Revert of de-proc sk_float_rsqrt (patchset #3 id:40001 of https://codereview.chromium.org/1616013003/ )

Reason for revert:
This is somehow blocking the Google3 roll in ways neither Ben nor I understand.  Precautionary revert... will try again Monday.

Original issue's description:
> de-proc sk_float_rsqrt
>
> This is the first of many little baby steps to have us stop runtime-detecting NEON.
>
> BUG=skia:
> GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1616013003
> CQ_EXTRA_TRYBOTS=client.skia:Test-Ubuntu-GCC-GCE-CPU-AVX2-x86_64-Release-SKNX_NO_SIMD-Trybot
>
> Committed: https://skia.googlesource.com/skia/+/efcc125acd2d71eb077caf6db65fdd6b9eb1dc0d

TBR=reed@google.com,mtklein@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=skia:

Review URL: https://codereview.chromium.org/1629503002

1 files changed, 5 insertions, 7 deletions

diff --git a/tests/MathTest.cpp b/tests/MathTest.cpp
index de7ad1db78..24e46f3097 100644
--- a/tests/MathTest.cpp
+++ b/tests/MathTest.cpp
@@ -382,15 +382,14 @@ static void unittest_half(skiatest::Reporter* reporter) {
 
 }
 
-template <typename RSqrtFn>
-static void test_rsqrt(skiatest::Reporter* reporter, RSqrtFn rsqrt) {
+static void test_rsqrt(skiatest::Reporter* reporter) {
     const float maxRelativeError = 6.50196699e-4f;
 
     // test close to 0 up to 1
     float input = 0.000001f;
     for (int i = 0; i < 1000; ++i) {
         float exact = 1.0f/sk_float_sqrt(input);
-        float estimate = rsqrt(input);
+        float estimate = sk_float_rsqrt(input);
         float relativeError = sk_float_abs(exact - estimate)/exact;
         REPORTER_ASSERT(reporter, relativeError <= maxRelativeError);
         input += 0.001f;
@@ -400,7 +399,7 @@ static void test_rsqrt(skiatest::Reporter* reporter, RSqrtFn rsqrt) {
     input = 1.0f;
     for (int i = 0; i < 1000; ++i) {
         float exact = 1.0f/sk_float_sqrt(input);
-        float estimate = rsqrt(input);
+        float estimate = sk_float_rsqrt(input);
         float relativeError = sk_float_abs(exact - estimate)/exact;
         REPORTER_ASSERT(reporter, relativeError <= maxRelativeError);
         input += 0.01f;
@@ -410,7 +409,7 @@ static void test_rsqrt(skiatest::Reporter* reporter, RSqrtFn rsqrt) {
     input = 1000000.0f;
     for (int i = 0; i < 100; ++i) {
         float exact = 1.0f/sk_float_sqrt(input);
-        float estimate = rsqrt(input);
+        float estimate = sk_float_rsqrt(input);
         float relativeError = sk_float_abs(exact - estimate)/exact;
         REPORTER_ASSERT(reporter, relativeError <= maxRelativeError);
         input += 754326.f;
@@ -556,8 +555,7 @@ DEF_TEST(Math, reporter) {
     unittest_fastfloat(reporter);
     unittest_isfinite(reporter);
     unittest_half(reporter);
-    test_rsqrt(reporter, sk_float_rsqrt);
-    test_rsqrt(reporter, sk_float_rsqrt_portable);
+    test_rsqrt(reporter);
 
     for (i = 0; i < 10000; i++) {
         SkFixed numer = rand.nextS();