Enable BMI1 too when using BMI2 ARCH
authorJean-Francois Romang <jromang@posteo.de>
Mon, 14 Apr 2014 05:10:39 +0000 (07:10 +0200)
committerMarco Costalba <mcostalba@gmail.com>
Mon, 14 Apr 2014 05:54:24 +0000 (07:54 +0200)
Adding BMI1 allows the compiler to use _blsr_u64
automatically (the advertised 0.3% speed gain).
I verified that the compiler does not use this
instruction with the -mbmi2 flag only. Also, all
processors supporting BMI2 is also supporting BMI1.

No functional change

src/Makefile

index 2be749ce67b3e89ae06369dfee4aaed3d0ca369c..1ae8bfac884a7d878257c47f0f353f345b2e2e90 100644 (file)
@@ -293,7 +293,7 @@ endif
 ifeq ($(pext),yes)
        CXXFLAGS += -DUSE_PEXT
        ifeq ($(comp),$(filter $(comp),gcc clang mingw))
-               CXXFLAGS += -mbmi2
+               CXXFLAGS += -mbmi -mbmi2
        endif
 endif