From 3fdd4310608e4db3c35e35a623ba43410234c06a Mon Sep 17 00:00:00 2001
From: Ed J <mohawk2@users.noreply.github.com>
Date: Mon, 11 Nov 2024 01:29:22 +0000
Subject: [PATCH] add IO::Misc::bswap16

---
 Basic/IO-Misc/misc.pd  | 102 ++++++++++-------------------------------
 Basic/IO-Misc/t/misc.t |   6 +--
 Changes                |   1 +
 3 files changed, 29 insertions(+), 80 deletions(-)

diff --git a/Basic/IO-Misc/misc.pd b/Basic/IO-Misc/misc.pd
index 19b50b911..c0591dda7 100644
--- a/Basic/IO-Misc/misc.pd
+++ b/Basic/IO-Misc/misc.pd
@@ -14,7 +14,7 @@ PDL::IO::Misc - misc IO routines for PDL
 
 =head1 DESCRIPTION
 
-Some basic I/O functionality: FITS, tables, byte-swapping
+Some basic I/O functionality: tables, byte-swapping
 
 =head1 SYNOPSIS
 
@@ -53,78 +53,36 @@ use PDL::Bad;
 use Carp;
 use Symbol qw/ gensym /;
 use List::Util;
-use strict;
 
 !NO!SUBS!
 
-defpdl(
-        'bswap2',
-        'x(); ',
-        '',
-        '
-      int i;
-      PDL_Short *aa; PDL_Short bb;
-      PDL_Byte *a,*b;
-
-      int n = sizeof($x()) / sizeof(PDL_Short);
-      aa = (PDL_Short*) &$x();
-
-      for(i=0;i<n; i++) {
-         bb = aa[i]; a = (PDL_Byte*) (void*) (aa+i);
-         b = (PDL_Byte*) &bb;
-         *a = *(b+1);  *(a+1) = *b;
-     }',
-     "Swaps pairs of bytes in argument x()"
-);
-
-
-defpdl(
-        'bswap4',
-        'x(); ',
-        '',
-        '
-      int i;
-      PDL_Long *aa; PDL_Long bb;
-      PDL_Byte *a,*b;
-
-      int n = sizeof($x()) / sizeof(PDL_Long);
-      aa = (PDL_Long*) &$x();
-
-      for(i=0;i<n; i++) {
-         bb = aa[i]; a = (PDL_Byte*) (void*) (aa+i);
-         b = (PDL_Byte*) &bb;
-         *a = *(b+3);  *(a+1) = *(b+2);  *(a+2) = *(b+1); *(a+3) = *b;
-     }',
-     "Swaps quads of bytes in argument x()"
-);
-
-
-defpdl(
-        'bswap8',
-        'x(); ',
-        '',
-        '
-      int i;
-      PDL_Double *aa; PDL_Double bb;
-      PDL_Byte *a,*b;
-
-      int n = sizeof($x()) / sizeof(PDL_Double);
-      aa = (PDL_Double*) &$x();
-
-      for(i=0;i<n; i++) {
-         bb = aa[i]; a = (PDL_Byte*) (void*) (aa+i);
-         b = (PDL_Byte*) &bb;
-         *a     = *(b+7);  *(a+1) = *(b+6);  *(a+2) = *(b+5); *(a+3) = *(b+4);
-         *(a+4) = *(b+3);  *(a+5) = *(b+2);  *(a+6) = *(b+1); *(a+7) = *b;
-     }',
-     "Swaps octets of bytes in argument x()"
-);
-
+sub defswap {
+  my ($bytes, $doc) = @_;
+  my $sized_type = "uint".($bytes*8)."_t";
+  pp_def(
+    "bswap$bytes",
+    Pars => '[io] x()',
+    Code => <<EOF,
+int i;
+int n = sizeof(\$x()) / sizeof($sized_type);
+$sized_type *aa = ($sized_type*) &\$x();
+for (i=0;i<n; i++) {
+  $sized_type bb = aa[i];
+  PDL_Byte *a = (PDL_Byte*) (void*) (aa+i);
+  PDL_Byte *b = (PDL_Byte*) &bb;
+  @{[map "a[$_] = b[".($bytes-$_-1)."];", 0..$bytes-1]}
+}
+EOF
+    Doc  => $doc,
+  );
+}
+defswap(2, "Swaps pairs of bytes in argument x()");
+defswap(4, "Swaps quads of bytes in argument x()");
+defswap(8, "Swaps octets of bytes in argument x()");
+defswap(16, "Swaps 16s of bytes in argument x()");
 
 pp_addpm(<<'!NO!SUBS!');
 
-
-
 # Internal routine to extend PDL array by size $n along last dimension
 # - Would be nice to have a proper extend function rather than hack
 # - Is a NO-OP when handed a perl ARRAY ref rather than an ndarray arg
@@ -1180,16 +1138,6 @@ pp_add_exported("", "isbigendian");
 
 ################################ XS CODE ######################################
 
-sub defpdl {
-        pp_def(
-                $_[0],
-                Pars => $_[1],
-                OtherPars => $_[2],
-                Code => $_[3],
-                Doc  => $_[4],
-        );
-}
-
 pp_add_exported('', 'rcube');
 pp_addpm(<<'EOPM');
 =head2 rcube
diff --git a/Basic/IO-Misc/t/misc.t b/Basic/IO-Misc/t/misc.t
index 2656fe9c7..f1a54dfa5 100644
--- a/Basic/IO-Misc/t/misc.t
+++ b/Basic/IO-Misc/t/misc.t
@@ -86,11 +86,11 @@ is( (sum($x)==15 && max($y)==66 && $y->getdim(0)==5), 1, "rgrep" );
 
 $x = short(3); $y = long(3); # $c=long([3,3]);
 bswap2($x); bswap4($y);
-is sum($x)."", 768, "bswap2";
-is sum($y)."", 50331648, "bswap4";
+is_pdl $x, short(768), "bswap2";
+is_pdl $y, long(50331648), "bswap4";
 $x = short(3);
 $x->type->bswap->($x);
-is sum($x)."", 768, "bswap Type method";
+is_pdl $x, short(768), "bswap Type method";
 
 ############# Test rasc  #############
 
diff --git a/Changes b/Changes
index 285efc2aa..6ca3d2029 100644
--- a/Changes
+++ b/Changes
@@ -1,6 +1,7 @@
 - CallExt removed - use `Inline with => "PDL"; use Inline C => "..."`
 - Inline::MakePdlppInstallable removed - use Inline::Module
 - PDL::PP::Dump removed - set $::PP_VERBOSE in .pd instead
+- add IO::Misc::bswap16
 
 2.095 2024-11-03
 - add PDL_GENTYPE_IS_{REAL,FLOATREAL,COMPLEX,SIGNED,UNSIGNED}_##ppsym (#502)