From 58319b41de4c69a9d68a449612ade518e5548c34 Mon Sep 17 00:00:00 2001 From: lkcl Date: Sat, 29 Apr 2023 13:27:07 +0100 Subject: [PATCH] remove Rc=1 variants from twin butterfly instructions --- openpower/sv/twin_butterfly.mdwn | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-) diff --git a/openpower/sv/twin_butterfly.mdwn b/openpower/sv/twin_butterfly.mdwn index 5862253df..f6d3882eb 100644 --- a/openpower/sv/twin_butterfly.mdwn +++ b/openpower/sv/twin_butterfly.mdwn @@ -9,7 +9,7 @@ * [[openpower/isa/svfixedarith]] -# Twin Butterfly Integer DCT Instruction(s) +# Rationale for Twin Butterfly Integer DCT Instruction(s) The goal is to implement instructions that calculate the expression: @@ -39,11 +39,13 @@ The instruction will run in accumulate mode, so in order to calculate the 2-coef ## Integer Butterfly Multiply Add/Sub FFT/DCT +**Add the following to Book I Section 3.3.9.1** + A-Form ``` |0 |6 |11 |16 |21 |26 |31 | - | PO | RT | RA | RB | SH | XO |Rc | + | PO | RT | RA | RB | SH | XO |/ | ``` @@ -80,15 +82,16 @@ Special Registers Altered: ## Floating Twin Multiply-Add DCT [Single] +**Add the following to Book I Section 4.6.6.3 ** + X-Form ``` |0 |6 |11 |16 |21 |31 | - | PO | FRT | FRA | FRB | XO | Rc| + | PO | FRT | FRA | FRB | XO |/ | ``` * fdmadds FRT,FRA,FRB (Rc=0) -* fdmadds. FRT,FRA,FRB (Rc=1) Pseudo-code: @@ -104,20 +107,20 @@ Special Registers Altered: FPRF FR FI FX OX UX XX VXSNAN VXISI VXIMZ - CR1 (if Rc=1) ``` ## Floating Multiply-Add FFT [Single] +**Add the following to Book I Section 4.6.6.3 ** + X-Form ``` |0 |6 |11 |16 |21 |31 | - | PO | FRT | FRA | FRB | XO | Rc| + | PO | FRT | FRA | FRB | XO |/ | ``` * ffmadds FRT,FRA,FRB (Rc=0) -* ffmadds. FRT,FRA,FRB (Rc=1) Pseudo-code: @@ -132,5 +135,4 @@ Special Registers Altered: FPRF FR FI FX OX UX XX VXSNAN VXISI VXIMZ - CR1 (if Rc=1) ``` -- 2.30.2