Tests are still running, but I believe I've addressed the comment.
> There are ways in which we could reduce the amount of cut-&-paste here,
> but I guess everything is a trade-off between clarity and compactness.
> One extreme is to write them all out explicitly, another extreme would
> be to have one define_expand and various iterators and attributes.
>
> I think the vec_widen_<su>mult_*_<mode> patterns strike a good balance:
> the use ANY_EXTEND to hide the sign difference while still having
> separate hi and lo patterns:
Done
gcc/ChangeLog:
2020-11-13 Joel Hutton <joel.hut...@arm.com>
* config/aarch64/aarch64-simd.md: New patterns
vec_widen_saddl_lo/hi_<mode>.
From c52fd11f5d471200c1292fad3bc04056e7721f06 Mon Sep 17 00:00:00 2001
From: Joel Hutton <joel.hut...@arm.com>
Date: Mon, 9 Nov 2020 15:35:57 +0000
Subject: [PATCH 1/3] [aarch64] Add vec_widen patterns to aarch64
Add widening add and subtract patterns to the aarch64
backend. These allow taking vectors of N elements of size S
and performing and add/subtract on the high or low half
widening the resulting elements and storing N/2 elements of size 2*S.
These correspond to the addl,addl2,subl,subl2 instructions.
---
gcc/config/aarch64/aarch64-simd.md | 47 ++++++++++++++++++++++++++++++
1 file changed, 47 insertions(+)
diff --git a/gcc/config/aarch64/aarch64-simd.md b/gcc/config/aarch64/aarch64-simd.md
index 2cf6fe9154a..30299610635 100644
--- a/gcc/config/aarch64/aarch64-simd.md
+++ b/gcc/config/aarch64/aarch64-simd.md
@@ -3382,6 +3382,53 @@
[(set_attr "type" "neon_<ADDSUB:optab>_long")]
)
+(define_expand "vec_widen_<su>addl_lo_<mode>"
+ [(match_operand:<VWIDE> 0 "register_operand")
+ (ANY_EXTEND:<VWIDE> (match_operand:VQW 1 "register_operand"))
+ (ANY_EXTEND:<VWIDE> (match_operand:VQW 2 "register_operand"))]
+ "TARGET_SIMD"
+{
+ rtx p = aarch64_simd_vect_par_cnst_half (<MODE>mode, <nunits>, false);
+ emit_insn (gen_aarch64_<su>addl<mode>_lo_internal (operands[0], operands[1],
+ operands[2], p));
+ DONE;
+})
+
+(define_expand "vec_widen_<su>addl_hi_<mode>"
+ [(match_operand:<VWIDE> 0 "register_operand")
+ (ANY_EXTEND:<VWIDE> (match_operand:VQW 1 "register_operand"))
+ (ANY_EXTEND:<VWIDE> (match_operand:VQW 2 "register_operand"))]
+ "TARGET_SIMD"
+{
+ rtx p = aarch64_simd_vect_par_cnst_half (<MODE>mode, <nunits>, true);
+ emit_insn (gen_aarch64_<su>addl<mode>_hi_internal (operands[0], operands[1],
+ operands[2], p));
+ DONE;
+})
+
+(define_expand "vec_widen_<su>subl_lo_<mode>"
+ [(match_operand:<VWIDE> 0 "register_operand")
+ (ANY_EXTEND:<VWIDE> (match_operand:VQW 1 "register_operand"))
+ (ANY_EXTEND:<VWIDE> (match_operand:VQW 2 "register_operand"))]
+ "TARGET_SIMD"
+{
+ rtx p = aarch64_simd_vect_par_cnst_half (<MODE>mode, <nunits>, false);
+ emit_insn (gen_aarch64_<su>subl<mode>_lo_internal (operands[0], operands[1],
+ operands[2], p));
+ DONE;
+})
+
+(define_expand "vec_widen_<su>subl_hi_<mode>"
+ [(match_operand:<VWIDE> 0 "register_operand")
+ (ANY_EXTEND:<VWIDE> (match_operand:VQW 1 "register_operand"))
+ (ANY_EXTEND:<VWIDE> (match_operand:VQW 2 "register_operand"))]
+ "TARGET_SIMD"
+{
+ rtx p = aarch64_simd_vect_par_cnst_half (<MODE>mode, <nunits>, true);
+ emit_insn (gen_aarch64_<su>subl<mode>_hi_internal (operands[0], operands[1],
+ operands[2], p));
+ DONE;
+})
(define_expand "aarch64_saddl2<mode>"
[(match_operand:<VWIDE> 0 "register_operand")
--
2.17.1
