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Commit d2150c83 authored by Alexandru Moșoi's avatar Alexandru Moșoi Committed by Keith Randall
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[dev.ssa] cmd/compile/internal/ssa/gen: generate better code when right-shifting with a constant. 

The lowering rules were missing the non-64 bit case.

SBBLcarrymask can be folded to a int32 integer whose
type has a smaller bit size. Without the new AND rules
the following would be generated:

    v19 = MOVLconst <uint8> [-1] : SI
    v20 = ANDB <uint8> v18 v19 : DI

which is obviously a NOP.

Fixes #12022

Change-Id: I5f4209f78edc0f118e5b9b2908739f09cefebca4
Reviewed-on: https://go-review.googlesource.com/13301Reviewed-by: 's avatarKeith Randall <khr@golang.org>
parent ca088cf4
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Showing with 293 additions and 0 deletions
src/cmd/compile/internal/ssa/gen/AMD64.rules
View file @ d2150c83
......@@ -279,8 +279,12 @@
(ANDQ (MOVQconst [c]) x) && is32Bit(c) -> (ANDQconst [c] x)
(ANDL x (MOVLconst [c])) -> (ANDLconst [c] x)
(ANDL (MOVLconst [c]) x) -> (ANDLconst [c] x)
(ANDW x (MOVLconst [c])) -> (ANDWconst [c] x)
(ANDW (MOVLconst [c]) x) -> (ANDWconst [c] x)
(ANDW x (MOVWconst [c])) -> (ANDWconst [c] x)
(ANDW (MOVWconst [c]) x) -> (ANDWconst [c] x)
(ANDB x (MOVLconst [c])) -> (ANDBconst [c] x)
(ANDB (MOVLconst [c]) x) -> (ANDBconst [c] x)
(ANDB x (MOVBconst [c])) -> (ANDBconst [c] x)
(ANDB (MOVBconst [c]) x) -> (ANDBconst [c] x)
......@@ -424,6 +428,14 @@
(SBBQcarrymask (CMPWconst [c] (MOVWconst [d]))) && !inBounds(int64(int16(d)), int64(int16(c))) -> (MOVQconst [0])
(SBBQcarrymask (CMPBconst [c] (MOVBconst [d]))) && inBounds(int64(int8(d)), int64(int8(c))) -> (MOVQconst [-1])
(SBBQcarrymask (CMPBconst [c] (MOVBconst [d]))) && !inBounds(int64(int8(d)), int64(int8(c))) -> (MOVQconst [0])
(SBBLcarrymask (CMPQconst [c] (MOVQconst [d]))) && inBounds(d, c) -> (MOVLconst [-1])
(SBBLcarrymask (CMPQconst [c] (MOVQconst [d]))) && !inBounds(d, c) -> (MOVLconst [0])
(SBBLcarrymask (CMPLconst [c] (MOVLconst [d]))) && inBounds(int64(int32(d)), int64(int32(c))) -> (MOVLconst [-1])
(SBBLcarrymask (CMPLconst [c] (MOVLconst [d]))) && !inBounds(int64(int32(d)), int64(int32(c))) -> (MOVLconst [0])
(SBBLcarrymask (CMPWconst [c] (MOVWconst [d]))) && inBounds(int64(int16(d)), int64(int16(c))) -> (MOVLconst [-1])
(SBBLcarrymask (CMPWconst [c] (MOVWconst [d]))) && !inBounds(int64(int16(d)), int64(int16(c))) -> (MOVLconst [0])
(SBBLcarrymask (CMPBconst [c] (MOVBconst [d]))) && inBounds(int64(int8(d)), int64(int8(c))) -> (MOVLconst [-1])
(SBBLcarrymask (CMPBconst [c] (MOVBconst [d]))) && !inBounds(int64(int8(d)), int64(int8(c))) -> (MOVLconst [0])
(ANDQconst [0] _) -> (MOVQconst [0])
(ANDLconst [c] _) && int32(c)==0 -> (MOVLconst [0])
(ANDWconst [c] _) && int16(c)==0 -> (MOVWconst [0])
......
src/cmd/compile/internal/ssa/rewriteAMD64.go
View file @ d2150c83
......@@ -484,6 +484,46 @@ func rewriteValueAMD64(v *Value, config *Config) bool {
end73944f6ddda7e4c050f11d17484ff9a5:
;
case OpAMD64ANDB:
// match: (ANDB x (MOVLconst [c]))
// cond:
// result: (ANDBconst [c] x)
{
x := v.Args[0]
if v.Args[1].Op != OpAMD64MOVLconst {
goto end01100cd255396e29bfdb130f4fbc9bbc
}
c := v.Args[1].AuxInt
v.Op = OpAMD64ANDBconst
v.AuxInt = 0
v.Aux = nil
v.resetArgs()
v.AuxInt = c
v.AddArg(x)
return true
}
goto end01100cd255396e29bfdb130f4fbc9bbc
end01100cd255396e29bfdb130f4fbc9bbc:
;
// match: (ANDB (MOVLconst [c]) x)
// cond:
// result: (ANDBconst [c] x)
{
if v.Args[0].Op != OpAMD64MOVLconst {
goto end70830ce2834dc5f8d786fa6789460926
}
c := v.Args[0].AuxInt
x := v.Args[1]
v.Op = OpAMD64ANDBconst
v.AuxInt = 0
v.Aux = nil
v.resetArgs()
v.AuxInt = c
v.AddArg(x)
return true
}
goto end70830ce2834dc5f8d786fa6789460926
end70830ce2834dc5f8d786fa6789460926:
;
// match: (ANDB x (MOVBconst [c]))
// cond:
// result: (ANDBconst [c] x)
......@@ -836,6 +876,46 @@ func rewriteValueAMD64(v *Value, config *Config) bool {
end67ca66494705b0345a5f22c710225292:
;
case OpAMD64ANDW:
// match: (ANDW x (MOVLconst [c]))
// cond:
// result: (ANDWconst [c] x)
{
x := v.Args[0]
if v.Args[1].Op != OpAMD64MOVLconst {
goto endce6f557823ee2fdd7a8f47b6f925fc7c
}
c := v.Args[1].AuxInt
v.Op = OpAMD64ANDWconst
v.AuxInt = 0
v.Aux = nil
v.resetArgs()
v.AuxInt = c
v.AddArg(x)
return true
}
goto endce6f557823ee2fdd7a8f47b6f925fc7c
endce6f557823ee2fdd7a8f47b6f925fc7c:
;
// match: (ANDW (MOVLconst [c]) x)
// cond:
// result: (ANDWconst [c] x)
{
if v.Args[0].Op != OpAMD64MOVLconst {
goto endc46af0d9265c08b09f1f1fba24feda80
}
c := v.Args[0].AuxInt
x := v.Args[1]
v.Op = OpAMD64ANDWconst
v.AuxInt = 0
v.Aux = nil
v.resetArgs()
v.AuxInt = c
v.AddArg(x)
return true
}
goto endc46af0d9265c08b09f1f1fba24feda80
endc46af0d9265c08b09f1f1fba24feda80:
;
// match: (ANDW x (MOVWconst [c]))
// cond:
// result: (ANDWconst [c] x)
......@@ -5766,6 +5846,207 @@ func rewriteValueAMD64(v *Value, config *Config) bool {
goto endc46e3f211f94238f9a0aec3c498af490
endc46e3f211f94238f9a0aec3c498af490:
;
case OpAMD64SBBLcarrymask:
// match: (SBBLcarrymask (CMPQconst [c] (MOVQconst [d])))
// cond: inBounds(d, c)
// result: (MOVLconst [-1])
{
if v.Args[0].Op != OpAMD64CMPQconst {
goto enda9e02a887246381d02b3259b9df4050c
}
c := v.Args[0].AuxInt
if v.Args[0].Args[0].Op != OpAMD64MOVQconst {
goto enda9e02a887246381d02b3259b9df4050c
}
d := v.Args[0].Args[0].AuxInt
if !(inBounds(d, c)) {
goto enda9e02a887246381d02b3259b9df4050c
}
v.Op = OpAMD64MOVLconst
v.AuxInt = 0
v.Aux = nil
v.resetArgs()
v.AuxInt = -1
return true
}
goto enda9e02a887246381d02b3259b9df4050c
enda9e02a887246381d02b3259b9df4050c:
;
// match: (SBBLcarrymask (CMPQconst [c] (MOVQconst [d])))
// cond: !inBounds(d, c)
// result: (MOVLconst [0])
{
if v.Args[0].Op != OpAMD64CMPQconst {
goto end3f8220527278b72a64148fcf9dc58bfe
}
c := v.Args[0].AuxInt
if v.Args[0].Args[0].Op != OpAMD64MOVQconst {
goto end3f8220527278b72a64148fcf9dc58bfe
}
d := v.Args[0].Args[0].AuxInt
if !(!inBounds(d, c)) {
goto end3f8220527278b72a64148fcf9dc58bfe
}
v.Op = OpAMD64MOVLconst
v.AuxInt = 0
v.Aux = nil
v.resetArgs()
v.AuxInt = 0
return true
}
goto end3f8220527278b72a64148fcf9dc58bfe
end3f8220527278b72a64148fcf9dc58bfe:
;
// match: (SBBLcarrymask (CMPLconst [c] (MOVLconst [d])))
// cond: inBounds(int64(int32(d)), int64(int32(c)))
// result: (MOVLconst [-1])
{
if v.Args[0].Op != OpAMD64CMPLconst {
goto end880a2b9a12ed4f551bbd46473b9439bc
}
c := v.Args[0].AuxInt
if v.Args[0].Args[0].Op != OpAMD64MOVLconst {
goto end880a2b9a12ed4f551bbd46473b9439bc
}
d := v.Args[0].Args[0].AuxInt
if !(inBounds(int64(int32(d)), int64(int32(c)))) {
goto end880a2b9a12ed4f551bbd46473b9439bc
}
v.Op = OpAMD64MOVLconst
v.AuxInt = 0
v.Aux = nil
v.resetArgs()
v.AuxInt = -1
return true
}
goto end880a2b9a12ed4f551bbd46473b9439bc
end880a2b9a12ed4f551bbd46473b9439bc:
;
// match: (SBBLcarrymask (CMPLconst [c] (MOVLconst [d])))
// cond: !inBounds(int64(int32(d)), int64(int32(c)))
// result: (MOVLconst [0])
{
if v.Args[0].Op != OpAMD64CMPLconst {
goto end3f08080e0f55d51afca2a131ed0c672e
}
c := v.Args[0].AuxInt
if v.Args[0].Args[0].Op != OpAMD64MOVLconst {
goto end3f08080e0f55d51afca2a131ed0c672e
}
d := v.Args[0].Args[0].AuxInt
if !(!inBounds(int64(int32(d)), int64(int32(c)))) {
goto end3f08080e0f55d51afca2a131ed0c672e
}
v.Op = OpAMD64MOVLconst
v.AuxInt = 0
v.Aux = nil
v.resetArgs()
v.AuxInt = 0
return true
}
goto end3f08080e0f55d51afca2a131ed0c672e
end3f08080e0f55d51afca2a131ed0c672e:
;
// match: (SBBLcarrymask (CMPWconst [c] (MOVWconst [d])))
// cond: inBounds(int64(int16(d)), int64(int16(c)))
// result: (MOVLconst [-1])
{
if v.Args[0].Op != OpAMD64CMPWconst {
goto end91ed02166e0c0d696730e1704d0a682e
}
c := v.Args[0].AuxInt
if v.Args[0].Args[0].Op != OpAMD64MOVWconst {
goto end91ed02166e0c0d696730e1704d0a682e
}
d := v.Args[0].Args[0].AuxInt
if !(inBounds(int64(int16(d)), int64(int16(c)))) {
goto end91ed02166e0c0d696730e1704d0a682e
}
v.Op = OpAMD64MOVLconst
v.AuxInt = 0
v.Aux = nil
v.resetArgs()
v.AuxInt = -1
return true
}
goto end91ed02166e0c0d696730e1704d0a682e
end91ed02166e0c0d696730e1704d0a682e:
;
// match: (SBBLcarrymask (CMPWconst [c] (MOVWconst [d])))
// cond: !inBounds(int64(int16(d)), int64(int16(c)))
// result: (MOVLconst [0])
{
if v.Args[0].Op != OpAMD64CMPWconst {
goto endc7edc3a13ec73ec4e6e87e7ab421a71a
}
c := v.Args[0].AuxInt
if v.Args[0].Args[0].Op != OpAMD64MOVWconst {
goto endc7edc3a13ec73ec4e6e87e7ab421a71a
}
d := v.Args[0].Args[0].AuxInt
if !(!inBounds(int64(int16(d)), int64(int16(c)))) {
goto endc7edc3a13ec73ec4e6e87e7ab421a71a
}
v.Op = OpAMD64MOVLconst
v.AuxInt = 0
v.Aux = nil
v.resetArgs()
v.AuxInt = 0
return true
}
goto endc7edc3a13ec73ec4e6e87e7ab421a71a
endc7edc3a13ec73ec4e6e87e7ab421a71a:
;
// match: (SBBLcarrymask (CMPBconst [c] (MOVBconst [d])))
// cond: inBounds(int64(int8(d)), int64(int8(c)))
// result: (MOVLconst [-1])
{
if v.Args[0].Op != OpAMD64CMPBconst {
goto end0fe2997fc76ce00b1d496f7289ab345a
}
c := v.Args[0].AuxInt
if v.Args[0].Args[0].Op != OpAMD64MOVBconst {
goto end0fe2997fc76ce00b1d496f7289ab345a
}
d := v.Args[0].Args[0].AuxInt
if !(inBounds(int64(int8(d)), int64(int8(c)))) {
goto end0fe2997fc76ce00b1d496f7289ab345a
}
v.Op = OpAMD64MOVLconst
v.AuxInt = 0
v.Aux = nil
v.resetArgs()
v.AuxInt = -1
return true
}
goto end0fe2997fc76ce00b1d496f7289ab345a
end0fe2997fc76ce00b1d496f7289ab345a:
;
// match: (SBBLcarrymask (CMPBconst [c] (MOVBconst [d])))
// cond: !inBounds(int64(int8(d)), int64(int8(c)))
// result: (MOVLconst [0])
{
if v.Args[0].Op != OpAMD64CMPBconst {
goto end3a07121fcc82f1a19da4226b07a757ce
}
c := v.Args[0].AuxInt
if v.Args[0].Args[0].Op != OpAMD64MOVBconst {
goto end3a07121fcc82f1a19da4226b07a757ce
}
d := v.Args[0].Args[0].AuxInt
if !(!inBounds(int64(int8(d)), int64(int8(c)))) {
goto end3a07121fcc82f1a19da4226b07a757ce
}
v.Op = OpAMD64MOVLconst
v.AuxInt = 0
v.Aux = nil
v.resetArgs()
v.AuxInt = 0
return true
}
goto end3a07121fcc82f1a19da4226b07a757ce
end3a07121fcc82f1a19da4226b07a757ce:
;
case OpAMD64SBBQcarrymask:
// match: (SBBQcarrymask (CMPQconst [c] (MOVQconst [d])))
// cond: inBounds(d, c)
......
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