diff --git a/gm/blurroundrect.cpp b/gm/blurroundrect.cpp
index fe608c5..8e10957 100644
--- a/gm/blurroundrect.cpp
+++ b/gm/blurroundrect.cpp
@@ -101,3 +101,21 @@
 //DEF_GM(return new BlurRoundRectGM(600, 5514, 6);)
 
 DEF_GM(return new SimpleBlurRoundRectGM();)
+
+// From crbug.com/1138810
+DEF_SIMPLE_GM(blur_large_rrects, canvas, 300, 300) {
+    SkPaint paint;
+    paint.setMaskFilter(SkMaskFilter::MakeBlur(kNormal_SkBlurStyle, 20.f));
+
+    auto rect = SkRect::MakeLTRB(5.f, -20000.f, 240.f,  25.f);
+    SkRRect rrect = SkRRect::MakeRectXY(rect, 40.f, 40.f);
+    for (int i = 0; i < 4; ++i) {
+        SkColor4f color{(i & 1) ? 1.f : 0.f,
+                        (i & 2) ? 1.f : 0.f,
+                        (i < 2) ? 1.f : 0.f,
+                        1.f};
+        paint.setColor(color);
+        canvas->drawRRect(rrect, paint);
+        canvas->rotate(90.f, 150.f, 150.f);
+    }
+}
diff --git a/src/gpu/effects/GrRRectBlurEffect.fp b/src/gpu/effects/GrRRectBlurEffect.fp
index df41c09..8ee69f9 100644
--- a/src/gpu/effects/GrRRectBlurEffect.fp
+++ b/src/gpu/effects/GrRRectBlurEffect.fp
@@ -373,37 +373,37 @@
 void main() {
     // Warp the fragment position to the appropriate part of the 9-patch blur texture by snipping
     // out the middle section of the proxy rect.
-    half2 translatedFragPos = half2(sk_FragCoord.xy - proxyRect.LT);
-    half2 proxyCenter = half2((proxyRect.RB - proxyRect.LT) * 0.5);
+    float2 translatedFragPosFloat = sk_FragCoord.xy - proxyRect.LT;
+    float2 proxyCenter = (proxyRect.RB - proxyRect.LT) * 0.5;
     half edgeSize = 2.0 * blurRadius + cornerRadius + 0.5;
 
     // Position the fragment so that (0, 0) marks the center of the proxy rectangle.
     // Negative coordinates are on the left/top side and positive numbers are on the right/bottom.
-    translatedFragPos -= proxyCenter;
+    translatedFragPosFloat -= proxyCenter;
 
     // Temporarily strip off the fragment's sign. x/y are now strictly increasing as we move away
     // from the center.
-    half2 fragDirection = sign(translatedFragPos);
-    translatedFragPos = abs(translatedFragPos);
+    half2 fragDirection = half2(sign(translatedFragPosFloat));
+    translatedFragPosFloat = abs(translatedFragPosFloat);
 
     // Our goal is to snip out the "middle section" of the proxy rect (everything but the edge).
     // We've repositioned our fragment position so that (0, 0) is the centerpoint and x/y are always
     // positive, so we can subtract here and interpret negative results as being within the middle
     // section.
-    translatedFragPos -= proxyCenter - edgeSize;
+    half2 translatedFragPosHalf = half2(translatedFragPosFloat - (proxyCenter - edgeSize));
 
     // Remove the middle section by clamping to zero.
-    translatedFragPos = max(translatedFragPos, 0);
+    translatedFragPosHalf = max(translatedFragPosHalf, 0);
 
     // Reapply the fragment's sign, so that negative coordinates once again mean left/top side and
     // positive means bottom/right side.
-    translatedFragPos *= fragDirection;
+    translatedFragPosHalf *= fragDirection;
 
     // Offset the fragment so that (0, 0) marks the upper-left again, instead of the center point.
-    translatedFragPos += half2(edgeSize);
+    translatedFragPosHalf += half2(edgeSize);
 
     half2 proxyDims = half2(2.0 * edgeSize);
-    half2 texCoord = translatedFragPos / proxyDims;
+    half2 texCoord = translatedFragPosHalf / proxyDims;
 
     half4 inputColor = sample(inputFP);
     sk_OutColor = inputColor * sample(ninePatchFP, texCoord);
diff --git a/src/gpu/effects/generated/GrRRectBlurEffect.cpp b/src/gpu/effects/generated/GrRRectBlurEffect.cpp
index e93e6f2..255f855 100644
--- a/src/gpu/effects/generated/GrRRectBlurEffect.cpp
+++ b/src/gpu/effects/generated/GrRRectBlurEffect.cpp
@@ -359,35 +359,35 @@
         blurRadiusVar = args.fUniformHandler->addUniform(&_outer, kFragment_GrShaderFlag,
                                                          kHalf_GrSLType, "blurRadius");
         fragBuilder->codeAppendf(
-                R"SkSL(half2 translatedFragPos = half2(sk_FragCoord.xy - %s.xy);
-half2 proxyCenter = half2((%s.zw - %s.xy) * 0.5);
+                R"SkSL(float2 translatedFragPosFloat = sk_FragCoord.xy - %s.xy;
+float2 proxyCenter = (%s.zw - %s.xy) * 0.5;
 half edgeSize = (2.0 * %s + %s) + 0.5;
-translatedFragPos -= proxyCenter;
-half2 fragDirection = sign(translatedFragPos);
-translatedFragPos = abs(translatedFragPos);
-translatedFragPos -= proxyCenter - edgeSize;
-translatedFragPos = max(translatedFragPos, 0.0);
-translatedFragPos *= fragDirection;
-translatedFragPos += half2(edgeSize);
+translatedFragPosFloat -= proxyCenter;
+half2 fragDirection = half2(sign(translatedFragPosFloat));
+translatedFragPosFloat = abs(translatedFragPosFloat);
+half2 translatedFragPosHalf = half2(translatedFragPosFloat - (proxyCenter - float(edgeSize)));
+translatedFragPosHalf = max(translatedFragPosHalf, 0.0);
+translatedFragPosHalf *= fragDirection;
+translatedFragPosHalf += half2(edgeSize);
 half2 proxyDims = half2(2.0 * edgeSize);
-half2 texCoord = translatedFragPos / proxyDims;)SkSL",
+half2 texCoord = translatedFragPosHalf / proxyDims;)SkSL",
                 args.fUniformHandler->getUniformCStr(proxyRectVar),
                 args.fUniformHandler->getUniformCStr(proxyRectVar),
                 args.fUniformHandler->getUniformCStr(proxyRectVar),
                 args.fUniformHandler->getUniformCStr(blurRadiusVar),
                 args.fUniformHandler->getUniformCStr(cornerRadiusVar));
-        SkString _sample17184 = this->invokeChild(0, args);
+        SkString _sample17267 = this->invokeChild(0, args);
         fragBuilder->codeAppendf(
                 R"SkSL(
 half4 inputColor = %s;)SkSL",
-                _sample17184.c_str());
-        SkString _coords17232("float2(texCoord)");
-        SkString _sample17232 = this->invokeChild(1, args, _coords17232.c_str());
+                _sample17267.c_str());
+        SkString _coords17315("float2(texCoord)");
+        SkString _sample17315 = this->invokeChild(1, args, _coords17315.c_str());
         fragBuilder->codeAppendf(
                 R"SkSL(
 %s = inputColor * %s;
 )SkSL",
-                args.fOutputColor, _sample17232.c_str());
+                args.fOutputColor, _sample17315.c_str());
     }
 
 private: