p.errorf("expected g or R0 through R15; found %s", name)
		return 0
	}
	return uint16(reg)
}

// Note: There are two changes in the expression handling here
// compared to the old yacc/C implementations. Neither has
// much practical consequence because the expressions we
// see in assembly code are simple, but for the record:
//

import (
	"errors"
	"net/http"
	"time"
)

// Supported amz date formats.
var amzDateFormats = []string{
	// Do not change this order, x-amz-date format is usually in
	// iso8601Format rest are meant for relaxed handling of other
	// odd SDKs that might be out there.
	"20060102T150405Z",
	time.RFC1123,
	time.RFC1123Z,
	// Add new AMZ date formats here.
}

// ErrMalformedDate always returned for dates that cannot be parsed.