[Carob-commits] CVS update of carob/src (SQLDataSerialization.cpp)

[marc]

    Date: Wednesday, February 1, 2006 @ 16:39:16
  Author: marc
    Path: /cvsroot/carob/carob/src

Modified: SQLDataSerialization.cpp (1.24 -> 1.25)

Unrolled loops in portable int/float-point converters. Thanks to Zsolt for the 
benchmarking. CAROB-31.


--------------------------+
 SQLDataSerialization.cpp |   53 +++++++++++++++++++++++++++++----------------
 1 files changed, 35 insertions(+), 18 deletions(-)


Index: carob/src/SQLDataSerialization.cpp
diff -u carob/src/SQLDataSerialization.cpp:1.24 
carob/src/SQLDataSerialization.cpp:1.25
--- carob/src/SQLDataSerialization.cpp:1.24     Wed Feb  1 16:26:08 2006
+++ carob/src/SQLDataSerialization.cpp  Wed Feb  1 16:39:16 2006
@@ -103,7 +103,7 @@
 
 // Float
 
-uint32_t
+inline uint32_t
 SQLDataSerialization::floatToU32Bits(float f)
 {
     // "union casting" using { float; uint32_t; } or the simpler:
@@ -115,19 +115,23 @@
     // The more portable code below should not cost more than a couple
     // of CPU cycles/converted float
     const unsigned char *bytes = reinterpret_cast<const unsigned char *>(&f);
-    uint32_t ires = 0;
-    for (int c=0, shift=0; c<4; c++, shift+=8)
-        ires |= (uint32_t) bytes[c] << shift;
-    return ires;
+    return (uint32_t) bytes[3] << 24
+        | (uint32_t) bytes[2] << 16
+        | (uint32_t) bytes[1] << 8
+        | (uint32_t) bytes[0];
 }
 
-float
+inline float
 SQLDataSerialization::U32BitsToFloat(const uint32_t ui)
 {
     float res;
-    unsigned char *bytes = reinterpret_cast<unsigned char *>(&res);
-    for (int c=0, shift=0; c<4; c++, shift+=8)
-        bytes[c] = ui >> shift;
+    unsigned char *f_bytes = reinterpret_cast<unsigned char *>(&res);
+
+    f_bytes[3] = ui >> 24;
+    f_bytes[2] = ui >> 16;
+    f_bytes[1] = ui >> 8;
+    f_bytes[0] = ui;
+
     return res;
 }
 
@@ -157,23 +161,36 @@
 }
 
 // Double
-uint64_t
+inline uint64_t
 SQLDataSerialization::doubleToU64Bits(double d)
 {
-    uint64_t ires = 0;
     const unsigned char *bytes = reinterpret_cast<const unsigned char *>(&d);
-    for (int c=0, shift=0; c<8; c++, shift+=8)
-        ires |= (uint64_t) bytes[c] << shift;
-    return ires;
+
+    return (uint64_t) bytes[7] << 56
+        | (uint64_t) bytes[6] << 48
+        | (uint64_t) bytes[5] << 40
+        | (uint64_t) bytes[4] << 32
+        | (uint64_t) bytes[3] << 24
+        | (uint64_t) bytes[2] << 16
+        | (uint64_t) bytes[1] << 8
+        | (uint64_t) bytes[0];
 }
 
-double
+inline double
 SQLDataSerialization::U64BitsToDouble(const uint64_t ui)
 {
     double res;
-    unsigned char *bytes = reinterpret_cast<unsigned char *>(&res);
-    for (int c=0, shift=0; c<8; c++, shift+=8)
-        bytes[c] = ui >> shift;
+    unsigned char *d_bytes = reinterpret_cast<unsigned char *>(&res);
+
+    d_bytes[7] = ui >> 56;
+    d_bytes[6] = ui >> 48;
+    d_bytes[5] = ui >> 40;
+    d_bytes[4] = ui >> 32;
+    d_bytes[3] = ui >> 24;
+    d_bytes[2] = ui >> 16;
+    d_bytes[1] = ui >> 8;
+    d_bytes[0] = ui;
+
     return res;
 }
 

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