cmd/compile: simplify isUintXPowerOfTwo implementation

By calling isUnsignedPowerOfTwo instead of duplicating the same ones.

Change-Id: I1e29d3b7eda1bc8773fcd25728d8f508ae633ac9
Reviewed-on: https://go-review.googlesource.com/c/go/+/692916
Reviewed-by: Keith Randall <[email protected]>
Reviewed-by: Dmitri Shuralyov <[email protected]>
Reviewed-by: Keith Randall <[email protected]>
Auto-Submit: Cuong Manh Le <[email protected]>
LUCI-TryBot-Result: Go LUCI <[email protected]>

Author: cuonglm

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

@@ -505,16 +505,10 @@ func isUnsignedPowerOfTwo[T uint8 | uint16 | uint32 | uint64](n T) bool {
 }
 
 // isUint64PowerOfTwo reports whether uint64(n) is a power of 2.
-func isUint64PowerOfTwo(in int64) bool {
-	n := uint64(in)
-	return n != 0 && n&(n-1) == 0
-}
+func isUint64PowerOfTwo(in int64) bool { return isUnsignedPowerOfTwo(uint64(in)) }
 
 // isUint32PowerOfTwo reports whether uint32(n) is a power of 2.
-func isUint32PowerOfTwo(in int64) bool {
-	n := uint64(uint32(in))
-	return n != 0 && n&(n-1) == 0
-}
+func isUint32PowerOfTwo(in int64) bool { return isUnsignedPowerOfTwo(uint32(in)) }
 
 // is32Bit reports whether n can be represented as a signed 32 bit integer.
 func is32Bit(n int64) bool {