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1 files changed, 29 insertions, 0 deletions

diff --git a/sys/osb/bswap4.f b/sys/osb/bswap4.f
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+c BSWAP4 - Move bytes from array "a" to array "b", swapping the four bytes
+c in each successive 4 byte group, i.e., 12345678 becomes 43218765.
+
+	subroutine bswap4 (a, aoff, b, boff, nbytes)
+
+	character*1 a(*), b(*), temp
+	integer	aoff, boff, nbytes, i
+	integer aoff1, boff1, aoff2, boff2, aoff3, boff3
+
+		if (nbytes .le. 4) then
+		    return
+		endif
+
+		aoff1 = aoff + 1
+		boff1 = boff + 1
+		aoff2 = aoff + 2
+		boff2 = boff + 2
+		aoff3 = aoff + 3
+		boff3 = boff + 3
+
+ 		do 10 i = 0, nbytes-3, 4
+		    temp = a(aoff1+i)
+		    b(boff1+i) = a(aoff2+i)
+		    b(boff2+i) = temp
+		    temp = a(aoff3+i)
+		    b(boff3+i) = a(aoff+i)
+		    b(boff+i) = temp
+ 10		continue
+	end