From: Nikos Nikoleris <nikos.nikoleris@arm.com>
Date: Sun, 26 May 2019 22:31:22 +0000 (+0100)
Subject: base: Add function to count trailing zeros in a 64-bit integer
X-Git-Tag: v19.0.0.0~774
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=542fd370b285b0bd0e13ffa186e46e128e84273f;p=gem5.git

base: Add function to count trailing zeros in a 64-bit integer

Change-Id: Iaad0679b403bc5015ffeacbf7284313e41a36cd0
Signed-off-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/19128
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>
Tested-by: kokoro <noreply+kokoro@google.com>
---

diff --git a/src/base/bitfield.hh b/src/base/bitfield.hh
index ec1ffce50..59b239a88 100644
--- a/src/base/bitfield.hh
+++ b/src/base/bitfield.hh
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017 ARM Limited
+ * Copyright (c) 2017, 2019 ARM Limited
  * All rights reserved
  *
  * The license below extends only to copyright in the software and shall
@@ -293,4 +293,15 @@ inline int ctz32(uint32_t value)
     return value ? __builtin_ctz(value) : 32;
 }
 
+/**
+ * Count trailing zeros in a 64-bit value.
+ *
+ * @param An input value
+ * @return The number of trailing zeros or 64 if the value is zero.
+ */
+inline int ctz64(uint64_t value)
+{
+    return value ? __builtin_ctzll(value) : 64;
+}
+
 #endif // __BASE_BITFIELD_HH__