the target code, the patch uses gen_vec_duplicate instead of
gen_rtx_VEC_DUPLICATE if handling constants correctly is potentially
useful.  It might be that some or all of the call sites only handle
non-constants in practice, in which case the change is a harmless
no-op (and a saving of a few characters).

Otherwise, the target changes use gen_const_vec_duplicate instead
of gen_rtx_CONST_VECTOR if the constant is obviously a duplicate.
They also include some changes to use CONSTxx_RTX for easy global
constants.

2017-11-01  Richard Sandiford  <richard.sandiford@linaro.org>
	    Alan Hayward  <alan.hayward@arm.com>
	    David Sherwood  <david.sherwood@arm.com>

gcc/
	* emit-rtl.h (gen_const_vec_duplicate): Declare.
	(gen_vec_duplicate): Likewise.
	* emit-rtl.c (gen_const_vec_duplicate_1): New function, split
	out from...
	(gen_const_vector): ...here.
	(gen_const_vec_duplicate, gen_vec_duplicate): New functions.
	(gen_rtx_CONST_VECTOR): Use gen_const_vec_duplicate for constants
	whose elements are all equal.
	* optabs.c (expand_vector_broadcast): Use gen_const_vec_duplicate.
	* simplify-rtx.c (simplify_const_unary_operation): Likewise.
	(simplify_relational_operation): Likewise.
	* config/aarch64/aarch64.c (aarch64_simd_gen_const_vector_dup):
	Likewise.
	(aarch64_simd_dup_constant): Use gen_vec_duplicate.
	(aarch64_expand_vector_init): Likewise.
	* config/arm/arm.c (neon_vdup_constant): Likewise.
	(neon_expand_vector_init): Likewise.
	(arm_expand_vec_perm): Use gen_const_vec_duplicate.
	(arm_block_set_unaligned_vect): Likewise.
	(arm_block_set_aligned_vect): Likewise.
	* config/arm/neon.md (neon_copysignf<mode>): Likewise.
	* config/i386/i386.c (ix86_expand_vec_perm): Likewise.
	(expand_vec_perm_even_odd_pack): Likewise.
	(ix86_vector_duplicate_value): Use gen_vec_duplicate.
	* config/i386/sse.md (one_cmpl<mode>2): Use CONSTM1_RTX.
	* config/ia64/ia64.c (ia64_expand_vecint_compare): Use
	gen_const_vec_duplicate.
	* config/ia64/vect.md (addv2sf3, subv2sf3): Use CONST1_RTX.
	* config/mips/mips.c (mips_gen_const_int_vector): Use
	gen_const_vec_duplicate.
	(mips_expand_vector_init): Use CONST0_RTX.
	* config/powerpcspe/altivec.md (abs<mode>2, nabs<mode>2): Likewise.
	(define_split): Use gen_const_vec_duplicate.
	* config/rs6000/altivec.md (abs<mode>2, nabs<mode>2): Use CONST0_RTX.
	(define_split): Use gen_const_vec_duplicate.
	* config/s390/vx-builtins.md (vec_genmask<mode>): Likewise.
	(vec_ctd_s64, vec_ctd_u64, vec_ctsl, vec_ctul): Likewise.
	* config/spu/spu.c (spu_const): Likewise.

Co-Authored-By: Alan Hayward <alan.hayward@arm.com>
Co-Authored-By: David Sherwood <david.sherwood@arm.com>

From-SVN: r254292

1 files changed, 1 insertions, 10 deletions

diff --git a/gcc/config/spu/spu.c b/gcc/config/spu/spu.c
index bf21cca..7825210 100644
--- a/gcc/config/spu/spu.c
+++ b/gcc/config/spu/spu.c
@@ -1903,8 +1903,6 @@ rtx
 spu_const (machine_mode mode, HOST_WIDE_INT val)
 {
   rtx inner;
-  rtvec v;
-  int units, i;
 
   gcc_assert (GET_MODE_CLASS (mode) == MODE_INT
 	      || GET_MODE_CLASS (mode) == MODE_FLOAT
@@ -1923,14 +1921,7 @@ spu_const (machine_mode mode, HOST_WIDE_INT val)
   else 
     inner = hwint_to_const_double (GET_MODE_INNER (mode), val);
 
-  units = GET_MODE_NUNITS (mode);
-
-  v = rtvec_alloc (units);
-
-  for (i = 0; i < units; ++i)
-    RTVEC_ELT (v, i) = inner;
-
-  return gen_rtx_CONST_VECTOR (mode, v);
+  return gen_const_vec_duplicate (mode, inner);
 }
 
 /* Create a MODE vector constant from 4 ints. */