clarify isans letter

diff --git a/openpower/isans_letter.mdwn b/openpower/isans_letter.mdwn
index df5a11cf82e2583d10ded40c9383e2893b014893..4cb9dd1e614271ae93fd454d2f89782f0f70a3fc 100644 (file)
--- a/openpower/isans_letter.mdwn
+++ b/openpower/isans_letter.mdwn
@@ -28,6 +28,12 @@ encoded, some unary encoded, some "offical", some "experimental" and some
 and the OpenPOWER Foundation to be given an IANA-like role in atomically
 allocating mode bits.
 
+Instructions that we need to add, which are a normal part of GPUs,
+include ATAN2, LOG, NORMALISE, YUV2RGB, Khronos Compliance FP mode
+(different from both IEEE754 and "NI" mode), and many more.  Many of
+these may turn out to be useful in a wider context: they however need
+to be fully isolated behind "mode-setting".
+
 # Summary of Libre-SOC Commercial Project
 
 The Libre-SOC Commercial Product is a hybrid GPU-GPU-VPU intended for
@@ -55,11 +61,13 @@ proprietary, secretive approach.
 
 Therefore, to meet our business objectives:
 
-* A "traditional" general-purpose Vector System (such as that in POWER9)
-  is *NOT* an adequate basis for a GPU.  Nyuzi's conclusion is that using
-  such general-purpose Vector ISAs results in reaching only 25% performance
-   (or requiring 4-fold increase in power consumption) to achieve par with
-   current commercial-grade GPUs.
+* As shown from Nyuzi and Larrabee, although ideally suited to high
+  performance compute tasks, a "traditional" general-purpose full
+  IEEE754-compliant Vector ISA (such as that in POWER9) is not an adequate
+  basis for a commercially competitive GPU.  Nyuzi's conclusion is that
+  using such general-purpose Vector ISAs results in reaching only 25%
+  performance (or requiring 4-fold increase in power consumption) to
+  achieve par with current commercial-grade GPUs.
 * We are not going the "traditional" (separate custom GPU) route because
   it is not practical for a new team to design hardware and spend 8+
   man-years on massively complex inter-processor driver development as well