Fix aprox fs function names

bug b206696

Change-Id: I64c092c1f6b8d990783bf5d31db37e12a4dbdb82

Author: Jason Sams

tests/RenderScriptTests/ComputeBenchmark/src/com/example/android/rs/computebench/compute_benchmark.rs

@@ -383,13 +383,12 @@ static void bench_fp_math() {
 }
 
 static void bench_approx_math() {
-    BENCH_FN_FUNC_FN(approx_recip);
-    BENCH_FN_FUNC_FN(approx_sqrt);
-    BENCH_FN_FUNC_FN(approx_rsqrt);
-    BENCH_FN_FUNC_FN(approx_length);
-    BENCH_FN_FUNC_FN_FN(approx_distance);
-    BENCH_FN_FUNC_FN(approx_normalize);
-    BENCH_FN_FUNC_FN(approx_atan);
+    BENCH_FN_FUNC_FN(half_recip);
+    BENCH_FN_FUNC_FN(half_sqrt);
+    BENCH_FN_FUNC_FN(half_rsqrt);
+    BENCH_FN_FUNC_FN(fast_length);
+    BENCH_FN_FUNC_FN_FN(fast_distance);
+    BENCH_FN_FUNC_FN(fast_normalize);
 }
 
 void bench() {

tests/RenderScriptTests/ImageProcessing/src/com/android/rs/image/fisheye_approx.rsh

@@ -48,8 +48,8 @@ void root(uchar4 *out, uint32_t x, uint32_t y) {
     const float2 coord = mad(inCoord, inv_dimensions, neg_center);
     const float2 scaledCoord = axis_scale * coord;
     const float dist2 = scaledCoord.x*scaledCoord.x + scaledCoord.y*scaledCoord.y;
-    const float inv_dist = approx_rsqrt(dist2);
-    const float radian = M_PI_2 - approx_atan((alpha * approx_sqrt(radius2 - dist2)) * inv_dist);
+    const float inv_dist = half_rsqrt(dist2);
+    const float radian = M_PI_2 - atan((alpha * half_sqrt(radius2 - dist2)) * inv_dist);
     const float scalar = radian * factor * inv_dist;
     const float2 new_coord = mad(coord, scalar, center);
     const float4 fout = rsSample(in_alloc, sampler, new_coord);

tests/RenderScriptTests/ImageProcessing/src/com/android/rs/image/vignette_approx.rsh

@@ -49,9 +49,9 @@ void root(const uchar4 *in, uchar4 *out, uint32_t x, uint32_t y) {
     const float4 fin = convert_float4(*in);
     const float2 inCoord = {(float)x, (float)y};
     const float2 coord = mad(inCoord, inv_dimensions, neg_center);
-    const float sloped_dist_ratio = approx_length(axis_scale * coord)  * sloped_inv_max_dist;
-    // TODO:  add approx_exp once implemented
-    const float lumen = opp_shade + shade * approx_recip(1.f + sloped_neg_range * exp(sloped_dist_ratio));
+    const float sloped_dist_ratio = fast_length(axis_scale * coord)  * sloped_inv_max_dist;
+    // TODO:  add half_exp once implemented
+    const float lumen = opp_shade + shade * half_recip(1.f + sloped_neg_range * exp(sloped_dist_ratio));
     float4 fout;
     fout.rgb = fin.rgb * lumen;
     fout.w = fin.w;