Vectorise conversions between differently-sized integer vectors

This patch adds AArch64 patterns for converting between 64-bit and
128-bit integer vectors, and makes the vectoriser and expand pass
use them.

2019-11-14  Richard Sandiford  <richard.sandiford@arm.com>

gcc/
	* tree-cfg.c (verify_gimple_assign_unary): Handle conversions
	between vector types.
	* tree-vect-stmts.c (vectorizable_conversion): Extend the
	non-widening and non-narrowing path to handle standard
	conversion codes, if the target supports them.
	* expr.c (convert_move): Try using the extend and truncate optabs
	for vectors.
	* optabs-tree.c (supportable_convert_operation): Likewise.
	* config/aarch64/iterators.md (Vnarroqw): New iterator.
	* config/aarch64/aarch64-simd.md (<optab><Vnarrowq><mode>2)
	(trunc<mode><Vnarrowq>2): New patterns.

gcc/testsuite/
	* gcc.dg/vect/bb-slp-pr69907.c: Do not expect BB vectorization
	to fail for aarch64 targets.
	* gcc.dg/vect/no-scevccp-outer-12.c: Expect the test to pass
	on aarch64 targets.
	* gcc.dg/vect/vect-double-reduc-5.c: Likewise.
	* gcc.dg/vect/vect-outer-4e.c: Likewise.
	* gcc.target/aarch64/vect_mixed_sizes_5.c: New test.
	* gcc.target/aarch64/vect_mixed_sizes_6.c: Likewise.
	* gcc.target/aarch64/vect_mixed_sizes_7.c: Likewise.
	* gcc.target/aarch64/vect_mixed_sizes_8.c: Likewise.
	* gcc.target/aarch64/vect_mixed_sizes_9.c: Likewise.
	* gcc.target/aarch64/vect_mixed_sizes_10.c: Likewise.
	* gcc.target/aarch64/vect_mixed_sizes_11.c: Likewise.
	* gcc.target/aarch64/vect_mixed_sizes_12.c: Likewise.
	* gcc.target/aarch64/vect_mixed_sizes_13.c: Likewise.

From-SVN: r278245

1 files changed, 25 insertions, 0 deletions

diff --git a/gcc/expr.c b/gcc/expr.c
index 0fd5890f..ed50586 100644
--- a/gcc/expr.c
+++ b/gcc/expr.c
@@ -250,6 +250,31 @@ convert_move (rtx to, rtx from, int unsignedp)
 
   if (VECTOR_MODE_P (to_mode) || VECTOR_MODE_P (from_mode))
     {
+      if (GET_MODE_UNIT_PRECISION (to_mode)
+	  > GET_MODE_UNIT_PRECISION (from_mode))
+	{
+	  optab op = unsignedp ? zext_optab : sext_optab;
+	  insn_code icode = convert_optab_handler (op, to_mode, from_mode);
+	  if (icode != CODE_FOR_nothing)
+	    {
+	      emit_unop_insn (icode, to, from,
+			      unsignedp ? ZERO_EXTEND : SIGN_EXTEND);
+	      return;
+	    }
+	}
+
+      if (GET_MODE_UNIT_PRECISION (to_mode)
+	  < GET_MODE_UNIT_PRECISION (from_mode))
+	{
+	  insn_code icode = convert_optab_handler (trunc_optab,
+						   to_mode, from_mode);
+	  if (icode != CODE_FOR_nothing)
+	    {
+	      emit_unop_insn (icode, to, from, TRUNCATE);
+	      return;
+	    }
+	}
+
       gcc_assert (known_eq (GET_MODE_BITSIZE (from_mode),
 			    GET_MODE_BITSIZE (to_mode)));