cmd/compile: combine more constant stores on amd64

Fixes #53324

Change-Id: I06149d860f858b082235e9d80bf0ea494679b386
Reviewed-on: https://go-review.googlesource.com/c/go/+/411614
Reviewed-by: Keith Randall <khr@google.com>
Run-TryBot: Wayne Zuo <wdvxdr@golangcn.org>
Reviewed-by: Keith Randall <khr@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@google.com>

diff --git a/src/cmd/compile/internal/ssa/gen/AMD64.rules b/src/cmd/compile/internal/ssa/gen/AMD64.rules
index d96a37f7ce5926b53752d18e5934b4e78affd495..6a96b2d61eda2c42bfdd2d7944c1212b46b2d5f3 100644 (file)
--- a/src/cmd/compile/internal/ssa/gen/AMD64.rules
+++ b/src/cmd/compile/internal/ssa/gen/AMD64.rules
@@ -1929,52 +1929,52 @@
   => (MOVQstore [i] {s} p0 (BSWAPQ <w.Type> w) mem)
 
 // Combine constant stores into larger (unaligned) stores.
-(MOVBstoreconst [c] {s} p x:(MOVBstoreconst [a] {s} p mem))
+(MOVBstoreconst [c] {s} p1 x:(MOVBstoreconst [a] {s} p0 mem))
   && x.Uses == 1
-  && a.Off() + 1 == c.Off()
+  && sequentialAddresses(p0, p1, int64(a.Off()+1-c.Off()))
   && clobber(x)
-  => (MOVWstoreconst [makeValAndOff(a.Val()&0xff | c.Val()<<8, a.Off())] {s} p mem)
-(MOVBstoreconst [a] {s} p x:(MOVBstoreconst [c] {s} p mem))
+  => (MOVWstoreconst [makeValAndOff(a.Val()&0xff | c.Val()<<8, a.Off())] {s} p0 mem)
+(MOVBstoreconst [a] {s} p0 x:(MOVBstoreconst [c] {s} p1 mem))
   && x.Uses == 1
-  && a.Off() + 1 == c.Off()
+  && sequentialAddresses(p0, p1, int64(a.Off()+1-c.Off()))
   && clobber(x)
-  => (MOVWstoreconst [makeValAndOff(a.Val()&0xff | c.Val()<<8, a.Off())] {s} p mem)
-(MOVWstoreconst [c] {s} p x:(MOVWstoreconst [a] {s} p mem))
+  => (MOVWstoreconst [makeValAndOff(a.Val()&0xff | c.Val()<<8, a.Off())] {s} p0 mem)
+(MOVWstoreconst [c] {s} p1 x:(MOVWstoreconst [a] {s} p0 mem))
   && x.Uses == 1
-  && a.Off() + 2 == c.Off()
+  && sequentialAddresses(p0, p1, int64(a.Off()+2-c.Off()))
   && clobber(x)
-  => (MOVLstoreconst [makeValAndOff(a.Val()&0xffff | c.Val()<<16, a.Off())] {s} p mem)
-(MOVWstoreconst [a] {s} p x:(MOVWstoreconst [c] {s} p mem))
+  => (MOVLstoreconst [makeValAndOff(a.Val()&0xffff | c.Val()<<16, a.Off())] {s} p0 mem)
+(MOVWstoreconst [a] {s} p0 x:(MOVWstoreconst [c] {s} p1 mem))
   && x.Uses == 1
-  && a.Off() + 2 == c.Off()
+  && sequentialAddresses(p0, p1, int64(a.Off()+2-c.Off()))
   && clobber(x)
-  => (MOVLstoreconst [makeValAndOff(a.Val()&0xffff | c.Val()<<16, a.Off())] {s} p mem)
-(MOVLstoreconst [c] {s} p x:(MOVLstoreconst [a] {s} p mem))
+  => (MOVLstoreconst [makeValAndOff(a.Val()&0xffff | c.Val()<<16, a.Off())] {s} p0 mem)
+(MOVLstoreconst [c] {s} p1 x:(MOVLstoreconst [a] {s} p0 mem))
   && x.Uses == 1
-  && a.Off() + 4 == c.Off()
+  && sequentialAddresses(p0, p1, int64(a.Off()+4-c.Off()))
   && clobber(x)
-  => (MOVQstore [a.Off()] {s} p (MOVQconst [a.Val64()&0xffffffff | c.Val64()<<32]) mem)
-(MOVLstoreconst [a] {s} p x:(MOVLstoreconst [c] {s} p mem))
+  => (MOVQstore [a.Off()] {s} p0 (MOVQconst [a.Val64()&0xffffffff | c.Val64()<<32]) mem)
+(MOVLstoreconst [a] {s} p0 x:(MOVLstoreconst [c] {s} p1 mem))
   && x.Uses == 1
-  && a.Off() + 4 == c.Off()
+  && sequentialAddresses(p0, p1, int64(a.Off()+4-c.Off()))
   && clobber(x)
-  => (MOVQstore [a.Off()] {s} p (MOVQconst [a.Val64()&0xffffffff | c.Val64()<<32]) mem)
-(MOVQstoreconst [c] {s} p x:(MOVQstoreconst [a] {s} p mem))
+  => (MOVQstore [a.Off()] {s} p0 (MOVQconst [a.Val64()&0xffffffff | c.Val64()<<32]) mem)
+(MOVQstoreconst [c] {s} p1 x:(MOVQstoreconst [a] {s} p0 mem))
   && config.useSSE
   && x.Uses == 1
-  && a.Off() + 8 == c.Off()
+  && sequentialAddresses(p0, p1, int64(a.Off()+8-c.Off()))
   && a.Val() == 0
   && c.Val() == 0
   && clobber(x)
-  => (MOVOstoreconst [makeValAndOff(0,a.Off())] {s} p mem)
-(MOVQstoreconst [a] {s} p x:(MOVQstoreconst [c] {s} p mem))
+  => (MOVOstoreconst [makeValAndOff(0,a.Off())] {s} p0 mem)
+(MOVQstoreconst [a] {s} p0 x:(MOVQstoreconst [c] {s} p1 mem))
   && config.useSSE
   && x.Uses == 1
-  && a.Off() + 8 == c.Off()
+  && sequentialAddresses(p0, p1, int64(a.Off()+8-c.Off()))
   && a.Val() == 0
   && c.Val() == 0
   && clobber(x)
-  => (MOVOstoreconst [makeValAndOff(0,a.Off())] {s} p mem)
+  => (MOVOstoreconst [makeValAndOff(0,a.Off())] {s} p0 mem)
 
 // Combine stores into larger (unaligned) stores. Little endian.
 (MOVBstore [i] {s} p (SHR(W|L|Q)const [8] w) x:(MOVBstore [i-1] {s} p w mem))

diff --git a/src/cmd/compile/internal/ssa/rewriteAMD64.go b/src/cmd/compile/internal/ssa/rewriteAMD64.go
index 434496bd2f192df1437cda1ea7a56a49430fb79f..9d8ce8708bcee7fca229b59ac2623e496a4dda47 100644 (file)
--- a/src/cmd/compile/internal/ssa/rewriteAMD64.go
+++ b/src/cmd/compile/internal/ssa/rewriteAMD64.go
@@ -11402,13 +11402,13 @@ func rewriteValueAMD64_OpAMD64MOVBstoreconst(v *Value) bool {
                v.AddArg2(ptr, mem)
                return true
        }
-       // match: (MOVBstoreconst [c] {s} p x:(MOVBstoreconst [a] {s} p mem))
-       // cond: x.Uses == 1 && a.Off() + 1 == c.Off() && clobber(x)
-       // result: (MOVWstoreconst [makeValAndOff(a.Val()&0xff | c.Val()<<8, a.Off())] {s} p mem)
+       // match: (MOVBstoreconst [c] {s} p1 x:(MOVBstoreconst [a] {s} p0 mem))
+       // cond: x.Uses == 1 && sequentialAddresses(p0, p1, int64(a.Off()+1-c.Off())) && clobber(x)
+       // result: (MOVWstoreconst [makeValAndOff(a.Val()&0xff | c.Val()<<8, a.Off())] {s} p0 mem)
        for {
                c := auxIntToValAndOff(v.AuxInt)
                s := auxToSym(v.Aux)
-               p := v_0
+               p1 := v_0
                x := v_1
                if x.Op != OpAMD64MOVBstoreconst {
                        break
@@ -11418,22 +11418,23 @@ func rewriteValueAMD64_OpAMD64MOVBstoreconst(v *Value) bool {
                        break
                }
                mem := x.Args[1]
-               if p != x.Args[0] || !(x.Uses == 1 && a.Off()+1 == c.Off() && clobber(x)) {
+               p0 := x.Args[0]
+               if !(x.Uses == 1 && sequentialAddresses(p0, p1, int64(a.Off()+1-c.Off())) && clobber(x)) {
                        break
                }
                v.reset(OpAMD64MOVWstoreconst)
                v.AuxInt = valAndOffToAuxInt(makeValAndOff(a.Val()&0xff|c.Val()<<8, a.Off()))
                v.Aux = symToAux(s)
-               v.AddArg2(p, mem)
+               v.AddArg2(p0, mem)
                return true
        }
-       // match: (MOVBstoreconst [a] {s} p x:(MOVBstoreconst [c] {s} p mem))
-       // cond: x.Uses == 1 && a.Off() + 1 == c.Off() && clobber(x)
-       // result: (MOVWstoreconst [makeValAndOff(a.Val()&0xff | c.Val()<<8, a.Off())] {s} p mem)
+       // match: (MOVBstoreconst [a] {s} p0 x:(MOVBstoreconst [c] {s} p1 mem))
+       // cond: x.Uses == 1 && sequentialAddresses(p0, p1, int64(a.Off()+1-c.Off())) && clobber(x)
+       // result: (MOVWstoreconst [makeValAndOff(a.Val()&0xff | c.Val()<<8, a.Off())] {s} p0 mem)
        for {
                a := auxIntToValAndOff(v.AuxInt)
                s := auxToSym(v.Aux)
-               p := v_0
+               p0 := v_0
                x := v_1
                if x.Op != OpAMD64MOVBstoreconst {
                        break
@@ -11443,13 +11444,14 @@ func rewriteValueAMD64_OpAMD64MOVBstoreconst(v *Value) bool {
                        break
                }
                mem := x.Args[1]
-               if p != x.Args[0] || !(x.Uses == 1 && a.Off()+1 == c.Off() && clobber(x)) {
+               p1 := x.Args[0]
+               if !(x.Uses == 1 && sequentialAddresses(p0, p1, int64(a.Off()+1-c.Off())) && clobber(x)) {
                        break
                }
                v.reset(OpAMD64MOVWstoreconst)
                v.AuxInt = valAndOffToAuxInt(makeValAndOff(a.Val()&0xff|c.Val()<<8, a.Off()))
                v.Aux = symToAux(s)
-               v.AddArg2(p, mem)
+               v.AddArg2(p0, mem)
                return true
        }
        return false
@@ -12632,13 +12634,13 @@ func rewriteValueAMD64_OpAMD64MOVLstoreconst(v *Value) bool {
                v.AddArg2(ptr, mem)
                return true
        }
-       // match: (MOVLstoreconst [c] {s} p x:(MOVLstoreconst [a] {s} p mem))
-       // cond: x.Uses == 1 && a.Off() + 4 == c.Off() && clobber(x)
-       // result: (MOVQstore [a.Off()] {s} p (MOVQconst [a.Val64()&0xffffffff | c.Val64()<<32]) mem)
+       // match: (MOVLstoreconst [c] {s} p1 x:(MOVLstoreconst [a] {s} p0 mem))
+       // cond: x.Uses == 1 && sequentialAddresses(p0, p1, int64(a.Off()+4-c.Off())) && clobber(x)
+       // result: (MOVQstore [a.Off()] {s} p0 (MOVQconst [a.Val64()&0xffffffff | c.Val64()<<32]) mem)
        for {
                c := auxIntToValAndOff(v.AuxInt)
                s := auxToSym(v.Aux)
-               p := v_0
+               p1 := v_0
                x := v_1
                if x.Op != OpAMD64MOVLstoreconst {
                        break
@@ -12648,7 +12650,8 @@ func rewriteValueAMD64_OpAMD64MOVLstoreconst(v *Value) bool {
                        break
                }
                mem := x.Args[1]
-               if p != x.Args[0] || !(x.Uses == 1 && a.Off()+4 == c.Off() && clobber(x)) {
+               p0 := x.Args[0]
+               if !(x.Uses == 1 && sequentialAddresses(p0, p1, int64(a.Off()+4-c.Off())) && clobber(x)) {
                        break
                }
                v.reset(OpAMD64MOVQstore)
@@ -12656,16 +12659,16 @@ func rewriteValueAMD64_OpAMD64MOVLstoreconst(v *Value) bool {
                v.Aux = symToAux(s)
                v0 := b.NewValue0(x.Pos, OpAMD64MOVQconst, typ.UInt64)
                v0.AuxInt = int64ToAuxInt(a.Val64()&0xffffffff | c.Val64()<<32)
-               v.AddArg3(p, v0, mem)
+               v.AddArg3(p0, v0, mem)
                return true
        }
-       // match: (MOVLstoreconst [a] {s} p x:(MOVLstoreconst [c] {s} p mem))
-       // cond: x.Uses == 1 && a.Off() + 4 == c.Off() && clobber(x)
-       // result: (MOVQstore [a.Off()] {s} p (MOVQconst [a.Val64()&0xffffffff | c.Val64()<<32]) mem)
+       // match: (MOVLstoreconst [a] {s} p0 x:(MOVLstoreconst [c] {s} p1 mem))
+       // cond: x.Uses == 1 && sequentialAddresses(p0, p1, int64(a.Off()+4-c.Off())) && clobber(x)
+       // result: (MOVQstore [a.Off()] {s} p0 (MOVQconst [a.Val64()&0xffffffff | c.Val64()<<32]) mem)
        for {
                a := auxIntToValAndOff(v.AuxInt)
                s := auxToSym(v.Aux)
-               p := v_0
+               p0 := v_0
                x := v_1
                if x.Op != OpAMD64MOVLstoreconst {
                        break
@@ -12675,7 +12678,8 @@ func rewriteValueAMD64_OpAMD64MOVLstoreconst(v *Value) bool {
                        break
                }
                mem := x.Args[1]
-               if p != x.Args[0] || !(x.Uses == 1 && a.Off()+4 == c.Off() && clobber(x)) {
+               p1 := x.Args[0]
+               if !(x.Uses == 1 && sequentialAddresses(p0, p1, int64(a.Off()+4-c.Off())) && clobber(x)) {
                        break
                }
                v.reset(OpAMD64MOVQstore)
@@ -12683,7 +12687,7 @@ func rewriteValueAMD64_OpAMD64MOVLstoreconst(v *Value) bool {
                v.Aux = symToAux(s)
                v0 := b.NewValue0(x.Pos, OpAMD64MOVQconst, typ.UInt64)
                v0.AuxInt = int64ToAuxInt(a.Val64()&0xffffffff | c.Val64()<<32)
-               v.AddArg3(p, v0, mem)
+               v.AddArg3(p0, v0, mem)
                return true
        }
        return false
@@ -13593,13 +13597,13 @@ func rewriteValueAMD64_OpAMD64MOVQstoreconst(v *Value) bool {
                v.AddArg2(ptr, mem)
                return true
        }
-       // match: (MOVQstoreconst [c] {s} p x:(MOVQstoreconst [a] {s} p mem))
-       // cond: config.useSSE && x.Uses == 1 && a.Off() + 8 == c.Off() && a.Val() == 0 && c.Val() == 0 && clobber(x)
-       // result: (MOVOstoreconst [makeValAndOff(0,a.Off())] {s} p mem)
+       // match: (MOVQstoreconst [c] {s} p1 x:(MOVQstoreconst [a] {s} p0 mem))
+       // cond: config.useSSE && x.Uses == 1 && sequentialAddresses(p0, p1, int64(a.Off()+8-c.Off())) && a.Val() == 0 && c.Val() == 0 && clobber(x)
+       // result: (MOVOstoreconst [makeValAndOff(0,a.Off())] {s} p0 mem)
        for {
                c := auxIntToValAndOff(v.AuxInt)
                s := auxToSym(v.Aux)
-               p := v_0
+               p1 := v_0
                x := v_1
                if x.Op != OpAMD64MOVQstoreconst {
                        break
@@ -13609,22 +13613,23 @@ func rewriteValueAMD64_OpAMD64MOVQstoreconst(v *Value) bool {
                        break
                }
                mem := x.Args[1]
-               if p != x.Args[0] || !(config.useSSE && x.Uses == 1 && a.Off()+8 == c.Off() && a.Val() == 0 && c.Val() == 0 && clobber(x)) {
+               p0 := x.Args[0]
+               if !(config.useSSE && x.Uses == 1 && sequentialAddresses(p0, p1, int64(a.Off()+8-c.Off())) && a.Val() == 0 && c.Val() == 0 && clobber(x)) {
                        break
                }
                v.reset(OpAMD64MOVOstoreconst)
                v.AuxInt = valAndOffToAuxInt(makeValAndOff(0, a.Off()))
                v.Aux = symToAux(s)
-               v.AddArg2(p, mem)
+               v.AddArg2(p0, mem)
                return true
        }
-       // match: (MOVQstoreconst [a] {s} p x:(MOVQstoreconst [c] {s} p mem))
-       // cond: config.useSSE && x.Uses == 1 && a.Off() + 8 == c.Off() && a.Val() == 0 && c.Val() == 0 && clobber(x)
-       // result: (MOVOstoreconst [makeValAndOff(0,a.Off())] {s} p mem)
+       // match: (MOVQstoreconst [a] {s} p0 x:(MOVQstoreconst [c] {s} p1 mem))
+       // cond: config.useSSE && x.Uses == 1 && sequentialAddresses(p0, p1, int64(a.Off()+8-c.Off())) && a.Val() == 0 && c.Val() == 0 && clobber(x)
+       // result: (MOVOstoreconst [makeValAndOff(0,a.Off())] {s} p0 mem)
        for {
                a := auxIntToValAndOff(v.AuxInt)
                s := auxToSym(v.Aux)
-               p := v_0
+               p0 := v_0
                x := v_1
                if x.Op != OpAMD64MOVQstoreconst {
                        break
@@ -13634,13 +13639,14 @@ func rewriteValueAMD64_OpAMD64MOVQstoreconst(v *Value) bool {
                        break
                }
                mem := x.Args[1]
-               if p != x.Args[0] || !(config.useSSE && x.Uses == 1 && a.Off()+8 == c.Off() && a.Val() == 0 && c.Val() == 0 && clobber(x)) {
+               p1 := x.Args[0]
+               if !(config.useSSE && x.Uses == 1 && sequentialAddresses(p0, p1, int64(a.Off()+8-c.Off())) && a.Val() == 0 && c.Val() == 0 && clobber(x)) {
                        break
                }
                v.reset(OpAMD64MOVOstoreconst)
                v.AuxInt = valAndOffToAuxInt(makeValAndOff(0, a.Off()))
                v.Aux = symToAux(s)
-               v.AddArg2(p, mem)
+               v.AddArg2(p0, mem)
                return true
        }
        return false
@@ -14724,13 +14730,13 @@ func rewriteValueAMD64_OpAMD64MOVWstoreconst(v *Value) bool {
                v.AddArg2(ptr, mem)
                return true
        }
-       // match: (MOVWstoreconst [c] {s} p x:(MOVWstoreconst [a] {s} p mem))
-       // cond: x.Uses == 1 && a.Off() + 2 == c.Off() && clobber(x)
-       // result: (MOVLstoreconst [makeValAndOff(a.Val()&0xffff | c.Val()<<16, a.Off())] {s} p mem)
+       // match: (MOVWstoreconst [c] {s} p1 x:(MOVWstoreconst [a] {s} p0 mem))
+       // cond: x.Uses == 1 && sequentialAddresses(p0, p1, int64(a.Off()+2-c.Off())) && clobber(x)
+       // result: (MOVLstoreconst [makeValAndOff(a.Val()&0xffff | c.Val()<<16, a.Off())] {s} p0 mem)
        for {
                c := auxIntToValAndOff(v.AuxInt)
                s := auxToSym(v.Aux)
-               p := v_0
+               p1 := v_0
                x := v_1
                if x.Op != OpAMD64MOVWstoreconst {
                        break
@@ -14740,22 +14746,23 @@ func rewriteValueAMD64_OpAMD64MOVWstoreconst(v *Value) bool {
                        break
                }
                mem := x.Args[1]
-               if p != x.Args[0] || !(x.Uses == 1 && a.Off()+2 == c.Off() && clobber(x)) {
+               p0 := x.Args[0]
+               if !(x.Uses == 1 && sequentialAddresses(p0, p1, int64(a.Off()+2-c.Off())) && clobber(x)) {
                        break
                }
                v.reset(OpAMD64MOVLstoreconst)
                v.AuxInt = valAndOffToAuxInt(makeValAndOff(a.Val()&0xffff|c.Val()<<16, a.Off()))
                v.Aux = symToAux(s)
-               v.AddArg2(p, mem)
+               v.AddArg2(p0, mem)
                return true
        }
-       // match: (MOVWstoreconst [a] {s} p x:(MOVWstoreconst [c] {s} p mem))
-       // cond: x.Uses == 1 && a.Off() + 2 == c.Off() && clobber(x)
-       // result: (MOVLstoreconst [makeValAndOff(a.Val()&0xffff | c.Val()<<16, a.Off())] {s} p mem)
+       // match: (MOVWstoreconst [a] {s} p0 x:(MOVWstoreconst [c] {s} p1 mem))
+       // cond: x.Uses == 1 && sequentialAddresses(p0, p1, int64(a.Off()+2-c.Off())) && clobber(x)
+       // result: (MOVLstoreconst [makeValAndOff(a.Val()&0xffff | c.Val()<<16, a.Off())] {s} p0 mem)
        for {
                a := auxIntToValAndOff(v.AuxInt)
                s := auxToSym(v.Aux)
-               p := v_0
+               p0 := v_0
                x := v_1
                if x.Op != OpAMD64MOVWstoreconst {
                        break
@@ -14765,13 +14772,14 @@ func rewriteValueAMD64_OpAMD64MOVWstoreconst(v *Value) bool {
                        break
                }
                mem := x.Args[1]
-               if p != x.Args[0] || !(x.Uses == 1 && a.Off()+2 == c.Off() && clobber(x)) {
+               p1 := x.Args[0]
+               if !(x.Uses == 1 && sequentialAddresses(p0, p1, int64(a.Off()+2-c.Off())) && clobber(x)) {
                        break
                }
                v.reset(OpAMD64MOVLstoreconst)
                v.AuxInt = valAndOffToAuxInt(makeValAndOff(a.Val()&0xffff|c.Val()<<16, a.Off()))
                v.Aux = symToAux(s)
-               v.AddArg2(p, mem)
+               v.AddArg2(p0, mem)
                return true
        }
        return false

diff --git a/test/codegen/memcombine.go b/test/codegen/memcombine.go
index 6e0132744ce42050ed0e228a00aad7d9d4b82380..8143b6bed5beac7d2bfc2431fd14754625b8975d 100644 (file)
--- a/test/codegen/memcombine.go
+++ b/test/codegen/memcombine.go
@@ -377,6 +377,11 @@ func store_le64_idx2(dst []byte, d, length, offset int) []byte {
        return dst
 }
 
+func store_le64_idx_const(b []byte, idx int) {
+       // amd64:`MOVQ\s\$123, \(.*\)\(.*\*1\)$`
+       binary.LittleEndian.PutUint64(b[idx:], 123)
+}
+
 func store_le64_load(b []byte, x *[8]byte) {
        _ = b[8]
        // amd64:-`MOV[BWL]`
@@ -402,6 +407,11 @@ func store_le32_idx(b []byte, x uint32, idx int) {
        binary.LittleEndian.PutUint32(b[idx:], x)
 }
 
+func store_le32_idx_const(b []byte, idx int) {
+       // amd64:`MOVL\s\$123, \(.*\)\(.*\*1\)$`
+       binary.LittleEndian.PutUint32(b[idx:], 123)
+}
+
 func store_le16(b []byte, x uint16) {
        // amd64:`MOVW\s`
        // arm64:`MOVH`,-`MOVB`
@@ -418,6 +428,11 @@ func store_le16_idx(b []byte, x uint16, idx int) {
        binary.LittleEndian.PutUint16(b[idx:], x)
 }
 
+func store_le16_idx_const(b []byte, idx int) {
+       // amd64:`MOVW\s\$123, \(.*\)\(.*\*1\)$`
+       binary.LittleEndian.PutUint16(b[idx:], 123)
+}
+
 func store_be64(b []byte, x uint64) {
        // amd64/v1,amd64/v2:`BSWAPQ`,-`SHR.`
        // amd64/v3: `MOVBEQ`