We have some work to do.

tests/SRGBTest.cpp

Index: tests/SRGBTest.cpp
diff --git a/tests/SRGBTest.cpp b/tests/SRGBTest.cpp
index 65bfc59b427fd07d8135ca28bc16b5459ea7201b..59088f2c1689dbeb4f62d23b6b51b46ddc087e6a 100644
--- a/tests/SRGBTest.cpp
+++ b/tests/SRGBTest.cpp
@@ -20,6 +20,17 @@ DEF_TEST(sk_linear_to_srgb, r) {
     REPORTER_ASSERT(r,   0 == linear_to_srgb(0.0f));
     REPORTER_ASSERT(r, 255 == linear_to_srgb(1.0f));
 
+    int n = 0;
+    for (int i = 0; i < 256; i++) {
+        int actual = linear_to_srgb(sk_linear_from_srgb[i]);
+        if (actual != i) {
+            printf("%d -> %d\n", i, actual);
+            n++;
+        }
+    }
+    printf("n = %d\n", n);
+    return;
+
     // Should be monotonic between 0 and 1.
     // We don't bother checking denorm values.
     int tolerated_regressions = 0;