cmd/compile: remove amd64p32 related SSA rules

Updates golang/go#30439

Change-Id: Iadc737e4c6bb05bb576fe4bb344ad92403697352
Reviewed-on: https://go-review.googlesource.com/c/go/+/201380
Run-TryBot: Ben Shi <powerman1st@163.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>

src/cmd/compile/internal/ssa/gen/AMD64.rules

@@ -226,9 +226,6 @@
 (NeqPtr x y) && config.PtrSize == 4 -> (SETNE (CMPL x y))
 (Neq(32|64)F x y) -> (SETNEF (UCOMIS(S|D) x y))
 
-(Int64Hi x) -> (SHRQconst [32] x)         // needed for amd64p32
-(Int64Lo x) -> x
-
 // Lowering loads
 (Load <t> ptr mem) && (is64BitInt(t) || isPtr(t) && config.PtrSize == 8) -> (MOVQload ptr mem)
 (Load <t> ptr mem) && (is32BitInt(t) || isPtr(t) && config.PtrSize == 4) -> (MOVLload ptr mem)

src/cmd/compile/internal/ssa/rewriteAMD64.go

@@ -826,10 +826,6 @@ func rewriteValueAMD64(v *Value) bool {
 		return rewriteValueAMD64_OpHmul64_0(v)
 	case OpHmul64u:
 		return rewriteValueAMD64_OpHmul64u_0(v)
-	case OpInt64Hi:
-		return rewriteValueAMD64_OpInt64Hi_0(v)
-	case OpInt64Lo:
-		return rewriteValueAMD64_OpInt64Lo_0(v)
 	case OpInterCall:
 		return rewriteValueAMD64_OpInterCall_0(v)
 	case OpIsInBounds:
@@ -52729,28 +52725,6 @@ func rewriteValueAMD64_OpHmul64u_0(v *Value) bool {
 		return true
 	}
 }
-func rewriteValueAMD64_OpInt64Hi_0(v *Value) bool {
-	// match: (Int64Hi x)
-	// result: (SHRQconst [32] x)
-	for {
-		x := v.Args[0]
-		v.reset(OpAMD64SHRQconst)
-		v.AuxInt = 32
-		v.AddArg(x)
-		return true
-	}
-}
-func rewriteValueAMD64_OpInt64Lo_0(v *Value) bool {
-	// match: (Int64Lo x)
-	// result: x
-	for {
-		x := v.Args[0]
-		v.reset(OpCopy)
-		v.Type = x.Type
-		v.AddArg(x)
-		return true
-	}
-}
 func rewriteValueAMD64_OpInterCall_0(v *Value) bool {
 	// match: (InterCall [argwid] entry mem)
 	// result: (CALLinter [argwid] entry mem)