[hash] Switch to Knuth multiplicative hash

Wow, the old adhoc one was why the cmap test was timing out!
2 years ago · 42f4dab8db
parent 0270e3e974
commit 42f4dab8db
1 changed files with 2 additions and 2 deletions
--- a/src/hb-algs.hh
+++ b/src/hb-algs.hh
@ -326,11 +326,11 @@ struct

  template <typename T,
 	    hb_enable_if (std::is_integral<T>::value && sizeof (T) <= sizeof (uint32_t))> constexpr auto
-  impl (const T& v, hb_priority<1>) const HB_RETURN (uint32_t, v * 131071u /* Mersenne prime */)
+  impl (const T& v, hb_priority<1>) const HB_RETURN (uint32_t, v * 2654435761)

  template <typename T,
 	    hb_enable_if (std::is_integral<T>::value && sizeof (T) > sizeof (uint32_t))> constexpr auto
-  impl (const T& v, hb_priority<1>) const HB_RETURN (uint32_t, (v ^ (v >> 32)) * 131071u /* Mersenne prime */)
+  impl (const T& v, hb_priority<1>) const HB_RETURN (uint32_t, (v ^ (v >> 32)) * 2654435761)
 #endif

  template <typename T> constexpr auto