cmd/compile: add specialized Value reset for OpCopy

This:

* Simplifies and shortens the generated code for rewrite rules.
* Shrinks cmd/compile by 86k (0.4%) and makes it easier to compile.
* Removes the stmt boundary code wrangling from Value.reset,
  in favor of doing it in the one place where it actually does some work,
  namely the writebarrier pass. (This was ascertained by inspecting the
  code for cases in which notStmtBoundary values were generated.)

Passes toolstash-check -all.

Change-Id: I25671d4c4bbd772f235195d11da090878ea2cc07
Reviewed-on: https://go-review.googlesource.com/c/go/+/221421
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>

1 files changed, 35 insertions, 91 deletions

diff --git a/src/cmd/compile/internal/ssa/rewrite386.go b/src/cmd/compile/internal/ssa/rewrite386.go
index 7a75b7121f..bff76e9029 100644
--- a/src/cmd/compile/internal/ssa/rewrite386.go
+++ b/src/cmd/compile/internal/ssa/rewrite386.go
@@ -1235,9 +1235,7 @@ func rewriteValue386_Op386ADDLconst(v *Value) bool {
 		if !(int32(c) == 0) {
 			break
 		}
-		v.reset(OpCopy)
-		v.Type = x.Type
-		v.AddArg(x)
+		v.copyOf(x)
 		return true
 	}
 	// match: (ADDLconst [c] (MOVLconst [d]))
@@ -1950,9 +1948,7 @@ func rewriteValue386_Op386ANDL(v *Value) bool {
 		if x != v_1 {
 			break
 		}
-		v.reset(OpCopy)
-		v.Type = x.Type
-		v.AddArg(x)
+		v.copyOf(x)
 		return true
 	}
 	return false
@@ -1994,9 +1990,7 @@ func rewriteValue386_Op386ANDLconst(v *Value) bool {
 		if !(int32(c) == -1) {
 			break
 		}
-		v.reset(OpCopy)
-		v.Type = x.Type
-		v.AddArg(x)
+		v.copyOf(x)
 		return true
 	}
 	// match: (ANDLconst [c] (MOVLconst [d]))
@@ -2706,8 +2700,7 @@ func rewriteValue386_Op386CMPBconst(v *Value) bool {
 		}
 		b = l.Block
 		v0 := b.NewValue0(l.Pos, Op386CMPBconstload, types.TypeFlags)
-		v.reset(OpCopy)
-		v.AddArg(v0)
+		v.copyOf(v0)
 		v0.AuxInt = makeValAndOff(c, off)
 		v0.Aux = sym
 		v0.AddArg2(ptr, mem)
@@ -3015,8 +3008,7 @@ func rewriteValue386_Op386CMPLconst(v *Value) bool {
 		}
 		b = l.Block
 		v0 := b.NewValue0(l.Pos, Op386CMPLconstload, types.TypeFlags)
-		v.reset(OpCopy)
-		v.AddArg(v0)
+		v.copyOf(v0)
 		v0.AuxInt = makeValAndOff(c, off)
 		v0.Aux = sym
 		v0.AddArg2(ptr, mem)
@@ -3309,8 +3301,7 @@ func rewriteValue386_Op386CMPWconst(v *Value) bool {
 		}
 		b = l.Block
 		v0 := b.NewValue0(l.Pos, Op386CMPWconstload, types.TypeFlags)
-		v.reset(OpCopy)
-		v.AddArg(v0)
+		v.copyOf(v0)
 		v0.AuxInt = makeValAndOff(c, off)
 		v0.Aux = sym
 		v0.AddArg2(ptr, mem)
@@ -4054,8 +4045,7 @@ func rewriteValue386_Op386MOVBLSX(v *Value) bool {
 		}
 		b = x.Block
 		v0 := b.NewValue0(x.Pos, Op386MOVBLSXload, v.Type)
-		v.reset(OpCopy)
-		v.AddArg(v0)
+		v.copyOf(v0)
 		v0.AuxInt = off
 		v0.Aux = sym
 		v0.AddArg2(ptr, mem)
@@ -4151,8 +4141,7 @@ func rewriteValue386_Op386MOVBLZX(v *Value) bool {
 		}
 		b = x.Block
 		v0 := b.NewValue0(x.Pos, Op386MOVBload, v.Type)
-		v.reset(OpCopy)
-		v.AddArg(v0)
+		v.copyOf(v0)
 		v0.AuxInt = off
 		v0.Aux = sym
 		v0.AddArg2(ptr, mem)
@@ -4176,8 +4165,7 @@ func rewriteValue386_Op386MOVBLZX(v *Value) bool {
 		}
 		b = x.Block
 		v0 := b.NewValue0(v.Pos, Op386MOVBloadidx1, v.Type)
-		v.reset(OpCopy)
-		v.AddArg(v0)
+		v.copyOf(v0)
 		v0.AuxInt = off
 		v0.Aux = sym
 		v0.AddArg3(ptr, idx, mem)
@@ -5127,9 +5115,7 @@ func rewriteValue386_Op386MOVLload(v *Value) bool {
 		if !(sym == sym2 && off == off2 && isSamePtr(ptr, ptr2)) {
 			break
 		}
-		v.reset(OpCopy)
-		v.Type = x.Type
-		v.AddArg(x)
+		v.copyOf(x)
 		return true
 	}
 	// match: (MOVLload [off1] {sym} (ADDLconst [off2] ptr) mem)
@@ -7495,8 +7481,7 @@ func rewriteValue386_Op386MOVWLSX(v *Value) bool {
 		}
 		b = x.Block
 		v0 := b.NewValue0(x.Pos, Op386MOVWLSXload, v.Type)
-		v.reset(OpCopy)
-		v.AddArg(v0)
+		v.copyOf(v0)
 		v0.AuxInt = off
 		v0.Aux = sym
 		v0.AddArg2(ptr, mem)
@@ -7592,8 +7577,7 @@ func rewriteValue386_Op386MOVWLZX(v *Value) bool {
 		}
 		b = x.Block
 		v0 := b.NewValue0(x.Pos, Op386MOVWload, v.Type)
-		v.reset(OpCopy)
-		v.AddArg(v0)
+		v.copyOf(v0)
 		v0.AuxInt = off
 		v0.Aux = sym
 		v0.AddArg2(ptr, mem)
@@ -7617,8 +7601,7 @@ func rewriteValue386_Op386MOVWLZX(v *Value) bool {
 		}
 		b = x.Block
 		v0 := b.NewValue0(v.Pos, Op386MOVWloadidx1, v.Type)
-		v.reset(OpCopy)
-		v.AddArg(v0)
+		v.copyOf(v0)
 		v0.AuxInt = off
 		v0.Aux = sym
 		v0.AddArg3(ptr, idx, mem)
@@ -7642,8 +7625,7 @@ func rewriteValue386_Op386MOVWLZX(v *Value) bool {
 		}
 		b = x.Block
 		v0 := b.NewValue0(v.Pos, Op386MOVWloadidx2, v.Type)
-		v.reset(OpCopy)
-		v.AddArg(v0)
+		v.copyOf(v0)
 		v0.AuxInt = off
 		v0.Aux = sym
 		v0.AddArg3(ptr, idx, mem)
@@ -8899,9 +8881,7 @@ func rewriteValue386_Op386MULLconst(v *Value) bool {
 			break
 		}
 		x := v_0
-		v.reset(OpCopy)
-		v.Type = x.Type
-		v.AddArg(x)
+		v.copyOf(x)
 		return true
 	}
 	// match: (MULLconst [3] x)
@@ -9750,9 +9730,7 @@ func rewriteValue386_Op386ORL(v *Value) bool {
 		if x != v_1 {
 			break
 		}
-		v.reset(OpCopy)
-		v.Type = x.Type
-		v.AddArg(x)
+		v.copyOf(x)
 		return true
 	}
 	// match: (ORL x0:(MOVBload [i0] {s} p mem) s0:(SHLLconst [8] x1:(MOVBload [i1] {s} p mem)))
@@ -9786,8 +9764,7 @@ func rewriteValue386_Op386ORL(v *Value) bool {
 			}
 			b = mergePoint(b, x0, x1)
 			v0 := b.NewValue0(x1.Pos, Op386MOVWload, typ.UInt16)
-			v.reset(OpCopy)
-			v.AddArg(v0)
+			v.copyOf(v0)
 			v0.AuxInt = i0
 			v0.Aux = s
 			v0.AddArg2(p, mem)
@@ -9850,8 +9827,7 @@ func rewriteValue386_Op386ORL(v *Value) bool {
 				}
 				b = mergePoint(b, x0, x1, x2)
 				v0 := b.NewValue0(x2.Pos, Op386MOVLload, typ.UInt32)
-				v.reset(OpCopy)
-				v.AddArg(v0)
+				v.copyOf(v0)
 				v0.AuxInt = i0
 				v0.Aux = s
 				v0.AddArg2(p, mem)
@@ -9898,8 +9874,7 @@ func rewriteValue386_Op386ORL(v *Value) bool {
 					}
 					b = mergePoint(b, x0, x1)
 					v0 := b.NewValue0(v.Pos, Op386MOVWloadidx1, v.Type)
-					v.reset(OpCopy)
-					v.AddArg(v0)
+					v.copyOf(v0)
 					v0.AuxInt = i0
 					v0.Aux = s
 					v0.AddArg3(p, idx, mem)
@@ -9974,8 +9949,7 @@ func rewriteValue386_Op386ORL(v *Value) bool {
 							}
 							b = mergePoint(b, x0, x1, x2)
 							v0 := b.NewValue0(v.Pos, Op386MOVLloadidx1, v.Type)
-							v.reset(OpCopy)
-							v.AddArg(v0)
+							v.copyOf(v0)
 							v0.AuxInt = i0
 							v0.Aux = s
 							v0.AddArg3(p, idx, mem)
@@ -10000,9 +9974,7 @@ func rewriteValue386_Op386ORLconst(v *Value) bool {
 		if !(int32(c) == 0) {
 			break
 		}
-		v.reset(OpCopy)
-		v.Type = x.Type
-		v.AddArg(x)
+		v.copyOf(x)
 		return true
 	}
 	// match: (ORLconst [c] _)
@@ -10489,9 +10461,7 @@ func rewriteValue386_Op386ROLBconst(v *Value) bool {
 			break
 		}
 		x := v_0
-		v.reset(OpCopy)
-		v.Type = x.Type
-		v.AddArg(x)
+		v.copyOf(x)
 		return true
 	}
 	return false
@@ -10519,9 +10489,7 @@ func rewriteValue386_Op386ROLLconst(v *Value) bool {
 			break
 		}
 		x := v_0
-		v.reset(OpCopy)
-		v.Type = x.Type
-		v.AddArg(x)
+		v.copyOf(x)
 		return true
 	}
 	return false
@@ -10549,9 +10517,7 @@ func rewriteValue386_Op386ROLWconst(v *Value) bool {
 			break
 		}
 		x := v_0
-		v.reset(OpCopy)
-		v.Type = x.Type
-		v.AddArg(x)
+		v.copyOf(x)
 		return true
 	}
 	return false
@@ -10583,9 +10549,7 @@ func rewriteValue386_Op386SARBconst(v *Value) bool {
 			break
 		}
 		x := v_0
-		v.reset(OpCopy)
-		v.Type = x.Type
-		v.AddArg(x)
+		v.copyOf(x)
 		return true
 	}
 	// match: (SARBconst [c] (MOVLconst [d]))
@@ -10641,9 +10605,7 @@ func rewriteValue386_Op386SARLconst(v *Value) bool {
 			break
 		}
 		x := v_0
-		v.reset(OpCopy)
-		v.Type = x.Type
-		v.AddArg(x)
+		v.copyOf(x)
 		return true
 	}
 	// match: (SARLconst [c] (MOVLconst [d]))
@@ -10687,9 +10649,7 @@ func rewriteValue386_Op386SARWconst(v *Value) bool {
 			break
 		}
 		x := v_0
-		v.reset(OpCopy)
-		v.Type = x.Type
-		v.AddArg(x)
+		v.copyOf(x)
 		return true
 	}
 	// match: (SARWconst [c] (MOVLconst [d]))
@@ -11469,9 +11429,7 @@ func rewriteValue386_Op386SHLLconst(v *Value) bool {
 			break
 		}
 		x := v_0
-		v.reset(OpCopy)
-		v.Type = x.Type
-		v.AddArg(x)
+		v.copyOf(x)
 		return true
 	}
 	return false
@@ -11522,9 +11480,7 @@ func rewriteValue386_Op386SHRBconst(v *Value) bool {
 			break
 		}
 		x := v_0
-		v.reset(OpCopy)
-		v.Type = x.Type
-		v.AddArg(x)
+		v.copyOf(x)
 		return true
 	}
 	return false
@@ -11568,9 +11524,7 @@ func rewriteValue386_Op386SHRLconst(v *Value) bool {
 			break
 		}
 		x := v_0
-		v.reset(OpCopy)
-		v.Type = x.Type
-		v.AddArg(x)
+		v.copyOf(x)
 		return true
 	}
 	return false
@@ -11621,9 +11575,7 @@ func rewriteValue386_Op386SHRWconst(v *Value) bool {
 			break
 		}
 		x := v_0
-		v.reset(OpCopy)
-		v.Type = x.Type
-		v.AddArg(x)
+		v.copyOf(x)
 		return true
 	}
 	return false
@@ -11747,9 +11699,7 @@ func rewriteValue386_Op386SUBLconst(v *Value) bool {
 		if !(int32(c) == 0) {
 			break
 		}
-		v.reset(OpCopy)
-		v.Type = x.Type
-		v.AddArg(x)
+		v.copyOf(x)
 		return true
 	}
 	// match: (SUBLconst [c] x)
@@ -12419,9 +12369,7 @@ func rewriteValue386_Op386XORLconst(v *Value) bool {
 		if !(int32(c) == 0) {
 			break
 		}
-		v.reset(OpCopy)
-		v.Type = x.Type
-		v.AddArg(x)
+		v.copyOf(x)
 		return true
 	}
 	// match: (XORLconst [c] (MOVLconst [d]))
@@ -14043,9 +13991,7 @@ func rewriteValue386_OpMove(v *Value) bool {
 			break
 		}
 		mem := v_2
-		v.reset(OpCopy)
-		v.Type = mem.Type
-		v.AddArg(mem)
+		v.copyOf(mem)
 		return true
 	}
 	// match: (Move [1] dst src mem)
@@ -15773,9 +15719,7 @@ func rewriteValue386_OpZero(v *Value) bool {
 			break
 		}
 		mem := v_1
-		v.reset(OpCopy)
-		v.Type = mem.Type
-		v.AddArg(mem)
+		v.copyOf(mem)
 		return true
 	}
 	// match: (Zero [1] destptr mem)