From: Vinson Lee <vlee@vmware.com>
Date: Thu, 1 Oct 2009 19:33:20 +0000 (-0600)
Subject: mesa: Return -FLT_MAX instead of 0 for LG2(0).
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=18883cdf2334511005973155fc517eb678dc0043;p=mesa.git

mesa: Return -FLT_MAX instead of 0 for LG2(0).

lim x->0 log(x) = -inf so -FLT_MAX is a better approximation than 0
for LG2(0).
---

diff --git a/src/mesa/shader/prog_execute.c b/src/mesa/shader/prog_execute.c
index 69b81e724a2..192d39aed1e 100644
--- a/src/mesa/shader/prog_execute.c
+++ b/src/mesa/shader/prog_execute.c
@@ -939,7 +939,7 @@ _mesa_execute_program(GLcontext * ctx,
 	    /* The fast LOG2 macro doesn't meet the precision requirements.
 	     */
             if (a[0] == 0.0F) {
-               val = 0.0F;
+               val = -FLT_MAX;
             }
             else {
                val = log(a[0]) * 1.442695F;