From 43483b3ddef03236029cd3baa6923cd91b09cf81 Mon Sep 17 00:00:00 2001
From: Valentin Antonescu <valentin@jhu.edu>
Date: Tue, 14 Jan 2014 16:11:33 -0500
Subject: [PATCH] Dropped the intrinsics dependency and replaced popcnt with
 plain asm code. Also POPCNT_CAPABILITY is not by default On.

---
 Makefile            | 4 ++--
 ebwt.h              | 4 +++-
 processor_support.h | 3 ---
 3 files changed, 5 insertions(+), 6 deletions(-)

diff --git a/Makefile b/Makefile
index 78b9be3..41fe19a 100644
--- a/Makefile
+++ b/Makefile
@@ -67,9 +67,9 @@ else
     PTHREAD_LIB = -lpthread
 endif
 
-POPCNT_CAPABILITY ?= 0
+POPCNT_CAPABILITY ?= 1
 ifeq (1, $(POPCNT_CAPABILITY))
-    EXTRA_FLAGS += -DPOPCNT_CAPABILITY -msse4.2
+    EXTRA_FLAGS += -DPOPCNT_CAPABILITY
     ifeq (1,$(MACOS))
         INC += -I third_party/macos
     endif
diff --git a/ebwt.h b/ebwt.h
index b4f3d07..4b43fd3 100644
--- a/ebwt.h
+++ b/ebwt.h
@@ -1905,7 +1905,9 @@ inline static int pop64(uint64_t x) {
 #ifdef POPCNT_CAPABILITY
     struct USE_POPCNT_INSTRUCTION {
         inline static int pop64(uint64_t x) {
-            return _mm_popcnt_u64(x);
+            int64_t count;
+            asm ("popcntq %[x],%[count]\n": [count] "=&r" (count): [x] "r" (x));
+            return count;
         }
     };
 #endif
diff --git a/processor_support.h b/processor_support.h
index 0851a23..f68ee65 100644
--- a/processor_support.h
+++ b/processor_support.h
@@ -12,15 +12,12 @@
 
 #if defined(__INTEL_COMPILER)
 #   define USING_INTEL_COMPILER
-#   include <immintrin.h>
 #elif defined(__GNUC__)
 #   define USING_GCC_COMPILER
-#   include <smmintrin.h>
 #   include <cpuid.h>
 #elif defined(_MSC_VER)
 // __MSC_VER defined by Microsoft compiler
 #define USING MSC_COMPILER
-#   include <intrin.h>
 #endif
 
 struct regs_t {unsigned int EAX, EBX, ECX, EDX;};