From: lkcl <lkcl@web>
Date: Fri, 7 Feb 2020 16:41:11 +0000 (+0000)
Subject: (no commit message)
X-Git-Tag: convert-csv-opcode-to-binary~3525
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=f1e73161d7283a5e7ba25a41f7781f285984f30f;p=libreriscv.git

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diff --git a/3d_gpu/architecture/dynamic_simd/shift.mdwn b/3d_gpu/architecture/dynamic_simd/shift.mdwn
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+# Dynamic Partitioned Shift
+
+This is almost as complex as multiplication, except there is a trick that can be deployed.  In the partitioned multiplier, it is necessary to compute a full NxN matrix of partial multiplication results, then perform a cascade of adds, using PartitionedAdd to "automatically" break them down into segments.
+
+Partitioned Shifting will also require to have an NxN matrix, however it is slightly different.  first, define the following:
+
+    a0 = a[7..0], a1 = a[15..8], ....
+    b0 = b[7..0], b1 = b[15..8], ....
+
+then, we compute the following matrix:
+
+    a0 << b0    a1 << b0    a2 << b0   a3 << b0