From 02614f2f1ac9ee1150f165df34546490612153aa Mon Sep 17 00:00:00 2001
From: Colin Snover
Date: Mon, 20 Nov 2017 10:22:40 -0600
Subject: COMMON: Fix UB shifting negative integers

Compilers optimise these back into shifts on architectures where
shifts of negative integers work the same as mul/div, so this
solves the UB without actually causing any performance issue.
---
 common/frac.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

(limited to 'common')

diff --git a/common/frac.h b/common/frac.h
index d71d31645b..4e3bcf267f 100644
--- a/common/frac.h
+++ b/common/frac.h
@@ -46,7 +46,7 @@ typedef int32 frac_t;
 inline frac_t doubleToFrac(double value) { return (frac_t)(value * FRAC_ONE); }
 inline double fracToDouble(frac_t value) { return ((double)value) / FRAC_ONE; }
 
-inline frac_t intToFrac(int16 value) { return value << FRAC_BITS; }
-inline int16 fracToInt(frac_t value) { return value >> FRAC_BITS; }
+inline frac_t intToFrac(int16 value) { return value * (1 << FRAC_BITS); }
+inline int16 fracToInt(frac_t value) { return value / (1 << FRAC_BITS); }
 
 #endif
-- 
cgit v1.2.3