diff --git a/src/cmd/compile/internal/amd64/galign.go b/src/cmd/compile/internal/amd64/galign.go
index 25d71e6fa65f4..364509292fe89 100644
--- a/src/cmd/compile/internal/amd64/galign.go
+++ b/src/cmd/compile/internal/amd64/galign.go
@@ -18,13 +18,6 @@ func betypeinit() {
 	if obj.GOARCH == "amd64p32" {
 		leaptr = x86.ALEAL
 	}
-	if gc.Ctxt.Flag_dynlink || obj.GOOS == "nacl" {
-		resvd = append(resvd, x86.REG_R15)
-	}
-	if gc.Ctxt.Framepointer_enabled || obj.GOOS == "nacl" {
-		resvd = append(resvd, x86.REG_BP)
-	}
-	gc.Thearch.ReservedRegs = resvd
 }
 
 func Main() {
@@ -34,13 +27,6 @@ func Main() {
 	}
 	gc.Thearch.REGSP = x86.REGSP
 	gc.Thearch.REGCTXT = x86.REGCTXT
-	gc.Thearch.REGCALLX = x86.REG_BX
-	gc.Thearch.REGCALLX2 = x86.REG_AX
-	gc.Thearch.REGRETURN = x86.REG_AX
-	gc.Thearch.REGMIN = x86.REG_AX
-	gc.Thearch.REGMAX = x86.REG_R15
-	gc.Thearch.FREGMIN = x86.REG_X0
-	gc.Thearch.FREGMAX = x86.REG_X15
 	gc.Thearch.MAXWIDTH = 1 << 50
 
 	gc.Thearch.Betypeinit = betypeinit
diff --git a/src/cmd/compile/internal/amd64/ggen.go b/src/cmd/compile/internal/amd64/ggen.go
index 2e1fb4a2c495c..c137b52d8042f 100644
--- a/src/cmd/compile/internal/amd64/ggen.go
+++ b/src/cmd/compile/internal/amd64/ggen.go
@@ -165,3 +165,14 @@ func zerorange(p *obj.Prog, frame int64, lo int64, hi int64, ax *uint32, x0 *uin
 
 	return p
 }
+
+func ginsnop() {
+	// This is actually not the x86 NOP anymore,
+	// but at the point where it gets used, AX is dead
+	// so it's okay if we lose the high bits.
+	p := gc.Prog(x86.AXCHGL)
+	p.From.Type = obj.TYPE_REG
+	p.From.Reg = x86.REG_AX
+	p.To.Type = obj.TYPE_REG
+	p.To.Reg = x86.REG_AX
+}
diff --git a/src/cmd/compile/internal/amd64/gsubr.go b/src/cmd/compile/internal/amd64/gsubr.go
deleted file mode 100644
index 1f5749315f789..0000000000000
--- a/src/cmd/compile/internal/amd64/gsubr.go
+++ /dev/null
@@ -1,58 +0,0 @@
-// Derived from Inferno utils/6c/txt.c
-// https://bitbucket.org/inferno-os/inferno-os/src/default/utils/6c/txt.c
-//
-//	Copyright © 1994-1999 Lucent Technologies Inc.  All rights reserved.
-//	Portions Copyright © 1995-1997 C H Forsyth (forsyth@terzarima.net)
-//	Portions Copyright © 1997-1999 Vita Nuova Limited
-//	Portions Copyright © 2000-2007 Vita Nuova Holdings Limited (www.vitanuova.com)
-//	Portions Copyright © 2004,2006 Bruce Ellis
-//	Portions Copyright © 2005-2007 C H Forsyth (forsyth@terzarima.net)
-//	Revisions Copyright © 2000-2007 Lucent Technologies Inc. and others
-//	Portions Copyright © 2009 The Go Authors. All rights reserved.
-//
-// Permission is hereby granted, free of charge, to any person obtaining a copy
-// of this software and associated documentation files (the "Software"), to deal
-// in the Software without restriction, including without limitation the rights
-// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-// copies of the Software, and to permit persons to whom the Software is
-// furnished to do so, subject to the following conditions:
-//
-// The above copyright notice and this permission notice shall be included in
-// all copies or substantial portions of the Software.
-//
-// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
-// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
-// THE SOFTWARE.
-
-package amd64
-
-import (
-	"cmd/compile/internal/gc"
-	"cmd/internal/obj"
-	"cmd/internal/obj/x86"
-)
-
-var resvd = []int{
-	x86.REG_DI, // for movstring
-	x86.REG_SI, // for movstring
-
-	x86.REG_AX, // for divide
-	x86.REG_CX, // for shift
-	x86.REG_DX, // for divide
-	x86.REG_SP, // for stack
-}
-
-func ginsnop() {
-	// This is actually not the x86 NOP anymore,
-	// but at the point where it gets used, AX is dead
-	// so it's okay if we lose the high bits.
-	p := gc.Prog(x86.AXCHGL)
-	p.From.Type = obj.TYPE_REG
-	p.From.Reg = x86.REG_AX
-	p.To.Type = obj.TYPE_REG
-	p.To.Reg = x86.REG_AX
-}
diff --git a/src/cmd/compile/internal/arm/galign.go b/src/cmd/compile/internal/arm/galign.go
index 090a6c25fb38a..db124f7a815b6 100644
--- a/src/cmd/compile/internal/arm/galign.go
+++ b/src/cmd/compile/internal/arm/galign.go
@@ -17,15 +17,7 @@ func Main() {
 	gc.Thearch.LinkArch = &arm.Linkarm
 	gc.Thearch.REGSP = arm.REGSP
 	gc.Thearch.REGCTXT = arm.REGCTXT
-	gc.Thearch.REGCALLX = arm.REG_R1
-	gc.Thearch.REGCALLX2 = arm.REG_R2
-	gc.Thearch.REGRETURN = arm.REG_R0
-	gc.Thearch.REGMIN = arm.REG_R0
-	gc.Thearch.REGMAX = arm.REGEXT
-	gc.Thearch.FREGMIN = arm.REG_F0
-	gc.Thearch.FREGMAX = arm.FREGEXT
 	gc.Thearch.MAXWIDTH = (1 << 32) - 1
-	gc.Thearch.ReservedRegs = resvd
 
 	gc.Thearch.Betypeinit = betypeinit
 	gc.Thearch.Defframe = defframe
diff --git a/src/cmd/compile/internal/arm/gsubr.go b/src/cmd/compile/internal/arm/gsubr.go
deleted file mode 100644
index 30c2b75598500..0000000000000
--- a/src/cmd/compile/internal/arm/gsubr.go
+++ /dev/null
@@ -1,38 +0,0 @@
-// Derived from Inferno utils/5c/txt.c
-// https://bitbucket.org/inferno-os/inferno-os/src/default/utils/5c/txt.c
-//
-//	Copyright © 1994-1999 Lucent Technologies Inc.  All rights reserved.
-//	Portions Copyright © 1995-1997 C H Forsyth (forsyth@terzarima.net)
-//	Portions Copyright © 1997-1999 Vita Nuova Limited
-//	Portions Copyright © 2000-2007 Vita Nuova Holdings Limited (www.vitanuova.com)
-//	Portions Copyright © 2004,2006 Bruce Ellis
-//	Portions Copyright © 2005-2007 C H Forsyth (forsyth@terzarima.net)
-//	Revisions Copyright © 2000-2007 Lucent Technologies Inc. and others
-//	Portions Copyright © 2009 The Go Authors. All rights reserved.
-//
-// Permission is hereby granted, free of charge, to any person obtaining a copy
-// of this software and associated documentation files (the "Software"), to deal
-// in the Software without restriction, including without limitation the rights
-// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-// copies of the Software, and to permit persons to whom the Software is
-// furnished to do so, subject to the following conditions:
-//
-// The above copyright notice and this permission notice shall be included in
-// all copies or substantial portions of the Software.
-//
-// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
-// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
-// THE SOFTWARE.
-
-package arm
-
-import "cmd/internal/obj/arm"
-
-var resvd = []int{
-	arm.REG_R9,  // formerly reserved for m; might be okay to reuse now; not sure about NaCl
-	arm.REG_R10, // reserved for g
-}
diff --git a/src/cmd/compile/internal/arm64/galign.go b/src/cmd/compile/internal/arm64/galign.go
index 6677fe6830856..27600579fa0c6 100644
--- a/src/cmd/compile/internal/arm64/galign.go
+++ b/src/cmd/compile/internal/arm64/galign.go
@@ -17,16 +17,7 @@ func Main() {
 	gc.Thearch.LinkArch = &arm64.Linkarm64
 	gc.Thearch.REGSP = arm64.REGSP
 	gc.Thearch.REGCTXT = arm64.REGCTXT
-	gc.Thearch.REGCALLX = arm64.REGRT1
-	gc.Thearch.REGCALLX2 = arm64.REGRT2
-	gc.Thearch.REGRETURN = arm64.REG_R0
-	gc.Thearch.REGMIN = arm64.REG_R0
-	gc.Thearch.REGMAX = arm64.REG_R31
-	gc.Thearch.REGZERO = arm64.REGZERO
-	gc.Thearch.FREGMIN = arm64.REG_F0
-	gc.Thearch.FREGMAX = arm64.REG_F31
 	gc.Thearch.MAXWIDTH = 1 << 50
-	gc.Thearch.ReservedRegs = resvd
 
 	gc.Thearch.Betypeinit = betypeinit
 	gc.Thearch.Defframe = defframe
diff --git a/src/cmd/compile/internal/arm64/gsubr.go b/src/cmd/compile/internal/arm64/gsubr.go
deleted file mode 100644
index f65ffe54b5820..0000000000000
--- a/src/cmd/compile/internal/arm64/gsubr.go
+++ /dev/null
@@ -1,41 +0,0 @@
-// Derived from Inferno utils/6c/txt.c
-// https://bitbucket.org/inferno-os/inferno-os/src/default/utils/6c/txt.c
-//
-//	Copyright © 1994-1999 Lucent Technologies Inc.  All rights reserved.
-//	Portions Copyright © 1995-1997 C H Forsyth (forsyth@terzarima.net)
-//	Portions Copyright © 1997-1999 Vita Nuova Limited
-//	Portions Copyright © 2000-2007 Vita Nuova Holdings Limited (www.vitanuova.com)
-//	Portions Copyright © 2004,2006 Bruce Ellis
-//	Portions Copyright © 2005-2007 C H Forsyth (forsyth@terzarima.net)
-//	Revisions Copyright © 2000-2007 Lucent Technologies Inc. and others
-//	Portions Copyright © 2009 The Go Authors. All rights reserved.
-//
-// Permission is hereby granted, free of charge, to any person obtaining a copy
-// of this software and associated documentation files (the "Software"), to deal
-// in the Software without restriction, including without limitation the rights
-// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-// copies of the Software, and to permit persons to whom the Software is
-// furnished to do so, subject to the following conditions:
-//
-// The above copyright notice and this permission notice shall be included in
-// all copies or substantial portions of the Software.
-//
-// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
-// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
-// THE SOFTWARE.
-
-package arm64
-
-import "cmd/internal/obj/arm64"
-
-var resvd = []int{
-	arm64.REGTMP,
-	arm64.REGG,
-	arm64.REGRT1,
-	arm64.REGRT2,
-	arm64.REG_R31, // REGZERO and REGSP
-}
diff --git a/src/cmd/compile/internal/gc/go.go b/src/cmd/compile/internal/gc/go.go
index f4696945cdf86..b44ad19e0d5a7 100644
--- a/src/cmd/compile/internal/gc/go.go
+++ b/src/cmd/compile/internal/gc/go.go
@@ -355,18 +355,9 @@ const (
 type Arch struct {
 	LinkArch *obj.LinkArch
 
-	REGSP        int
-	REGCTXT      int
-	REGCALLX     int // BX
-	REGCALLX2    int // AX
-	REGRETURN    int // AX
-	REGMIN       int
-	REGMAX       int
-	REGZERO      int // architectural zero register, if available
-	FREGMIN      int
-	FREGMAX      int
-	MAXWIDTH     int64
-	ReservedRegs []int
+	REGSP    int
+	REGCTXT  int
+	MAXWIDTH int64
 
 	Betypeinit func()
 	Defframe   func(*obj.Prog)
diff --git a/src/cmd/compile/internal/mips64/galign.go b/src/cmd/compile/internal/mips64/galign.go
index d8d12dec50c3e..a7ea66df0c243 100644
--- a/src/cmd/compile/internal/mips64/galign.go
+++ b/src/cmd/compile/internal/mips64/galign.go
@@ -21,15 +21,7 @@ func Main() {
 	}
 	gc.Thearch.REGSP = mips.REGSP
 	gc.Thearch.REGCTXT = mips.REGCTXT
-	gc.Thearch.REGCALLX = mips.REG_R1
-	gc.Thearch.REGCALLX2 = mips.REG_R2
-	gc.Thearch.REGRETURN = mips.REGRET
-	gc.Thearch.REGMIN = mips.REG_R0
-	gc.Thearch.REGMAX = mips.REG_R31
-	gc.Thearch.FREGMIN = mips.REG_F0
-	gc.Thearch.FREGMAX = mips.REG_F31
 	gc.Thearch.MAXWIDTH = 1 << 50
-	gc.Thearch.ReservedRegs = resvd
 
 	gc.Thearch.Betypeinit = betypeinit
 	gc.Thearch.Defframe = defframe
diff --git a/src/cmd/compile/internal/mips64/gsubr.go b/src/cmd/compile/internal/mips64/gsubr.go
deleted file mode 100644
index c67ad5530331e..0000000000000
--- a/src/cmd/compile/internal/mips64/gsubr.go
+++ /dev/null
@@ -1,44 +0,0 @@
-// Derived from Inferno utils/6c/txt.c
-// https://bitbucket.org/inferno-os/inferno-os/src/default/utils/6c/txt.c
-//
-//	Copyright © 1994-1999 Lucent Technologies Inc.  All rights reserved.
-//	Portions Copyright © 1995-1997 C H Forsyth (forsyth@terzarima.net)
-//	Portions Copyright © 1997-1999 Vita Nuova Limited
-//	Portions Copyright © 2000-2007 Vita Nuova Holdings Limited (www.vitanuova.com)
-//	Portions Copyright © 2004,2006 Bruce Ellis
-//	Portions Copyright © 2005-2007 C H Forsyth (forsyth@terzarima.net)
-//	Revisions Copyright © 2000-2007 Lucent Technologies Inc. and others
-//	Portions Copyright © 2009 The Go Authors. All rights reserved.
-//
-// Permission is hereby granted, free of charge, to any person obtaining a copy
-// of this software and associated documentation files (the "Software"), to deal
-// in the Software without restriction, including without limitation the rights
-// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-// copies of the Software, and to permit persons to whom the Software is
-// furnished to do so, subject to the following conditions:
-//
-// The above copyright notice and this permission notice shall be included in
-// all copies or substantial portions of the Software.
-//
-// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
-// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
-// THE SOFTWARE.
-
-package mips64
-
-import "cmd/internal/obj/mips"
-
-var resvd = []int{
-	mips.REGZERO,
-	mips.REGSP,   // reserved for SP
-	mips.REGSB,   // reserved for SB
-	mips.REGLINK, // reserved for link
-	mips.REGG,
-	mips.REGTMP,
-	mips.REG_R26, // kernel
-	mips.REG_R27, // kernel
-}
diff --git a/src/cmd/compile/internal/ppc64/galign.go b/src/cmd/compile/internal/ppc64/galign.go
index ddadf80aae0f2..1bbac5c868a9d 100644
--- a/src/cmd/compile/internal/ppc64/galign.go
+++ b/src/cmd/compile/internal/ppc64/galign.go
@@ -11,10 +11,6 @@ import (
 )
 
 func betypeinit() {
-	if gc.Ctxt.Flag_shared {
-		gc.Thearch.ReservedRegs = append(gc.Thearch.ReservedRegs, ppc64.REG_R2)
-		gc.Thearch.ReservedRegs = append(gc.Thearch.ReservedRegs, ppc64.REG_R12)
-	}
 }
 
 func Main() {
@@ -24,15 +20,7 @@ func Main() {
 	}
 	gc.Thearch.REGSP = ppc64.REGSP
 	gc.Thearch.REGCTXT = ppc64.REGCTXT
-	gc.Thearch.REGCALLX = ppc64.REG_R3
-	gc.Thearch.REGCALLX2 = ppc64.REG_R4
-	gc.Thearch.REGRETURN = ppc64.REG_R3
-	gc.Thearch.REGMIN = ppc64.REG_R0
-	gc.Thearch.REGMAX = ppc64.REG_R31
-	gc.Thearch.FREGMIN = ppc64.REG_F0
-	gc.Thearch.FREGMAX = ppc64.REG_F31
 	gc.Thearch.MAXWIDTH = 1 << 50
-	gc.Thearch.ReservedRegs = resvd
 
 	gc.Thearch.Betypeinit = betypeinit
 	gc.Thearch.Defframe = defframe
diff --git a/src/cmd/compile/internal/ppc64/gsubr.go b/src/cmd/compile/internal/ppc64/gsubr.go
deleted file mode 100644
index 16671b23eea35..0000000000000
--- a/src/cmd/compile/internal/ppc64/gsubr.go
+++ /dev/null
@@ -1,48 +0,0 @@
-// Derived from Inferno utils/6c/txt.c
-// https://bitbucket.org/inferno-os/inferno-os/src/default/utils/6c/txt.c
-//
-//	Copyright © 1994-1999 Lucent Technologies Inc.  All rights reserved.
-//	Portions Copyright © 1995-1997 C H Forsyth (forsyth@terzarima.net)
-//	Portions Copyright © 1997-1999 Vita Nuova Limited
-//	Portions Copyright © 2000-2007 Vita Nuova Holdings Limited (www.vitanuova.com)
-//	Portions Copyright © 2004,2006 Bruce Ellis
-//	Portions Copyright © 2005-2007 C H Forsyth (forsyth@terzarima.net)
-//	Revisions Copyright © 2000-2007 Lucent Technologies Inc. and others
-//	Portions Copyright © 2009 The Go Authors. All rights reserved.
-//
-// Permission is hereby granted, free of charge, to any person obtaining a copy
-// of this software and associated documentation files (the "Software"), to deal
-// in the Software without restriction, including without limitation the rights
-// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-// copies of the Software, and to permit persons to whom the Software is
-// furnished to do so, subject to the following conditions:
-//
-// The above copyright notice and this permission notice shall be included in
-// all copies or substantial portions of the Software.
-//
-// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
-// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
-// THE SOFTWARE.
-
-package ppc64
-
-import "cmd/internal/obj/ppc64"
-
-var resvd = []int{
-	ppc64.REGZERO,
-	ppc64.REGSP, // reserved for SP
-	// We need to preserve the C ABI TLS pointer because sigtramp
-	// may happen during C code and needs to access the g. C
-	// clobbers REGG, so if Go were to clobber REGTLS, sigtramp
-	// won't know which convention to use. By preserving REGTLS,
-	// we can just retrieve g from TLS when we aren't sure.
-	ppc64.REGTLS,
-
-	// TODO(austin): Consolidate REGTLS and REGG?
-	ppc64.REGG,
-	ppc64.REGTMP, // REGTMP
-}
diff --git a/src/cmd/compile/internal/s390x/galign.go b/src/cmd/compile/internal/s390x/galign.go
index a178041c808d7..5cf44345506ff 100644
--- a/src/cmd/compile/internal/s390x/galign.go
+++ b/src/cmd/compile/internal/s390x/galign.go
@@ -16,15 +16,7 @@ func Main() {
 	gc.Thearch.LinkArch = &s390x.Links390x
 	gc.Thearch.REGSP = s390x.REGSP
 	gc.Thearch.REGCTXT = s390x.REGCTXT
-	gc.Thearch.REGCALLX = s390x.REG_R3
-	gc.Thearch.REGCALLX2 = s390x.REG_R4
-	gc.Thearch.REGRETURN = s390x.REG_R3
-	gc.Thearch.REGMIN = s390x.REG_R0
-	gc.Thearch.REGMAX = s390x.REG_R15
-	gc.Thearch.FREGMIN = s390x.REG_F0
-	gc.Thearch.FREGMAX = s390x.REG_F15
 	gc.Thearch.MAXWIDTH = 1 << 50
-	gc.Thearch.ReservedRegs = resvd
 
 	gc.Thearch.Betypeinit = betypeinit
 	gc.Thearch.Defframe = defframe
diff --git a/src/cmd/compile/internal/s390x/gsubr.go b/src/cmd/compile/internal/s390x/gsubr.go
deleted file mode 100644
index 06043e225b792..0000000000000
--- a/src/cmd/compile/internal/s390x/gsubr.go
+++ /dev/null
@@ -1,43 +0,0 @@
-// Derived from Inferno utils/6c/txt.c
-// https://bitbucket.org/inferno-os/inferno-os/src/default/utils/6c/txt.c
-//
-//	Copyright © 1994-1999 Lucent Technologies Inc.  All rights reserved.
-//	Portions Copyright © 1995-1997 C H Forsyth (forsyth@terzarima.net)
-//	Portions Copyright © 1997-1999 Vita Nuova Limited
-//	Portions Copyright © 2000-2007 Vita Nuova Holdings Limited (www.vitanuova.com)
-//	Portions Copyright © 2004,2006 Bruce Ellis
-//	Portions Copyright © 2005-2007 C H Forsyth (forsyth@terzarima.net)
-//	Revisions Copyright © 2000-2007 Lucent Technologies Inc. and others
-//	Portions Copyright © 2009 The Go Authors.  All rights reserved.
-//
-// Permission is hereby granted, free of charge, to any person obtaining a copy
-// of this software and associated documentation files (the "Software"), to deal
-// in the Software without restriction, including without limitation the rights
-// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-// copies of the Software, and to permit persons to whom the Software is
-// furnished to do so, subject to the following conditions:
-//
-// The above copyright notice and this permission notice shall be included in
-// all copies or substantial portions of the Software.
-//
-// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
-// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
-// THE SOFTWARE.
-
-package s390x
-
-import "cmd/internal/obj/s390x"
-
-var resvd = []int{
-	s390x.REGZERO, // R0
-	s390x.REGTMP,  // R10
-	s390x.REGTMP2, // R11
-	s390x.REGCTXT, // R12
-	s390x.REGG,    // R13
-	s390x.REG_LR,  // R14
-	s390x.REGSP,   // R15
-}
diff --git a/src/cmd/compile/internal/x86/galign.go b/src/cmd/compile/internal/x86/galign.go
index df9f7748f3b63..9c014678c1910 100644
--- a/src/cmd/compile/internal/x86/galign.go
+++ b/src/cmd/compile/internal/x86/galign.go
@@ -19,25 +19,15 @@ func Main() {
 	gc.Thearch.LinkArch = &x86.Link386
 	gc.Thearch.REGSP = x86.REGSP
 	gc.Thearch.REGCTXT = x86.REGCTXT
-	gc.Thearch.REGCALLX = x86.REG_BX
-	gc.Thearch.REGCALLX2 = x86.REG_AX
-	gc.Thearch.REGRETURN = x86.REG_AX
-	gc.Thearch.REGMIN = x86.REG_AX
-	gc.Thearch.REGMAX = x86.REG_DI
 	switch v := obj.GO386; v {
 	case "387":
-		gc.Thearch.FREGMIN = x86.REG_F0
-		gc.Thearch.FREGMAX = x86.REG_F7
 		gc.Thearch.Use387 = true
 	case "sse2":
-		gc.Thearch.FREGMIN = x86.REG_X0
-		gc.Thearch.FREGMAX = x86.REG_X7
 	default:
 		fmt.Fprintf(os.Stderr, "unsupported setting GO386=%s\n", v)
 		gc.Exit(1)
 	}
 	gc.Thearch.MAXWIDTH = (1 << 32) - 1
-	gc.Thearch.ReservedRegs = resvd
 
 	gc.Thearch.Betypeinit = betypeinit
 	gc.Thearch.Defframe = defframe
diff --git a/src/cmd/compile/internal/x86/ggen.go b/src/cmd/compile/internal/x86/ggen.go
index 97788254f9d08..d146fb1b54590 100644
--- a/src/cmd/compile/internal/x86/ggen.go
+++ b/src/cmd/compile/internal/x86/ggen.go
@@ -83,3 +83,11 @@ func zerorange(p *obj.Prog, frame int64, lo int64, hi int64, ax *uint32) *obj.Pr
 
 	return p
 }
+
+func ginsnop() {
+	p := gc.Prog(x86.AXCHGL)
+	p.From.Type = obj.TYPE_REG
+	p.From.Reg = x86.REG_AX
+	p.To.Type = obj.TYPE_REG
+	p.To.Reg = x86.REG_AX
+}
diff --git a/src/cmd/compile/internal/x86/gsubr.go b/src/cmd/compile/internal/x86/gsubr.go
deleted file mode 100644
index 96105356fd72f..0000000000000
--- a/src/cmd/compile/internal/x86/gsubr.go
+++ /dev/null
@@ -1,55 +0,0 @@
-// Derived from Inferno utils/8c/txt.c
-// https://bitbucket.org/inferno-os/inferno-os/src/default/utils/8c/txt.c
-//
-//	Copyright © 1994-1999 Lucent Technologies Inc.  All rights reserved.
-//	Portions Copyright © 1995-1997 C H Forsyth (forsyth@terzarima.net)
-//	Portions Copyright © 1997-1999 Vita Nuova Limited
-//	Portions Copyright © 2000-2007 Vita Nuova Holdings Limited (www.vitanuova.com)
-//	Portions Copyright © 2004,2006 Bruce Ellis
-//	Portions Copyright © 2005-2007 C H Forsyth (forsyth@terzarima.net)
-//	Revisions Copyright © 2000-2007 Lucent Technologies Inc. and others
-//	Portions Copyright © 2009 The Go Authors. All rights reserved.
-//
-// Permission is hereby granted, free of charge, to any person obtaining a copy
-// of this software and associated documentation files (the "Software"), to deal
-// in the Software without restriction, including without limitation the rights
-// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-// copies of the Software, and to permit persons to whom the Software is
-// furnished to do so, subject to the following conditions:
-//
-// The above copyright notice and this permission notice shall be included in
-// all copies or substantial portions of the Software.
-//
-// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
-// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
-// THE SOFTWARE.
-
-package x86
-
-import (
-	"cmd/compile/internal/gc"
-	"cmd/internal/obj"
-	"cmd/internal/obj/x86"
-)
-
-var resvd = []int{
-	//	REG_DI,	// for movstring
-	//	REG_SI,	// for movstring
-
-	x86.REG_AX, // for divide
-	x86.REG_CX, // for shift
-	x86.REG_DX, // for divide, context
-	x86.REG_SP, // for stack
-}
-
-func ginsnop() {
-	p := gc.Prog(x86.AXCHGL)
-	p.From.Type = obj.TYPE_REG
-	p.From.Reg = x86.REG_AX
-	p.To.Type = obj.TYPE_REG
-	p.To.Reg = x86.REG_AX
-}