[release-branch.go1.20] cmd/compile: remove broken LEA "optimization"

CL 440035 added rewrite rules to simplify "costly" LEA
instructions, but the types in the rewrites were wrong and
the code would go bad if the wrong-typed register was spilled.

CL 482536 attempted to fix this by correcting the type in the
rewrite, but that "fix" broke something on windows-amd64-race.

Instead / for-now, remove the offending rewrite rules.

Updates #21735.
Updates #59432.
Fixes #59468.

Change-Id: I0497c42db414f2055e1378e0a53e2bceee9cd5d9
Reviewed-on: https://go-review.googlesource.com/c/go/+/482820
Run-TryBot: David Chase <drchase@google.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
(cherry picked from commit 6a97a60b4b80dfa9db91200c054d734e18dda115)
Reviewed-on: https://go-review.googlesource.com/c/go/+/482164
Auto-Submit: Dmitri Shuralyov <dmitshur@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Keith Randall <khr@google.com>

2 files changed, 0 insertions, 401 deletions

diff --git a/src/cmd/compile/internal/ssa/_gen/AMD64latelower.rules b/src/cmd/compile/internal/ssa/_gen/AMD64latelower.rules
index bcf453128a..a1e63d6249 100644
--- a/src/cmd/compile/internal/ssa/_gen/AMD64latelower.rules
+++ b/src/cmd/compile/internal/ssa/_gen/AMD64latelower.rules
@@ -2,14 +2,6 @@
 // Use of this source code is governed by a BSD-style

 // license that can be found in the LICENSE file.

 

-// split 3 operand LEA.

-// Note: Don't split pointer computations in order to avoid invalid pointers.

-(LEA(Q|L|W)1 <t> [c] {s} x y) &&  isPtr(x.Type) && c != 0 && s == nil => (ADD(Q|L|L) x (ADD(Q|L|L)const <y.Type> [c] y))

-(LEA(Q|L|W)1 <t> [c] {s} x y) && !isPtr(x.Type) && c != 0 && s == nil => (ADD(Q|L|L) y (ADD(Q|L|L)const <x.Type> [c] x))

-(LEA(Q|L|W)2 <t> [c] {s} x y) && !isPtr(t)      && c != 0 && s == nil => (ADD(Q|L|L)const [c] (LEA(Q|L|W)2 <x.Type> x y))

-(LEA(Q|L|W)4 <t> [c] {s} x y) && !isPtr(t)      && c != 0 && s == nil => (ADD(Q|L|L)const [c] (LEA(Q|L|W)4 <x.Type> x y))

-(LEA(Q|L|W)8 <t> [c] {s} x y) && !isPtr(t)      && c != 0 && s == nil => (ADD(Q|L|L)const [c] (LEA(Q|L|W)8 <x.Type> x y))

-

 // Prefer SARX/SHLX/SHRX instruction because it has less register restriction on the shift input.

 (SAR(Q|L) x y) && buildcfg.GOAMD64 >= 3 => (SARX(Q|L) x y)

 (SHL(Q|L) x y) && buildcfg.GOAMD64 >= 3 => (SHLX(Q|L) x y)

diff --git a/src/cmd/compile/internal/ssa/rewriteAMD64latelower.go b/src/cmd/compile/internal/ssa/rewriteAMD64latelower.go
index 792cddd09e..9072257168 100644
--- a/src/cmd/compile/internal/ssa/rewriteAMD64latelower.go
+++ b/src/cmd/compile/internal/ssa/rewriteAMD64latelower.go
@@ -7,30 +7,6 @@ import "internal/buildcfg"
 
 func rewriteValueAMD64latelower(v *Value) bool {
 	switch v.Op {
-	case OpAMD64LEAL1:
-		return rewriteValueAMD64latelower_OpAMD64LEAL1(v)
-	case OpAMD64LEAL2:
-		return rewriteValueAMD64latelower_OpAMD64LEAL2(v)
-	case OpAMD64LEAL4:
-		return rewriteValueAMD64latelower_OpAMD64LEAL4(v)
-	case OpAMD64LEAL8:
-		return rewriteValueAMD64latelower_OpAMD64LEAL8(v)
-	case OpAMD64LEAQ1:
-		return rewriteValueAMD64latelower_OpAMD64LEAQ1(v)
-	case OpAMD64LEAQ2:
-		return rewriteValueAMD64latelower_OpAMD64LEAQ2(v)
-	case OpAMD64LEAQ4:
-		return rewriteValueAMD64latelower_OpAMD64LEAQ4(v)
-	case OpAMD64LEAQ8:
-		return rewriteValueAMD64latelower_OpAMD64LEAQ8(v)
-	case OpAMD64LEAW1:
-		return rewriteValueAMD64latelower_OpAMD64LEAW1(v)
-	case OpAMD64LEAW2:
-		return rewriteValueAMD64latelower_OpAMD64LEAW2(v)
-	case OpAMD64LEAW4:
-		return rewriteValueAMD64latelower_OpAMD64LEAW4(v)
-	case OpAMD64LEAW8:
-		return rewriteValueAMD64latelower_OpAMD64LEAW8(v)
 	case OpAMD64SARL:
 		return rewriteValueAMD64latelower_OpAMD64SARL(v)
 	case OpAMD64SARQ:
@@ -46,375 +22,6 @@ func rewriteValueAMD64latelower(v *Value) bool {
 	}
 	return false
 }
-func rewriteValueAMD64latelower_OpAMD64LEAL1(v *Value) bool {
-	v_1 := v.Args[1]
-	v_0 := v.Args[0]
-	b := v.Block
-	// match: (LEAL1 <t> [c] {s} x y)
-	// cond: isPtr(x.Type) && c != 0 && s == nil
-	// result: (ADDL x (ADDLconst <y.Type> [c] y))
-	for {
-		c := auxIntToInt32(v.AuxInt)
-		s := auxToSym(v.Aux)
-		for _i0 := 0; _i0 <= 1; _i0, v_0, v_1 = _i0+1, v_1, v_0 {
-			x := v_0
-			y := v_1
-			if !(isPtr(x.Type) && c != 0 && s == nil) {
-				continue
-			}
-			v.reset(OpAMD64ADDL)
-			v0 := b.NewValue0(v.Pos, OpAMD64ADDLconst, y.Type)
-			v0.AuxInt = int32ToAuxInt(c)
-			v0.AddArg(y)
-			v.AddArg2(x, v0)
-			return true
-		}
-		break
-	}
-	// match: (LEAL1 <t> [c] {s} x y)
-	// cond: !isPtr(x.Type) && c != 0 && s == nil
-	// result: (ADDL y (ADDLconst <x.Type> [c] x))
-	for {
-		c := auxIntToInt32(v.AuxInt)
-		s := auxToSym(v.Aux)
-		for _i0 := 0; _i0 <= 1; _i0, v_0, v_1 = _i0+1, v_1, v_0 {
-			x := v_0
-			y := v_1
-			if !(!isPtr(x.Type) && c != 0 && s == nil) {
-				continue
-			}
-			v.reset(OpAMD64ADDL)
-			v0 := b.NewValue0(v.Pos, OpAMD64ADDLconst, x.Type)
-			v0.AuxInt = int32ToAuxInt(c)
-			v0.AddArg(x)
-			v.AddArg2(y, v0)
-			return true
-		}
-		break
-	}
-	return false
-}
-func rewriteValueAMD64latelower_OpAMD64LEAL2(v *Value) bool {
-	v_1 := v.Args[1]
-	v_0 := v.Args[0]
-	b := v.Block
-	// match: (LEAL2 <t> [c] {s} x y)
-	// cond: !isPtr(t) && c != 0 && s == nil
-	// result: (ADDLconst [c] (LEAL2 <x.Type> x y))
-	for {
-		t := v.Type
-		c := auxIntToInt32(v.AuxInt)
-		s := auxToSym(v.Aux)
-		x := v_0
-		y := v_1
-		if !(!isPtr(t) && c != 0 && s == nil) {
-			break
-		}
-		v.reset(OpAMD64ADDLconst)
-		v.AuxInt = int32ToAuxInt(c)
-		v0 := b.NewValue0(v.Pos, OpAMD64LEAL2, x.Type)
-		v0.AddArg2(x, y)
-		v.AddArg(v0)
-		return true
-	}
-	return false
-}
-func rewriteValueAMD64latelower_OpAMD64LEAL4(v *Value) bool {
-	v_1 := v.Args[1]
-	v_0 := v.Args[0]
-	b := v.Block
-	// match: (LEAL4 <t> [c] {s} x y)
-	// cond: !isPtr(t) && c != 0 && s == nil
-	// result: (ADDLconst [c] (LEAL4 <x.Type> x y))
-	for {
-		t := v.Type
-		c := auxIntToInt32(v.AuxInt)
-		s := auxToSym(v.Aux)
-		x := v_0
-		y := v_1
-		if !(!isPtr(t) && c != 0 && s == nil) {
-			break
-		}
-		v.reset(OpAMD64ADDLconst)
-		v.AuxInt = int32ToAuxInt(c)
-		v0 := b.NewValue0(v.Pos, OpAMD64LEAL4, x.Type)
-		v0.AddArg2(x, y)
-		v.AddArg(v0)
-		return true
-	}
-	return false
-}
-func rewriteValueAMD64latelower_OpAMD64LEAL8(v *Value) bool {
-	v_1 := v.Args[1]
-	v_0 := v.Args[0]
-	b := v.Block
-	// match: (LEAL8 <t> [c] {s} x y)
-	// cond: !isPtr(t) && c != 0 && s == nil
-	// result: (ADDLconst [c] (LEAL8 <x.Type> x y))
-	for {
-		t := v.Type
-		c := auxIntToInt32(v.AuxInt)
-		s := auxToSym(v.Aux)
-		x := v_0
-		y := v_1
-		if !(!isPtr(t) && c != 0 && s == nil) {
-			break
-		}
-		v.reset(OpAMD64ADDLconst)
-		v.AuxInt = int32ToAuxInt(c)
-		v0 := b.NewValue0(v.Pos, OpAMD64LEAL8, x.Type)
-		v0.AddArg2(x, y)
-		v.AddArg(v0)
-		return true
-	}
-	return false
-}
-func rewriteValueAMD64latelower_OpAMD64LEAQ1(v *Value) bool {
-	v_1 := v.Args[1]
-	v_0 := v.Args[0]
-	b := v.Block
-	// match: (LEAQ1 <t> [c] {s} x y)
-	// cond: isPtr(x.Type) && c != 0 && s == nil
-	// result: (ADDQ x (ADDQconst <y.Type> [c] y))
-	for {
-		c := auxIntToInt32(v.AuxInt)
-		s := auxToSym(v.Aux)
-		for _i0 := 0; _i0 <= 1; _i0, v_0, v_1 = _i0+1, v_1, v_0 {
-			x := v_0
-			y := v_1
-			if !(isPtr(x.Type) && c != 0 && s == nil) {
-				continue
-			}
-			v.reset(OpAMD64ADDQ)
-			v0 := b.NewValue0(v.Pos, OpAMD64ADDQconst, y.Type)
-			v0.AuxInt = int32ToAuxInt(c)
-			v0.AddArg(y)
-			v.AddArg2(x, v0)
-			return true
-		}
-		break
-	}
-	// match: (LEAQ1 <t> [c] {s} x y)
-	// cond: !isPtr(x.Type) && c != 0 && s == nil
-	// result: (ADDQ y (ADDQconst <x.Type> [c] x))
-	for {
-		c := auxIntToInt32(v.AuxInt)
-		s := auxToSym(v.Aux)
-		for _i0 := 0; _i0 <= 1; _i0, v_0, v_1 = _i0+1, v_1, v_0 {
-			x := v_0
-			y := v_1
-			if !(!isPtr(x.Type) && c != 0 && s == nil) {
-				continue
-			}
-			v.reset(OpAMD64ADDQ)
-			v0 := b.NewValue0(v.Pos, OpAMD64ADDQconst, x.Type)
-			v0.AuxInt = int32ToAuxInt(c)
-			v0.AddArg(x)
-			v.AddArg2(y, v0)
-			return true
-		}
-		break
-	}
-	return false
-}
-func rewriteValueAMD64latelower_OpAMD64LEAQ2(v *Value) bool {
-	v_1 := v.Args[1]
-	v_0 := v.Args[0]
-	b := v.Block
-	// match: (LEAQ2 <t> [c] {s} x y)
-	// cond: !isPtr(t) && c != 0 && s == nil
-	// result: (ADDQconst [c] (LEAQ2 <x.Type> x y))
-	for {
-		t := v.Type
-		c := auxIntToInt32(v.AuxInt)
-		s := auxToSym(v.Aux)
-		x := v_0
-		y := v_1
-		if !(!isPtr(t) && c != 0 && s == nil) {
-			break
-		}
-		v.reset(OpAMD64ADDQconst)
-		v.AuxInt = int32ToAuxInt(c)
-		v0 := b.NewValue0(v.Pos, OpAMD64LEAQ2, x.Type)
-		v0.AddArg2(x, y)
-		v.AddArg(v0)
-		return true
-	}
-	return false
-}
-func rewriteValueAMD64latelower_OpAMD64LEAQ4(v *Value) bool {
-	v_1 := v.Args[1]
-	v_0 := v.Args[0]
-	b := v.Block
-	// match: (LEAQ4 <t> [c] {s} x y)
-	// cond: !isPtr(t) && c != 0 && s == nil
-	// result: (ADDQconst [c] (LEAQ4 <x.Type> x y))
-	for {
-		t := v.Type
-		c := auxIntToInt32(v.AuxInt)
-		s := auxToSym(v.Aux)
-		x := v_0
-		y := v_1
-		if !(!isPtr(t) && c != 0 && s == nil) {
-			break
-		}
-		v.reset(OpAMD64ADDQconst)
-		v.AuxInt = int32ToAuxInt(c)
-		v0 := b.NewValue0(v.Pos, OpAMD64LEAQ4, x.Type)
-		v0.AddArg2(x, y)
-		v.AddArg(v0)
-		return true
-	}
-	return false
-}
-func rewriteValueAMD64latelower_OpAMD64LEAQ8(v *Value) bool {
-	v_1 := v.Args[1]
-	v_0 := v.Args[0]
-	b := v.Block
-	// match: (LEAQ8 <t> [c] {s} x y)
-	// cond: !isPtr(t) && c != 0 && s == nil
-	// result: (ADDQconst [c] (LEAQ8 <x.Type> x y))
-	for {
-		t := v.Type
-		c := auxIntToInt32(v.AuxInt)
-		s := auxToSym(v.Aux)
-		x := v_0
-		y := v_1
-		if !(!isPtr(t) && c != 0 && s == nil) {
-			break
-		}
-		v.reset(OpAMD64ADDQconst)
-		v.AuxInt = int32ToAuxInt(c)
-		v0 := b.NewValue0(v.Pos, OpAMD64LEAQ8, x.Type)
-		v0.AddArg2(x, y)
-		v.AddArg(v0)
-		return true
-	}
-	return false
-}
-func rewriteValueAMD64latelower_OpAMD64LEAW1(v *Value) bool {
-	v_1 := v.Args[1]
-	v_0 := v.Args[0]
-	b := v.Block
-	// match: (LEAW1 <t> [c] {s} x y)
-	// cond: isPtr(x.Type) && c != 0 && s == nil
-	// result: (ADDL x (ADDLconst <y.Type> [c] y))
-	for {
-		c := auxIntToInt32(v.AuxInt)
-		s := auxToSym(v.Aux)
-		for _i0 := 0; _i0 <= 1; _i0, v_0, v_1 = _i0+1, v_1, v_0 {
-			x := v_0
-			y := v_1
-			if !(isPtr(x.Type) && c != 0 && s == nil) {
-				continue
-			}
-			v.reset(OpAMD64ADDL)
-			v0 := b.NewValue0(v.Pos, OpAMD64ADDLconst, y.Type)
-			v0.AuxInt = int32ToAuxInt(c)
-			v0.AddArg(y)
-			v.AddArg2(x, v0)
-			return true
-		}
-		break
-	}
-	// match: (LEAW1 <t> [c] {s} x y)
-	// cond: !isPtr(x.Type) && c != 0 && s == nil
-	// result: (ADDL y (ADDLconst <x.Type> [c] x))
-	for {
-		c := auxIntToInt32(v.AuxInt)
-		s := auxToSym(v.Aux)
-		for _i0 := 0; _i0 <= 1; _i0, v_0, v_1 = _i0+1, v_1, v_0 {
-			x := v_0
-			y := v_1
-			if !(!isPtr(x.Type) && c != 0 && s == nil) {
-				continue
-			}
-			v.reset(OpAMD64ADDL)
-			v0 := b.NewValue0(v.Pos, OpAMD64ADDLconst, x.Type)
-			v0.AuxInt = int32ToAuxInt(c)
-			v0.AddArg(x)
-			v.AddArg2(y, v0)
-			return true
-		}
-		break
-	}
-	return false
-}
-func rewriteValueAMD64latelower_OpAMD64LEAW2(v *Value) bool {
-	v_1 := v.Args[1]
-	v_0 := v.Args[0]
-	b := v.Block
-	// match: (LEAW2 <t> [c] {s} x y)
-	// cond: !isPtr(t) && c != 0 && s == nil
-	// result: (ADDLconst [c] (LEAW2 <x.Type> x y))
-	for {
-		t := v.Type
-		c := auxIntToInt32(v.AuxInt)
-		s := auxToSym(v.Aux)
-		x := v_0
-		y := v_1
-		if !(!isPtr(t) && c != 0 && s == nil) {
-			break
-		}
-		v.reset(OpAMD64ADDLconst)
-		v.AuxInt = int32ToAuxInt(c)
-		v0 := b.NewValue0(v.Pos, OpAMD64LEAW2, x.Type)
-		v0.AddArg2(x, y)
-		v.AddArg(v0)
-		return true
-	}
-	return false
-}
-func rewriteValueAMD64latelower_OpAMD64LEAW4(v *Value) bool {
-	v_1 := v.Args[1]
-	v_0 := v.Args[0]
-	b := v.Block
-	// match: (LEAW4 <t> [c] {s} x y)
-	// cond: !isPtr(t) && c != 0 && s == nil
-	// result: (ADDLconst [c] (LEAW4 <x.Type> x y))
-	for {
-		t := v.Type
-		c := auxIntToInt32(v.AuxInt)
-		s := auxToSym(v.Aux)
-		x := v_0
-		y := v_1
-		if !(!isPtr(t) && c != 0 && s == nil) {
-			break
-		}
-		v.reset(OpAMD64ADDLconst)
-		v.AuxInt = int32ToAuxInt(c)
-		v0 := b.NewValue0(v.Pos, OpAMD64LEAW4, x.Type)
-		v0.AddArg2(x, y)
-		v.AddArg(v0)
-		return true
-	}
-	return false
-}
-func rewriteValueAMD64latelower_OpAMD64LEAW8(v *Value) bool {
-	v_1 := v.Args[1]
-	v_0 := v.Args[0]
-	b := v.Block
-	// match: (LEAW8 <t> [c] {s} x y)
-	// cond: !isPtr(t) && c != 0 && s == nil
-	// result: (ADDLconst [c] (LEAW8 <x.Type> x y))
-	for {
-		t := v.Type
-		c := auxIntToInt32(v.AuxInt)
-		s := auxToSym(v.Aux)
-		x := v_0
-		y := v_1
-		if !(!isPtr(t) && c != 0 && s == nil) {
-			break
-		}
-		v.reset(OpAMD64ADDLconst)
-		v.AuxInt = int32ToAuxInt(c)
-		v0 := b.NewValue0(v.Pos, OpAMD64LEAW8, x.Type)
-		v0.AddArg2(x, y)
-		v.AddArg(v0)
-		return true
-	}
-	return false
-}
 func rewriteValueAMD64latelower_OpAMD64SARL(v *Value) bool {
 	v_1 := v.Args[1]
 	v_0 := v.Args[0]