DRAFT Minimum/Maximum (Rc=1)

MM-Form

• minmax. RT,RA,RB,MMM (Rc=1)

Pseudo-code:

a <- (RA|0)
b <- (RB)
if MMM[0] then  # word mode
    # shift left by XLEN/2 to make the dword comparison
    # do word comparison of the original inputs
    a <- a[XLEN/2:XLEN-1] || [0] * XLEN/2
    b <- b[XLEN/2:XLEN-1] || [0] * XLEN/2
if MMM[1] then  # signed mode
    # invert sign bits to make the unsigned comparison
    # do signed comparison of the original inputs
    a[0] <- ¬a[0]
    b[0] <- ¬b[0]
# if Rc = 1 then store the result of comparing a and b to CR0
if Rc = 1 then
    if a <u b then
        CR0 <- 0b100 || XER[SO]
    if a = b then
        CR0 <- 0b001 || XER[SO]
    if a >u b then
        CR0 <- 0b010 || XER[SO]
if MMM[2] then  # max mode
    # swap a and b to make the less than comparison do
    # greater than comparison of the original inputs
    t <- a
    a <- b
    b <- t
# store the entire selected source (even in word mode)
# if Rc = 1 then store the result of comparing a and b to CR0
if a <u b then RT <- (RA|0)
else           RT <- (RB)

Special Registers Altered:

CR0                     (if Rc=1)

DRAFT Minimum/Maximum

MM-Form

• minmax RT,RA,RB,MMM (Rc=0)

Pseudo-code:

a <- (RA|0)
b <- (RB)
if MMM[0] then  # word mode
    # shift left by XLEN/2 to make the dword comparison
    # do word comparison of the original inputs
    a <- a[XLEN/2:XLEN-1] || [0] * XLEN/2
    b <- b[XLEN/2:XLEN-1] || [0] * XLEN/2
if MMM[1] then  # signed mode
    # invert sign bits to make the unsigned comparison
    # do signed comparison of the original inputs
    a[0] <- ¬a[0]
    b[0] <- ¬b[0]
# if Rc = 1 then store the result of comparing a and b to CR0
# if Rc = 1 then
#     if a <u b then
#         CR0 <- 0b100 || XER[SO]
#     if a = b then
#         CR0 <- 0b001 || XER[SO]
#     if a >u b then
#         CR0 <- 0b010 || XER[SO]
if MMM[2] then  # max mode
    # swap a and b to make the less than comparison do
    # greater than comparison of the original inputs
    t <- a
    a <- b
    b <- t
# store the entire selected source (even in word mode)
if a <u b then RT <- (RA|0)
else           RT <- (RB)

Special Registers Altered:

None

DRAFT Average Add

X-Form

• avgadd RT,RA,RB (Rc=0)
• avgadd. RT,RA,RB (Rc=1)

Pseudo-code:

a <- [0] * (XLEN+1)
b <- [0] * (XLEN+1)
a[1:XLEN] <- (RA)
b[1:XLEN] <- (RB)
r <- (a + b + 1)
RT <- r[0:XLEN-1]

Special Registers Altered:

CR0                     (if Rc=1)

DRAFT Absolute Signed Difference

X-Form

• absds RT,RA,RB (Rc=0)
• absds. RT,RA,RB (Rc=1)

Pseudo-code:

if (RA) < (RB) then RT <- ¬(RA) + (RB) + 1
else                RT <- ¬(RB) + (RA) + 1

Special Registers Altered:

CR0                     (if Rc=1)

DRAFT Absolute Unsigned Difference

X-Form

• absdu RT,RA,RB (Rc=0)
• absdu. RT,RA,RB (Rc=1)

Pseudo-code:

if (RA) <u (RB) then RT <- ¬(RA) + (RB) + 1
else                RT <- ¬(RB) + (RA) + 1

Special Registers Altered:

CR0                     (if Rc=1)

DRAFT Absolute Accumulate Unsigned Difference

X-Form

• absdacu RT,RA,RB (Rc=0)
• absdacu. RT,RA,RB (Rc=1)

Pseudo-code:

if (RA) <u (RB) then r <- ¬(RA) + (RB) + 1
else                 r <- ¬(RB) + (RA) + 1
RT <- (RT) + r

Special Registers Altered:

CR0                     (if Rc=1)

DRAFT Absolute Accumulate Signed Difference

X-Form

• absdacs RT,RA,RB (Rc=0)
• absdacs. RT,RA,RB (Rc=1)

Pseudo-code:

if (RA) < (RB) then r <- ¬(RA) + (RB) + 1
else                r <- ¬(RB) + (RA) + 1
RT <- (RT) + r

Special Registers Altered:

CR0                     (if Rc=1)

Carry Propagate

X-Form

• cprop RT,RA,RB (Rc=0)
• cprop. RT,RA,RB (Rc=1)

Pseudo-code:

P <- (RA)
G <- (RB)
temp <- (P|G)+G
RT <- temp^P

Special Registers Altered:

CR0                    (if Rc=1)

DRAFT Bitmanip Masked

BM2-Form

• bmask RT,RA,RB,bm,L

Pseudo-code:

if _RB = 0 then mask <- [1] * XLEN
else mask <- (RB)
ra <- (RA) & mask
a1 <- ra
if bm[4] = 0 then a1 <- ¬ra
mode2 <- bm[2:3]
if mode2 = 0 then a2 <- (¬ra)+1
if mode2 = 1 then a2 <- ra-1
if mode2 = 2 then a2 <- ra+1
if mode2 = 3 then a2 <- ¬(ra+1)
a1 <- a1 & mask
a2 <- a2 & mask
# select operator
mode3 <- bm[0:1]
if mode3 = 0 then result <- a1 | a2
if mode3 = 1 then result <- a1 & a2
if mode3 = 2 then result <- a1 ^ a2
if mode3 = 3 then result <- undefined([0]*XLEN)
result <- result & mask
# optionally restore masked-out bits
if L = 1 then
    result <- result | (RA & ¬mask)
RT <- result

Special Registers Altered:

None

Load Floating-Point Immediate

DX-Form

• fmvis FRS,D

Pseudo-code:

bf16 <- d0 || d1 || d2
fp32 <- bf16 || [0]*16
FRS  <- DOUBLE(fp32)

Special Registers Altered:

None

Float Replace Lower-Half Single, Immediate

DX-Form

• fishmv FRS,D

Pseudo-code:

fp32 <- SINGLE((FRS))
fp32[16:31] <- d0 || d1 || d2
FRS <- DOUBLE(fp32)

Special Registers Altered:

None