Implement fast native_exp*
Change-Id: I0989527a7993023131f991ba260c7bf9d9eae51c
diff --git a/lib/Renderscript/runtime/rs_cl.c b/lib/Renderscript/runtime/rs_cl.c
index 32b25d5..f85d61f 100644
--- a/lib/Renderscript/runtime/rs_cl.c
+++ b/lib/Renderscript/runtime/rs_cl.c
@@ -4,6 +4,10 @@
extern float3 __attribute__((overloadable)) convert_float3(int3 c);
extern float4 __attribute__((overloadable)) convert_float4(int4 c);
+extern int2 __attribute__((overloadable)) convert_int2(float2 c);
+extern int3 __attribute__((overloadable)) convert_int3(float3 c);
+extern int4 __attribute__((overloadable)) convert_int4(float4 c);
+
// Float ops, 6.11.2
#define FN_FUNC_FN(fnc) \
@@ -956,6 +960,111 @@
FN_FUNC_FN(approx_atan)
*/
+typedef union
+{
+ float fv;
+ int32_t iv;
+} ieee_float_shape_type;
+
+/* Get a 32 bit int from a float. */
+
+#define GET_FLOAT_WORD(i,d) \
+do { \
+ ieee_float_shape_type gf_u; \
+ gf_u.fv = (d); \
+ (i) = gf_u.iv; \
+} while (0)
+
+/* Set a float from a 32 bit int. */
+
+#define SET_FLOAT_WORD(d,i) \
+do { \
+ ieee_float_shape_type sf_u; \
+ sf_u.iv = (i); \
+ (d) = sf_u.fv; \
+} while (0)
+
+
+
+// Valid -125 to 125
+extern float __attribute__((overloadable)) native_exp2(float v) {
+ int32_t iv = (int)v;
+ int32_t x = iv + (iv >> 31); // ~floor(v)
+ float r = (v - x);
+
+ float fo;
+ SET_FLOAT_WORD(fo, (x + 127) << 23);
+
+ r *= 0.694f; // ~ log(e) / log(2)
+ float r2 = r*r;
+ float adj = 1.f + r + (r2 * 0.5f) + (r2*r * 0.166666f) + (r2*r2 * 0.0416666f);
+ return fo * adj;
+}
+
+extern float2 __attribute__((overloadable)) native_exp2(float2 v) {
+ int2 iv = convert_int2(v);
+ int2 x = iv + (iv >> (int2)31);//floor(v);
+ float2 r = (v - convert_float2(x));
+
+ x += 127;
+
+ float2 fo = (float2)(x << (int2)23);
+
+ r *= 0.694f; // ~ log(e) / log(2)
+ float2 r2 = r*r;
+ float2 adj = 1.f + r + (r2 * 0.5f) + (r2*r * 0.166666f) + (r2*r2 * 0.0416666f);
+ return fo * adj;
+}
+
+extern float4 __attribute__((overloadable)) native_exp2(float4 v) {
+ int4 iv = convert_int4(v);
+ int4 x = iv + (iv >> (int4)31);//floor(v);
+ float4 r = (v - convert_float4(x));
+
+ x += 127;
+
+ float4 fo = (float4)(x << (int4)23);
+
+ r *= 0.694f; // ~ log(e) / log(2)
+ float4 r2 = r*r;
+ float4 adj = 1.f + r + (r2 * 0.5f) + (r2*r * 0.166666f) + (r2*r2 * 0.0416666f);
+ return fo * adj;
+}
+
+extern float3 __attribute__((overloadable)) native_exp2(float3 v) {
+ float4 t = 1.f;
+ t.xyz = v;
+ return native_exp2(t).xyz;
+}
+
+
+extern float __attribute__((overloadable)) native_exp(float v) {
+ return native_exp2(v * 1.442695041f);
+}
+extern float2 __attribute__((overloadable)) native_exp(float2 v) {
+ return native_exp2(v * 1.442695041f);
+}
+extern float3 __attribute__((overloadable)) native_exp(float3 v) {
+ return native_exp2(v * 1.442695041f);
+}
+extern float4 __attribute__((overloadable)) native_exp(float4 v) {
+ return native_exp2(v * 1.442695041f);
+}
+
+extern float __attribute__((overloadable)) native_exp10(float v) {
+ return native_exp2(v * 3.321928095f);
+}
+extern float2 __attribute__((overloadable)) native_exp10(float2 v) {
+ return native_exp2(v * 3.321928095f);
+}
+extern float3 __attribute__((overloadable)) native_exp10(float3 v) {
+ return native_exp2(v * 3.321928095f);
+}
+extern float4 __attribute__((overloadable)) native_exp10(float4 v) {
+ return native_exp2(v * 3.321928095f);
+}
+
+
#undef FN_FUNC_FN
#undef IN_FUNC_FN
#undef FN_FUNC_FN_FN
