[dev.ssa] cmd/compile/internal/ssa/gen: more simplifications and foldings.

Change-Id: I74d1267dbfced2663072b4f091732c0fb328690f
Reviewed-on: https://go-review.googlesource.com/13641Reviewed-by: Keith Randall <khr@golang.org>

src/cmd/compile/internal/ssa/gen/AMD64.rules

@@ -490,6 +490,10 @@
 (SUBLconst [c] (SUBLconst [d] x)) -> (ADDLconst [-c-d] x)
 (SUBWconst [c] (SUBWconst [d] x)) -> (ADDWconst [-c-d] x)
 (SUBBconst [c] (SUBBconst [d] x)) -> (ADDBconst [-c-d] x)
+(SARQconst [c] (MOVQconst [d])) -> (MOVQconst [d>>uint64(c)])
+(SARLconst [c] (MOVQconst [d])) -> (MOVQconst [d>>uint64(c)])
+(SARWconst [c] (MOVQconst [d])) -> (MOVQconst [d>>uint64(c)])
+(SARBconst [c] (MOVQconst [d])) -> (MOVQconst [d>>uint64(c)])
 (NEGQ (MOVQconst [c])) -> (MOVQconst [-c])
 (NEGL (MOVLconst [c])) -> (MOVLconst [-c])
 (NEGW (MOVWconst [c])) -> (MOVWconst [-c])

src/cmd/compile/internal/ssa/gen/generic.rules

@@ -37,6 +37,23 @@
 (Neq16 x x) -> (ConstBool {false})
 (Neq8 x x) -> (ConstBool {false})
 
+// simplifications
+(Or64 x x) -> x
+(Or32 x x) -> x
+(Or16 x x) -> x
+(Or8 x x) -> x
+(And64 x x) -> x
+(And32 x x) -> x
+(And16 x x) -> x
+(And8 x x) -> x
+(Xor64 x x) -> (Const64 [0])
+(Xor32 x x) -> (Const32 [0])
+(Xor16 x x) -> (Const16 [0])
+(Xor8 x x) -> (Const8 [0])
+(Sub64 x x) -> (Const64 [0])
+(Sub32 x x) -> (Const32 [0])
+(Sub16 x x) -> (Const16 [0])
+(Sub8 x x) -> (Const8 [0])
 (Com8 (Com8 x)) -> x
 (Com16 (Com16 x)) -> x
 (Com32 (Com32 x)) -> x

src/cmd/compile/internal/ssa/rewriteAMD64.go

@@ -5974,6 +5974,26 @@ func rewriteValueAMD64(v *Value, config *Config) bool {
 		goto end3bf3d17717aa6c04462e56d1c87902ce
 	end3bf3d17717aa6c04462e56d1c87902ce:
 		;
+	case OpAMD64SARBconst:
+		// match: (SARBconst [c] (MOVQconst [d]))
+		// cond:
+		// result: (MOVQconst [d>>uint64(c)])
+		{
+			c := v.AuxInt
+			if v.Args[0].Op != OpAMD64MOVQconst {
+				goto end06e0e38775f0650ed672427d19cd8fff
+			}
+			d := v.Args[0].AuxInt
+			v.Op = OpAMD64MOVQconst
+			v.AuxInt = 0
+			v.Aux = nil
+			v.resetArgs()
+			v.AuxInt = d >> uint64(c)
+			return true
+		}
+		goto end06e0e38775f0650ed672427d19cd8fff
+	end06e0e38775f0650ed672427d19cd8fff:
+		;
 	case OpAMD64SARL:
 		// match: (SARL x (MOVLconst [c]))
 		// cond:
@@ -5995,6 +6015,26 @@ func rewriteValueAMD64(v *Value, config *Config) bool {
 		goto ende586a72c1b232ee0b63e37c71eeb8470
 	ende586a72c1b232ee0b63e37c71eeb8470:
 		;
+	case OpAMD64SARLconst:
+		// match: (SARLconst [c] (MOVQconst [d]))
+		// cond:
+		// result: (MOVQconst [d>>uint64(c)])
+		{
+			c := v.AuxInt
+			if v.Args[0].Op != OpAMD64MOVQconst {
+				goto end8f34dc94323303e75b7bcc8e731cf1db
+			}
+			d := v.Args[0].AuxInt
+			v.Op = OpAMD64MOVQconst
+			v.AuxInt = 0
+			v.Aux = nil
+			v.resetArgs()
+			v.AuxInt = d >> uint64(c)
+			return true
+		}
+		goto end8f34dc94323303e75b7bcc8e731cf1db
+	end8f34dc94323303e75b7bcc8e731cf1db:
+		;
 	case OpAMD64SARQ:
 		// match: (SARQ x (MOVQconst [c]))
 		// cond:
@@ -6016,6 +6056,26 @@ func rewriteValueAMD64(v *Value, config *Config) bool {
 		goto end25e720ab203be2745dded5550e6d8a7c
 	end25e720ab203be2745dded5550e6d8a7c:
 		;
+	case OpAMD64SARQconst:
+		// match: (SARQconst [c] (MOVQconst [d]))
+		// cond:
+		// result: (MOVQconst [d>>uint64(c)])
+		{
+			c := v.AuxInt
+			if v.Args[0].Op != OpAMD64MOVQconst {
+				goto endd949ba69a1ff71ba62c49b39c68f269e
+			}
+			d := v.Args[0].AuxInt
+			v.Op = OpAMD64MOVQconst
+			v.AuxInt = 0
+			v.Aux = nil
+			v.resetArgs()
+			v.AuxInt = d >> uint64(c)
+			return true
+		}
+		goto endd949ba69a1ff71ba62c49b39c68f269e
+	endd949ba69a1ff71ba62c49b39c68f269e:
+		;
 	case OpAMD64SARW:
 		// match: (SARW x (MOVWconst [c]))
 		// cond:
@@ -6037,6 +6097,26 @@ func rewriteValueAMD64(v *Value, config *Config) bool {
 		goto endc46e3f211f94238f9a0aec3c498af490
 	endc46e3f211f94238f9a0aec3c498af490:
 		;
+	case OpAMD64SARWconst:
+		// match: (SARWconst [c] (MOVQconst [d]))
+		// cond:
+		// result: (MOVQconst [d>>uint64(c)])
+		{
+			c := v.AuxInt
+			if v.Args[0].Op != OpAMD64MOVQconst {
+				goto endca23e80dba22ab574f843c7a4cef24ab
+			}
+			d := v.Args[0].AuxInt
+			v.Op = OpAMD64MOVQconst
+			v.AuxInt = 0
+			v.Aux = nil
+			v.resetArgs()
+			v.AuxInt = d >> uint64(c)
+			return true
+		}
+		goto endca23e80dba22ab574f843c7a4cef24ab
+	endca23e80dba22ab574f843c7a4cef24ab:
+		;
 	case OpAMD64SBBLcarrymask:
 		// match: (SBBLcarrymask (CMPQconst [c] (MOVQconst [d])))
 		// cond: inBounds64(d, c)

src/cmd/compile/internal/ssa/rewritegeneric.go

@@ -51,6 +51,86 @@ func rewriteValuegeneric(v *Value, config *Config) bool {
 		goto end145c1aec793b2befff34bc8983b48a38
 	end145c1aec793b2befff34bc8983b48a38:
 		;
+	case OpAnd16:
+		// match: (And16 x x)
+		// cond:
+		// result: x
+		{
+			x := v.Args[0]
+			if v.Args[1] != x {
+				goto end69ed6ee2a4fb0491b56c17f3c1926b10
+			}
+			v.Op = OpCopy
+			v.AuxInt = 0
+			v.Aux = nil
+			v.resetArgs()
+			v.Type = x.Type
+			v.AddArg(x)
+			return true
+		}
+		goto end69ed6ee2a4fb0491b56c17f3c1926b10
+	end69ed6ee2a4fb0491b56c17f3c1926b10:
+		;
+	case OpAnd32:
+		// match: (And32 x x)
+		// cond:
+		// result: x
+		{
+			x := v.Args[0]
+			if v.Args[1] != x {
+				goto endbbe8c3c5b2ca8f013aa178d856f3a99c
+			}
+			v.Op = OpCopy
+			v.AuxInt = 0
+			v.Aux = nil
+			v.resetArgs()
+			v.Type = x.Type
+			v.AddArg(x)
+			return true
+		}
+		goto endbbe8c3c5b2ca8f013aa178d856f3a99c
+	endbbe8c3c5b2ca8f013aa178d856f3a99c:
+		;
+	case OpAnd64:
+		// match: (And64 x x)
+		// cond:
+		// result: x
+		{
+			x := v.Args[0]
+			if v.Args[1] != x {
+				goto endc9736bf24d2e5cd8d662e1bcf3164640
+			}
+			v.Op = OpCopy
+			v.AuxInt = 0
+			v.Aux = nil
+			v.resetArgs()
+			v.Type = x.Type
+			v.AddArg(x)
+			return true
+		}
+		goto endc9736bf24d2e5cd8d662e1bcf3164640
+	endc9736bf24d2e5cd8d662e1bcf3164640:
+		;
+	case OpAnd8:
+		// match: (And8 x x)
+		// cond:
+		// result: x
+		{
+			x := v.Args[0]
+			if v.Args[1] != x {
+				goto endeaf127389bd0d4b0e0e297830f8f463b
+			}
+			v.Op = OpCopy
+			v.AuxInt = 0
+			v.Aux = nil
+			v.resetArgs()
+			v.Type = x.Type
+			v.AddArg(x)
+			return true
+		}
+		goto endeaf127389bd0d4b0e0e297830f8f463b
+	endeaf127389bd0d4b0e0e297830f8f463b:
+		;
 	case OpArrayIndex:
 		// match: (ArrayIndex (Load ptr mem) idx)
 		// cond:
@@ -612,6 +692,86 @@ func rewriteValuegeneric(v *Value, config *Config) bool {
 		goto end67d723bb0f39a5c897816abcf411e5cf
 	end67d723bb0f39a5c897816abcf411e5cf:
 		;
+	case OpOr16:
+		// match: (Or16 x x)
+		// cond:
+		// result: x
+		{
+			x := v.Args[0]
+			if v.Args[1] != x {
+				goto end47a2f25fd31a76807aced3e2b126acdc
+			}
+			v.Op = OpCopy
+			v.AuxInt = 0
+			v.Aux = nil
+			v.resetArgs()
+			v.Type = x.Type
+			v.AddArg(x)
+			return true
+		}
+		goto end47a2f25fd31a76807aced3e2b126acdc
+	end47a2f25fd31a76807aced3e2b126acdc:
+		;
+	case OpOr32:
+		// match: (Or32 x x)
+		// cond:
+		// result: x
+		{
+			x := v.Args[0]
+			if v.Args[1] != x {
+				goto end231e283e568e90bd9a3e6a4fa328c8a4
+			}
+			v.Op = OpCopy
+			v.AuxInt = 0
+			v.Aux = nil
+			v.resetArgs()
+			v.Type = x.Type
+			v.AddArg(x)
+			return true
+		}
+		goto end231e283e568e90bd9a3e6a4fa328c8a4
+	end231e283e568e90bd9a3e6a4fa328c8a4:
+		;
+	case OpOr64:
+		// match: (Or64 x x)
+		// cond:
+		// result: x
+		{
+			x := v.Args[0]
+			if v.Args[1] != x {
+				goto end6b0efc212016dc97d0e3939db04c81d9
+			}
+			v.Op = OpCopy
+			v.AuxInt = 0
+			v.Aux = nil
+			v.resetArgs()
+			v.Type = x.Type
+			v.AddArg(x)
+			return true
+		}
+		goto end6b0efc212016dc97d0e3939db04c81d9
+	end6b0efc212016dc97d0e3939db04c81d9:
+		;
+	case OpOr8:
+		// match: (Or8 x x)
+		// cond:
+		// result: x
+		{
+			x := v.Args[0]
+			if v.Args[1] != x {
+				goto end05295dbfafd6869af79b4daee9fda000
+			}
+			v.Op = OpCopy
+			v.AuxInt = 0
+			v.Aux = nil
+			v.resetArgs()
+			v.Type = x.Type
+			v.AddArg(x)
+			return true
+		}
+		goto end05295dbfafd6869af79b4daee9fda000
+	end05295dbfafd6869af79b4daee9fda000:
+		;
 	case OpPtrIndex:
 		// match: (PtrIndex <t> ptr idx)
 		// cond:
@@ -848,6 +1008,158 @@ func rewriteValuegeneric(v *Value, config *Config) bool {
 		}
 		goto end16fdb45e1dd08feb36e3cc3fb5ed8935
 	end16fdb45e1dd08feb36e3cc3fb5ed8935:
+		;
+	case OpSub16:
+		// match: (Sub16 x x)
+		// cond:
+		// result: (Const16 [0])
+		{
+			x := v.Args[0]
+			if v.Args[1] != x {
+				goto end83da541391be564f2a08464e674a49e7
+			}
+			v.Op = OpConst16
+			v.AuxInt = 0
+			v.Aux = nil
+			v.resetArgs()
+			v.AuxInt = 0
+			return true
+		}
+		goto end83da541391be564f2a08464e674a49e7
+	end83da541391be564f2a08464e674a49e7:
+		;
+	case OpSub32:
+		// match: (Sub32 x x)
+		// cond:
+		// result: (Const32 [0])
+		{
+			x := v.Args[0]
+			if v.Args[1] != x {
+				goto enda747581e798f199e07f4ad69747cd069
+			}
+			v.Op = OpConst32
+			v.AuxInt = 0
+			v.Aux = nil
+			v.resetArgs()
+			v.AuxInt = 0
+			return true
+		}
+		goto enda747581e798f199e07f4ad69747cd069
+	enda747581e798f199e07f4ad69747cd069:
+		;
+	case OpSub64:
+		// match: (Sub64 x x)
+		// cond:
+		// result: (Const64 [0])
+		{
+			x := v.Args[0]
+			if v.Args[1] != x {
+				goto end0387dc2b7bbe57d4aa54eab5d959da4b
+			}
+			v.Op = OpConst64
+			v.AuxInt = 0
+			v.Aux = nil
+			v.resetArgs()
+			v.AuxInt = 0
+			return true
+		}
+		goto end0387dc2b7bbe57d4aa54eab5d959da4b
+	end0387dc2b7bbe57d4aa54eab5d959da4b:
+		;
+	case OpSub8:
+		// match: (Sub8 x x)
+		// cond:
+		// result: (Const8 [0])
+		{
+			x := v.Args[0]
+			if v.Args[1] != x {
+				goto end4e2ee15ef17611919a1a6b5f80bbfe18
+			}
+			v.Op = OpConst8
+			v.AuxInt = 0
+			v.Aux = nil
+			v.resetArgs()
+			v.AuxInt = 0
+			return true
+		}
+		goto end4e2ee15ef17611919a1a6b5f80bbfe18
+	end4e2ee15ef17611919a1a6b5f80bbfe18:
+		;
+	case OpXor16:
+		// match: (Xor16 x x)
+		// cond:
+		// result: (Const16 [0])
+		{
+			x := v.Args[0]
+			if v.Args[1] != x {
+				goto end5733ceb1903b8140248d8e2cac02fefe
+			}
+			v.Op = OpConst16
+			v.AuxInt = 0
+			v.Aux = nil
+			v.resetArgs()
+			v.AuxInt = 0
+			return true
+		}
+		goto end5733ceb1903b8140248d8e2cac02fefe
+	end5733ceb1903b8140248d8e2cac02fefe:
+		;
+	case OpXor32:
+		// match: (Xor32 x x)
+		// cond:
+		// result: (Const32 [0])
+		{
+			x := v.Args[0]
+			if v.Args[1] != x {
+				goto end268ca02df6515d648e0bfb4e90981d25
+			}
+			v.Op = OpConst32
+			v.AuxInt = 0
+			v.Aux = nil
+			v.resetArgs()
+			v.AuxInt = 0
+			return true
+		}
+		goto end268ca02df6515d648e0bfb4e90981d25
+	end268ca02df6515d648e0bfb4e90981d25:
+		;
+	case OpXor64:
+		// match: (Xor64 x x)
+		// cond:
+		// result: (Const64 [0])
+		{
+			x := v.Args[0]
+			if v.Args[1] != x {
+				goto endaf44e7f9fc58af30df69070953fb45ce
+			}
+			v.Op = OpConst64
+			v.AuxInt = 0
+			v.Aux = nil
+			v.resetArgs()
+			v.AuxInt = 0
+			return true
+		}
+		goto endaf44e7f9fc58af30df69070953fb45ce
+	endaf44e7f9fc58af30df69070953fb45ce:
+		;
+	case OpXor8:
+		// match: (Xor8 x x)
+		// cond:
+		// result: (Const8 [0])
+		{
+			x := v.Args[0]
+			if v.Args[1] != x {
+				goto end949b3a60b7d181688e6f79f93c782fc8
+			}
+			v.Op = OpConst8
+			v.AuxInt = 0
+			v.Aux = nil
+			v.resetArgs()
+			v.AuxInt = 0
+			return true
+		}
+		goto end949b3a60b7d181688e6f79f93c782fc8
+	end949b3a60b7d181688e6f79f93c782fc8:
 	}
 	return false
 }