--- a/layout/base/nsLayoutUtils.cpp
+++ b/layout/base/nsLayoutUtils.cpp
@@ -3660,16 +3660,18 @@ GetIntrinsicCoord(const nsStyleCoord& aS
 }
 
 #undef  DEBUG_INTRINSIC_WIDTH
 
 #ifdef DEBUG_INTRINSIC_WIDTH
 static int32_t gNoiseIndent = 0;
 #endif
 
+#define MULDIV(a,b,c) (nscoord(int64_t(a) * int64_t(b) / int64_t(c)))
+
 /* static */ nscoord
 nsLayoutUtils::IntrinsicForContainer(nsRenderingContext *aRenderingContext,
                                      nsIFrame *aFrame,
                                      IntrinsicWidthType aType,
                                      uint32_t aFlags)
 {
   NS_PRECONDITION(aFrame, "null frame");
   NS_PRECONDITION(aType == MIN_WIDTH || aType == PREF_WIDTH, "bad type");
@@ -3781,34 +3783,31 @@ nsLayoutUtils::IntrinsicForContainer(nsR
         default:
           break;
         }
 
         nscoord h;
         if (GetAbsoluteCoord(styleHeight, h) ||
             GetPercentHeight(styleHeight, aFrame, h)) {
           h = std::max(0, h - heightTakenByBoxSizing);
-          result =
-            NSToCoordRound(h * (float(ratio.width) / float(ratio.height)));
+          result = MULDIV(h, ratio.width, ratio.height);
         }
 
         if (GetAbsoluteCoord(styleMaxHeight, h) ||
             GetPercentHeight(styleMaxHeight, aFrame, h)) {
           h = std::max(0, h - heightTakenByBoxSizing);
-          nscoord maxWidth =
-            NSToCoordRound(h * (float(ratio.width) / float(ratio.height)));
+          nscoord maxWidth = MULDIV(h, ratio.width, ratio.height);
           if (maxWidth < result)
             result = maxWidth;
         }
 
         if (GetAbsoluteCoord(styleMinHeight, h) ||
             GetPercentHeight(styleMinHeight, aFrame, h)) {
           h = std::max(0, h - heightTakenByBoxSizing);
-          nscoord minWidth =
-            NSToCoordRound(h * (float(ratio.width) / float(ratio.height)));
+          nscoord minWidth = MULDIV(h, ratio.width, ratio.height);
           if (minWidth > result)
             result = minWidth;
         }
       }
     }
   }
 
   if (aFrame->GetType() == nsGkAtoms::tableFrame) {
@@ -4078,18 +4077,16 @@ nsLayoutUtils::MarkDescendantsDirty(nsIF
           nsIFrame* kid = childFrames.get();
           stack.AppendElement(kid);
         }
       }
     } while (stack.Length() != 0);
   } while (subtrees.Length() != 0);
 }
 
-#define MULDIV(a,b,c) (nscoord(int64_t(a) * int64_t(b) / int64_t(c)))
-
 /* static */ nsSize
 nsLayoutUtils::ComputeSizeWithIntrinsicDimensions(
                    nsRenderingContext* aRenderingContext, nsIFrame* aFrame,
                    const IntrinsicSize& aIntrinsicSize,
                    nsSize aIntrinsicRatio, nsSize aCBSize,
                    nsSize aMargin, nsSize aBorder, nsSize aPadding)
 {
   const nsStylePosition* stylePos = aFrame->StylePosition();