assembly SIMD add: make uniform for all ISAs, mark as entry point to learning SIMD

userland/arch/aarch64/fadd_vector.S

@@ -0,0 +1,34 @@
+/* https://github.com/cirosantilli/linux-kernel-module-cheat#assembly-simd
+ *
+ * Add a bunch of floating point numbers in one go.
+ */
+
+#include "common.h"
+
+ENTRY
+.data
+    input0_4s: .float 1.5, 2.5,  3.5,  4.5
+    input1_4s: .float 5.5, 6.5,  7.5,  8.5
+    expect_4s: .float 7.0, 9.0, 11.0, 13.0
+    input0_2d: .double 1.5, 2.5
+    input1_2d: .double 5.5, 6.5
+    expect_2d: .double 7.0, 9.0
+.bss
+    output:    .skip 16
+.text
+#define TEST(size) \
+    adr x0, input0_ ## size; \
+    ld1 {v0. ## size}, [x0]; \
+    adr x1, input1_ ## size; \
+    ld1 {v1. ## size}, [x1]; \
+    fadd v2. ## size, v0. ## size, v1. ## size; \
+    adr x0, output; \
+    st1 {v2. ## size}, [x0]; \
+    ASSERT_MEMCMP(output, expect_ ## size, 0x10)
+
+    /* 4x 32-bit */
+    TEST(4s)
+    /* 2x 64-bit */
+    TEST(2d)
+#undef TEST
+EXIT