cmd/internal/obj/x86: add AVX2 gather and VSIB

Enables AVX2 gather instructions and VSIB support,
which makes vm32{x,y} vm64{x,y} operands encodable.

AXXX constants placed with respect to sorting order.
New VEX optabs inserted near non-VEX entries to simplify
potential transition to auto-generated VSIB optabs.

Tests go into new AMD64 encoder test file (amd64enc_extra.s)
to avoid unnecessary interactions with auto-generated "amd64enc.s".

Side note: x86avxgen did not produced these instructions
because x86.v0.2.csv misses them.
This also explains why x86 test suite have no AVX2 gather
instructions tests.

List of new instructions:
  VGATHERPDP
  VGATHERDPS
  VGATHERQPD
  VGATHERQPS
  VPGATHERDD
  VPGATHERDQ
  VPGATHERQD
  VPGATHERQQ

Change-Id: Iac852f3c5016523670bd99de6bec6a48f66fb4f6
Reviewed-on: https://go-review.googlesource.com/77970
Run-TryBot: Iskander Sharipov <iskander.sharipov@intel.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ilya Tocar <ilya.tocar@intel.com>

3 files changed, 263 insertions, 0 deletions

diff --git a/src/cmd/asm/internal/asm/endtoend_test.go b/src/cmd/asm/internal/asm/endtoend_test.go
index e5bc34edec..092b237efb 100644
--- a/src/cmd/asm/internal/asm/endtoend_test.go
+++ b/src/cmd/asm/internal/asm/endtoend_test.go
@@ -391,6 +391,7 @@ func TestAMD64EndToEnd(t *testing.T) {
 
 func TestAMD64Encoder(t *testing.T) {
 	testEndToEnd(t, "amd64", "amd64enc")
+	testEndToEnd(t, "amd64", "amd64enc_extra")
 }
 
 func TestAMD64Errors(t *testing.T) {
diff --git a/src/cmd/asm/internal/asm/testdata/amd64enc_extra.s b/src/cmd/asm/internal/asm/testdata/amd64enc_extra.s
new file mode 100644
index 0000000000..6b4d7c7356
--- /dev/null
+++ b/src/cmd/asm/internal/asm/testdata/amd64enc_extra.s
@@ -0,0 +1,237 @@
+// Copyright 2017 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This input extends auto-generated amd64enc.s test suite
+// with manually added tests.
+
+#include "../../../../../runtime/textflag.h"
+
+TEXT asmtest(SB),DUPOK|NOSPLIT,$0
+	// AVX2GATHER: basic combinations.
+	VPGATHERDQ Y2, (BP)(X7*2), Y1           // c4e2ed904c7d00
+	VPGATHERDQ X12, (R13)(X14*2), X11       // c40299905c7500
+	VPGATHERDQ Y12, (R13)(X14*2), Y11       // c4029d905c7500
+	VPGATHERDQ Y0, 8(X4*1), Y6              // c4e2fd90342508000000
+	VPGATHERDQ Y0, -8(X4*1), Y6             // c4e2fd903425f8ffffff
+	VPGATHERDQ Y0, 0(X4*1), Y6              // c4e2fd90342500000000
+	VPGATHERDQ Y0, 664(X4*1), Y6            // c4e2fd90342598020000
+	VPGATHERDQ Y0, 8(X4*8), Y6              // c4e2fd9034e508000000
+	VPGATHERDQ Y0, -8(X4*8), Y6             // c4e2fd9034e5f8ffffff
+	VPGATHERDQ Y0, 0(X4*8), Y6              // c4e2fd9034e500000000
+	VPGATHERDQ Y0, 664(X4*8), Y6            // c4e2fd9034e598020000
+	VPGATHERDQ Y0, 8(X14*1), Y6             // c4a2fd90343508000000
+	VPGATHERDQ Y0, -8(X14*1), Y6            // c4a2fd903435f8ffffff
+	VPGATHERDQ Y0, 0(X14*1), Y6             // c4a2fd90343500000000
+	VPGATHERDQ Y0, 664(X14*1), Y6           // c4a2fd90343598020000
+	VPGATHERDQ Y0, 8(X14*8), Y6             // c4a2fd9034f508000000
+	VPGATHERDQ Y0, -8(X14*8), Y6            // c4a2fd9034f5f8ffffff
+	VPGATHERDQ Y0, 0(X14*8), Y6             // c4a2fd9034f500000000
+	VPGATHERDQ Y0, 664(X14*8), Y6           // c4a2fd9034f598020000
+	VPGATHERDQ X2, (BP)(X7*2), X1           // c4e2e9904c7d00
+	VPGATHERDQ Y2, (BP)(X7*2), Y1           // c4e2ed904c7d00
+	VPGATHERDQ X12, (R13)(X14*2), X11       // c40299905c7500
+	VPGATHERDQ Y12, (R13)(X14*2), Y11       // c4029d905c7500
+	VPGATHERDQ Y0, 8(X4*1), Y6              // c4e2fd90342508000000
+	VPGATHERDQ Y0, -8(X4*1), Y6             // c4e2fd903425f8ffffff
+	VPGATHERDQ Y0, 0(X4*1), Y6              // c4e2fd90342500000000
+	VPGATHERDQ Y0, 664(X4*1), Y6            // c4e2fd90342598020000
+	VPGATHERDQ Y0, 8(X4*8), Y6              // c4e2fd9034e508000000
+	VPGATHERDQ Y0, -8(X4*8), Y6             // c4e2fd9034e5f8ffffff
+	VPGATHERDQ Y0, 0(X4*8), Y6              // c4e2fd9034e500000000
+	VPGATHERDQ Y0, 664(X4*8), Y6            // c4e2fd9034e598020000
+	VPGATHERDQ Y0, 8(X14*1), Y6             // c4a2fd90343508000000
+	VPGATHERDQ Y0, -8(X14*1), Y6            // c4a2fd903435f8ffffff
+	VPGATHERDQ Y0, 0(X14*1), Y6             // c4a2fd90343500000000
+	VPGATHERDQ Y0, 664(X14*1), Y6           // c4a2fd90343598020000
+	VPGATHERDQ Y0, 8(X14*8), Y6             // c4a2fd9034f508000000
+	VPGATHERDQ Y0, -8(X14*8), Y6            // c4a2fd9034f5f8ffffff
+	VPGATHERDQ Y0, 0(X14*8), Y6             // c4a2fd9034f500000000
+	VPGATHERDQ Y0, 664(X14*8), Y6           // c4a2fd9034f598020000
+	VPGATHERQQ X2, (BP)(X7*2), X1           // c4e2e9914c7d00
+	VPGATHERQQ Y2, (BP)(Y7*2), Y1           // c4e2ed914c7d00
+	VPGATHERQQ X12, (R13)(X14*2), X11       // c40299915c7500
+	VPGATHERQQ Y12, (R13)(Y14*2), Y11       // c4029d915c7500
+	VPGATHERQQ X2, (BP)(X7*2), X1           // c4e2e9914c7d00
+	VPGATHERQQ Y2, (BP)(Y7*2), Y1           // c4e2ed914c7d00
+	VPGATHERQQ X12, (R13)(X14*2), X11       // c40299915c7500
+	VPGATHERQQ Y12, (R13)(Y14*2), Y11       // c4029d915c7500
+	VGATHERDPD X2, (BP)(X7*2), X1           // c4e2e9924c7d00
+	VGATHERDPD Y2, (BP)(X7*2), Y1           // c4e2ed924c7d00
+	VGATHERDPD X12, (R13)(X14*2), X11       // c40299925c7500
+	VGATHERDPD Y12, (R13)(X14*2), Y11       // c4029d925c7500
+	VGATHERDPD Y0, 8(X4*1), Y6              // c4e2fd92342508000000
+	VGATHERDPD Y0, -8(X4*1), Y6             // c4e2fd923425f8ffffff
+	VGATHERDPD Y0, 0(X4*1), Y6              // c4e2fd92342500000000
+	VGATHERDPD Y0, 664(X4*1), Y6            // c4e2fd92342598020000
+	VGATHERDPD Y0, 8(X4*8), Y6              // c4e2fd9234e508000000
+	VGATHERDPD Y0, -8(X4*8), Y6             // c4e2fd9234e5f8ffffff
+	VGATHERDPD Y0, 0(X4*8), Y6              // c4e2fd9234e500000000
+	VGATHERDPD Y0, 664(X4*8), Y6            // c4e2fd9234e598020000
+	VGATHERDPD Y0, 8(X14*1), Y6             // c4a2fd92343508000000
+	VGATHERDPD Y0, -8(X14*1), Y6            // c4a2fd923435f8ffffff
+	VGATHERDPD Y0, 0(X14*1), Y6             // c4a2fd92343500000000
+	VGATHERDPD Y0, 664(X14*1), Y6           // c4a2fd92343598020000
+	VGATHERDPD Y0, 8(X14*8), Y6             // c4a2fd9234f508000000
+	VGATHERDPD Y0, -8(X14*8), Y6            // c4a2fd9234f5f8ffffff
+	VGATHERDPD Y0, 0(X14*8), Y6             // c4a2fd9234f500000000
+	VGATHERDPD Y0, 664(X14*8), Y6           // c4a2fd9234f598020000
+	VGATHERDPD X2, (BP)(X7*2), X1           // c4e2e9924c7d00
+	VGATHERDPD Y2, (BP)(X7*2), Y1           // c4e2ed924c7d00
+	VGATHERDPD X12, (R13)(X14*2), X11       // c40299925c7500
+	VGATHERDPD Y12, (R13)(X14*2), Y11       // c4029d925c7500
+	VGATHERDPD Y0, 8(X4*1), Y6              // c4e2fd92342508000000
+	VGATHERDPD Y0, -8(X4*1), Y6             // c4e2fd923425f8ffffff
+	VGATHERDPD Y0, 0(X4*1), Y6              // c4e2fd92342500000000
+	VGATHERDPD Y0, 664(X4*1), Y6            // c4e2fd92342598020000
+	VGATHERDPD Y0, 8(X4*8), Y6              // c4e2fd9234e508000000
+	VGATHERDPD Y0, -8(X4*8), Y6             // c4e2fd9234e5f8ffffff
+	VGATHERDPD Y0, 0(X4*8), Y6              // c4e2fd9234e500000000
+	VGATHERDPD Y0, 664(X4*8), Y6            // c4e2fd9234e598020000
+	VGATHERDPD Y0, 8(X14*1), Y6             // c4a2fd92343508000000
+	VGATHERDPD Y0, -8(X14*1), Y6            // c4a2fd923435f8ffffff
+	VGATHERDPD Y0, 0(X14*1), Y6             // c4a2fd92343500000000
+	VGATHERDPD Y0, 664(X14*1), Y6           // c4a2fd92343598020000
+	VGATHERDPD Y0, 8(X14*8), Y6             // c4a2fd9234f508000000
+	VGATHERDPD Y0, -8(X14*8), Y6            // c4a2fd9234f5f8ffffff
+	VGATHERDPD Y0, 0(X14*8), Y6             // c4a2fd9234f500000000
+	VGATHERDPD Y0, 664(X14*8), Y6           // c4a2fd9234f598020000
+	VGATHERQPD X2, (BP)(X7*2), X1           // c4e2e9934c7d00
+	VGATHERQPD Y2, (BP)(Y7*2), Y1           // c4e2ed934c7d00
+	VGATHERQPD X12, (R13)(X14*2), X11       // c40299935c7500
+	VGATHERQPD Y12, (R13)(Y14*2), Y11       // c4029d935c7500
+	VGATHERQPD X2, (BP)(X7*2), X1           // c4e2e9934c7d00
+	VGATHERQPD Y2, (BP)(Y7*2), Y1           // c4e2ed934c7d00
+	VGATHERQPD X12, (R13)(X14*2), X11       // c40299935c7500
+	VGATHERQPD Y12, (R13)(Y14*2), Y11       // c4029d935c7500
+	VGATHERDPS X2, (BP)(X7*2), X1           // c4e269924c7d00
+	VGATHERDPS Y2, (BP)(Y7*2), Y1           // c4e26d924c7d00
+	VGATHERDPS X12, (R13)(X14*2), X11       // c40219925c7500
+	VGATHERDPS Y12, (R13)(Y14*2), Y11       // c4021d925c7500
+	VGATHERDPS X3, 8(X4*1), X6              // c4e26192342508000000
+	VGATHERDPS X3, -8(X4*1), X6             // c4e261923425f8ffffff
+	VGATHERDPS X3, 0(X4*1), X6              // c4e26192342500000000
+	VGATHERDPS X3, 664(X4*1), X6            // c4e26192342598020000
+	VGATHERDPS X3, 8(X4*8), X6              // c4e2619234e508000000
+	VGATHERDPS X3, -8(X4*8), X6             // c4e2619234e5f8ffffff
+	VGATHERDPS X3, 0(X4*8), X6              // c4e2619234e500000000
+	VGATHERDPS X3, 664(X4*8), X6            // c4e2619234e598020000
+	VGATHERDPS X3, 8(X14*1), X6             // c4a26192343508000000
+	VGATHERDPS X3, -8(X14*1), X6            // c4a261923435f8ffffff
+	VGATHERDPS X3, 0(X14*1), X6             // c4a26192343500000000
+	VGATHERDPS X3, 664(X14*1), X6           // c4a26192343598020000
+	VGATHERDPS X3, 8(X14*8), X6             // c4a2619234f508000000
+	VGATHERDPS X3, -8(X14*8), X6            // c4a2619234f5f8ffffff
+	VGATHERDPS X3, 0(X14*8), X6             // c4a2619234f500000000
+	VGATHERDPS X3, 664(X14*8), X6           // c4a2619234f598020000
+	VGATHERDPS X2, (BP)(X7*2), X1           // c4e269924c7d00
+	VGATHERDPS Y2, (BP)(Y7*2), Y1           // c4e26d924c7d00
+	VGATHERDPS X12, (R13)(X14*2), X11       // c40219925c7500
+	VGATHERDPS Y12, (R13)(Y14*2), Y11       // c4021d925c7500
+	VGATHERDPS X5, 8(X4*1), X6              // c4e25192342508000000
+	VGATHERDPS X3, -8(X4*1), X6             // c4e261923425f8ffffff
+	VGATHERDPS X3, 0(X4*1), X6              // c4e26192342500000000
+	VGATHERDPS X3, 664(X4*1), X6            // c4e26192342598020000
+	VGATHERDPS X3, 8(X4*8), X6              // c4e2619234e508000000
+	VGATHERDPS X3, -8(X4*8), X6             // c4e2619234e5f8ffffff
+	VGATHERDPS X3, 0(X4*8), X6              // c4e2619234e500000000
+	VGATHERDPS X3, 664(X4*8), X6            // c4e2619234e598020000
+	VGATHERDPS X3, 8(X14*1), X6             // c4a26192343508000000
+	VGATHERDPS X3, -8(X14*1), X6            // c4a261923435f8ffffff
+	VGATHERDPS X3, 0(X14*1), X6             // c4a26192343500000000
+	VGATHERDPS X3, 664(X14*1), X6           // c4a26192343598020000
+	VGATHERDPS X3, 8(X14*8), X6             // c4a2619234f508000000
+	VGATHERDPS X3, -8(X14*8), X6            // c4a2619234f5f8ffffff
+	VGATHERDPS X3, 0(X14*8), X6             // c4a2619234f500000000
+	VGATHERDPS X3, 664(X14*8), X6           // c4a2619234f598020000
+	VGATHERQPS X2, (BP)(X7*2), X1           // c4e269934c7d00
+	VGATHERQPS X2, (BP)(Y7*2), X1           // c4e26d934c7d00
+	VGATHERQPS X12, (R13)(X14*2), X11       // c40219935c7500
+	VGATHERQPS X12, (R13)(Y14*2), X11       // c4021d935c7500
+	VGATHERQPS X2, (BP)(X7*2), X1           // c4e269934c7d00
+	VGATHERQPS X2, (BP)(Y7*2), X1           // c4e26d934c7d00
+	VGATHERQPS X12, (R13)(X14*2), X11       // c40219935c7500
+	VGATHERQPS X12, (R13)(Y14*2), X11       // c4021d935c7500
+	VPGATHERDD X2, (BP)(X7*2), X1           // c4e269904c7d00
+	VPGATHERDD Y2, (BP)(Y7*2), Y1           // c4e26d904c7d00
+	VPGATHERDD X12, (R13)(X14*2), X11       // c40219905c7500
+	VPGATHERDD Y12, (R13)(Y14*2), Y11       // c4021d905c7500
+	VPGATHERDD X3, 8(X4*1), X6              // c4e26190342508000000
+	VPGATHERDD X3, -8(X4*1), X6             // c4e261903425f8ffffff
+	VPGATHERDD X3, 0(X4*1), X6              // c4e26190342500000000
+	VPGATHERDD X3, 664(X4*1), X6            // c4e26190342598020000
+	VPGATHERDD X3, 8(X4*8), X6              // c4e2619034e508000000
+	VPGATHERDD X3, -8(X4*8), X6             // c4e2619034e5f8ffffff
+	VPGATHERDD X3, 0(X4*8), X6              // c4e2619034e500000000
+	VPGATHERDD X3, 664(X4*8), X6            // c4e2619034e598020000
+	VPGATHERDD X3, 8(X14*1), X6             // c4a26190343508000000
+	VPGATHERDD X3, -8(X14*1), X6            // c4a261903435f8ffffff
+	VPGATHERDD X3, 0(X14*1), X6             // c4a26190343500000000
+	VPGATHERDD X3, 664(X14*1), X6           // c4a26190343598020000
+	VPGATHERDD X3, 8(X14*8), X6             // c4a2619034f508000000
+	VPGATHERDD X3, -8(X14*8), X6            // c4a2619034f5f8ffffff
+	VPGATHERDD X3, 0(X14*8), X6             // c4a2619034f500000000
+	VPGATHERDD X3, 664(X14*8), X6           // c4a2619034f598020000
+	VPGATHERDD X2, (BP)(X7*2), X1           // c4e269904c7d00
+	VPGATHERDD Y2, (BP)(Y7*2), Y1           // c4e26d904c7d00
+	VPGATHERDD X12, (R13)(X14*2), X11       // c40219905c7500
+	VPGATHERDD Y12, (R13)(Y14*2), Y11       // c4021d905c7500
+	VPGATHERDD X3, 8(X4*1), X6              // c4e26190342508000000
+	VPGATHERDD X3, -8(X4*1), X6             // c4e261903425f8ffffff
+	VPGATHERDD X3, 0(X4*1), X6              // c4e26190342500000000
+	VPGATHERDD X3, 664(X4*1), X6            // c4e26190342598020000
+	VPGATHERDD X3, 8(X4*8), X6              // c4e2619034e508000000
+	VPGATHERDD X3, -8(X4*8), X6             // c4e2619034e5f8ffffff
+	VPGATHERDD X3, 0(X4*8), X6              // c4e2619034e500000000
+	VPGATHERDD X3, 664(X4*8), X6            // c4e2619034e598020000
+	VPGATHERDD X3, 8(X14*1), X6             // c4a26190343508000000
+	VPGATHERDD X3, -8(X14*1), X6            // c4a261903435f8ffffff
+	VPGATHERDD X3, 0(X14*1), X6             // c4a26190343500000000
+	VPGATHERDD X3, 664(X14*1), X6           // c4a26190343598020000
+	VPGATHERDD X3, 8(X14*8), X6             // c4a2619034f508000000
+	VPGATHERDD X3, -8(X14*8), X6            // c4a2619034f5f8ffffff
+	VPGATHERDD X3, 0(X14*8), X6             // c4a2619034f500000000
+	VPGATHERDD X3, 664(X14*8), X6           // c4a2619034f598020000
+	VPGATHERQD X2, (BP)(X7*2), X1           // c4e269914c7d00
+	VPGATHERQD X2, (BP)(Y7*2), X1           // c4e26d914c7d00
+	VPGATHERQD X12, (R13)(X14*2), X11       // c40219915c7500
+	VPGATHERQD X12, (R13)(Y14*2), X11       // c4021d915c7500
+	VPGATHERQD X2, (BP)(X7*2), X1           // c4e269914c7d00
+	VPGATHERQD X2, (BP)(Y7*2), X1           // c4e26d914c7d00
+	VPGATHERQD X12, (R13)(X14*2), X11       // c40219915c7500
+	VPGATHERQD X12, (R13)(Y14*2), X11       // c4021d915c7500
+	VPGATHERQQ X0, 0(X1*1), X2              // c4e2f991140d00000000
+	VPGATHERQQ Y0, 0(Y1*1), Y2              // c4e2fd91140d00000000
+	VPGATHERQQ X8, 0(X9*1), X10             // c422b991140d00000000
+	VPGATHERQQ Y8, 0(Y9*1), Y10             // c422bd91140d00000000
+	VPGATHERQQ X0, 0(X1*4), X2              // c4e2f991148d00000000
+	VPGATHERQQ Y0, 0(Y1*4), Y2              // c4e2fd91148d00000000
+	VPGATHERQQ X8, 0(X9*4), X10             // c422b991148d00000000
+	VPGATHERQQ Y8, 0(Y9*4), Y10             // c422bd91148d00000000
+	// AVX2GATHER: test SP/BP base with different displacements.
+	VPGATHERQQ X0, (SP)(X1*1), X2           // c4e2f991140c
+	VPGATHERQQ X0, 16(SP)(X1*1), X2         // c4e2f991540c10
+	VPGATHERQQ X0, 512(SP)(X1*1), X2        // c4e2f991940c00020000
+	VPGATHERQQ X0, (R12)(X1*1), X2          // c4c2f991140c
+	VPGATHERQQ X0, 16(R12)(X1*1), X2        // c4c2f991540c10
+	VPGATHERQQ X0, 512(R12)(X1*1), X2       // c4c2f991940c00020000
+	VPGATHERQQ X0, (BP)(X1*1), X2           // c4e2f991540d00
+	VPGATHERQQ X0, 16(BP)(X1*1), X2         // c4e2f991540d10
+	VPGATHERQQ X0, 512(BP)(X1*1), X2        // c4e2f991940d00020000
+	VPGATHERQQ X0, (R13)(X1*1), X2          // c4c2f991540d00
+	VPGATHERQQ X0, 16(R13)(X1*1), X2        // c4c2f991540d10
+	VPGATHERQQ X0, 512(R13)(X1*1), X2       // c4c2f991940d00020000
+	VPGATHERQQ Y0, (SP)(Y1*1), Y2           // c4e2fd91140c
+	VPGATHERQQ Y0, 16(SP)(Y1*1), Y2         // c4e2fd91540c10
+	VPGATHERQQ Y0, 512(SP)(Y1*1), Y2        // c4e2fd91940c00020000
+	VPGATHERQQ Y0, (R12)(Y1*1), Y2          // c4c2fd91140c
+	VPGATHERQQ Y0, 16(R12)(Y1*1), Y2        // c4c2fd91540c10
+	VPGATHERQQ Y0, 512(R12)(Y1*1), Y2       // c4c2fd91940c00020000
+	VPGATHERQQ Y0, (BP)(Y1*1), Y2           // c4e2fd91540d00
+	VPGATHERQQ Y0, 16(BP)(Y1*1), Y2         // c4e2fd91540d10
+	VPGATHERQQ Y0, 512(BP)(Y1*1), Y2        // c4e2fd91940d00020000
+	VPGATHERQQ Y0, (R13)(Y1*1), Y2          // c4c2fd91540d00
+	VPGATHERQQ Y0, 16(R13)(Y1*1), Y2        // c4c2fd91540d10
+	VPGATHERQQ Y0, 512(R13)(Y1*1), Y2       // c4c2fd91940d00020000
+	// End of tests.
+	RET
diff --git a/src/cmd/asm/internal/asm/testdata/amd64error.s b/src/cmd/asm/internal/asm/testdata/amd64error.s
index 2cb082dacc..7d850f7844 100644
--- a/src/cmd/asm/internal/asm/testdata/amd64error.s
+++ b/src/cmd/asm/internal/asm/testdata/amd64error.s
@@ -7,4 +7,29 @@ TEXT errors(SB),$0
 	MOVL	(AX)(SP*1), AX		// ERROR "invalid instruction"
 	EXTRACTPS $4, X2, (BX)          // ERROR "invalid instruction"
 	EXTRACTPS $-1, X2, (BX)         // ERROR "invalid instruction"
+	// VSIB addressing does not permit non-vector (X/Y)
+	// scaled index register.
+	VPGATHERDQ X12,(R13)(AX*2), X11 // ERROR "invalid instruction"
+	VPGATHERDQ X2, 664(BX*1), X1    // ERROR "invalid instruction"
+	VPGATHERDQ Y2, (BP)(AX*2), Y1   // ERROR "invalid instruction"
+	VPGATHERDQ Y5, 664(DX*8), Y6    // ERROR "invalid instruction"
+	VPGATHERDQ Y5, (DX), Y0         // ERROR "invalid instruction"
+	// VM/X rejects Y index register.
+	VPGATHERDQ Y5, 664(Y14*8), Y6   // ERROR "invalid instruction"
+	VPGATHERQQ X2, (BP)(Y7*2), X1   // ERROR "invalid instruction"
+	// VM/Y rejects X index register.
+	VPGATHERQQ Y2, (BP)(X7*2), Y1   // ERROR "invalid instruction"
+	VPGATHERDD Y5, -8(X14*8), Y6    // ERROR "invalid instruction"
+	// No VSIB for legacy instructions.
+	MOVL (AX)(X0*1), AX             // ERROR "invalid instruction"
+	MOVL (AX)(Y0*1), AX             // ERROR "invalid instruction"
+	// AVX2GATHER mask/index/dest #UD cases.
+	VPGATHERQQ Y2, (BP)(X2*2), Y2   // ERROR "mask, index, and destination registers should be distinct"
+	VPGATHERQQ Y2, (BP)(X2*2), Y7   // ERROR "mask, index, and destination registers should be distinct"
+	VPGATHERQQ Y2, (BP)(X7*2), Y2   // ERROR "mask, index, and destination registers should be distinct"
+	VPGATHERQQ Y7, (BP)(X2*2), Y2   // ERROR "mask, index, and destination registers should be distinct"
+	VPGATHERDQ X2, 664(X2*8), X2    // ERROR "mask, index, and destination registers should be distinct"
+	VPGATHERDQ X2, 664(X2*8), X7    // ERROR "mask, index, and destination registers should be distinct"
+	VPGATHERDQ X2, 664(X7*8), X2    // ERROR "mask, index, and destination registers should be distinct"
+	VPGATHERDQ X7, 664(X2*8), X2    // ERROR "mask, index, and destination registers should be distinct"
 	RET