From d18201bcc2eb61e94240d484fd226889acd91ab1 Mon Sep 17 00:00:00 2001 From: Luke Kenneth Casson Leighton Date: Mon, 19 Jul 2021 14:41:04 +0100 Subject: [PATCH] swap the indices rather than the data in DCT top half: bizarrely this works! --- src/openpower/decoder/isa/fastdctlee.py | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/src/openpower/decoder/isa/fastdctlee.py b/src/openpower/decoder/isa/fastdctlee.py index 903749c8..1462d648 100644 --- a/src/openpower/decoder/isa/fastdctlee.py +++ b/src/openpower/decoder/isa/fastdctlee.py @@ -199,15 +199,19 @@ def transform2(vec, reverse=True): k += tablestep # instead of using jl+halfsize, perform a swap here. # use half of j/jr because actually jl+halfsize = reverse(j) + # actually: swap the *indices*... not the actual data. + # incredibly... bizarrely... this works *without* having + # to do anything else. if len(j) > 1: hz2 = halfsize // 2 for ci, (jl, jh) in enumerate(zip(j[:hz2], jr[:hz2])): - tmp = vec[ri[jl+halfsize]] - vec[ri[jl+halfsize]] = vec[ri[jh]] - vec[ri[jh]] = tmp - #print (" swap", size, i, ri[jl+halfsize], ri[jh]) + tmp = ri[jl+halfsize] + ri[jl+halfsize] = ri[jh] + ri[jh] = tmp + print (" swap", size, i, ri[jl+halfsize], ri[jh]) size //= 2 + print("post-swapped", ri) print("transform2 pre-itersum", vec) n = len(vec) -- 2.30.2