Revert "Use compiler intrinsic instead of assembly for popcnt"

This reverts commit a69f1d7c2060dc7b320a7b4801105df00b22a96a.

diff --git a/src/Makefile b/src/Makefile
index 562192c..187e7b3 100644 (file)
--- a/src/Makefile
+++ b/src/Makefile
@@ -285,7 +285,7 @@ endif
 
 ### 3.9 popcnt
 ifeq ($(popcnt),yes)
-       CXXFLAGS += -msse4.2 -DUSE_POPCNT
+       CXXFLAGS += -msse3 -DUSE_POPCNT
 endif
 
 ### 3.10 pext

diff --git a/src/bitcount.h b/src/bitcount.h
index 9feed19..f84c51c 100644 (file)
--- a/src/bitcount.h
+++ b/src/bitcount.h
@@ -96,7 +96,8 @@ inline int popcount<CNT_HW_POPCNT>(Bitboard b) {
 
 #else
 
-  return __builtin_popcountll(b);
+  __asm__("popcnt %1, %0" : "=r" (b) : "r" (b));
+  return b;
 
 #endif
 }