Hi All,

Currently we often times generate an r -> r add even if it means we need two
reloads to perform it, i.e. in the case that the values are on the SIMD side.

The pairwise operations expose these more now and so we get suboptimal codegen.

Normally I would have liked to use ^ or $ here, but while this works for the
simple examples, reload inexplicably falls apart on examples that should have
been trivial. It forces a move to r -> w to use the w ADD, which is counter to
what ^ and $ should do.

However ! seems to fix all the regression and still maintains the good codegen.

I have tried looking into whether it's our costings that are off, but I can't
seem anything logical here.  So I'd like to push this change instead along with
test that augment the other testcases that guard the r -> r variants.

Bootstrapped Regtested on aarch64-none-linux-gnu and no issues.

Ok for master?

Thanks,
Tamar

gcc/ChangeLog:

	* config/aarch64/aarch64.md (*add<mode>3_aarch64): Add ! to the r -> r
	alternative.

gcc/testsuite/ChangeLog:

	* gcc.target/aarch64/simd/scalar_addp.c: New test.
	* gcc.target/aarch64/simd/scalar_faddp.c: New test.
	* gcc.target/aarch64/simd/scalar_faddp2.c: New test.
	* gcc.target/aarch64/simd/scalar_fmaxp.c: New test.
	* gcc.target/aarch64/simd/scalar_fminp.c: New test.
	* gcc.target/aarch64/simd/scalar_maxp.c: New test.
	* gcc.target/aarch64/simd/scalar_minp.c: New test.

--- inline copy of patch -- 
diff --git a/gcc/config/aarch64/aarch64.md b/gcc/config/aarch64/aarch64.md
index 09ae1118371f82ca63146fceb953eb9e820d05a4..c333fb1f72725992bb304c560f1245a242d5192d 100644
--- a/gcc/config/aarch64/aarch64.md
+++ b/gcc/config/aarch64/aarch64.md
@@ -2043,7 +2043,7 @@ (define_expand "add<mode>3"
 
 (define_insn "*add<mode>3_aarch64"
   [(set
-    (match_operand:GPI 0 "register_operand" "=rk,rk,w,rk,r,r,rk")
+    (match_operand:GPI 0 "register_operand" "=rk,!rk,w,rk,r,r,rk")
     (plus:GPI
      (match_operand:GPI 1 "register_operand" "%rk,rk,w,rk,rk,0,rk")
      (match_operand:GPI 2 "aarch64_pluslong_operand" "I,r,w,J,Uaa,Uai,Uav")))]
diff --git a/gcc/testsuite/gcc.target/aarch64/simd/scalar_addp.c b/gcc/testsuite/gcc.target/aarch64/simd/scalar_addp.c
new file mode 100644
index 0000000000000000000000000000000000000000..5b8d40f19884fc7b4e7decd80758bc36fa76d058
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/simd/scalar_addp.c
@@ -0,0 +1,70 @@
+/* { dg-do assemble } */
+/* { dg-additional-options "-save-temps -O1 -std=c99" } */
+/* { dg-final { check-function-bodies "**" "" "" { target { le } } } } */
+
+typedef long long v2di __attribute__((vector_size (16)));
+typedef unsigned long long v2udi __attribute__((vector_size (16)));
+typedef int v2si __attribute__((vector_size (16)));
+typedef unsigned int v2usi __attribute__((vector_size (16)));
+
+/*
+** foo:
+** 	addp	d0, v0.2d
+** 	fmov	x0, d0
+** 	ret
+*/
+long long
+foo (v2di x)
+{
+  return x[1] + x[0];
+}
+
+/*
+** foo1:
+** 	saddlp	v0.1d, v0.2s
+** 	fmov	x0, d0
+** 	ret
+*/
+long long
+foo1 (v2si x)
+{
+  return x[1] + x[0];
+}
+
+/*
+** foo2:
+** 	uaddlp	v0.1d, v0.2s
+** 	fmov	x0, d0
+** 	ret
+*/
+unsigned long long
+foo2 (v2usi x)
+{
+  return x[1] + x[0];
+}
+
+/*
+** foo3:
+** 	uaddlp	v0.1d, v0.2s
+** 	add	d0, d0, d1
+** 	fmov	x0, d0
+** 	ret
+*/
+unsigned long long
+foo3 (v2usi x, v2udi y)
+{
+  return (x[1] + x[0]) + y[0];
+}
+
+/*
+** foo4:
+** 	saddlp	v0.1d, v0.2s
+** 	add	d0, d0, d1
+** 	fmov	x0, d0
+** 	ret
+*/
+long long
+foo4 (v2si x, v2di y)
+{
+  return (x[1] + x[0]) + y[0];
+}
diff --git a/gcc/testsuite/gcc.target/aarch64/simd/scalar_faddp.c b/gcc/testsuite/gcc.target/aarch64/simd/scalar_faddp.c
new file mode 100644
index 0000000000000000000000000000000000000000..ff455e060fc833b2f63e89c467b91a76fbe31aff
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/simd/scalar_faddp.c
@@ -0,0 +1,66 @@
+/* { dg-do assemble } */
+/* { dg-require-effective-target arm_v8_2a_fp16_scalar_ok } */
+/* { dg-add-options arm_v8_2a_fp16_scalar } */
+/* { dg-additional-options "-save-temps -O1" } */
+/* { dg-final { check-function-bodies "**" "" "" { target { le } } } } */
+
+typedef double v2df __attribute__((vector_size (16)));
+typedef float v4sf __attribute__((vector_size (16)));
+typedef __fp16 v8hf __attribute__((vector_size (16)));
+
+/*
+** foo:
+** 	faddp	d0, v0.2d
+** 	ret
+*/
+double
+foo (v2df x)
+{
+  return x[1] + x[0];
+}
+
+/*
+** foo1:
+** 	faddp	s0, v0.2s
+** 	ret
+*/
+float
+foo1 (v4sf x)
+{
+  return x[0] + x[1];
+}
+
+/*
+** foo2:
+** 	faddp	h0, v0.2h
+** 	ret
+*/
+__fp16
+foo2 (v8hf x)
+{
+  return x[0] + x[1];
+}
+
+/*
+** foo3:
+** 	ext	v0.16b, v0.16b, v0.16b, #4
+** 	faddp	s0, v0.2s
+** 	ret
+*/
+float
+foo3 (v4sf x)
+{
+  return x[1] + x[2];
+}
+
+/*
+** foo4:
+** 	dup	s0, v0.s\[3\]
+** 	faddp	h0, v0.2h
+** 	ret
+*/
+__fp16
+foo4 (v8hf x)
+{
+  return x[6] + x[7];
+}
diff --git a/gcc/testsuite/gcc.target/aarch64/simd/scalar_faddp2.c b/gcc/testsuite/gcc.target/aarch64/simd/scalar_faddp2.c
new file mode 100644
index 0000000000000000000000000000000000000000..04412c3b45c51648e46ff20f730b1213e940391a
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/simd/scalar_faddp2.c
@@ -0,0 +1,14 @@
+/* { dg-do assemble } */
+/* { dg-additional-options "-save-temps -O1 -w" } */
+
+typedef __m128i __attribute__((__vector_size__(2 * sizeof(long))));
+double a[];
+*b;
+fn1() {
+  __m128i c;
+  *(__m128i *)a = c;
+  *b = a[0] + a[1];
+}
+
+/* { dg-final { scan-assembler-times {faddp\td0, v0\.2d} 1 } } */
+
diff --git a/gcc/testsuite/gcc.target/aarch64/simd/scalar_fmaxp.c b/gcc/testsuite/gcc.target/aarch64/simd/scalar_fmaxp.c
new file mode 100644
index 0000000000000000000000000000000000000000..aa1d2bf17cd707b74d8f7c574506610ab4fd7299
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/simd/scalar_fmaxp.c
@@ -0,0 +1,56 @@
+/* { dg-do assemble } */
+/* { dg-require-effective-target arm_v8_2a_fp16_scalar_ok } */
+/* { dg-add-options arm_v8_2a_fp16_scalar } */
+/* { dg-additional-options "-save-temps -O1" } */
+/* { dg-final { check-function-bodies "**" "" "" { target { le } } } } */
+
+typedef double v2df __attribute__((vector_size (16)));
+typedef float v4sf __attribute__((vector_size (16)));
+typedef __fp16 v8hf __attribute__((vector_size (16)));
+
+/*
+** foo:
+** 	fmaxnmp	d0, v0.2d
+** 	ret
+*/
+double
+foo (v2df x)
+{
+  return x[0] > x[1] ? x[0] : x[1];
+}
+
+/* 
+** foo1:
+** 	fmaxnmp	s0, v0.2s
+** 	ret
+*/
+float
+foo1 (v4sf x)
+{
+  return x[0] > x[1] ? x[0] : x[1];
+}
+
+/*
+** foo2:
+** 	fmaxnmp	h0, v0.2h
+** 	ret
+*/
+__fp16
+foo2 (v8hf x)
+{
+  return x[0] > x[1] ? x[0] : x[1];
+}
+
+/* 
+** foo3:
+** 	fmaxnmp	s0, v0.2s
+** 	fcvt	d0, s0
+** 	fadd	d0, d0, d1
+** 	ret
+*/
+double
+foo3 (v4sf x, v2df y)
+{
+  return (x[0] > x[1] ? x[0] : x[1]) + y[0];
+}
+
diff --git a/gcc/testsuite/gcc.target/aarch64/simd/scalar_fminp.c b/gcc/testsuite/gcc.target/aarch64/simd/scalar_fminp.c
new file mode 100644
index 0000000000000000000000000000000000000000..6136c5272069c4d86f09951cdff25f1494e839f0
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/simd/scalar_fminp.c
@@ -0,0 +1,55 @@
+/* { dg-do assemble } */
+/* { dg-require-effective-target arm_v8_2a_fp16_scalar_ok } */
+/* { dg-add-options arm_v8_2a_fp16_scalar } */
+/* { dg-additional-options "-save-temps -O1" } */
+/* { dg-final { check-function-bodies "**" "" "" { target { le } } } } */
+
+typedef double v2df __attribute__((vector_size (16)));
+typedef float v4sf __attribute__((vector_size (16)));
+typedef __fp16 v8hf __attribute__((vector_size (16)));
+
+/*
+** foo:
+** 	fminnmp	d0, v0.2d
+** 	ret
+*/
+double
+foo (v2df x)
+{
+  return x[0] < x[1] ? x[0] : x[1];
+}
+
+/* 
+** foo1:
+** 	fminnmp	s0, v0.2s
+** 	ret
+*/
+float
+foo1 (v4sf x)
+{
+  return x[0] < x[1] ? x[0] : x[1];
+}
+
+/* 
+** foo2:
+** 	fminnmp	h0, v0.2h
+** 	ret
+*/
+__fp16
+foo2 (v8hf x)
+{
+  return x[0] < x[1] ? x[0] : x[1];
+}
+
+/* 
+** foo3:
+** 	fminnmp	s0, v0.2s
+** 	fcvt	d0, s0
+** 	fadd	d0, d0, d1
+** 	ret
+*/
+double
+foo3 (v4sf x, v2df y)
+{
+  return (x[0] < x[1] ? x[0] : x[1]) + y[0];
+}
diff --git a/gcc/testsuite/gcc.target/aarch64/simd/scalar_maxp.c b/gcc/testsuite/gcc.target/aarch64/simd/scalar_maxp.c
new file mode 100644
index 0000000000000000000000000000000000000000..e219a13abc745b83dca58633fd2d812e276d6b2d
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/simd/scalar_maxp.c
@@ -0,0 +1,74 @@
+/* { dg-do assemble } */
+/* { dg-additional-options "-save-temps -O1 -std=c99" } */
+/* { dg-final { check-function-bodies "**" "" "" { target { le } } } } */
+
+typedef long long v2di __attribute__((vector_size (16)));
+typedef unsigned long long v2udi __attribute__((vector_size (16)));
+typedef int v2si __attribute__((vector_size (16)));
+typedef unsigned int v2usi __attribute__((vector_size (16)));
+
+/*
+** foo:
+** 	umov	x0, v0.d\[1\]
+** 	fmov	x1, d0
+** 	cmp	x0, x1
+** 	csel	x0, x0, x1, ge
+** 	ret
+*/
+long long
+foo (v2di x)
+{
+  return x[0] > x[1] ? x[0] : x[1];
+}
+
+/* 
+** foo1:
+** 	smaxp	v0.2s, v0.2s, v0.2s
+** 	smov	x0, v0.s\[0\]
+** 	ret
+*/
+long long
+foo1 (v2si x)
+{
+  return x[0] > x[1] ? x[0] : x[1];
+}
+
+/* 
+** foo2:
+** 	umaxp	v0.2s, v0.2s, v0.2s
+** 	fmov	w0, s0
+** 	ret
+*/
+unsigned long long
+foo2 (v2usi x)
+{
+  return x[0] > x[1] ? x[0] : x[1];
+}
+
+/* 
+** foo3:
+** 	umaxp	v0.2s, v0.2s, v0.2s
+** 	fmov	w0, s0
+** 	fmov	x1, d1
+** 	add	x0, x1, w0, uxtw
+** 	ret
+*/
+unsigned long long
+foo3 (v2usi x, v2udi y)
+{
+  return (x[0] > x[1] ? x[0] : x[1]) + y[0];
+}
+
+/* 
+** foo4:
+** 	smaxp	v0.2s, v0.2s, v0.2s
+** 	fmov	w0, s0
+** 	fmov	x1, d1
+** 	add	x0, x1, w0, sxtw
+** 	ret
+*/
+long long
+foo4 (v2si x, v2di y)
+{
+  return (x[0] > x[1] ? x[0] : x[1]) + y[0];
+}
diff --git a/gcc/testsuite/gcc.target/aarch64/simd/scalar_minp.c b/gcc/testsuite/gcc.target/aarch64/simd/scalar_minp.c
new file mode 100644
index 0000000000000000000000000000000000000000..2a32fb4ea3edaa4c547a7a481c3ddca6b477430e
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/simd/scalar_minp.c
@@ -0,0 +1,74 @@
+/* { dg-do assemble } */
+/* { dg-additional-options "-save-temps -O1 -std=c99" } */
+/* { dg-final { check-function-bodies "**" "" "" { target { le } } } } */
+
+typedef long long v2di __attribute__((vector_size (16)));
+typedef unsigned long long v2udi __attribute__((vector_size (16)));
+typedef int v2si __attribute__((vector_size (16)));
+typedef unsigned int v2usi __attribute__((vector_size (16)));
+
+/*
+** foo:
+** 	umov	x0, v0.d\[1\]
+** 	fmov	x1, d0
+** 	cmp	x0, x1
+** 	csel	x0, x0, x1, le
+** 	ret
+*/
+long long
+foo (v2di x)
+{
+  return x[0] < x[1] ? x[0] : x[1];
+}
+
+/* 
+** foo1:
+** 	sminp	v0.2s, v0.2s, v0.2s
+** 	smov	x0, v0.s\[0\]
+** 	ret
+*/
+long long
+foo1 (v2si x)
+{
+  return x[0] < x[1] ? x[0] : x[1];
+}
+
+/* 
+** foo2:
+** 	uminp	v0.2s, v0.2s, v0.2s
+** 	fmov	w0, s0
+** 	ret
+*/
+unsigned long long
+foo2 (v2usi x)
+{
+  return x[0] < x[1] ? x[0] : x[1];
+}
+
+/* 
+** foo3:
+** 	uminp	v0.2s, v0.2s, v0.2s
+** 	fmov	w0, s0
+** 	fmov	x1, d1
+** 	add	x0, x1, w0, uxtw
+** 	ret
+*/
+unsigned long long
+foo3 (v2usi x, v2udi y)
+{
+  return (x[0] < x[1] ? x[0] : x[1]) + y[0];
+}
+
+/* 
+** foo4:
+** 	sminp	v0.2s, v0.2s, v0.2s
+** 	fmov	w0, s0
+** 	fmov	x1, d1
+** 	add	x0, x1, w0, sxtw
+** 	ret
+*/
+long long
+foo4 (v2si x, v2di y)
+{
+  return (x[0] < x[1] ? x[0] : x[1]) + y[0];
+}




--