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Commit e4bee4be authored by Alexandru Moșoi's avatar Alexandru Moșoi Committed by David Chase
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[dev.ssa] cmd/compile/internal/ssa: constant fold truncates and bool comparisons 

Change-Id: I731722eb77f373ff7d6101f93830ab0a50497e2c
Reviewed-on: https://go-review.googlesource.com/19542
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: default avatarDavid Chase <drchase@google.com>
parent ae276d8c
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Showing with 265 additions and 0 deletions
src/cmd/compile/internal/ssa/gen/generic.rules
View file @ e4bee4be
......@@ -20,6 +20,13 @@
// For now, the generated successors must be a permutation of the matched successors.
// constant folding
(Trunc16to8 (Const16 [c])) -> (Const8 [int64(int8(c))])
(Trunc32to8 (Const32 [c])) -> (Const8 [int64(int8(c))])
(Trunc32to16 (Const32 [c])) -> (Const16 [int64(int16(c))])
(Trunc64to8 (Const64 [c])) -> (Const8 [int64(int8(c))])
(Trunc64to16 (Const64 [c])) -> (Const16 [int64(int16(c))])
(Trunc64to32 (Const64 [c])) -> (Const32 [int64(int32(c))])
(Neg8 (Const8 [c])) -> (Const8 [-c])
(Neg16 (Const16 [c])) -> (Const16 [-c])
(Neg32 (Const32 [c])) -> (Const32 [-c])
......@@ -70,14 +77,22 @@
(IsInBounds (Const64 [c]) (Const64 [d])) -> (ConstBool [b2i(inBounds64(c,d))])
(IsSliceInBounds (Const32 [c]) (Const32 [d])) -> (ConstBool [b2i(sliceInBounds32(c,d))])
(IsSliceInBounds (Const64 [c]) (Const64 [d])) -> (ConstBool [b2i(sliceInBounds64(c,d))])
(Eq64 x x) -> (ConstBool [1])
(Eq32 x x) -> (ConstBool [1])
(Eq16 x x) -> (ConstBool [1])
(Eq8 x x) -> (ConstBool [1])
(Eq8 (ConstBool [c]) (ConstBool [d])) -> (ConstBool [b2i((int8(c) != 0) == (int8(d) != 0))])
(Eq8 (ConstBool [0]) x) -> (Not x)
(Eq8 (ConstBool [1]) x) -> x
(Neq64 x x) -> (ConstBool [0])
(Neq32 x x) -> (ConstBool [0])
(Neq16 x x) -> (ConstBool [0])
(Neq8 x x) -> (ConstBool [0])
(Neq8 (ConstBool [c]) (ConstBool [d])) -> (ConstBool [b2i((int8(c) != 0) != (int8(d) != 0))])
(Neq8 (ConstBool [0]) x) -> x
(Neq8 (ConstBool [1]) x) -> (Not x)
(Eq64 (Const64 <t> [c]) (Add64 (Const64 <t> [d]) x)) -> (Eq64 (Const64 <t> [c-d]) x)
(Eq32 (Const32 <t> [c]) (Add32 (Const32 <t> [d]) x)) -> (Eq32 (Const32 <t> [c-d]) x)
......@@ -94,11 +109,13 @@
(Eq32 x (Const32 <t> [c])) && x.Op != OpConst32 -> (Eq32 (Const32 <t> [c]) x)
(Eq16 x (Const16 <t> [c])) && x.Op != OpConst16 -> (Eq16 (Const16 <t> [c]) x)
(Eq8 x (Const8 <t> [c])) && x.Op != OpConst8 -> (Eq8 (Const8 <t> [c]) x)
(Eq8 x (ConstBool <t> [c])) && x.Op != OpConstBool -> (Eq8 (ConstBool <t> [c]) x)
(Neq64 x (Const64 <t> [c])) && x.Op != OpConst64 -> (Neq64 (Const64 <t> [c]) x)
(Neq32 x (Const32 <t> [c])) && x.Op != OpConst32 -> (Neq32 (Const32 <t> [c]) x)
(Neq16 x (Const16 <t> [c])) && x.Op != OpConst16 -> (Neq16 (Const16 <t> [c]) x)
(Neq8 x (Const8 <t> [c])) && x.Op != OpConst8 -> (Neq8 (Const8 <t> [c]) x)
(Neq8 x (ConstBool <t> [c])) && x.Op != OpConstBool -> (Neq8 (ConstBool <t> [c]) x)
(Add64 x (Const64 <t> [c])) && x.Op != OpConst64 -> (Add64 (Const64 <t> [c]) x)
(Add32 x (Const32 <t> [c])) && x.Op != OpConst32 -> (Add32 (Const32 <t> [c]) x)
......
src/cmd/compile/internal/ssa/rewritegeneric.go
View file @ e4bee4be
......@@ -303,6 +303,18 @@ func rewriteValuegeneric(v *Value, config *Config) bool {
return rewriteValuegeneric_OpSub64(v, config)
case OpSub8:
return rewriteValuegeneric_OpSub8(v, config)
case OpTrunc16to8:
return rewriteValuegeneric_OpTrunc16to8(v, config)
case OpTrunc32to16:
return rewriteValuegeneric_OpTrunc32to16(v, config)
case OpTrunc32to8:
return rewriteValuegeneric_OpTrunc32to8(v, config)
case OpTrunc64to16:
return rewriteValuegeneric_OpTrunc64to16(v, config)
case OpTrunc64to32:
return rewriteValuegeneric_OpTrunc64to32(v, config)
case OpTrunc64to8:
return rewriteValuegeneric_OpTrunc64to8(v, config)
case OpXor16:
return rewriteValuegeneric_OpXor16(v, config)
case OpXor32:
......@@ -1899,6 +1911,53 @@ func rewriteValuegeneric_OpEq8(v *Value, config *Config) bool {
v.AuxInt = 1
return true
}
// match: (Eq8 (ConstBool [c]) (ConstBool [d]))
// cond:
// result: (ConstBool [b2i((int8(c) != 0) == (int8(d) != 0))])
for {
if v.Args[0].Op != OpConstBool {
break
}
c := v.Args[0].AuxInt
if v.Args[1].Op != OpConstBool {
break
}
d := v.Args[1].AuxInt
v.reset(OpConstBool)
v.AuxInt = b2i((int8(c) != 0) == (int8(d) != 0))
return true
}
// match: (Eq8 (ConstBool [0]) x)
// cond:
// result: (Not x)
for {
if v.Args[0].Op != OpConstBool {
break
}
if v.Args[0].AuxInt != 0 {
break
}
x := v.Args[1]
v.reset(OpNot)
v.AddArg(x)
return true
}
// match: (Eq8 (ConstBool [1]) x)
// cond:
// result: x
for {
if v.Args[0].Op != OpConstBool {
break
}
if v.Args[0].AuxInt != 1 {
break
}
x := v.Args[1]
v.reset(OpCopy)
v.Type = x.Type
v.AddArg(x)
return true
}
// match: (Eq8 (Const8 <t> [c]) (Add8 (Const8 <t> [d]) x))
// cond:
// result: (Eq8 (Const8 <t> [c-d]) x)
......@@ -1946,6 +2005,26 @@ func rewriteValuegeneric_OpEq8(v *Value, config *Config) bool {
v.AddArg(x)
return true
}
// match: (Eq8 x (ConstBool <t> [c]))
// cond: x.Op != OpConstBool
// result: (Eq8 (ConstBool <t> [c]) x)
for {
x := v.Args[0]
if v.Args[1].Op != OpConstBool {
break
}
t := v.Args[1].Type
c := v.Args[1].AuxInt
if !(x.Op != OpConstBool) {
break
}
v.reset(OpEq8)
v0 := b.NewValue0(v.Line, OpConstBool, t)
v0.AuxInt = c
v.AddArg(v0)
v.AddArg(x)
return true
}
// match: (Eq8 (Const8 [c]) (Const8 [d]))
// cond:
// result: (ConstBool [b2i(int8(c) == int8(d))])
......@@ -4429,6 +4508,53 @@ func rewriteValuegeneric_OpNeq8(v *Value, config *Config) bool {
v.AuxInt = 0
return true
}
// match: (Neq8 (ConstBool [c]) (ConstBool [d]))
// cond:
// result: (ConstBool [b2i((int8(c) != 0) != (int8(d) != 0))])
for {
if v.Args[0].Op != OpConstBool {
break
}
c := v.Args[0].AuxInt
if v.Args[1].Op != OpConstBool {
break
}
d := v.Args[1].AuxInt
v.reset(OpConstBool)
v.AuxInt = b2i((int8(c) != 0) != (int8(d) != 0))
return true
}
// match: (Neq8 (ConstBool [0]) x)
// cond:
// result: x
for {
if v.Args[0].Op != OpConstBool {
break
}
if v.Args[0].AuxInt != 0 {
break
}
x := v.Args[1]
v.reset(OpCopy)
v.Type = x.Type
v.AddArg(x)
return true
}
// match: (Neq8 (ConstBool [1]) x)
// cond:
// result: (Not x)
for {
if v.Args[0].Op != OpConstBool {
break
}
if v.Args[0].AuxInt != 1 {
break
}
x := v.Args[1]
v.reset(OpNot)
v.AddArg(x)
return true
}
// match: (Neq8 (Const8 <t> [c]) (Add8 (Const8 <t> [d]) x))
// cond:
// result: (Neq8 (Const8 <t> [c-d]) x)
......@@ -4476,6 +4602,26 @@ func rewriteValuegeneric_OpNeq8(v *Value, config *Config) bool {
v.AddArg(x)
return true
}
// match: (Neq8 x (ConstBool <t> [c]))
// cond: x.Op != OpConstBool
// result: (Neq8 (ConstBool <t> [c]) x)
for {
x := v.Args[0]
if v.Args[1].Op != OpConstBool {
break
}
t := v.Args[1].Type
c := v.Args[1].AuxInt
if !(x.Op != OpConstBool) {
break
}
v.reset(OpNeq8)
v0 := b.NewValue0(v.Line, OpConstBool, t)
v0.AuxInt = c
v.AddArg(v0)
v.AddArg(x)
return true
}
// match: (Neq8 (Const8 [c]) (Const8 [d]))
// cond:
// result: (ConstBool [b2i(int8(c) != int8(d))])
......@@ -7275,6 +7421,108 @@ func rewriteValuegeneric_OpSub8(v *Value, config *Config) bool {
}
return false
}
func rewriteValuegeneric_OpTrunc16to8(v *Value, config *Config) bool {
b := v.Block
_ = b
// match: (Trunc16to8 (Const16 [c]))
// cond:
// result: (Const8 [int64(int8(c))])
for {
if v.Args[0].Op != OpConst16 {
break
}
c := v.Args[0].AuxInt
v.reset(OpConst8)
v.AuxInt = int64(int8(c))
return true
}
return false
}
func rewriteValuegeneric_OpTrunc32to16(v *Value, config *Config) bool {
b := v.Block
_ = b
// match: (Trunc32to16 (Const32 [c]))
// cond:
// result: (Const16 [int64(int16(c))])
for {
if v.Args[0].Op != OpConst32 {
break
}
c := v.Args[0].AuxInt
v.reset(OpConst16)
v.AuxInt = int64(int16(c))
return true
}
return false
}
func rewriteValuegeneric_OpTrunc32to8(v *Value, config *Config) bool {
b := v.Block
_ = b
// match: (Trunc32to8 (Const32 [c]))
// cond:
// result: (Const8 [int64(int8(c))])
for {
if v.Args[0].Op != OpConst32 {
break
}
c := v.Args[0].AuxInt
v.reset(OpConst8)
v.AuxInt = int64(int8(c))
return true
}
return false
}
func rewriteValuegeneric_OpTrunc64to16(v *Value, config *Config) bool {
b := v.Block
_ = b
// match: (Trunc64to16 (Const64 [c]))
// cond:
// result: (Const16 [int64(int16(c))])
for {
if v.Args[0].Op != OpConst64 {
break
}
c := v.Args[0].AuxInt
v.reset(OpConst16)
v.AuxInt = int64(int16(c))
return true
}
return false
}
func rewriteValuegeneric_OpTrunc64to32(v *Value, config *Config) bool {
b := v.Block
_ = b
// match: (Trunc64to32 (Const64 [c]))
// cond:
// result: (Const32 [int64(int32(c))])
for {
if v.Args[0].Op != OpConst64 {
break
}
c := v.Args[0].AuxInt
v.reset(OpConst32)
v.AuxInt = int64(int32(c))
return true
}
return false
}
func rewriteValuegeneric_OpTrunc64to8(v *Value, config *Config) bool {
b := v.Block
_ = b
// match: (Trunc64to8 (Const64 [c]))
// cond:
// result: (Const8 [int64(int8(c))])
for {
if v.Args[0].Op != OpConst64 {
break
}
c := v.Args[0].AuxInt
v.reset(OpConst8)
v.AuxInt = int64(int8(c))
return true
}
return false
}
func rewriteValuegeneric_OpXor16(v *Value, config *Config) bool {
b := v.Block
_ = b
......
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