From a2d90ea958bf8eb23b3d69a321237dd58ec6c206 Mon Sep 17 00:00:00 2001
From: Giovanni Bussi <giovanni.bussi@gmail.com>
Date: Wed, 13 Jun 2012 18:13:16 +0200
Subject: [PATCH] Optimized conversion to/from FORTRAN
Conversion is done with trivial int operations, avoiding sprintf() and sscanf()
---
src/Plumed.c | 46 +++++++++++++++++++++++++++++-----------------
1 file changed, 29 insertions(+), 17 deletions(-)
diff --git a/src/Plumed.c b/src/Plumed.c
index 4cdd79273..ff3b2f146 100644
--- a/src/Plumed.c
+++ b/src/Plumed.c
@@ -6,7 +6,7 @@
#include <stdio.h>
#include <assert.h>
#include <stdlib.h>
-#include <string.h>
+#include <limits.h>
/* DECLARATION USED ONLY IN THIS FILE */
@@ -172,33 +172,45 @@ int plumed_ginitialized(void){
}
void plumed_c2f(plumed p,char*c){
- int n,i;
+ unsigned i;
+ unsigned char* cc;
/*
- Since a bug here would be almost impossible to
- find, I prefer to stay safer and use a longer buffer
- to temporarily store the pointer. Then, 32 characters
- are copied to the target array.
+ Convert the address stored in p.p into a proper FORTRAN string
+ made of only ASCII characters. For this to work, the two following
+ assertions should be satisfied:
*/
- char cc[256];
+ assert(CHAR_BIT<=12);
+ assert(sizeof(p.p)<=16);
+
assert(c);
- n=sprintf(cc,"%31p",p.p);
- assert(n==31);
- for(i=0;i<32;i++) c[i]=cc[i];
+ cc=(unsigned char*)&p.p;
+ for(i=0;i<sizeof(p.p);i++){
+/*
+ characters will range between '0' (ASCII 48) and 'o' (ASCII 111=48+63)
+*/
+ c[2*i]=cc[i]/64+48;
+ c[2*i+1]=cc[i]%64+48;
+ }
}
plumed plumed_f2c(const char*c){
plumed p;
- char* cc;
- assert(c);
-/* this is to avoid sscanf implementations which are not const-correct */
- cc=(char*)c;
- sscanf(cc,"%p",&p.p);
- return p;
-}
+ unsigned i;
+ unsigned char* cc;
+ assert(CHAR_BIT<=12);
+ assert(sizeof(p.p)<=16);
+ assert(c);
+ cc=(unsigned char*)&p.p;
+ for(i=0;i<sizeof(p.p);i++){
/*
+ perform the reversed transform
*/
+ cc[i]=(c[2*i]-48)*64 + (c[2*i+1]-48);
+ }
+ return p;
+}
#ifdef __cplusplus
--
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