From 8565de2c5b38cd355ea15f1da3f460f352162f86 Mon Sep 17 00:00:00 2001
From: Nikolaj Bjorner <nbjorner@microsoft.com>
Date: Wed, 6 Jun 2018 19:17:37 -0700
Subject: [PATCH] deal with shift exponent error

Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
---
 src/util/mpz.cpp | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/src/util/mpz.cpp b/src/util/mpz.cpp
index 6387fccd9..2a85320a5 100644
--- a/src/util/mpz.cpp
+++ b/src/util/mpz.cpp
@@ -49,9 +49,13 @@ Revision History:
 #if 1
 #include <immintrin.h> 
 
-#define _trailing_zeros32(x) _tzcnt_u32(x)
+#if defined(__GNUC__)
+#define _trailing_zeros32(X) __builtin_ctz(X)
+#else
+#define _trailing_zeros32(X) _tzcnt_u32(X)
+#endif
 
-#ifdef _AMD64_
+#if defined(_AMD64_) && !defined(__GNUC__)
 #define _trailing_zeros64(x) _tzcnt_u64(x)
 #else
 inline uint64 _trailing_zeros64(uint64 x) {