[PATCH][1/4][committed] aarch64: Convert UABDL and SABDL patterns to standard RTL codes

[PATCH][1/4][committed] aarch64: Convert UABDL and SABDL patterns to standard RTL codes

[Kyrylo Tkachov]

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Hi all,

This is the first patch in a series to improve the RTL representation of the sum-of-absolute-differences patterns
in the backend. We can use standard RTL codes and remove some unspecs.
For UABDL and SABDL we have a widening of the result so we can represent uabdl (x, y) as (zero_extend (minus (smax (x, y) (smin (x, y)))))
and sabdl (x, y) as (zero_extend (minus (umax (x, y) (umin (x, y))))).
It is important to use zero_extend rather than sign_extend for the sabdl case, as the result of the absolute difference is still a positive unsigned value
(the signedness of the operation refers to the values being diffed, not the absolute value of the difference) that must be zero-extended.

Bootstrapped and tested on aarch64-none-linux-gnu (these intrinsics are reasonably well-covered by the advsimd-intrinsics.exp tests)
Pushing to trunk.
Thanks,
Kyrill

gcc/ChangeLog:

	* config/aarch64/aarch64-simd.md (aarch64_<sur>abdl<mode>): Rename to...
	(aarch64_<su>abdl<mode>): ... This.  Use standard RTL ops instead of
	unspec.
	* config/aarch64/aarch64.md (UNSPEC_SABDL, UNSPEC_UABDL): Delete.
	* config/aarch64/iterators.md (ABDL): Delete.
	(sur): Remove handling of UNSPEC_SABDL and UNSPEC_UABDL.

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diff --git a/gcc/config/aarch64/aarch64-simd.md b/gcc/config/aarch64/aarch64-simd.md
index 772dd7693b3ea5bcf40fb0c8d0d2b9e6cae02342..bcea3194bb4a58e6e3dd4a320670926e34965696 100644
--- a/gcc/config/aarch64/aarch64-simd.md
+++ b/gcc/config/aarch64/aarch64-simd.md
@@ -871,14 +871,18 @@ (define_insn "aarch64_<su>abd<mode>"
   [(set_attr "type" "neon_abd<q>")]
 )
 
-
-(define_insn "aarch64_<sur>abdl<mode>"
+(define_insn "aarch64_<su>abdl<mode>"
   [(set (match_operand:<VWIDE> 0 "register_operand" "=w")
-	(unspec:<VWIDE> [(match_operand:VD_BHSI 1 "register_operand" "w")
-			 (match_operand:VD_BHSI 2 "register_operand" "w")]
-	ABDL))]
+	(zero_extend:<VWIDE>
+	  (minus:VD_BHSI
+	    (USMAX:VD_BHSI
+	      (match_operand:VD_BHSI 1 "register_operand" "w")
+	      (match_operand:VD_BHSI 2 "register_operand" "w"))
+	    (<max_opp>:VD_BHSI
+	      (match_dup 1)
+	      (match_dup 2)))))]
   "TARGET_SIMD"
-  "<sur>abdl\t%0.<Vwtype>, %1.<Vtype>, %2.<Vtype>"
+  "<su>abdl\t%0.<Vwtype>, %1.<Vtype>, %2.<Vtype>"
   [(set_attr "type" "neon_abd<q>")]
 )
 
diff --git a/gcc/config/aarch64/aarch64.md b/gcc/config/aarch64/aarch64.md
index 0b326d497b47e1909d8cb2e136952253336bc333..46d86c105395493777e6812699de9624101ba609 100644
--- a/gcc/config/aarch64/aarch64.md
+++ b/gcc/config/aarch64/aarch64.md
@@ -206,7 +206,6 @@ (define_c_enum "unspec" [
     UNSPEC_RBIT
     UNSPEC_SABAL
     UNSPEC_SABAL2
-    UNSPEC_SABDL
     UNSPEC_SABDL2
     UNSPEC_SADALP
     UNSPEC_SCVTF
@@ -230,7 +229,6 @@ (define_c_enum "unspec" [
     UNSPEC_TLSLE48
     UNSPEC_UABAL
     UNSPEC_UABAL2
-    UNSPEC_UABDL
     UNSPEC_UABDL2
     UNSPEC_UADALP
     UNSPEC_UCVTF
diff --git a/gcc/config/aarch64/iterators.md b/gcc/config/aarch64/iterators.md
index 6cbc97cc82c06a68259bdf4dec8a0eab230081e5..4f2430c434165043c1ec814751ff106a6414d408 100644
--- a/gcc/config/aarch64/iterators.md
+++ b/gcc/config/aarch64/iterators.md
@@ -2565,9 +2565,6 @@ (define_code_attr inc_dec [(minus "dec") (ss_minus "sqdec") (us_minus "uqdec")
 ;; The unspec codes for the SABAL, UABAL AdvancedSIMD instructions.
 (define_int_iterator ABAL [UNSPEC_SABAL UNSPEC_UABAL])
 
-;; The unspec codes for the SABDL, UABDL AdvancedSIMD instructions.
-(define_int_iterator ABDL [UNSPEC_SABDL UNSPEC_UABDL])
-
 ;; The unspec codes for the SABAL2, UABAL2 AdvancedSIMD instructions.
 (define_int_iterator ABAL2 [UNSPEC_SABAL2 UNSPEC_UABAL2])
 
@@ -3357,7 +3354,6 @@ (define_int_attr sur [(UNSPEC_SHADD "s") (UNSPEC_UHADD "u")
 		      (UNSPEC_ADDHN "") (UNSPEC_RADDHN "r")
 		      (UNSPEC_SABAL "s") (UNSPEC_UABAL "u")
 		      (UNSPEC_SABAL2 "s") (UNSPEC_UABAL2 "u")
-		      (UNSPEC_SABDL "s") (UNSPEC_UABDL "u")
 		      (UNSPEC_SABDL2 "s") (UNSPEC_UABDL2 "u")
 		      (UNSPEC_SADALP "s") (UNSPEC_UADALP "u")
 		      (UNSPEC_SUBHN "") (UNSPEC_RSUBHN "r")