diff --git a/engine/src/flutter/impeller/compiler/shader_lib/impeller/path.glsl b/engine/src/flutter/impeller/compiler/shader_lib/impeller/path.glsl
index 774648f345a..e0e0a969347 100644
--- a/engine/src/flutter/impeller/compiler/shader_lib/impeller/path.glsl
+++ b/engine/src/flutter/impeller/compiler/shader_lib/impeller/path.glsl
@@ -5,11 +5,6 @@
 #ifndef PATH_GLSL_
 #define PATH_GLSL_
 
-#define MOVE 0
-#define LINE 1
-#define QUAD 2
-#define CUBIC 3
-
 struct LineData {
   vec2 p1;
   vec2 p2;
diff --git a/engine/src/flutter/impeller/fixtures/cubic_to_quads.comp b/engine/src/flutter/impeller/fixtures/cubic_to_quads.comp
index 3748a7a0f39..a2249f56caf 100644
--- a/engine/src/flutter/impeller/fixtures/cubic_to_quads.comp
+++ b/engine/src/flutter/impeller/fixtures/cubic_to_quads.comp
@@ -28,6 +28,19 @@ config;
 shared uint quad_counts[512];
 shared uint count_sums[512];
 
+uint ComputePosition(uint index) {
+  if (index < gl_SubgroupSize) {
+    return count_sums[index];
+  }
+  int position = -1;
+  uint count_sum = count_sums[index];
+  do {
+    position += int(gl_SubgroupSize);
+    count_sum += count_sums[position];
+  } while (position < index);
+  return count_sum;
+}
+
 void main() {
   uint ident = gl_GlobalInvocationID.x;
   CubicData cubic;
@@ -45,9 +58,9 @@ void main() {
 
   count_sums[ident] = subgroupInclusiveAdd(quad_counts[ident]);
 
-  quads.count = count_sums[cubics.count - 1];
+  quads.count = ComputePosition(cubics.count - 1);
+  uint offset = ComputePosition(ident) - quad_count;
   for (uint i = 0; i < quad_count; i++) {
-    uint offset = count_sums[ident] - quad_count;
     quads.data[offset + i] = GenerateQuadraticFromCubic(cubic, i, quad_count);
   }
 }
diff --git a/engine/src/flutter/impeller/fixtures/quad_polyline.comp b/engine/src/flutter/impeller/fixtures/quad_polyline.comp
index b483da8e35a..e581775bbac 100644
--- a/engine/src/flutter/impeller/fixtures/quad_polyline.comp
+++ b/engine/src/flutter/impeller/fixtures/quad_polyline.comp
@@ -28,6 +28,19 @@ config;
 shared uint point_counts[512];
 shared uint count_sums[512];
 
+uint ComputePosition(uint index) {
+  if (index < gl_SubgroupSize) {
+    return count_sums[index];
+  }
+  int position = -1;
+  uint count_sum = count_sums[index];
+  do {
+    position += int(gl_SubgroupSize);
+    count_sum += count_sums[position];
+  } while (position < index);
+  return count_sum;
+}
+
 void main() {
   uint ident = gl_GlobalInvocationID.x;
   QuadData quad;
@@ -45,15 +58,16 @@ void main() {
   }
   count_sums[ident] = subgroupInclusiveAdd(point_counts[ident]);
 
-  polyline.count = count_sums[quads.count - 1] + 1;
+  polyline.count = ComputePosition(quads.count - 1) + 1;
   polyline.data[0] = quads.data[0].p1;
 
   // In theory this could be unrolled into a separate shader, but in practice
   // line_count usually pretty low and currently lack benchmark data to show
   // how much it would even help.
+  uint position = ComputePosition(ident);
+  uint offset = position - uint(decomposition.line_count);
   for (uint i = 1; i < decomposition.line_count; i += 1) {
-    uint offset = count_sums[ident] - uint(decomposition.line_count);
     polyline.data[offset + i] = GenerateLineFromQuad(quad, i, decomposition);
   }
-  polyline.data[count_sums[ident]] = quad.p2;
+  polyline.data[position] = quad.p2;
 }
diff --git a/engine/src/flutter/impeller/renderer/compute_subgroup_unittests.cc b/engine/src/flutter/impeller/renderer/compute_subgroup_unittests.cc
index 39c36c6ce28..e0f6b86dfec 100644
--- a/engine/src/flutter/impeller/renderer/compute_subgroup_unittests.cc
+++ b/engine/src/flutter/impeller/renderer/compute_subgroup_unittests.cc
@@ -32,9 +32,7 @@ namespace testing {
 using ComputeTest = ComputePlaygroundTest;
 INSTANTIATE_COMPUTE_SUITE(ComputeTest);
 
-// TODO(dnfield): Re-enable
-// https://github.com/flutter/flutter/issues/122828
-TEST_P(ComputeTest, DISABLED_HeartCubicsToStrokeVertices) {
+TEST_P(ComputeTest, HeartCubicsToStrokeVertices) {
   using CS = CubicToQuadsComputeShader;
   using QS = QuadPolylineComputeShader;
   using SS = StrokeComputeShader;
@@ -258,9 +256,7 @@ TEST_P(ComputeTest, DISABLED_HeartCubicsToStrokeVertices) {
   ASSERT_TRUE(OpenPlaygroundHere(callback));
 }
 
-// TODO(dnfield): Re-enable
-// https://github.com/flutter/flutter/issues/122828
-TEST_P(ComputeTest, DISABLED_QuadsToPolyline) {
+TEST_P(ComputeTest, QuadsToPolyline) {
   using QS = QuadPolylineComputeShader;
   auto context = GetContext();
   ASSERT_TRUE(context);