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Commit ac74225d authored by Keith Randall's avatar Keith Randall
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cmd/compile: remove redundant extension after shift 

var x uint64
uint8(x >> 56)

We don't need to generate any code for the uint8().

Update #15090

Change-Id: Ie1ca4e32022dccf7f7bc42d531a285521fb67872
Reviewed-on: https://go-review.googlesource.com/28191
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: default avatarDavid Chase <drchase@google.com>
parent deb4177c
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Showing with 398 additions and 0 deletions
src/cmd/compile/internal/ssa/gen/generic.rules
View file @ ac74225d
......@@ -602,6 +602,20 @@
(Trunc32to16 (And32 (Const32 [y]) x)) && y&0xFFFF == 0xFFFF -> (Trunc32to16 x)
(Trunc16to8 (And16 (Const16 [y]) x)) && y&0xFF == 0xFF -> (Trunc16to8 x)
(ZeroExt8to64 (Trunc64to8 x:(Rsh64Ux64 _ (Const64 [s])))) && s >= 56 -> x
(ZeroExt16to64 (Trunc64to16 x:(Rsh64Ux64 _ (Const64 [s])))) && s >= 48 -> x
(ZeroExt32to64 (Trunc64to32 x:(Rsh64Ux64 _ (Const64 [s])))) && s >= 32 -> x
(ZeroExt8to32 (Trunc32to8 x:(Rsh32Ux64 _ (Const64 [s])))) && s >= 24 -> x
(ZeroExt16to32 (Trunc32to16 x:(Rsh32Ux64 _ (Const64 [s])))) && s >= 16 -> x
(ZeroExt8to16 (Trunc16to8 x:(Rsh16Ux64 _ (Const64 [s])))) && s >= 8 -> x
(SignExt8to64 (Trunc64to8 x:(Rsh64x64 _ (Const64 [s])))) && s >= 56 -> x
(SignExt16to64 (Trunc64to16 x:(Rsh64x64 _ (Const64 [s])))) && s >= 48 -> x
(SignExt32to64 (Trunc64to32 x:(Rsh64x64 _ (Const64 [s])))) && s >= 32 -> x
(SignExt8to32 (Trunc32to8 x:(Rsh32x64 _ (Const64 [s])))) && s >= 24 -> x
(SignExt16to32 (Trunc32to16 x:(Rsh32x64 _ (Const64 [s])))) && s >= 16 -> x
(SignExt8to16 (Trunc16to8 x:(Rsh16x64 _ (Const64 [s])))) && s >= 8 -> x
(Slicemask (Const32 [x])) && x > 0 -> (Const32 [-1])
(Slicemask (Const32 [0])) -> (Const32 [0])
(Slicemask (Const64 [x])) && x > 0 -> (Const64 [-1])
......
src/cmd/compile/internal/ssa/rewritegeneric.go
View file @ ac74225d
......@@ -314,6 +314,18 @@ func rewriteValuegeneric(v *Value, config *Config) bool {
return rewriteValuegeneric_OpRsh8x64(v, config)
case OpRsh8x8:
return rewriteValuegeneric_OpRsh8x8(v, config)
case OpSignExt16to32:
return rewriteValuegeneric_OpSignExt16to32(v, config)
case OpSignExt16to64:
return rewriteValuegeneric_OpSignExt16to64(v, config)
case OpSignExt32to64:
return rewriteValuegeneric_OpSignExt32to64(v, config)
case OpSignExt8to16:
return rewriteValuegeneric_OpSignExt8to16(v, config)
case OpSignExt8to32:
return rewriteValuegeneric_OpSignExt8to32(v, config)
case OpSignExt8to64:
return rewriteValuegeneric_OpSignExt8to64(v, config)
case OpSliceCap:
return rewriteValuegeneric_OpSliceCap(v, config)
case OpSliceLen:
......@@ -366,6 +378,18 @@ func rewriteValuegeneric(v *Value, config *Config) bool {
return rewriteValuegeneric_OpXor8(v, config)
case OpZero:
return rewriteValuegeneric_OpZero(v, config)
case OpZeroExt16to32:
return rewriteValuegeneric_OpZeroExt16to32(v, config)
case OpZeroExt16to64:
return rewriteValuegeneric_OpZeroExt16to64(v, config)
case OpZeroExt32to64:
return rewriteValuegeneric_OpZeroExt32to64(v, config)
case OpZeroExt8to16:
return rewriteValuegeneric_OpZeroExt8to16(v, config)
case OpZeroExt8to32:
return rewriteValuegeneric_OpZeroExt8to32(v, config)
case OpZeroExt8to64:
return rewriteValuegeneric_OpZeroExt8to64(v, config)
}
return false
}
......@@ -9636,6 +9660,186 @@ func rewriteValuegeneric_OpRsh8x8(v *Value, config *Config) bool {
}
return false
}
func rewriteValuegeneric_OpSignExt16to32(v *Value, config *Config) bool {
b := v.Block
_ = b
// match: (SignExt16to32 (Trunc32to16 x:(Rsh32x64 _ (Const64 [s]))))
// cond: s >= 16
// result: x
for {
v_0 := v.Args[0]
if v_0.Op != OpTrunc32to16 {
break
}
x := v_0.Args[0]
if x.Op != OpRsh32x64 {
break
}
x_1 := x.Args[1]
if x_1.Op != OpConst64 {
break
}
s := x_1.AuxInt
if !(s >= 16) {
break
}
v.reset(OpCopy)
v.Type = x.Type
v.AddArg(x)
return true
}
return false
}
func rewriteValuegeneric_OpSignExt16to64(v *Value, config *Config) bool {
b := v.Block
_ = b
// match: (SignExt16to64 (Trunc64to16 x:(Rsh64x64 _ (Const64 [s]))))
// cond: s >= 48
// result: x
for {
v_0 := v.Args[0]
if v_0.Op != OpTrunc64to16 {
break
}
x := v_0.Args[0]
if x.Op != OpRsh64x64 {
break
}
x_1 := x.Args[1]
if x_1.Op != OpConst64 {
break
}
s := x_1.AuxInt
if !(s >= 48) {
break
}
v.reset(OpCopy)
v.Type = x.Type
v.AddArg(x)
return true
}
return false
}
func rewriteValuegeneric_OpSignExt32to64(v *Value, config *Config) bool {
b := v.Block
_ = b
// match: (SignExt32to64 (Trunc64to32 x:(Rsh64x64 _ (Const64 [s]))))
// cond: s >= 32
// result: x
for {
v_0 := v.Args[0]
if v_0.Op != OpTrunc64to32 {
break
}
x := v_0.Args[0]
if x.Op != OpRsh64x64 {
break
}
x_1 := x.Args[1]
if x_1.Op != OpConst64 {
break
}
s := x_1.AuxInt
if !(s >= 32) {
break
}
v.reset(OpCopy)
v.Type = x.Type
v.AddArg(x)
return true
}
return false
}
func rewriteValuegeneric_OpSignExt8to16(v *Value, config *Config) bool {
b := v.Block
_ = b
// match: (SignExt8to16 (Trunc16to8 x:(Rsh16x64 _ (Const64 [s]))))
// cond: s >= 8
// result: x
for {
v_0 := v.Args[0]
if v_0.Op != OpTrunc16to8 {
break
}
x := v_0.Args[0]
if x.Op != OpRsh16x64 {
break
}
x_1 := x.Args[1]
if x_1.Op != OpConst64 {
break
}
s := x_1.AuxInt
if !(s >= 8) {
break
}
v.reset(OpCopy)
v.Type = x.Type
v.AddArg(x)
return true
}
return false
}
func rewriteValuegeneric_OpSignExt8to32(v *Value, config *Config) bool {
b := v.Block
_ = b
// match: (SignExt8to32 (Trunc32to8 x:(Rsh32x64 _ (Const64 [s]))))
// cond: s >= 24
// result: x
for {
v_0 := v.Args[0]
if v_0.Op != OpTrunc32to8 {
break
}
x := v_0.Args[0]
if x.Op != OpRsh32x64 {
break
}
x_1 := x.Args[1]
if x_1.Op != OpConst64 {
break
}
s := x_1.AuxInt
if !(s >= 24) {
break
}
v.reset(OpCopy)
v.Type = x.Type
v.AddArg(x)
return true
}
return false
}
func rewriteValuegeneric_OpSignExt8to64(v *Value, config *Config) bool {
b := v.Block
_ = b
// match: (SignExt8to64 (Trunc64to8 x:(Rsh64x64 _ (Const64 [s]))))
// cond: s >= 56
// result: x
for {
v_0 := v.Args[0]
if v_0.Op != OpTrunc64to8 {
break
}
x := v_0.Args[0]
if x.Op != OpRsh64x64 {
break
}
x_1 := x.Args[1]
if x_1.Op != OpConst64 {
break
}
s := x_1.AuxInt
if !(s >= 56) {
break
}
v.reset(OpCopy)
v.Type = x.Type
v.AddArg(x)
return true
}
return false
}
func rewriteValuegeneric_OpSliceCap(v *Value, config *Config) bool {
b := v.Block
_ = b
......@@ -11831,6 +12035,186 @@ func rewriteValuegeneric_OpZero(v *Value, config *Config) bool {
}
return false
}
func rewriteValuegeneric_OpZeroExt16to32(v *Value, config *Config) bool {
b := v.Block
_ = b
// match: (ZeroExt16to32 (Trunc32to16 x:(Rsh32Ux64 _ (Const64 [s]))))
// cond: s >= 16
// result: x
for {
v_0 := v.Args[0]
if v_0.Op != OpTrunc32to16 {
break
}
x := v_0.Args[0]
if x.Op != OpRsh32Ux64 {
break
}
x_1 := x.Args[1]
if x_1.Op != OpConst64 {
break
}
s := x_1.AuxInt
if !(s >= 16) {
break
}
v.reset(OpCopy)
v.Type = x.Type
v.AddArg(x)
return true
}
return false
}
func rewriteValuegeneric_OpZeroExt16to64(v *Value, config *Config) bool {
b := v.Block
_ = b
// match: (ZeroExt16to64 (Trunc64to16 x:(Rsh64Ux64 _ (Const64 [s]))))
// cond: s >= 48
// result: x
for {
v_0 := v.Args[0]
if v_0.Op != OpTrunc64to16 {
break
}
x := v_0.Args[0]
if x.Op != OpRsh64Ux64 {
break
}
x_1 := x.Args[1]
if x_1.Op != OpConst64 {
break
}
s := x_1.AuxInt
if !(s >= 48) {
break
}
v.reset(OpCopy)
v.Type = x.Type
v.AddArg(x)
return true
}
return false
}
func rewriteValuegeneric_OpZeroExt32to64(v *Value, config *Config) bool {
b := v.Block
_ = b
// match: (ZeroExt32to64 (Trunc64to32 x:(Rsh64Ux64 _ (Const64 [s]))))
// cond: s >= 32
// result: x
for {
v_0 := v.Args[0]
if v_0.Op != OpTrunc64to32 {
break
}
x := v_0.Args[0]
if x.Op != OpRsh64Ux64 {
break
}
x_1 := x.Args[1]
if x_1.Op != OpConst64 {
break
}
s := x_1.AuxInt
if !(s >= 32) {
break
}
v.reset(OpCopy)
v.Type = x.Type
v.AddArg(x)
return true
}
return false
}
func rewriteValuegeneric_OpZeroExt8to16(v *Value, config *Config) bool {
b := v.Block
_ = b
// match: (ZeroExt8to16 (Trunc16to8 x:(Rsh16Ux64 _ (Const64 [s]))))
// cond: s >= 8
// result: x
for {
v_0 := v.Args[0]
if v_0.Op != OpTrunc16to8 {
break
}
x := v_0.Args[0]
if x.Op != OpRsh16Ux64 {
break
}
x_1 := x.Args[1]
if x_1.Op != OpConst64 {
break
}
s := x_1.AuxInt
if !(s >= 8) {
break
}
v.reset(OpCopy)
v.Type = x.Type
v.AddArg(x)
return true
}
return false
}
func rewriteValuegeneric_OpZeroExt8to32(v *Value, config *Config) bool {
b := v.Block
_ = b
// match: (ZeroExt8to32 (Trunc32to8 x:(Rsh32Ux64 _ (Const64 [s]))))
// cond: s >= 24
// result: x
for {
v_0 := v.Args[0]
if v_0.Op != OpTrunc32to8 {
break
}
x := v_0.Args[0]
if x.Op != OpRsh32Ux64 {
break
}
x_1 := x.Args[1]
if x_1.Op != OpConst64 {
break
}
s := x_1.AuxInt
if !(s >= 24) {
break
}
v.reset(OpCopy)
v.Type = x.Type
v.AddArg(x)
return true
}
return false
}
func rewriteValuegeneric_OpZeroExt8to64(v *Value, config *Config) bool {
b := v.Block
_ = b
// match: (ZeroExt8to64 (Trunc64to8 x:(Rsh64Ux64 _ (Const64 [s]))))
// cond: s >= 56
// result: x
for {
v_0 := v.Args[0]
if v_0.Op != OpTrunc64to8 {
break
}
x := v_0.Args[0]
if x.Op != OpRsh64Ux64 {
break
}
x_1 := x.Args[1]
if x_1.Op != OpConst64 {
break
}
s := x_1.AuxInt
if !(s >= 56) {
break
}
v.reset(OpCopy)
v.Type = x.Type
v.AddArg(x)
return true
}
return false
}
func rewriteBlockgeneric(b *Block, config *Config) bool {
switch b.Kind {
case BlockIf:
......
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