Index: src/core/SkFloatBits.cpp |
diff --git a/src/core/SkFloatBits.cpp b/src/core/SkFloatBits.cpp |
index 39b51abf1dc8a9939c41e69463ee50a37b9b1956..6b35a75c88f72a30652c883eb598fda7cfb30a0c 100644 |
--- a/src/core/SkFloatBits.cpp |
+++ b/src/core/SkFloatBits.cpp |
@@ -85,7 +85,16 @@ int32_t SkFloatBits_toIntFloor(int32_t packed) { |
value = SkApplySign(value, SkExtractSign(packed)); |
exp = -exp; |
if (exp > 25) { // underflow |
+#ifdef SK_DISCARD_DENORMALIZED_FOR_SPEED |
+ // The iOS ARM processor discards small denormalized numbers to go faster. |
+ // The comparision below empirically causes the result to agree with the |
+ // tests in MathTest test_float_floor |
+ if (exp > 149) { |
+ return 0; |
+ } |
+#else |
exp = 25; |
+#endif |
} |
// int add = 0; |
return value >> exp; |
@@ -145,7 +154,17 @@ int32_t SkFloatBits_toIntCeil(int32_t packed) { |
value = SkApplySign(value, SkExtractSign(packed)); |
exp = -exp; |
if (exp > 25) { // underflow |
+#ifdef SK_DISCARD_DENORMALIZED_FOR_SPEED |
+ // The iOS ARM processor discards small denormalized numbers to go faster. |
+ // The comparision below empirically causes the result to agree with the |
+ // tests in MathTest test_float_ceil |
+ if (exp > 149) { |
+ return 0; |
+ } |
+ return 0 < value; |
+#else |
exp = 25; |
+#endif |
} |
int add = (1 << exp) - 1; |
return (value + add) >> exp; |