extsb, integer twin-pred mask: source is ~r3 (0b01), dest r3 (0b10)
works as follows, where any zeros indicate "skip element"
- - sources are 9 and 10
- - dests are 5 and 6
- - source mask says "pick first element from source (5)
- - dest mask says "pick *second* element from dest (10)
- therefore the operation that's carried out is:
+ * sources are 9 and 10
+ * dests are 5 and 6
+ * source mask says "pick first element from source (5)
+ * dest mask says "pick *second* element from dest (10)
+
+ therefore the operation that's carried out is::
+
GPR(10) = extsb(GPR(5))
this is a type of back-to-back VREDUCE and VEXPAND but it applies
to *operations*, not just MVs like in traditional Vector ISAs
- ascii graphic:
+ ascii graphic::
- reg num 0 1 2 3 4 5 6 7 8 9 10
- predicate src ~r3=0b01 Y N
- |
- +-----+
- |
- predicate dest r3=0b10 N Y
+ reg num 0 1 2 3 4 5 6 7 8 9 10
+ predicate src ~r3=0b01 Y N
+ |
+ +-----+
+ |
+ predicate dest r3=0b10 N Y
expected results:
- r5 = 0x0 dest r3 is 0b10: skip
- r6 = 0xffff_ffff_ffff_ff91 2nd bit of r3 is 1
+ * r5 = 0x0 dest r3 is 0b10: skip
+ * r6 = 0xffff_ffff_ffff_ff91 2nd bit of r3 is 1
"""
isa = SVP64Asm(['sv.extsb/sm=~r3/dm=r3 5.v, 9.v'])
lst = list(isa)
def case_10_intpred_vcompress(self):
""">>> lst = ['sv.extsb/sm=r3 5.v, 9.v']
- reg num 0 1 2 3 4 5 6 7 8 9 10 11
- predicate src r3=0b101 Y N Y
- | |
- +-------+ |
- | +-----------+
- | |
- predicate dest always Y Y Y
+ ascii graphic::
+
+ reg num 0 1 2 3 4 5 6 7 8 9 10 11
+ predicate src r3=0b101 Y N Y
+ | |
+ +-------+ |
+ | +-----------+
+ | |
+ predicate dest always Y Y Y
expected results:
- r5 = 0xffff_ffff_ffff_ff90 (from r9)
- r6 = 0xffff_ffff_ffff_ff92 (from r11)
- r7 = 0x0 (VL loop runs out before we can use it)
+ * r5 = 0xffff_ffff_ffff_ff90 (from r9)
+ * r6 = 0xffff_ffff_ffff_ff92 (from r11)
+ * r7 = 0x0 (VL loop runs out before we can use it)
"""
isa = SVP64Asm(['sv.extsb/sm=r3 5.v, 9.v'])
lst = list(isa)
def case_11_intpred_vexpand(self):
""">>> lst = ['sv.extsb/dm=r3 5.v, 9.v']
- reg num 0 1 2 3 4 5 6 7 8 9 10 11
- predicate src always Y Y Y
- | |
- +-------+ |
- | +------+
- | |
- predicate dest r3=0b101 Y N Y
+ ascii graphic::
+
+ reg num 0 1 2 3 4 5 6 7 8 9 10 11
+ predicate src always Y Y Y
+ | |
+ +-------+ |
+ | +------+
+ | |
+ predicate dest r3=0b101 Y N Y
expected results:
- r5 = 0xffff_ffff_ffff_ff90 1st bit of r3 is 1
- r6 = 0x0 skip
- r7 = 0xffff_ffff_ffff_ff91 3nd bit of r3 is 1
+ * r5 = 0xffff_ffff_ffff_ff90 1st bit of r3 is 1
+ * r6 = 0x0 skip
+ * r7 = 0xffff_ffff_ffff_ff91 3nd bit of r3 is 1
"""
isa = SVP64Asm(['sv.extsb/dm=r3 5.v, 9.v'])
lst = list(isa)
def case_12_sv_twinpred(self):
""">>> lst = ['sv.extsb/sm=r3/dm=~r3 5.v, 9.v']
- reg num 0 1 2 3 4 5 6 7 8 9 10 11
- predicate src r3=0b101 Y N Y
- |
- +-----+
- |
- predicate dest ~r3=0b010 N Y N
+ ascii graphic::
+
+ reg num 0 1 2 3 4 5 6 7 8 9 10 11
+ predicate src r3=0b101 Y N Y
+ |
+ +-----+
+ |
+ predicate dest ~r3=0b010 N Y N
expected results:
- r5 = 0x0 dest ~r3 is 0b010: skip
- r6 = 0xffff_ffff_ffff_ff90 2nd bit of ~r3 is 1
- r7 = 0x0 dest ~r3 is 0b010: skip
+ * r5 = 0x0 dest ~r3 is 0b010: skip
+ * r6 = 0xffff_ffff_ffff_ff90 2nd bit of ~r3 is 1
+ * r7 = 0x0 dest ~r3 is 0b010: skip
"""
isa = SVP64Asm(['sv.extsb/sm=r3/dm=~r3 5.v, 9.v'])
lst = list(isa)
make sure to skip mask bits before the initial step,
to save clock cycles. or not. your choice.
- reg num 0 1 2 3 4 5 6 7 8 9 10 11 12
- srcstep=1 v
- src r3=0b0101 Y N Y N
- : |
- + - - + |
- : +-------+
- : |
- dest ~r3=0b1010 N Y N Y
- dststep=2 ^
+ ascii graphic::
+
+ reg num 0 1 2 3 4 5 6 7 8 9 10 11 12
+ srcstep=1 v
+ src r3=0b0101 Y N Y N
+ : |
+ + - - + |
+ : +-------+
+ : |
+ dest ~r3=0b1010 N Y N Y
+ dststep=2 ^
expected results:
- r5 = 0x0 # skip
- r6 = 0x0 # dststep starts at 3, so this gets skipped
- r7 = 0x0 # skip
- r8 = 0xffff_ffff_ffff_ff92 # this will be used
+ * r5 = 0x0 # skip
+ * r6 = 0x0 # dststep starts at 3, so this gets skipped
+ * r7 = 0x0 # skip
+ * r8 = 0xffff_ffff_ffff_ff92 # this will be used
"""
isa = SVP64Asm(['sv.extsb/sm=r3/dm=~r3 5.v, 9.v'])
lst = list(isa)
lots of opportunity for hardware optimisation, it effectively
allows dynamic indexing of the register file
- reg num 0 1 2 3 4 5 6 7 8 9 10 11
- src r30=0b100 N N Y
- |
- +-----------+
- |
- dest r3=1: 1<<r3=0b010 N Y N
+ ascii graphic::
+
+ reg num 0 1 2 3 4 5 6 7 8 9 10 11
+ src r30=0b100 N N Y
+ |
+ +-----------+
+ |
+ dest r3=1: 1<<r3=0b010 N Y N
expected results:
- r5 = 0x0 skipped
- r6 = 0xffff_ffff_ffff_ff92 r3 is 1, so this is used
- r7 = 0x0 skipped
+ * r5 = 0x0 skipped
+ * r6 = 0xffff_ffff_ffff_ff92 r3 is 1, so this is used
+ * r7 = 0x0 skipped
"""
isa = SVP64Asm(['sv.extsb/dm=1<<r3/sm=r30 5.v, 9.v'])
lst = list(isa)
def case_17_shift_one_by_r3_source(self):
""">>> lst = ['sv.extsb/sm=1<<r3/dm=r30 5.v, 9.v']
- reg num 0 1 2 3 4 5 6 7 8 9 10 11
- src r3=2: 1<<r3=0b100 N N Y
- |
- +-----------+
- |
- dest r30=0b010 N Y N
+ ascii graphic::
+
+ reg num 0 1 2 3 4 5 6 7 8 9 10 11
+ src r3=2: 1<<r3=0b100 N N Y
+ |
+ +-----------+
+ |
+ dest r30=0b010 N Y N
expected results:
- r5 = 0x0 skipped
- r6 = 0xffff_ffff_ffff_ff92 2nd bit of r30 is 1
- r7 = 0x0 skipped
+ * r5 = 0x0 skipped
+ * r6 = 0xffff_ffff_ffff_ff92 2nd bit of r30 is 1
+ * r7 = 0x0 skipped
"""
isa = SVP64Asm(['sv.extsb/sm=1<<r3/dm=r30 5.v, 9.v'])
lst = list(isa)
checks reentrant CR predication. note that the source CR-mask
and destination CR-mask use *different bits* of the CR fields,
despite both predicates starting from the same CR field number.
- cr4.lt is zero, cr7.lt is zero AND
- cr5.eq is zero, cr6.eq is zero.
-
- reg num 0 1 2 3 4 5 6 7 8 9 10 11 12
- srcstep=1 v
- src cr4.eq=1 Y N Y N
- cr6.eq=1 : |
- + - - + |
- : +-------+
- dest cr5.lt=1 : |
- cr7.lt=1 N Y N Y
- dststep=2 ^
+
+ * cr4.lt is zero, cr7.lt is zero AND
+ * cr5.eq is zero, cr6.eq is zero.
+
+ ascii graphic::
+
+ reg num 0 1 2 3 4 5 6 7 8 9 10 11 12
+ srcstep=1 v
+ src cr4.eq=1 Y N Y N
+ cr6.eq=1 : |
+ + - - + |
+ : +-------+
+ dest cr5.lt=1 : |
+ cr7.lt=1 N Y N Y
+ dststep=2 ^
expected results:
- r5 = 0x0 skip
- r6 = 0x0 dststep starts at 3, so this gets skipped
- r7 = 0x0 skip
- r8 = 0xffff_ffff_ffff_ff92 this will be used
+ * r5 = 0x0 skip
+ * r6 = 0x0 dststep starts at 3, so this gets skipped
+ * r7 = 0x0 skip
+ * r8 = 0xffff_ffff_ffff_ff92 this will be used
"""
isa = SVP64Asm(['sv.extsb/sm=eq/dm=lt 5.v, 9.v'])
lst = list(isa)
projects / openpower-isa.git / blobdiff