From 348ccdfd5bbbd492b7e306cb0f450ac83f88004e Mon Sep 17 00:00:00 2001
From: hendricks266 <hendricks266@1a8010ca-5511-0410-912e-c29ae57300e0>
Date: Tue, 26 Nov 2019 08:25:13 +0000
Subject: [PATCH] Templatize the branchless negation method used for
 GV_FLAG_NEGATIVE

git-svn-id: https://svn.eduke32.com/eduke32@8312 1a8010ca-5511-0410-912e-c29ae57300e0

# Conflicts:
#	source/build/include/compat.h
---
 source/build/include/compat.h  | 11 +++++++++--
 source/duke3d/src/gamevars.cpp |  3 +--
 2 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/source/build/include/compat.h b/source/build/include/compat.h
index 54b49d33c..2bcbbf5a3 100644
--- a/source/build/include/compat.h
+++ b/source/build/include/compat.h
@@ -1067,6 +1067,13 @@ FORCE_INLINE CONSTEXPR DivResult<T> divrhs(T lhs)
 {
     return divide(lhs, (T)base);
 }
+
+template <typename T, typename T2>
+static FORCE_INLINE CONSTEXPR_CXX14 enable_if_t<is_signed<T>::value, T> NEGATE_ON_CONDITION(T value, T2 condition)
+{
+    T const invert = !!condition;
+    return (value ^ -invert) + invert;
+}
 #endif
 
 template <size_t base, typename T>
@@ -1081,11 +1088,11 @@ CONSTEXPR size_t logbasenegative(T n)
     return n > static_cast<T>(-(native_t)base) ? 1 : 1 + logbase<base>(n / static_cast<T>(-(native_t)base));
 }
 
+#endif
+
 #define isPow2OrZero(v) (((v) & ((v) - 1)) == 0)
 #define isPow2(v) (isPow2OrZero(v) && (v))
 
-#endif
-
 ////////// Bitfield manipulation //////////
 
 #if 0
diff --git a/source/duke3d/src/gamevars.cpp b/source/duke3d/src/gamevars.cpp
index 7bbda3cd6..1b4a5deb0 100644
--- a/source/duke3d/src/gamevars.cpp
+++ b/source/duke3d/src/gamevars.cpp
@@ -760,7 +760,6 @@ static FORCE_INLINE int __fastcall getvar__(int const gameVar, int const spriteN
 
         int       returnValue  = 0;
         int const varFlags     = var.flags & (GAMEVAR_USER_MASK|GAMEVAR_PTR_MASK);
-        int const invertResult = !!(gameVar & GV_FLAG_NEGATIVE);
 
         if (!varFlags) returnValue = var.global;
         else if (varFlags == GAMEVAR_PERACTOR)
@@ -775,7 +774,7 @@ static FORCE_INLINE int __fastcall getvar__(int const gameVar, int const spriteN
             case GAMEVAR_Q16PTR:   returnValue = fix16_to_int(*(fix16_t *)var.global); break;
         }
 
-        return (returnValue ^ -invertResult) + invertResult;
+        return NEGATE_ON_CONDITION(returnValue, gameVar & GV_FLAG_NEGATIVE);
     }
 }