[aarch64]: add support for fabd in sve

This patch adds support in SVE to combine:
- fsub and fabs into fabd

fsub    z0.s, z0.s, z1.s
fabs    z0.s, p1/m, z0.s
---
fabd    z0.s, p1/m, z0.s, z1.s

2019-05-30  Sylvia Taylor  <sylvia.taylor@arm.com>

gcc/
	* config/aarch64/aarch64-sve.md (*fabd<mode>3): New.

gcc/testsuite/
	* gcc.target/aarch64/sve/fabd_1.c: New.

From-SVN: r271785

gcc/ChangeLog

+2019-05-30  Sylvia Taylor  <sylvia.taylor@arm.com>
+
+	* config/aarch64/aarch64-sve.md (*fabd<mode>3): New.
+
 2019-05-30  Bill Schmidt  <wschmidt@linux.ibm.com>
 	    Michael Meissner  <meissner@linux.ibm.com>
 

gcc/config/aarch64/aarch64-sve.md

@@ -2528,6 +2528,19 @@
   "<sve_fp_op>\t%0.<Vetype>, %1/m, %2.<Vetype>"
 )
 
+(define_insn "*fabd<mode>3"
+  [(set (match_operand:SVE_F 0 "register_operand" "=w")
+	(unspec:SVE_F
+	  [(match_operand:<VPRED> 1 "register_operand" "Upl")
+	   (abs:SVE_F
+	    (minus:SVE_F
+		(match_operand:SVE_F 2 "register_operand" "0")
+		(match_operand:SVE_F 3 "register_operand" "w")))]
+	UNSPEC_MERGE_PTRUE))]
+  "TARGET_SVE"
+  "fabd\t%0.<Vetype>, %1/m, %2.<Vetype>, %3.<Vetype>"
+)
+
 ;; Unpredicated FRINTy.
 (define_expand "<frint_pattern><mode>2"
   [(set (match_operand:SVE_F 0 "register_operand")

gcc/testsuite/ChangeLog

+2019-05-30  Sylvia Taylor  <sylvia.taylor@arm.com>
+
+	* gcc.target/aarch64/sve/fabd_1.c: New.
+
 2019-05-30  Iain Sandoe  <iain@sandoe.co.uk>
 
 	* gcc.target/i386/pr86257.c: Require native TLS support.

gcc/testsuite/gcc.target/aarch64/sve/fabd_1.c

+/* { dg-do assemble { target aarch64_asm_sve_ok } } */
+/* { dg-options "-O3 --save-temps" } */
+
+#define N 16
+
+typedef float *__restrict__ vnx4sf;
+typedef double *__restrict__ vnx2df;
+typedef _Float16 *__restrict__ vnx8hf_a;
+typedef __fp16 *__restrict__ vnx8hf_b;
+
+extern float fabsf (float);
+extern double fabs (double);
+
+#define FABD(type, abs, n)				\
+	void fabd_##type (type res, type a, type b)	\
+	{						\
+	    int i;					\
+	    for (i = 0; i < n; i++)			\
+		res[i] = abs (a[i] - b[i]);		\
+	}
+
+#define TEST_SVE_F_MODES(FUNC)	\
+  FUNC (vnx2df, fabs, N)	\
+  FUNC (vnx4sf, fabsf, N)	\
+  FUNC (vnx8hf_a, fabsf, N)	\
+  FUNC (vnx8hf_b, fabsf, N)	\
+
+TEST_SVE_F_MODES (FABD)
+
+/* { dg-final { scan-assembler "fabd" } } */
+/* { dg-final { scan-assembler-not "fsub" } } */
+/* { dg-final { scan-assembler-not "fabs" } } */
+/* { dg-final { scan-assembler-times {\tfabd\tz[0-9]+\.d, p[0-7]/m, z[0-9]+\.d, z[0-9]+\.d\n} 1 } } */
+/* { dg-final { scan-assembler-times {\tfabd\tz[0-9]+\.s, p[0-7]/m, z[0-9]+\.s, z[0-9]+\.s\n} 1 } } */
+/* { dg-final { scan-assembler-times {\tfabd\tz[0-9]+\.h, p[0-7]/m, z[0-9]+\.h, z[0-9]+\.h\n} 4 } } */