(no commit message)

diff --git a/openpower/sv/av_opcodes.mdwn b/openpower/sv/av_opcodes.mdwn
index 617bf7f8381529dee6fc00241d450c658588962c..34c528d0c92256fcab7367ff3a3a667bd3c1d77f 100644 (file)
--- a/openpower/sv/av_opcodes.mdwn
+++ b/openpower/sv/av_opcodes.mdwn
@@ -49,7 +49,7 @@ The fundamental principle for these instructions is:
 
 Thus for example, where OpenPOWER VSX has vpkswss, this would be achieved in SV with simply:
 
-* addition of a scalar ext/clamp instruction
+* applying saturation to maxu (sv.maxu/satu)
 * 1st op, swizzle-selection vec2 "select X only" from source to dest:
   dest.X = extclamp(src.X)
 * 2nd op, swizzle-select vec2 "select Y only" from source to dest
@@ -57,6 +57,14 @@ Thus for example, where OpenPOWER VSX has vpkswss, this would be achieved in SV
 
 Macro-op fusion may be used to detect that these two interleave cleanly, overlapping the vec2.X with vec2.Y to produce a single vec2.XY operation.
 
+Alternatively Twin-Predication may be applied, with every even bit set in
+the source mask and every odd bit set in the destination mask:
+
+    r3=0b10101010
+    r10=0b01010101
+    r0=0x00007fff # or other limit
+    sv.maxu/satu/sm=r3/dm=r10/ew=32 *r20,*r20,r0
+
 ## Scalar element operations
 
 * clamping / saturation for signed and unsigned.  best done similar to FP rounding modes, i.e. with an SPR.