powerpc64: add single-instruction math functions

while the official elfv2 abi for "powerpc64le" sets power8 as the
baseline isa, we use it for both little and big endian powerpc64
targets and need to maintain compatibility with pre-power8 models. the
instructions for sqrt, fabs, and fma are in the baseline isa; support
for the rest is conditional via predefined isa-level macros.

patch by David Edelsohn.

1 files changed, 15 insertions, 0 deletions

diff --git a/src/math/powerpc64/truncf.c b/src/math/powerpc64/truncf.c
new file mode 100644
index 00000000..94e638fb
--- /dev/null
+++ b/src/math/powerpc64/truncf.c
@@ -0,0 +1,15 @@
+#include <math.h>
+
+#ifdef _ARCH_PWR5X
+
+float truncf(float x)
+{
+	__asm__ ("friz %0, %1" : "=f"(x) : "f"(x));
+	return x;
+}
+
+#else
+
+#include "../truncf.c"
+
+#endif