--- a/gfx/skia/generate_mozbuild.py
+++ b/gfx/skia/generate_mozbuild.py
@@ -60,16 +60,18 @@ LOCAL_INCLUDES += [
     'skia/src/sfnt',
     'skia/src/sksl',
     'skia/src/utils',
     'skia/src/utils/mac',
     'skia/src/utils/win',
 ]
 
 if CONFIG['MOZ_WIDGET_TOOLKIT'] == 'windows':
+    if CONFIG['CC_TYPE'] == 'gcc':
+        DEFINES['SK_JUMPER_USE_ASSEMBLY'] = False
     DEFINES['UNICODE'] = True
     DEFINES['_UNICODE'] = True
     UNIFIED_SOURCES += [
         'skia/src/fonts/SkFontMgr_indirect.cpp',
         'skia/src/fonts/SkRemotableFontMgr.cpp',
     ]
 
 # We should autogenerate these SSE related flags.
@@ -192,16 +194,17 @@ def generate_separated_sources(platform_
     'GrGLAssembleInterface',
     'GrGLTestInterface',
     'ImageEncoder',
     'skia/src/c/',
     'skia/src/effects/Gr',
     'skia/src/effects/Sk',
     'skia/src/fonts/',
     'skia/src/images/',
+    'skia/src/jumper/SkJumper_generated_win.S',
     'skia/src/ports/SkImageGenerator',
     'skia/src/gpu/vk/',
     'SkBitmapRegion',
     'SkLight',
     'SkRadialShadow',
     'SkShadow',
     'SkNormal',
     'SkLite',
@@ -257,16 +260,19 @@ def generate_separated_sources(platform_
       'skia/src/ports/SkFontHost_FreeType_common.cpp',
       # 'skia/src/ports/SkTime_Unix.cpp',
       # 'skia/src/utils/SkThreadUtils_pthread.cpp',
     },
     'linux': {
       'skia/src/ports/SkFontHost_cairo.cpp',
       'skia/src/ports/SkFontHost_FreeType_common.cpp',
     },
+    'no-mingw': {
+      'skia/src/jumper/SkJumper_generated_win.S',
+    },
     'intel': set(),
     'arm': set(),
     'arm64': set(),
     'none': set(),
     'pdf': {
       'skia/src/core/SkMD5.cpp',
     },
     'gpu': set()
@@ -428,16 +434,18 @@ def write_mozbuild(sources):
 
   f.write("if CONFIG['MOZ_WIDGET_TOOLKIT'] in ('cocoa', 'uikit'):\n")
   write_sources(f, sources['mac'], 4)
 
   f.write("if CONFIG['MOZ_WIDGET_TOOLKIT'] in ('gtk2', 'gtk3'):\n")
   write_sources(f, sources['linux'], 4)
 
   f.write("if CONFIG['MOZ_WIDGET_TOOLKIT'] == 'windows':\n")
+  f.write("    if CONFIG['CC_TYPE'] != 'gcc':\n")
+  write_list(f, "SOURCES", sources['no-mingw'], 8)
   # Windows-specific files don't get unification because of nasty headers.
   # Luckily there are not many files in this.
   write_list(f, "SOURCES", sources['win'], 4)
 
   f.write("if CONFIG['INTEL_ARCHITECTURE']:\n")
   write_sources(f, sources['intel'], 4)
   write_cflags(f, sources['intel'], opt_whitelist, 'skia_opt_flags', 4)
 

old mode 100644
new mode 100755
--- a/gfx/skia/moz.build
+++ b/gfx/skia/moz.build
@@ -592,18 +592,21 @@ if CONFIG['MOZ_WIDGET_TOOLKIT'] in ('gtk
         'skia/src/utils/SkThreadUtils_pthread.cpp',
     ]
     SOURCES += [
         'skia/src/jumper/SkJumper_generated.S',
         'skia/src/ports/SkFontHost_cairo.cpp',
         'skia/src/ports/SkFontHost_FreeType_common.cpp',
     ]
 if CONFIG['MOZ_WIDGET_TOOLKIT'] == 'windows':
+    if CONFIG['CC_TYPE'] != 'gcc':
+        SOURCES += [
+            'skia/src/jumper/SkJumper_generated_win.S',
+        ]
     SOURCES += [
-        'skia/src/jumper/SkJumper_generated_win.S',
         'skia/src/ports/SkDebug_win.cpp',
         'skia/src/ports/SkFontHost_win.cpp',
         'skia/src/ports/SkFontMgr_win_dw.cpp',
         'skia/src/ports/SkFontMgr_win_dw_factory.cpp',
         'skia/src/ports/SkOSFile_win.cpp',
         'skia/src/ports/SkOSLibrary_win.cpp',
         'skia/src/ports/SkScalerContext_win_dw.cpp',
         'skia/src/ports/SkTLS_win.cpp',
@@ -702,16 +705,18 @@ LOCAL_INCLUDES += [
     'skia/src/sfnt',
     'skia/src/sksl',
     'skia/src/utils',
     'skia/src/utils/mac',
     'skia/src/utils/win',
 ]
 
 if CONFIG['MOZ_WIDGET_TOOLKIT'] == 'windows':
+    if CONFIG['CC_TYPE'] == 'gcc':
+        DEFINES['SK_JUMPER_USE_ASSEMBLY'] = False
     DEFINES['UNICODE'] = True
     DEFINES['_UNICODE'] = True
     UNIFIED_SOURCES += [
         'skia/src/fonts/SkFontMgr_indirect.cpp',
         'skia/src/fonts/SkRemotableFontMgr.cpp',
     ]
 
 # We should autogenerate these SSE related flags.

--- a/gfx/skia/skia/src/jumper/SkJumper.cpp
+++ b/gfx/skia/skia/src/jumper/SkJumper.cpp
@@ -7,17 +7,17 @@
 
 #include "SkColorPriv.h"
 #include "SkCpu.h"
 #include "SkJumper.h"
 #include "SkRasterPipeline.h"
 #include "SkTemplates.h"
 
 // A debugging mode that helps prioritize porting stages to SkJumper.
-#if 0
+#if 0 && SK_JUMPER_USE_ASSEMBLY
     #include "SkOnce.h"
     #include <atomic>
 
     #define M(st) {0},
     static std::atomic<int> gMissing[] = { SK_RASTER_PIPELINE_STAGES(M) };
     #undef M
 
     #define M(st) #st,
@@ -27,16 +27,23 @@
     #define WHATS_NEXT
 #endif
 
 // We'll use __has_feature(memory_sanitizer) to detect MSAN.
 // SkJumper_generated.S is not compiled with MSAN, so MSAN would yell really loud.
 #if !defined(__has_feature)
     #define __has_feature(x) 0
 #endif
+#if !defined(SK_JUMPER_USE_ASSEMBLY)
+#if __has_feature(memory_sanitizer)
+#define SK_JUMPER_USE_ASSEMBLY 0
+#else
+#define SK_JUMPER_USE_ASSEMBLY 1
+#endif
+#endif
 
 // Stages expect these constants to be set to these values.
 // It's fine to rearrange and add new ones if you update SkJumper_constants.
 using K = const SkJumper_constants;
 static K kConstants = {
     {0.0f, 1.0f, 2.0f, 3.0f, 4.0f, 5.0f, 6.0f, 7.0f},
 };
 
@@ -139,17 +146,17 @@ using StageFn = void(void);
 #if defined(__APPLE__)
     #define ASM(name, suffix)  sk_##name##_##suffix
 #else
     #define ASM(name, suffix) _sk_##name##_##suffix
 #endif
 
 extern "C" {
 
-#if __has_feature(memory_sanitizer)
+#if !SK_JUMPER_USE_ASSEMBLY
     // We'll just run portable code.
 
 #elif defined(__aarch64__)
     size_t ASM(start_pipeline,aarch64)(size_t, void**, K*, size_t);
     StageFn ASM(just_return,aarch64);
     #define M(st) StageFn ASM(st,aarch64);
         STAGES(M)
     #undef M
@@ -191,17 +198,17 @@ extern "C" {
     StageFn sk_just_return;
     #define M(st) StageFn sk_##st;
         STAGES(M)
     #undef M
 }
 
 // Translate SkRasterPipeline's StockStage enum to StageFn function pointers.
 
-#if __has_feature(memory_sanitizer)
+#if !SK_JUMPER_USE_ASSEMBLY
     // We'll just run portable code.
 
 #elif defined(__aarch64__)
     static StageFn* lookup_aarch64(SkRasterPipeline::StockStage st) {
         switch (st) {
             default: return nullptr;
         #define M(st) case SkRasterPipeline::st: return ASM(st,aarch64);
             STAGES(M)
@@ -311,17 +318,17 @@ bool SkRasterPipeline::run_with_jumper(s
             *ip = (void*)just_return;
 
             x = start_pipeline(x, program.get(), &kConstants, limit);
         }
         return true;
     };
 
     // While possible, build and run at full vector stride.
-#if __has_feature(memory_sanitizer)
+#if !SK_JUMPER_USE_ASSEMBLY
     // We'll just run portable code.
 
 #elif defined(__aarch64__)
     if (!build_and_run(4, lookup_aarch64, ASM(just_return,aarch64), ASM(start_pipeline,aarch64))) {
         return false;
     }
 
 #elif defined(__arm__)