(no commit message)

[libreriscv.git] / simple_v_extension.mdwn

diff --git a/simple_v_extension.mdwn b/simple_v_extension.mdwn
index e526acff191f5661e17083659290653eeacbc14d..1f479badad0209ee49ebd85864e2376ee9613fb4 100644 (file)
--- a/simple_v_extension.mdwn
+++ b/simple_v_extension.mdwn
@@ -393,7 +393,7 @@ imm[11:0]               |||| rs1   | funct3  | rd   | opcode |
 The exact same corresponding adaptation is also carried out on the single,
 double and quad precision floating-point LOAD-FP and STORE-FP operations,
 which fit the exact same instruction format.  Thus all three types
-(unit, stride and indexed) may be fitted into FLW, FLD and FLQ, 
+(unit, stride and indexed) may be fitted into FLW, FLD and FLQ,
 as well as FSW, FSD and FSQ.
 
 Notes:
@@ -458,14 +458,25 @@ offset to 4 bits and utilising the 5th bit to indicate whether "stride"
 is to be enabled.  In this way it is at least possible to introduce
 that functionality.
 
+(**TODO**: *assess whether the loss of one bit from offset is worth having
+"stride" capability.*)
+
 We also assume (including for the "stride" variant) that the "width"
 parameter, which is missing, is derived and implicit, just as it is
 with the standard Compressed LOAD/STORE instructions.  For C.LW, C.LD
 and C.LQ, the width is implicitly 4, 8 and 16 respectively, whilst for
 C.FLW and C.FLD the width is implicitly 4 and 8 respectively.
 
-**TODO**: assess whether the loss of one bit from offset is worth having
-"stride" capability.
+Interestingly we note that the Vectorised Simple-V variant of
+LOAD/STORE (Compressed and otherwise), due to it effectively using the
+standard register file(s), is the direct functional equivalent of
+standard load-multiple and store-multiple instructions found in other
+processors.
+
+In Section 12.3 riscv-isa manual V2.3-draft it is noted the comments on
+page 76, "For virtual memory systems some data accesses could be resident
+in physical memory and some not".  The interesting question then arises:
+how does RVV deal with the exact same scenario?
 
 # Note on implementation of parallelism