rem-mixin with oldIE-Fallback

SassMeister-input.scss

// ----
// Sass (v3.3.14)
// Compass (v1.0.0)
// ----

// http://css-tricks.com/snippets/css/less-mixin-for-rem-font-sizing/

@function strip-unit($value) {
    @return $value / ($value * 0 + 1);
}
@mixin rem($property, $values...) {
  $max: length($values);
  $pxValues: '';
  $remValues: '';
	
	
	@if $property == fz {
		$property: font-size;
	} @else if $property == m {
		$property: margin;
	}	@else if $property == mt {
		$property: margin-top;
	}	@else if $property == mr {
		$property: margin-right;
	}	@else if $property == mb {
		$property: margin-bottom;
	}	@else if $property == ml {
		$property: margin-left;
	} @else if $property == p {
	 	$property: padding;
	 }	@else if $property == pt {
	 	$property: padding-top;
	 }	@else if $property == pr {
	 	$property: padding-right;
	 }	@else if $property == pb {
	 	$property: padding-bottom;
	 }	@else if $property == pl {
	 	$property: padding-left;
	 }

  @for $i from 1 through $max {
    $value: strip-unit(nth($values, $i));
    $pxValues: #{$pxValues + $value}px;

    @if $i < $max {
      $pxValues: #{$pxValues + " "};
    }
  } 

  @for $i from 1 through $max {
    $value: strip-unit(nth($values, $i));
    $remValues: #{$remValues + $value/16}rem;

    @if $i < $max {
      $remValues: #{$remValues + " "};
    }
  } 
  
	@if $isoldIE == true {
  	#{$property}: $pxValues; 
	} @else {
	  #{$property}: $remValues; 		
	}
}

/* für den IE8 | for IE8 */
$isoldIE: true;
.font-size {
  @include rem(fz,20);
}

/* für Browser | for real browsers */
$isoldIE: false;
.font-size {
  @include rem(fz,20);
}

/* für den IE8 | for IE8 */
$isoldIE: true;
.padding {
  @include rem(p,20,20,15,15);
}

/* für Browser | for real browsers */
$isoldIE: false;
.padding {
  @include rem(fz,20,20,15,15);
}


/* für den IE8 | for IE8 */
$isoldIE: true;
.margin-left {
  @include rem(ml,50);
}

/* für Browser | for real browsers */
$isoldIE: false;
.margin-left {
  @include rem(ml,50);
}

SassMeister-output.css

@charset "UTF-8";
/* für den IE8 | for IE8 */
.font-size {
  font-size: 20px;
}

/* für Browser | for real browsers */
.font-size {
  font-size: 1.25rem;
}

/* für den IE8 | for IE8 */
.padding {
  padding: 20px 20px 15px 15px;
}

/* für Browser | for real browsers */
.padding {
  font-size: 1.25rem 1.25rem 0.9375rem 0.9375rem;
}

/* für den IE8 | for IE8 */
.margin-left {
  margin-left: 50px;
}

/* für Browser | for real browsers */
.margin-left {
  margin-left: 3.125rem;
}