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execute: Consolidate count-leading/trailing-zeroes implementations
authorPaul Mackerras <paulus@ozlabs.org>
Tue, 8 Oct 2019 21:55:43 +0000 (08:55 +1100)
committerPaul Mackerras <paulus@ozlabs.org>
Tue, 8 Oct 2019 22:18:31 +0000 (09:18 +1100)
commit24a4a796ce1e4bf370e00f801bc1cee6faf7d8f7
tree5510420d0d298d1915697cd71de645fba78c2397tree
parentb8fb721b813785e19591fcc39354dfd8615b99d3commit | diff
execute: Consolidate count-leading/trailing-zeroes implementations

This adds combinatorial logic that does 32-bit and 64-bit count
leading and trailing zeroes in one unit, and consolidates the
four instructions under a single OP_CNTZ opcode.

This saves 84 slice LUTs on the Arty A7-100.

Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Makefile diff | blob | history
countzero.vhdl [new file with mode: 0644] blob
decode1.vhdl diff | blob | history
decode_types.vhdl diff | blob | history
execute1.vhdl diff | blob | history
microwatt.core diff | blob | history