x86: Detect BMI2 instruction support.

2016-03-28 23:04:33 +02:00
parent c24c8e5312
commit 6801e7165c
4 changed files with 10 additions and 1 deletions
--- a/src/lib_jit.c
+++ b/src/lib_jit.c
@@ -668,6 +668,11 @@ static uint32_t jit_cpudetect(lua_State *L)
      if (fam >= 0x00000f00)  /* K8, K10. */
 	flags |= JIT_F_PREFER_IMUL;
    }
+    if (vendor[0] >= 7) {
+      uint32_t xfeatures[4];
+      lj_vm_cpuid(7, xfeatures);
+      flags |= ((xfeatures[1] >> 8)&1) * JIT_F_BMI2;
+    }
 #endif
  }
  /* Check for required instruction set support on x86 (unnecessary on x64). */