AVR: target/114981 - Tweak __builtin_powif / __powisf2

Implement __powisf2 in assembly.

	PR target/114981
libgcc/
	* config/avr/t-avr (LIB2FUNCS_EXCLUDE): Add _powisf2.
	(LIB1ASMFUNCS) [!avrtiny]: Add _powif.
	* config/avr/lib1funcs.S (mov4): New .macro.
	(L_powif, __powisf2) [!avrtiny]: New module and function.

gcc/testsuite/
	* gcc.target/avr/pr114981-powif.c: New test.

1 files changed, 33 insertions, 0 deletions

diff --git a/gcc/testsuite/gcc.target/avr/pr114981-powif.c b/gcc/testsuite/gcc.target/avr/pr114981-powif.c
new file mode 100644
index 0000000..191dcc6
--- /dev/null
+++ b/gcc/testsuite/gcc.target/avr/pr114981-powif.c
@@ -0,0 +1,33 @@
+/* { dg-do run { target { ! avr_tiny } } } */
+/* { dg-additional-options "-Os" } */
+
+const float vals[] =
+  {
+    0.0625f, -0.125f, 0.25f, -0.5f,
+    1.0f,
+    -2.0f, 4.0f, -8.0f, 16.0f
+  };
+
+#define ARRAY_SIZE(X) ((int) (sizeof(X) / sizeof(*X)))
+
+__attribute__((noinline,noclone))
+void test1 (float x)
+{
+  int i;
+
+  for (i = 0; i < ARRAY_SIZE (vals); ++i)
+    {
+      float val0 = vals[i];
+      float val1 = __builtin_powif (x, i - 4);
+      __asm ("" : "+r" (val0));
+
+      if (val0 != val1)
+	__builtin_exit (__LINE__);
+    }
+}
+
+int main (void)
+{
+  test1 (-2.0f);
+  return 0;
+}