cmd/compile: absorb more Not ops into Neq* and Eq* ops

We absorbed Not into most integer comparisons but not into pointer
and floating point equality checks.

The new cases trigger more than 300 times during make.bash.

Change-Id: I77c6b31fcacde10da5470b73fc001a19521ce78d
Reviewed-on: https://go-review.googlesource.com/c/go/+/200618
Run-TryBot: Michael Munday <mike.munday@ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>

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

@@ -260,8 +260,8 @@
 (Sub8  x (Const8  <t> [c])) && x.Op != OpConst8  -> (Add8  (Const8  <t> [int64(int8(-c))]) x)
 
 // fold negation into comparison operators
-(Not (Eq(64|32|16|8|B) x y)) -> (Neq(64|32|16|8|B) x y)
-(Not (Neq(64|32|16|8|B) x y)) -> (Eq(64|32|16|8|B) x y)
+(Not (Eq(64|32|16|8|B|Ptr|64F|32F) x y)) -> (Neq(64|32|16|8|B|Ptr|64F|32F) x y)
+(Not (Neq(64|32|16|8|B|Ptr|64F|32F) x y)) -> (Eq(64|32|16|8|B|Ptr|64F|32F) x y)
 
 (Not (Greater(64|32|16|8) x y)) -> (Leq(64|32|16|8) x y)
 (Not (Greater(64|32|16|8)U x y)) -> (Leq(64|32|16|8)U x y)
@@ -273,7 +273,6 @@
 (Not (Leq(64|32|16|8) x y)) -> (Greater(64|32|16|8) x y)
 (Not (Leq(64|32|16|8)U x y)) -> (Greater(64|32|16|8)U x y)
 
-
 // Distribute multiplication c * (d+x) -> c*d + c*x. Useful for:
 // a[i].b = ...; a[i+1].b = ...
 (Mul64 (Const64 <t> [c]) (Add64 <t> (Const64 <t> [d]) x)) ->

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

@@ -36678,6 +36678,48 @@ func rewriteValuegeneric_OpNot_0(v *Value) bool {
 		v.AddArg(y)
 		return true
 	}
+	// match: (Not (EqPtr x y))
+	// result: (NeqPtr x y)
+	for {
+		v_0 := v.Args[0]
+		if v_0.Op != OpEqPtr {
+			break
+		}
+		y := v_0.Args[1]
+		x := v_0.Args[0]
+		v.reset(OpNeqPtr)
+		v.AddArg(x)
+		v.AddArg(y)
+		return true
+	}
+	// match: (Not (Eq64F x y))
+	// result: (Neq64F x y)
+	for {
+		v_0 := v.Args[0]
+		if v_0.Op != OpEq64F {
+			break
+		}
+		y := v_0.Args[1]
+		x := v_0.Args[0]
+		v.reset(OpNeq64F)
+		v.AddArg(x)
+		v.AddArg(y)
+		return true
+	}
+	// match: (Not (Eq32F x y))
+	// result: (Neq32F x y)
+	for {
+		v_0 := v.Args[0]
+		if v_0.Op != OpEq32F {
+			break
+		}
+		y := v_0.Args[1]
+		x := v_0.Args[0]
+		v.reset(OpNeq32F)
+		v.AddArg(x)
+		v.AddArg(y)
+		return true
+	}
 	// match: (Not (Neq64 x y))
 	// result: (Eq64 x y)
 	for {
@@ -36692,6 +36734,9 @@ func rewriteValuegeneric_OpNot_0(v *Value) bool {
 		v.AddArg(y)
 		return true
 	}
+	return false
+}
+func rewriteValuegeneric_OpNot_10(v *Value) bool {
 	// match: (Not (Neq32 x y))
 	// result: (Eq32 x y)
 	for {
@@ -36734,9 +36779,6 @@ func rewriteValuegeneric_OpNot_0(v *Value) bool {
 		v.AddArg(y)
 		return true
 	}
-	return false
-}
-func rewriteValuegeneric_OpNot_10(v *Value) bool {
 	// match: (Not (NeqB x y))
 	// result: (EqB x y)
 	for {
@@ -36751,6 +36793,48 @@ func rewriteValuegeneric_OpNot_10(v *Value) bool {
 		v.AddArg(y)
 		return true
 	}
+	// match: (Not (NeqPtr x y))
+	// result: (EqPtr x y)
+	for {
+		v_0 := v.Args[0]
+		if v_0.Op != OpNeqPtr {
+			break
+		}
+		y := v_0.Args[1]
+		x := v_0.Args[0]
+		v.reset(OpEqPtr)
+		v.AddArg(x)
+		v.AddArg(y)
+		return true
+	}
+	// match: (Not (Neq64F x y))
+	// result: (Eq64F x y)
+	for {
+		v_0 := v.Args[0]
+		if v_0.Op != OpNeq64F {
+			break
+		}
+		y := v_0.Args[1]
+		x := v_0.Args[0]
+		v.reset(OpEq64F)
+		v.AddArg(x)
+		v.AddArg(y)
+		return true
+	}
+	// match: (Not (Neq32F x y))
+	// result: (Eq32F x y)
+	for {
+		v_0 := v.Args[0]
+		if v_0.Op != OpNeq32F {
+			break
+		}
+		y := v_0.Args[1]
+		x := v_0.Args[0]
+		v.reset(OpEq32F)
+		v.AddArg(x)
+		v.AddArg(y)
+		return true
+	}
 	// match: (Not (Greater64 x y))
 	// result: (Leq64 x y)
 	for {
@@ -36793,6 +36877,9 @@ func rewriteValuegeneric_OpNot_10(v *Value) bool {
 		v.AddArg(y)
 		return true
 	}
+	return false
+}
+func rewriteValuegeneric_OpNot_20(v *Value) bool {
 	// match: (Not (Greater8 x y))
 	// result: (Leq8 x y)
 	for {
@@ -36877,9 +36964,6 @@ func rewriteValuegeneric_OpNot_10(v *Value) bool {
 		v.AddArg(y)
 		return true
 	}
-	return false
-}
-func rewriteValuegeneric_OpNot_20(v *Value) bool {
 	// match: (Not (Geq32 x y))
 	// result: (Less32 x y)
 	for {
@@ -36936,6 +37020,9 @@ func rewriteValuegeneric_OpNot_20(v *Value) bool {
 		v.AddArg(y)
 		return true
 	}
+	return false
+}
+func rewriteValuegeneric_OpNot_30(v *Value) bool {
 	// match: (Not (Geq32U x y))
 	// result: (Less32U x y)
 	for {
@@ -37020,9 +37107,6 @@ func rewriteValuegeneric_OpNot_20(v *Value) bool {
 		v.AddArg(y)
 		return true
 	}
-	return false
-}
-func rewriteValuegeneric_OpNot_30(v *Value) bool {
 	// match: (Not (Less8 x y))
 	// result: (Geq8 x y)
 	for {
@@ -37079,6 +37163,9 @@ func rewriteValuegeneric_OpNot_30(v *Value) bool {
 		v.AddArg(y)
 		return true
 	}
+	return false
+}
+func rewriteValuegeneric_OpNot_40(v *Value) bool {
 	// match: (Not (Less8U x y))
 	// result: (Geq8U x y)
 	for {
@@ -37163,9 +37250,6 @@ func rewriteValuegeneric_OpNot_30(v *Value) bool {
 		v.AddArg(y)
 		return true
 	}
-	return false
-}
-func rewriteValuegeneric_OpNot_40(v *Value) bool {
 	// match: (Not (Leq32U x y))
 	// result: (Greater32U x y)
 	for {