From e6f07bb537fd656776d281a2b053a1ca48e9f0b4 Mon Sep 17 00:00:00 2001
From: x <powturbo@gmail.com>
Date: Sat, 21 Dec 2019 14:06:33 +0100
Subject: [PATCH] TurboPFor: Elias fano encode/decode

---
 eliasfano.c | 76 ++++++++++++++++++++++++++---------------------------
 1 file changed, 38 insertions(+), 38 deletions(-)

diff --git a/eliasfano.c b/eliasfano.c
index 4ba7346..e47af1e 100644
--- a/eliasfano.c
+++ b/eliasfano.c
@@ -1,7 +1,7 @@
 /**
     Copyright (C) powturbo 2013-2019
     GPL v2 License
-  
+
     This program is free software; you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
     the Free Software Foundation; either version 2 of the License, or
@@ -25,9 +25,9 @@
 //    eliasfano.c - "Integer Compression" Elias Fano
 #ifndef USIZE
 #include <string.h>
-#pragma warning( disable : 4005) 
-#pragma warning( disable : 4090) 
-#pragma warning( disable : 4068) 
+#pragma warning( disable : 4005)
+#pragma warning( disable : 4090)
+#pragma warning( disable : 4068)
 
 #include "conf.h"
 #include "bitpack.h"
@@ -42,13 +42,13 @@
 #define bslr32(x) _blsr_u32(x)
 #define bslr64(x) _blsr_u64(x)
   #else
-//static inline unsigned long long blsr(unsigned long long x) { return x & (x - 1); } 
+//static inline unsigned long long blsr(unsigned long long x) { return x & (x - 1); }
 #define blsr32(_x_) ((_x_) & ((_x_) - 1))
 #define blsr64(_x_) ((_x_) & ((_x_) - 1))
   #endif
 #define blsr8(_x_)  blsr32(_x_)
 #define blsr16(_x_) blsr32(_x_)
- 
+
 #define EFE(__x,__i,__start) ((__x[__i] - __start)-(__i)*EF_INC)
 
 #define BITPACK bitpack
@@ -112,7 +112,7 @@
 
 #include "eliasfano.c"
   #endif
-	
+
   #ifdef __AVX2__
 #define VSIZE 256
 #define BITPACK bitpack256v
@@ -131,22 +131,22 @@
 #else //--------------------------------------------- implementation ---------------------------------------------------------------
 #define uint_t TEMPLATE3(uint, USIZE, _t)
 
-#pragma clang diagnostic push 
+#pragma clang diagnostic push
 #pragma clang diagnostic ignored "-Wparentheses"
 
-unsigned char *TEMPLATE2(EFANOENC, USIZE)(uint_t *__restrict in, unsigned n, unsigned char *__restrict out, uint_t start) { 
-  uint_t *ip, e,x,hl,i;					 		
+unsigned char *TEMPLATE2(EFANOENC, USIZE)(uint_t *__restrict in, unsigned n, unsigned char *__restrict out, uint_t start) {
+  uint_t *ip, e,x,hl,i;
   unsigned char *op;
   unsigned lb;
-  uint_t _pa[1024+64],*pa=_pa;										
-  if(!n) return out; 
+  uint_t _pa[1024+64],*pa=_pa;
+  if(!n) return out;
   if(n > 1024) pa = malloc(sizeof(pa[0])*(n+64));    if(!pa) die("efanoenc:malloc error size=%d ", n);
   e = EFE(in,n-1,start);
-  if(!e) { out[0] = 0; if(pa != _pa) free(pa);return out+1; }	
-  
-  lb = TEMPLATE2(bsr, USIZE)(e/n); 
-  x = ((uint_t)1 << lb)-1; hl = PAD8((e>>lb)+n); 
-  
+  if(!e) { out[0] = 0; if(pa != _pa) free(pa);return out+1; }
+
+  lb = TEMPLATE2(bsr, USIZE)(e/n);
+  x = ((uint_t)1 << lb)-1; hl = PAD8((e>>lb)+n);
+
   for(i = 0; i != n&~3;) {
     pa[i] = EFE(in,i,start) & x; ++i;
     pa[i] = EFE(in,i,start) & x; ++i;
@@ -154,9 +154,9 @@ unsigned char *TEMPLATE2(EFANOENC, USIZE)(uint_t *__restrict in, unsigned n, uns
     pa[i] = EFE(in,i,start) & x; ++i;
   }
   while(i < n) pa[i] = EFE(in,i,start) & x, ++i;
-  *out = lb+1; 
+  *out = lb+1;
   op = TEMPLATE2(BITPACK,USIZE)(pa, n, out+1, lb);
-  
+
   memset(op, 0, hl);
   for(i = 0; i != n&~3; ) {
     x = i + (EFE(in,i,start) >> lb), op[x >> 3] |= (uint_t)1 << (x & 7); ++i;
@@ -170,38 +170,38 @@ unsigned char *TEMPLATE2(EFANOENC, USIZE)(uint_t *__restrict in, unsigned n, uns
 }
 
 unsigned char *TEMPLATE2(EFANODEC, USIZE)(unsigned char *__restrict in, unsigned n, uint_t *__restrict out, uint_t start) {
-  unsigned char *ip = in;  																										
-  uint_t        i,j,lb = *ip++;           	
-  uint64_t      b,x; 
-  if(!n) 
-	return in;
-   
-  if(!lb) { 
+  unsigned char *ip = in;
+  uint_t        i,j,lb = *ip++;
+  uint64_t      b,x;
+  if(!n)
+    return in;
+
+  if(!lb) {
       #if (defined(__SSE2__) || defined(__ARM_NEON)) && USIZE == 32
         #if EF_INC == 1
     BITFORZERO32(out, n, start, 1);
         #else
     BITZERO32( out, n, start);
         #endif
-	  #else 
+      #else
     BITFORSET_(out, n, start, EF_INC);
       #endif
-	return ip; 
+    return ip;
   }
-  
+
   ip = TEMPLATE2(BITUNPACK,USIZE)(ip, n, out, --lb);
   #define EFD(i) if(!b) break; out[i] += ((uint_t)(j+ctz64(b)-i) << lb) + start+i*EF_INC; b = blsr64(b); ++i;
-  
-  for(i=j=0;; j += sizeof(uint64_t)*8) {											//PREFETCH(ip+256,0);
-    for(b = ctou64(ip+(j>>3)); ; ) { 
-	  EFD(i); EFD(i); EFD(i); EFD(i); 
-	  if(!b) break; out[i] += ((uint_t)(j+ctz64(b)-i) << lb) + start+i*EF_INC;
-	  if(unlikely(++i >= n))
-        goto e; 
+
+  for(i=j=0;; j += sizeof(uint64_t)*8) {                                            //PREFETCH(ip+256,0);
+    for(b = ctou64(ip+(j>>3)); ; ) {
+      EFD(i); EFD(i); EFD(i); EFD(i);
+      if(!b) break; out[i] += ((uint_t)(j+ctz64(b)-i) << lb) + start+i*EF_INC;
+      if(unlikely(++i >= n))
+        goto e;
       b = blsr64(b);
-	}
+    }
   }
-  e:return ip + PAD8((EFE(out,n-1,start)>>lb)+n); 
+  e:return ip + PAD8((EFE(out,n-1,start)>>lb)+n);
 }
 
 #pragma clang diagnostic pop