Previously we convert $0 to the ZR register for some reasons, which causes
two problems:
1. Confusion, the special case of the ZR register needs to be considered
when dealing with constants. For encoding, some places we encode ZR, and
some places we encode $0, although we have converted $0 to ZR.
2. Unexpected instruction format. All instructions that support ZR register
operands can be replaced by $0.
This patch removes this conversion. Note that this patch may cause previously
unintendedly supported instruction formats to no longer be supported.
Change-Id: I3d8d2c06711b7614a38191397da7776417f1861c
Reviewed-on: https://go-review.googlesource.com/c/go/+/404316
Reviewed-by: David Chase <drchase@google.com>
Run-TryBot: Eric Fang <eric.fang@arm.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Add a new rewrite rule to merge ANDconst and UBFX into
UBFX.
Add test cases.
Change-Id: I24d6442d0c956d7ce092c3a3858d4a3a41771670
Reviewed-on: https://go-review.googlesource.com/c/go/+/377054
Trust: Fannie Zhang <Fannie.Zhang@arm.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Run-TryBot: Cherry Mui <cherryyz@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
In some rewrite rules for arm64 bitfield optimizations, the
bitfield lsb value and the bitfield width value are related
to datasize, some of them use datasize directly to check the
bitfield lsb value is valid, to get the bitfiled width value,
but some of them call isARM64BFMask() and arm64BFWidth()
functions. In order to be consistent, this patch changes them
all to use datasize.
Besides, this patch sorts the codegen test cases.
Run the "toolstash-check -all" command and find one inconsistent code
is as the following.
new: src/math/fma.go:104 BEQ 247
master: src/math/fma.go:104 BEQ 248
The above inconsistence is due to this patch changing the range of the
field lsb value in "UBFIZ" optimization rules from "lc+(32|16|8)<64" to
"lc<64", so that the following code is generated as "UBFIZ". The logical
of changed code is still correct.
The code of src/math/fma.go:160:
const uvinf = 0x7FF0000000000000
func FMA(a, b uint32) float64 {
ps := a+b
return Float64frombits(uint64(ps)<<63 | uvinf)
}
The new assembly code:
TEXT "".FMA(SB), LEAF|NOFRAME|ABIInternal, $0-16
MOVWU "".a(FP), R0
MOVWU "".b+4(FP), R1
ADD R1, R0, R0
UBFIZ $63, R0, $1, R0
ORR $9218868437227405312, R0, R0
MOVD R0, "".~r2+8(FP)
RET (R30)
The master assembly code:
TEXT "".FMA(SB), LEAF|NOFRAME|ABIInternal, $0-16
MOVWU "".a(FP), R0
MOVWU "".b+4(FP), R1
ADD R1, R0, R0
MOVWU R0, R0
LSL $63, R0, R0
ORR $9218868437227405312, R0, R0
MOVD R0, "".~r2+8(FP)
RET (R30)
Change-Id: I9061104adfdfd3384d0525327ae1e5c8b0df5c35
Reviewed-on: https://go-review.googlesource.com/c/go/+/265038
Trust: fannie zhang <Fannie.Zhang@arm.com>
Run-TryBot: fannie zhang <Fannie.Zhang@arm.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Cherry Mui <cherryyz@google.com>
The codegen tests are currently skipped (see #48247) and the
bitfield tests do not actually compile due to a duplicate function
name (sbfiz5) added in CL 267602. Renaming the function fixes the
issue.
Updates #48247.
Change-Id: I626fd5ef13732dc358e73ace9ddcc4cbb6ae5b21
Reviewed-on: https://go-review.googlesource.com/c/go/+/348391
Trust: Michael Munday <mike.munday@lowrisc.org>
Run-TryBot: Michael Munday <mike.munday@lowrisc.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Cherry Mui <cherryyz@google.com>
This patch adds some rules to rewrite "(LeftShift (SignExtend x) lc)"
expression as "SBFIZ".
Add the test cases.
Change-Id: I294c4ba09712eeb02c7a952447bb006780f1e60d
Reviewed-on: https://go-review.googlesource.com/c/go/+/267602
Trust: fannie zhang <Fannie.Zhang@arm.com>
Trust: Cherry Mui <cherryyz@google.com>
Run-TryBot: fannie zhang <Fannie.Zhang@arm.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
The UBFX and SBFX already zero/sign extend the result. Further
zero/sign extensions are thus unnecessary as long as they leave
the top bits unaltered. This patch absorbs zero/sign extensions
into UBFX/SBFX.
Add the related test cases.
Change-Id: I7c4516c8b52d677f77bf3aaedab87c4a28056ec0
Reviewed-on: https://go-review.googlesource.com/c/go/+/265039
Trust: fannie zhang <Fannie.Zhang@arm.com>
Trust: Keith Randall <khr@golang.org>
Run-TryBot: fannie zhang <Fannie.Zhang@arm.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Optimize some patterns into rev16/rev16w instruction.
Pattern1:
(c & 0xff00ff00)>>8 | (c & 0x00ff00ff)<<8
To:
rev16w c
Pattern2:
(c & 0xff00ff00ff00ff00)>>8 | (c & 0x00ff00ff00ff00ff)<<8
To:
rev16 c
This patch is a copy of CL 239637, contributed by Alice Xu(dianhong.xu@arm.com).
Change-Id: I96936c1db87618bc1903c04221c7e9b2779455b3
Reviewed-on: https://go-review.googlesource.com/c/go/+/268377
Trust: fannie zhang <Fannie.Zhang@arm.com>
Run-TryBot: fannie zhang <Fannie.Zhang@arm.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Optimize combinations of left and right shifts by a constant value
into a 'rotate then insert selected bits [into zero]' instruction.
Use the same instruction for contiguous masks since it has some
benefits over 'and immediate' (not restricted to 32-bits, does not
overwrite source register).
To keep the complexity of this change under control I've only
implemented 64 bit operations for now.
There are a lot more optimizations that can be done with this
instruction family. However, since their function overlaps with other
instructions we need to be somewhat careful not to break existing
optimization rules by creating optimization dead ends. This is
particularly true of the load/store merging rules which contain lots
of zero extensions and shifts.
This CL does interfere with the store merging rules when an operand
is shifted left before it is stored:
binary.BigEndian.PutUint64(b, x << 1)
This is unfortunate but it's not critical and somewhat complex so
I plan to fix that in a follow up CL.
file before after Δ %
addr2line 4117446 4117282 -164 -0.004%
api 4945184 4942752 -2432 -0.049%
asm 4998079 4991891 -6188 -0.124%
buildid 2685158 2684074 -1084 -0.040%
cgo 4553732 4553394 -338 -0.007%
compile 19294446 19245070 -49376 -0.256%
cover 4897105 4891319 -5786 -0.118%
dist 3544389 3542785 -1604 -0.045%
doc 3926795 3927617 +822 +0.021%
fix 3302958 3293868 -9090 -0.275%
link 6546274 6543456 -2818 -0.043%
nm 4102021 4100825 -1196 -0.029%
objdump 4542431 4548483 +6052 +0.133%
pack 2482465 2416389 -66076 -2.662%
pprof 13366541 13363915 -2626 -0.020%
test2json 2829007 2761515 -67492 -2.386%
trace 10216164 10219684 +3520 +0.034%
vet 6773956 6773572 -384 -0.006%
total 107124151 106917891 -206260 -0.193%
Change-Id: I7591cce41e06867ba10a745daae9333513062746
Reviewed-on: https://go-review.googlesource.com/c/go/+/233317
Run-TryBot: Michael Munday <mike.munday@ibm.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Trust: Michael Munday <mike.munday@ibm.com>
And delete them from asm_test.
Change-Id: I9a75efe9858ef9d7ac86065f860c2ae3f25b0941
Reviewed-on: https://go-review.googlesource.com/105597
Reviewed-by: Daniel Martí <mvdan@mvdan.cc>
