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Commit 156c830b authored by Tobias Klauser's avatar Tobias Klauser Committed by Tobias Klauser
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cmd/compile: eliminate unnecessary type conversions in TrailingZeros(16|8) for arm 

This follows CL 156999 which did the same for arm64.

name               old time/op  new time/op  delta
TrailingZeros-4    7.30ns ± 1%  7.30ns ± 0%     ~     (p=0.413 n=9+9)
TrailingZeros8-4   8.32ns ± 0%  7.17ns ± 0%  -13.77%  (p=0.000 n=10+9)
TrailingZeros16-4  8.30ns ± 0%  7.18ns ± 0%  -13.50%  (p=0.000 n=9+10)
TrailingZeros32-4  6.46ns ± 1%  6.47ns ± 1%     ~     (p=0.325 n=10+10)
TrailingZeros64-4  16.3ns ± 0%  16.2ns ± 0%   -0.61%  (p=0.000 n=7+10)

Change-Id: I7e9e1abf7e30d811aa474d272b2824ec7cbbaa98
Reviewed-on: https://go-review.googlesource.com/c/go/+/167797
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: default avatarCherry Zhang <cherryyz@google.com>
parent d9db9e32
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Inline Side-by-side
Showing with 158 additions and 5 deletions
src/cmd/compile/internal/gc/ssa.go
View file @ 156c830b
......@@ -3288,12 +3288,12 @@ func init() {
y := s.newValue2(ssa.OpOr32, types.Types[TUINT32], x, c)
return s.newValue1(ssa.OpCtz32, types.Types[TINT], y)
},
sys.ARM, sys.MIPS)
sys.MIPS)
addF("math/bits", "TrailingZeros16",
func(s *state, n *Node, args []*ssa.Value) *ssa.Value {
return s.newValue1(ssa.OpCtz16, types.Types[TINT], args[0])
},
sys.AMD64, sys.ARM64, sys.Wasm)
sys.AMD64, sys.ARM, sys.ARM64, sys.Wasm)
addF("math/bits", "TrailingZeros16",
func(s *state, n *Node, args []*ssa.Value) *ssa.Value {
x := s.newValue1(ssa.OpZeroExt16to64, types.Types[TUINT64], args[0])
......@@ -3309,12 +3309,12 @@ func init() {
y := s.newValue2(ssa.OpOr32, types.Types[TUINT32], x, c)
return s.newValue1(ssa.OpCtz32, types.Types[TINT], y)
},
sys.ARM, sys.MIPS)
sys.MIPS)
addF("math/bits", "TrailingZeros8",
func(s *state, n *Node, args []*ssa.Value) *ssa.Value {
return s.newValue1(ssa.OpCtz8, types.Types[TINT], args[0])
},
sys.AMD64, sys.ARM64, sys.Wasm)
sys.AMD64, sys.ARM, sys.ARM64, sys.Wasm)
addF("math/bits", "TrailingZeros8",
func(s *state, n *Node, args []*ssa.Value) *ssa.Value {
x := s.newValue1(ssa.OpZeroExt8to64, types.Types[TUINT64], args[0])
......
src/cmd/compile/internal/ssa/gen/ARM.rules
View file @ 156c830b
......@@ -59,13 +59,22 @@
// TODO: optimize this for ARMv5 and ARMv6
(Ctz32NonZero x) -> (Ctz32 x)
(Ctz16NonZero x) -> (Ctz32 x)
(Ctz8NonZero x) -> (Ctz32 x)
// count trailing zero for ARMv5 and ARMv6
// 32 - CLZ(x&-x - 1)
(Ctz32 <t> x) && objabi.GOARM<=6 -> (RSBconst [32] (CLZ <t> (SUBconst <t> (AND <t> x (RSBconst <t> [0] x)) [1])))
(Ctz32 <t> x) && objabi.GOARM<=6 ->
(RSBconst [32] (CLZ <t> (SUBconst <t> (AND <t> x (RSBconst <t> [0] x)) [1])))
(Ctz16 <t> x) && objabi.GOARM<=6 ->
(RSBconst [32] (CLZ <t> (SUBconst <typ.UInt32> (AND <typ.UInt32> (ORconst <typ.UInt32> [0x10000] x) (RSBconst <typ.UInt32> [0] (ORconst <typ.UInt32> [0x10000] x))) [1])))
(Ctz8 <t> x) && objabi.GOARM<=6 ->
(RSBconst [32] (CLZ <t> (SUBconst <typ.UInt32> (AND <typ.UInt32> (ORconst <typ.UInt32> [0x100] x) (RSBconst <typ.UInt32> [0] (ORconst <typ.UInt32> [0x100] x))) [1])))
// count trailing zero for ARMv7
(Ctz32 <t> x) && objabi.GOARM==7 -> (CLZ <t> (RBIT <t> x))
(Ctz16 <t> x) && objabi.GOARM==7 -> (CLZ <t> (RBIT <typ.UInt32> (ORconst <typ.UInt32> [0x10000] x)))
(Ctz8 <t> x) && objabi.GOARM==7 -> (CLZ <t> (RBIT <typ.UInt32> (ORconst <typ.UInt32> [0x100] x)))
// bit length
(BitLen32 <t> x) -> (RSBconst [32] (CLZ <t> x))
......
src/cmd/compile/internal/ssa/rewriteARM.go
View file @ 156c830b
......@@ -483,10 +483,18 @@ func rewriteValueARM(v *Value) bool {
return rewriteValueARM_OpConstBool_0(v)
case OpConstNil:
return rewriteValueARM_OpConstNil_0(v)
case OpCtz16:
return rewriteValueARM_OpCtz16_0(v)
case OpCtz16NonZero:
return rewriteValueARM_OpCtz16NonZero_0(v)
case OpCtz32:
return rewriteValueARM_OpCtz32_0(v)
case OpCtz32NonZero:
return rewriteValueARM_OpCtz32NonZero_0(v)
case OpCtz8:
return rewriteValueARM_OpCtz8_0(v)
case OpCtz8NonZero:
return rewriteValueARM_OpCtz8NonZero_0(v)
case OpCvt32Fto32:
return rewriteValueARM_OpCvt32Fto32_0(v)
case OpCvt32Fto32U:
......@@ -17550,6 +17558,72 @@ func rewriteValueARM_OpConstNil_0(v *Value) bool {
return true
}
}
func rewriteValueARM_OpCtz16_0(v *Value) bool {
b := v.Block
typ := &b.Func.Config.Types
// match: (Ctz16 <t> x)
// cond: objabi.GOARM<=6
// result: (RSBconst [32] (CLZ <t> (SUBconst <typ.UInt32> (AND <typ.UInt32> (ORconst <typ.UInt32> [0x10000] x) (RSBconst <typ.UInt32> [0] (ORconst <typ.UInt32> [0x10000] x))) [1])))
for {
t := v.Type
x := v.Args[0]
if !(objabi.GOARM <= 6) {
break
}
v.reset(OpARMRSBconst)
v.AuxInt = 32
v0 := b.NewValue0(v.Pos, OpARMCLZ, t)
v1 := b.NewValue0(v.Pos, OpARMSUBconst, typ.UInt32)
v1.AuxInt = 1
v2 := b.NewValue0(v.Pos, OpARMAND, typ.UInt32)
v3 := b.NewValue0(v.Pos, OpARMORconst, typ.UInt32)
v3.AuxInt = 0x10000
v3.AddArg(x)
v2.AddArg(v3)
v4 := b.NewValue0(v.Pos, OpARMRSBconst, typ.UInt32)
v4.AuxInt = 0
v5 := b.NewValue0(v.Pos, OpARMORconst, typ.UInt32)
v5.AuxInt = 0x10000
v5.AddArg(x)
v4.AddArg(v5)
v2.AddArg(v4)
v1.AddArg(v2)
v0.AddArg(v1)
v.AddArg(v0)
return true
}
// match: (Ctz16 <t> x)
// cond: objabi.GOARM==7
// result: (CLZ <t> (RBIT <typ.UInt32> (ORconst <typ.UInt32> [0x10000] x)))
for {
t := v.Type
x := v.Args[0]
if !(objabi.GOARM == 7) {
break
}
v.reset(OpARMCLZ)
v.Type = t
v0 := b.NewValue0(v.Pos, OpARMRBIT, typ.UInt32)
v1 := b.NewValue0(v.Pos, OpARMORconst, typ.UInt32)
v1.AuxInt = 0x10000
v1.AddArg(x)
v0.AddArg(v1)
v.AddArg(v0)
return true
}
return false
}
func rewriteValueARM_OpCtz16NonZero_0(v *Value) bool {
// match: (Ctz16NonZero x)
// cond:
// result: (Ctz32 x)
for {
x := v.Args[0]
v.reset(OpCtz32)
v.AddArg(x)
return true
}
}
func rewriteValueARM_OpCtz32_0(v *Value) bool {
b := v.Block
// match: (Ctz32 <t> x)
......@@ -17606,6 +17680,72 @@ func rewriteValueARM_OpCtz32NonZero_0(v *Value) bool {
return true
}
}
func rewriteValueARM_OpCtz8_0(v *Value) bool {
b := v.Block
typ := &b.Func.Config.Types
// match: (Ctz8 <t> x)
// cond: objabi.GOARM<=6
// result: (RSBconst [32] (CLZ <t> (SUBconst <typ.UInt32> (AND <typ.UInt32> (ORconst <typ.UInt32> [0x100] x) (RSBconst <typ.UInt32> [0] (ORconst <typ.UInt32> [0x100] x))) [1])))
for {
t := v.Type
x := v.Args[0]
if !(objabi.GOARM <= 6) {
break
}
v.reset(OpARMRSBconst)
v.AuxInt = 32
v0 := b.NewValue0(v.Pos, OpARMCLZ, t)
v1 := b.NewValue0(v.Pos, OpARMSUBconst, typ.UInt32)
v1.AuxInt = 1
v2 := b.NewValue0(v.Pos, OpARMAND, typ.UInt32)
v3 := b.NewValue0(v.Pos, OpARMORconst, typ.UInt32)
v3.AuxInt = 0x100
v3.AddArg(x)
v2.AddArg(v3)
v4 := b.NewValue0(v.Pos, OpARMRSBconst, typ.UInt32)
v4.AuxInt = 0
v5 := b.NewValue0(v.Pos, OpARMORconst, typ.UInt32)
v5.AuxInt = 0x100
v5.AddArg(x)
v4.AddArg(v5)
v2.AddArg(v4)
v1.AddArg(v2)
v0.AddArg(v1)
v.AddArg(v0)
return true
}
// match: (Ctz8 <t> x)
// cond: objabi.GOARM==7
// result: (CLZ <t> (RBIT <typ.UInt32> (ORconst <typ.UInt32> [0x100] x)))
for {
t := v.Type
x := v.Args[0]
if !(objabi.GOARM == 7) {
break
}
v.reset(OpARMCLZ)
v.Type = t
v0 := b.NewValue0(v.Pos, OpARMRBIT, typ.UInt32)
v1 := b.NewValue0(v.Pos, OpARMORconst, typ.UInt32)
v1.AuxInt = 0x100
v1.AddArg(x)
v0.AddArg(v1)
v.AddArg(v0)
return true
}
return false
}
func rewriteValueARM_OpCtz8NonZero_0(v *Value) bool {
// match: (Ctz8NonZero x)
// cond:
// result: (Ctz32 x)
for {
x := v.Args[0]
v.reset(OpCtz32)
v.AddArg(x)
return true
}
}
func rewriteValueARM_OpCvt32Fto32_0(v *Value) bool {
// match: (Cvt32Fto32 x)
// cond:
......
test/codegen/mathbits.go
View file @ 156c830b
......@@ -258,6 +258,7 @@ func RotateLeftVariable32(n uint32, m int) uint32 {
func TrailingZeros(n uint) int {
// amd64:"BSFQ","MOVL\t\\$64","CMOVQEQ"
// arm:"CLZ"
// arm64:"RBIT","CLZ"
// s390x:"FLOGR"
// ppc64:"ANDN","POPCNTD"
......@@ -278,6 +279,7 @@ func TrailingZeros64(n uint64) int {
func TrailingZeros32(n uint32) int {
// amd64:"BTSQ\\t\\$32","BSFQ"
// arm:"CLZ"
// arm64:"RBITW","CLZW"
// s390x:"FLOGR","MOVWZ"
// ppc64:"ANDN","POPCNTW"
......@@ -288,6 +290,7 @@ func TrailingZeros32(n uint32) int {
func TrailingZeros16(n uint16) int {
// amd64:"BSFL","BTSL\\t\\$16"
// arm:"ORR\t\\$65536","CLZ",-"MOVHU\tR"
// arm64:"ORR\t\\$65536","RBITW","CLZW",-"MOVHU\tR",-"RBIT\t",-"CLZ\t"
// s390x:"FLOGR","OR\t\\$65536"
// ppc64:"POPCNTD","OR\\t\\$65536"
......@@ -298,6 +301,7 @@ func TrailingZeros16(n uint16) int {
func TrailingZeros8(n uint8) int {
// amd64:"BSFL","BTSL\\t\\$8"
// arm:"ORR\t\\$256","CLZ",-"MOVBU\tR"
// arm64:"ORR\t\\$256","RBITW","CLZW",-"MOVBU\tR",-"RBIT\t",-"CLZ\t"
// s390x:"FLOGR","OR\t\\$256"
// wasm:"I64Ctz"
......
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