diff --git a/gm/gmmain.cpp b/gm/gmmain.cpp
index 742fb46..54bbd8b 100644
--- a/gm/gmmain.cpp
+++ b/gm/gmmain.cpp
@@ -748,11 +748,7 @@
 };
 
 static void usage(const char * argv0) {
-    // TODO: rearrange into alphabetical order
-    // TODO: add documentation for missing options
     SkDebugf("%s\n", argv0);
-    SkDebugf("    [-w writePath] [-r readPath] [-d diffPath] [-i resourcePath]\n");
-    SkDebugf("    [-wp writePicturePath]\n");
     SkDebugf("    [--config ");
     for (size_t i = 0; i < SK_ARRAY_COUNT(gRec); ++i) {
         if (i > 0) {
@@ -760,31 +756,37 @@
         }
         SkDebugf(gRec[i].fName);
     }
-    SkDebugf(" ]\n");
-    SkDebugf("    [--noreplay] [--nopipe] [--noserialize] [--forceBWtext] [--nopdf] \n"
-             "    [--tiledPipe] [--hierarchy | --nohierarchy]\n"
-             "    [--nodeferred] [--match substring] [--notexturecache]\n"
-             "    [-h|--help]\n"
+    SkDebugf("]:\n        run these configurations\n");
+    SkDebugf(
+// Alphabetized ignoring "no" prefix ("readPath", "noreplay", "resourcePath").
+// It would probably be better if we allowed both yes-and-no settings for each
+// one, e.g.:
+// [--replay|--noreplay]: whether to exercise SkPicture replay; default is yes
+"    [--nodeferred]: skip the deferred rendering test pass\n"
+"    [--diffPath|-d <path>]: write difference images into this directory\n"
+"    [--disable-missing-warning]: don't print a message to stderr if\n"
+"        unable to read a reference image for any tests (NOT default behavior)\n"
+"    [--enable-missing-warning]: print message to stderr (but don't fail) if\n"
+"        unable to read a reference image for any tests (default behavior)\n"
+"    [--forceBWtext]: disable text anti-aliasing\n"
+"    [--help|-h]: show this help message\n"
+"    [--hierarchy|--nohierarchy]: whether to use multilevel directory structure\n"
+"        when reading/writing files; default is no\n"
+"    [--match <substring>]: only run tests whose name includes this substring\n"
+"    [--modulo <remainder> <divisor>]: only run tests for which \n"
+"        testIndex %% divisor == remainder\n"
+"    [--nopdf]: skip the pdf rendering test pass\n"
+"    [--nopipe]: Skip SkGPipe replay\n"
+"    [--readPath|-r <path>]: read reference images from this dir, and report\n"
+"        any differences between those and the newly generated ones\n"
+"    [--noreplay]: do not exercise SkPicture replay\n"
+"    [--resourcePath|-i <path>]: directory that stores image resources\n"
+"    [--noserialize]: do not exercise SkPicture serialization & deserialization\n"
+"    [--notexturecache]: disable the gpu texture cache\n"
+"    [--tiledPipe]: Exercise tiled SkGPipe replay\n"
+"    [--writePath|-w <path>]: write rendered images into this directory\n"
+"    [--writePicturePath|-wp <path>]: write .skp files into this directory\n"
              );
-    SkDebugf("    writePath: directory to write rendered images in.\n");
-    SkDebugf("    writePicturePath: directory to write images to in .skp format.\n");
-    SkDebugf(
-             "    readPath: directory to read reference images from;\n"
-             "        reports if any pixels mismatch between reference and new images\n");
-    SkDebugf("    diffPath: directory to write difference images in.\n");
-    SkDebugf("    resourcePath: directory that stores image resources.\n");
-    SkDebugf("    --noreplay: do not exercise SkPicture replay.\n");
-    SkDebugf("    --nopipe: Skip SkGPipe replay.\n");
-    SkDebugf("    --tiledPipe: Exercise tiled SkGPipe replay.\n");
-    SkDebugf(
-             "    --noserialize: do not exercise SkPicture serialization & deserialization.\n");
-    SkDebugf("    --forceBWtext: disable text anti-aliasing.\n");
-    SkDebugf("    --hierarchy: use multilevel directory structure when reading/writing files.\n");
-    SkDebugf("    --nopdf: skip the pdf rendering test pass.\n");
-    SkDebugf("    --nodeferred: skip the deferred rendering test pass.\n");
-    SkDebugf("    --match foo: will only run tests that substring match foo.\n");
-    SkDebugf("    --notexturecache: disable the gpu texture cache.\n");
-    SkDebugf("    -h|--help : Show this help message. \n");
 }
 
 static int findConfig(const char config[]) {
@@ -887,85 +889,13 @@
     SkTDArray<size_t> configs;
     bool userConfig = false;
 
-    int moduloIndex = -1;
-    int moduloCount = -1;
+    int moduloRemainder = -1;
+    int moduloDivisor = -1;
 
     const char* const commandName = argv[0];
     char* const* stop = argv + argc;
     for (++argv; argv < stop; ++argv) {
-        // TODO: rearrange options into alphabetical order
-        if (strcmp(*argv, "-w") == 0) {
-            argv++;
-            if (argv < stop && **argv) {
-                writePath = *argv;
-            }
-        } else if (strcmp(*argv, "-wp") == 0) {
-            argv++;
-            if (argv < stop && **argv) {
-                writePicturePath = *argv;
-            }
-        } else if (strcmp(*argv, "-r") == 0) {
-            argv++;
-            if (argv < stop && **argv) {
-                readPath = *argv;
-            }
-        } else if (strcmp(*argv, "-d") == 0) {
-            argv++;
-            if (argv < stop && **argv) {
-                diffPath = *argv;
-            }
-        } else if (strcmp(*argv, "-i") == 0) {
-            argv++;
-            if (argv < stop && **argv) {
-                resourcePath = *argv;
-            }
-        } else if (strcmp(*argv, "--forceBWtext") == 0) {
-            gForceBWtext = true;
-        } else if (strcmp(*argv, "--nopipe") == 0) {
-            doPipe = false;
-        } else if (strcmp(*argv, "--tiledPipe") == 0) {
-            doTiledPipe = true;
-        } else if (strcmp(*argv, "--noreplay") == 0) {
-            doReplay = false;
-        } else if (strcmp(*argv, "--nopdf") == 0) {
-            doPDF = false;
-        } else if (strcmp(*argv, "--nodeferred") == 0) {
-            doDeferred = false;
-        } else if (strcmp(*argv, "--modulo") == 0) {
-            ++argv;
-            if (argv >= stop) {
-                continue;
-            }
-            moduloIndex = atoi(*argv);
-
-            ++argv;
-            if (argv >= stop) {
-                continue;
-            }
-            moduloCount = atoi(*argv);
-        } else if (strcmp(*argv, "--disable-missing-warning") == 0) {
-            gmmain.fNotifyMissingReadReference = false;
-        } else if (strcmp(*argv, "--enable-missing-warning") == 0) {
-            gmmain.fNotifyMissingReadReference = true;
-        } else if (strcmp(*argv, "--hierarchy") == 0) {
-            gmmain.fUseFileHierarchy = true;
-        } else if (strcmp(*argv, "--nohierarchy") == 0) {
-            gmmain.fUseFileHierarchy = false;
-        } else if (strcmp(*argv, "--serialize") == 0) {
-            // Leaving in this option so that a user need not modify
-            // their command line arguments to still run.
-            doSerialize = true;
-        } else if (strcmp(*argv, "--noserialize") == 0) {
-            doSerialize = false;
-        } else if (strcmp(*argv, "--match") == 0) {
-            ++argv;
-            if (argv < stop && **argv) {
-                // just record the ptr, no need for a deep copy
-                *fMatches.append() = *argv;
-            }
-        } else if (strcmp(*argv, "--notexturecache") == 0) {
-            disableTextureCache = true;
-        } else if (strcmp(*argv, "--config") == 0) {
+        if (strcmp(*argv, "--config") == 0) {
             argv++;
             if (argv < stop) {
                 int index = findConfig(*argv);
@@ -984,9 +914,83 @@
                 usage(commandName);
                 return -1;
             }
+        } else if (strcmp(*argv, "--nodeferred") == 0) {
+            doDeferred = false;
+        } else if ((0 == strcmp(*argv, "--diffPath")) ||
+                   (0 == strcmp(*argv, "-d"))) {
+            argv++;
+            if (argv < stop && **argv) {
+                diffPath = *argv;
+            }
+        } else if (strcmp(*argv, "--disable-missing-warning") == 0) {
+            gmmain.fNotifyMissingReadReference = false;
+        } else if (strcmp(*argv, "--enable-missing-warning") == 0) {
+            gmmain.fNotifyMissingReadReference = true;
+        } else if (strcmp(*argv, "--forceBWtext") == 0) {
+            gForceBWtext = true;
         } else if (strcmp(*argv, "--help") == 0 || strcmp(*argv, "-h") == 0) {
             usage(commandName);
             return -1;
+        } else if (strcmp(*argv, "--hierarchy") == 0) {
+            gmmain.fUseFileHierarchy = true;
+        } else if (strcmp(*argv, "--nohierarchy") == 0) {
+            gmmain.fUseFileHierarchy = false;
+        } else if (strcmp(*argv, "--match") == 0) {
+            ++argv;
+            if (argv < stop && **argv) {
+                // just record the ptr, no need for a deep copy
+                *fMatches.append() = *argv;
+            }
+        } else if (strcmp(*argv, "--modulo") == 0) {
+            ++argv;
+            if (argv >= stop) {
+                continue;
+            }
+            moduloRemainder = atoi(*argv);
+
+            ++argv;
+            if (argv >= stop) {
+                continue;
+            }
+            moduloDivisor = atoi(*argv);
+        } else if (strcmp(*argv, "--nopdf") == 0) {
+            doPDF = false;
+        } else if (strcmp(*argv, "--nopipe") == 0) {
+            doPipe = false;
+        } else if ((0 == strcmp(*argv, "--readPath")) ||
+                   (0 == strcmp(*argv, "-r"))) {
+            argv++;
+            if (argv < stop && **argv) {
+                readPath = *argv;
+            }
+        } else if (strcmp(*argv, "--noreplay") == 0) {
+            doReplay = false;
+        } else if ((0 == strcmp(*argv, "--resourcePath")) ||
+                   (0 == strcmp(*argv, "-i"))) {
+            argv++;
+            if (argv < stop && **argv) {
+                resourcePath = *argv;
+            }
+        } else if (strcmp(*argv, "--serialize") == 0) {
+            doSerialize = true;
+        } else if (strcmp(*argv, "--noserialize") == 0) {
+            doSerialize = false;
+        } else if (strcmp(*argv, "--notexturecache") == 0) {
+            disableTextureCache = true;
+        } else if (strcmp(*argv, "--tiledPipe") == 0) {
+            doTiledPipe = true;
+        } else if ((0 == strcmp(*argv, "--writePath")) ||
+            (0 == strcmp(*argv, "-w"))) {
+            argv++;
+            if (argv < stop && **argv) {
+                writePath = *argv;
+            }
+        } else if ((0 == strcmp(*argv, "--writePicturePath")) ||
+                   (0 == strcmp(*argv, "-wp"))) {
+            argv++;
+            if (argv < stop && **argv) {
+                writePicturePath = *argv;
+            }
         } else {
             usage(commandName);
             return -1;
@@ -1019,11 +1023,11 @@
         fprintf(stderr, "reading resources from %s\n", resourcePath);
     }
 
-    if (moduloCount <= 0) {
-        moduloIndex = -1;
+    if (moduloDivisor <= 0) {
+        moduloRemainder = -1;
     }
-    if (moduloIndex < 0 || moduloIndex >= moduloCount) {
-        moduloIndex = -1;
+    if (moduloRemainder < 0 || moduloRemainder >= moduloDivisor) {
+        moduloRemainder = -1;
     }
 
     // Accumulate success of all tests.
@@ -1067,11 +1071,11 @@
     while ((gm = iter.next()) != NULL) {
 
         ++gmIndex;
-        if (moduloIndex >= 0) {
-            if ((gmIndex % moduloCount) != moduloIndex) {
+        if (moduloRemainder >= 0) {
+            if ((gmIndex % moduloDivisor) != moduloRemainder) {
                 continue;
             }
-            moduloStr.printf("[%d.%d] ", gmIndex, moduloCount);
+            moduloStr.printf("[%d.%d] ", gmIndex, moduloDivisor);
         }
 
         const char* shortName = gm->shortName();