From 3a13bc256077d250d6d40c87725170e78e381e2c Mon Sep 17 00:00:00 2001
From: "Stephen A. Wood" <zviwood@gmail.com>
Date: Sun, 2 Jun 2013 22:03:52 -0400
Subject: [PATCH] Fix nplaneshit>6 bug. (fix Count1Bits routine)
---
src/THcDriftChamber.cxx | 12 +++++-------
1 file changed, 5 insertions(+), 7 deletions(-)
diff --git a/src/THcDriftChamber.cxx b/src/THcDriftChamber.cxx
index 6987d00..fe9b490 100644
--- a/src/THcDriftChamber.cxx
+++ b/src/THcDriftChamber.cxx
@@ -836,13 +836,11 @@ void THcDriftChamber::CorrectHitTimes()
}
}
UInt_t THcDriftChamber::Count1Bits(UInt_t x)
-// From "Hacker's Delight"
+// From http://graphics.stanford.edu/~seander/bithacks.html
{
- x = x - ((x >> 1) & 0x55555555);
- x = (x & 0x33333333) + ((x >> 2) & 0x33333333);
- x = x + (x >> 8);
- x = x + (x >> 16);
- return x & 0x0000003F;
+ x = x - ((x >> 1) & 0x55555555);
+ x = (x & 0x33333333) + ((x >> 2) & 0x33333333);
+ return (((x + (x >> 4)) & 0x0F0F0F0F) * 0x01010101) >> 24;
}
//_____________________________________________________________________________
@@ -1003,7 +1001,7 @@ void THcDriftChamber::LeftRight()
// Calculate final coordinate based on plusminusbest
// Update the hit positions in the space points
- for(Int_t ihit; ihit<nhits; ihit++) {
+ for(Int_t ihit=0; ihit<nhits; ihit++) {
sp->GetHit(ihit)->SetLeftRight(plusminusbest[ihit]);
}
--
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