diff --git a/internal/cgen/base/fundamental-public.h b/internal/cgen/base/fundamental-public.h
index 5878ec3e..469a7f73 100644
--- a/internal/cgen/base/fundamental-public.h
+++ b/internal/cgen/base/fundamental-public.h
@@ -44,6 +44,8 @@
 #if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__ARM_CRC32) ||       \
     defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__ARM_NEON) ||        \
     defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64) ||          \
+    defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V2) ||       \
+    defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V3) ||       \
     defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_FAMILY) ||      \
     defined(WUFFS_PRIVATE_IMPL__HPD__DECIMAL_POINT__RANGE) || \
     defined(WUFFS_PRIVATE_IMPL__HPD__DIGITS_PRECISION) ||     \
@@ -107,6 +109,8 @@
 #define WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_FAMILY
 #if defined(__x86_64__)
 #define WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64
+#define WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V2
+#define WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V3
 #endif  // defined(__x86_64__)
 #endif  // !defined(__native_client__)
 #endif  // defined(__i386__) || defined(__x86_64__)
@@ -131,6 +135,8 @@
 #define WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_FAMILY
 #if defined(_M_X64)
 #define WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64
+#define WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V2
+#define WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V3
 #endif  // defined(_M_X64)
 
 #else  // defined(__AVX__) || defined(__clang__)
diff --git a/internal/cgen/base/pixconv-submodule-regular.c b/internal/cgen/base/pixconv-submodule-regular.c
index e659d5ea..702b4c3e 100644
--- a/internal/cgen/base/pixconv-submodule-regular.c
+++ b/internal/cgen/base/pixconv-submodule-regular.c
@@ -10,7 +10,7 @@
 
 // ---------------- Pixel Swizzler
 
-#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V2)
 WUFFS_BASE__MAYBE_ATTRIBUTE_TARGET("pclmul,popcnt,sse4.2")
 static uint64_t  //
 wuffs_private_impl__swizzle_bgrw__bgr__x86_sse42(uint8_t* dst_ptr,
@@ -45,7 +45,7 @@ wuffs_private_impl__swizzle_xxxx__y__x86_sse42(uint8_t* dst_ptr,
                                                size_t dst_palette_len,
                                                const uint8_t* src_ptr,
                                                size_t src_len);
-#endif  // defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#endif  // defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V2)
 
 // --------
 
@@ -881,7 +881,7 @@ wuffs_private_impl__swizzle_swap_rgb_bgr(uint8_t* dst_ptr,
 }
 
 // ‼ WUFFS MULTI-FILE SECTION +x86_sse42
-#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V2)
 WUFFS_BASE__MAYBE_ATTRIBUTE_TARGET("pclmul,popcnt,sse4.2")
 static uint64_t  //
 wuffs_private_impl__swizzle_swap_rgbx_bgrx__x86_sse42(uint8_t* dst_ptr,
@@ -925,7 +925,7 @@ wuffs_private_impl__swizzle_swap_rgbx_bgrx__x86_sse42(uint8_t* dst_ptr,
   }
   return len;
 }
-#endif  // defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#endif  // defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V2)
 // ‼ WUFFS MULTI-FILE SECTION -x86_sse42
 
 static uint64_t  //
@@ -3593,7 +3593,7 @@ wuffs_private_impl__swizzle_bgrw__bgrx(uint8_t* dst_ptr,
 }
 
 // ‼ WUFFS MULTI-FILE SECTION +x86_sse42
-#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V2)
 WUFFS_BASE__MAYBE_ATTRIBUTE_TARGET("pclmul,popcnt,sse4.2")
 static uint64_t  //
 wuffs_private_impl__swizzle_bgrw__bgr__x86_sse42(uint8_t* dst_ptr,
@@ -3699,7 +3699,7 @@ wuffs_private_impl__swizzle_bgrw__rgb__x86_sse42(uint8_t* dst_ptr,
 
   return len;
 }
-#endif  // defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#endif  // defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V2)
 // ‼ WUFFS MULTI-FILE SECTION -x86_sse42
 
 static uint64_t  //
@@ -4457,7 +4457,7 @@ wuffs_private_impl__swizzle_xxxx__index_binary_alpha__src_over(
 }
 
 // ‼ WUFFS MULTI-FILE SECTION +x86_sse42
-#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V2)
 WUFFS_BASE__MAYBE_ATTRIBUTE_TARGET("pclmul,popcnt,sse4.2")
 static uint64_t  //
 wuffs_private_impl__swizzle_xxxx__y__x86_sse42(uint8_t* dst_ptr,
@@ -4504,7 +4504,7 @@ wuffs_private_impl__swizzle_xxxx__y__x86_sse42(uint8_t* dst_ptr,
 
   return len;
 }
-#endif  // defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#endif  // defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V2)
 // ‼ WUFFS MULTI-FILE SECTION -x86_sse42
 
 static uint64_t  //
@@ -4906,7 +4906,7 @@ wuffs_private_impl__pixel_swizzler__prepare__y(
     case WUFFS_BASE__PIXEL_FORMAT__RGBA_PREMUL:
     case WUFFS_BASE__PIXEL_FORMAT__RGBA_BINARY:
     case WUFFS_BASE__PIXEL_FORMAT__RGBX:
-#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V2)
       if (wuffs_base__cpu_arch__have_x86_sse42()) {
         return wuffs_private_impl__swizzle_xxxx__y__x86_sse42;
       }
@@ -5377,7 +5377,7 @@ wuffs_private_impl__pixel_swizzler__prepare__bgr(
     case WUFFS_BASE__PIXEL_FORMAT__BGRA_PREMUL:
     case WUFFS_BASE__PIXEL_FORMAT__BGRA_BINARY:
     case WUFFS_BASE__PIXEL_FORMAT__BGRX:
-#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V2)
       if (wuffs_base__cpu_arch__have_x86_sse42()) {
         return wuffs_private_impl__swizzle_bgrw__bgr__x86_sse42;
       }
@@ -5395,7 +5395,7 @@ wuffs_private_impl__pixel_swizzler__prepare__bgr(
     case WUFFS_BASE__PIXEL_FORMAT__RGBA_PREMUL:
     case WUFFS_BASE__PIXEL_FORMAT__RGBA_BINARY:
     case WUFFS_BASE__PIXEL_FORMAT__RGBX:
-#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V2)
       if (wuffs_base__cpu_arch__have_x86_sse42()) {
         return wuffs_private_impl__swizzle_bgrw__rgb__x86_sse42;
       }
@@ -5484,7 +5484,7 @@ wuffs_private_impl__pixel_swizzler__prepare__bgra_nonpremul(
     case WUFFS_BASE__PIXEL_FORMAT__RGBA_NONPREMUL:
       switch (blend) {
         case WUFFS_BASE__PIXEL_BLEND__SRC:
-#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V2)
           if (wuffs_base__cpu_arch__have_x86_sse42()) {
             return wuffs_private_impl__swizzle_swap_rgbx_bgrx__x86_sse42;
           }
@@ -5679,7 +5679,7 @@ wuffs_private_impl__pixel_swizzler__prepare__bgra_premul(
     case WUFFS_BASE__PIXEL_FORMAT__RGBA_PREMUL:
       switch (blend) {
         case WUFFS_BASE__PIXEL_BLEND__SRC:
-#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V2)
           if (wuffs_base__cpu_arch__have_x86_sse42()) {
             return wuffs_private_impl__swizzle_swap_rgbx_bgrx__x86_sse42;
           }
@@ -5751,7 +5751,7 @@ wuffs_private_impl__pixel_swizzler__prepare__rgb(
     case WUFFS_BASE__PIXEL_FORMAT__BGRA_PREMUL:
     case WUFFS_BASE__PIXEL_FORMAT__BGRA_BINARY:
     case WUFFS_BASE__PIXEL_FORMAT__BGRX:
-#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V2)
       if (wuffs_base__cpu_arch__have_x86_sse42()) {
         return wuffs_private_impl__swizzle_bgrw__rgb__x86_sse42;
       }
@@ -5768,7 +5768,7 @@ wuffs_private_impl__pixel_swizzler__prepare__rgb(
     case WUFFS_BASE__PIXEL_FORMAT__RGBA_PREMUL:
     case WUFFS_BASE__PIXEL_FORMAT__RGBA_BINARY:
     case WUFFS_BASE__PIXEL_FORMAT__RGBX:
-#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V2)
       if (wuffs_base__cpu_arch__have_x86_sse42()) {
         return wuffs_private_impl__swizzle_bgrw__bgr__x86_sse42;
       }
@@ -5807,7 +5807,7 @@ wuffs_private_impl__pixel_swizzler__prepare__rgba_nonpremul(
     case WUFFS_BASE__PIXEL_FORMAT__BGRA_NONPREMUL:
       switch (blend) {
         case WUFFS_BASE__PIXEL_BLEND__SRC:
-#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V2)
           if (wuffs_base__cpu_arch__have_x86_sse42()) {
             return wuffs_private_impl__swizzle_swap_rgbx_bgrx__x86_sse42;
           }
@@ -5923,7 +5923,7 @@ wuffs_private_impl__pixel_swizzler__prepare__rgba_premul(
     case WUFFS_BASE__PIXEL_FORMAT__BGRA_PREMUL:
       switch (blend) {
         case WUFFS_BASE__PIXEL_BLEND__SRC:
-#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V2)
           if (wuffs_base__cpu_arch__have_x86_sse42()) {
             return wuffs_private_impl__swizzle_swap_rgbx_bgrx__x86_sse42;
           }
diff --git a/internal/cgen/base/pixconv-submodule-x86-avx2.c b/internal/cgen/base/pixconv-submodule-x86-avx2.c
index 403013af..bba8dadc 100644
--- a/internal/cgen/base/pixconv-submodule-x86-avx2.c
+++ b/internal/cgen/base/pixconv-submodule-x86-avx2.c
@@ -11,7 +11,7 @@
 // --------
 
 // ‼ WUFFS MULTI-FILE SECTION +x86_avx2
-#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V3)
 WUFFS_BASE__MAYBE_ATTRIBUTE_TARGET("pclmul,popcnt,sse4.2,avx2")
 static void  //
 wuffs_private_impl__swizzle_ycc__convert_3_bgrx_x86_avx2(
@@ -636,5 +636,5 @@ wuffs_private_impl__swizzle_ycc__upsample_inv_h2v2_triangle_x86_avx2(
   return dst_ptr;
 }
 #endif
-#endif  // defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#endif  // defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V3)
 // ‼ WUFFS MULTI-FILE SECTION -x86_avx2
diff --git a/internal/cgen/base/pixconv-submodule-ycck.c b/internal/cgen/base/pixconv-submodule-ycck.c
index 4be1d4c5..1f1ea4b5 100644
--- a/internal/cgen/base/pixconv-submodule-ycck.c
+++ b/internal/cgen/base/pixconv-submodule-ycck.c
@@ -10,7 +10,7 @@
 
 // --------
 
-#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V3)
 WUFFS_BASE__MAYBE_ATTRIBUTE_TARGET("pclmul,popcnt,sse4.2,avx2")
 static void  //
 wuffs_private_impl__swizzle_ycc__convert_3_bgrx_x86_avx2(
@@ -47,7 +47,7 @@ wuffs_private_impl__swizzle_ycc__upsample_inv_h2v2_triangle_x86_avx2(
     bool first_column,
     bool last_column);
 #endif
-#endif  // defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#endif  // defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V3)
 
 // --------
 
@@ -1277,7 +1277,7 @@ wuffs_base__pixel_swizzler__swizzle_ycck(
       case WUFFS_BASE__PIXEL_FORMAT__BGRA_NONPREMUL:
       case WUFFS_BASE__PIXEL_FORMAT__BGRA_PREMUL:
       case WUFFS_BASE__PIXEL_FORMAT__BGRX:
-#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V3)
         if (wuffs_base__cpu_arch__have_x86_avx2()) {
           conv3func = &wuffs_private_impl__swizzle_ycc__convert_3_bgrx_x86_avx2;
           break;
@@ -1288,7 +1288,7 @@ wuffs_base__pixel_swizzler__swizzle_ycck(
       case WUFFS_BASE__PIXEL_FORMAT__RGBA_NONPREMUL:
       case WUFFS_BASE__PIXEL_FORMAT__RGBA_PREMUL:
       case WUFFS_BASE__PIXEL_FORMAT__RGBX:
-#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V3)
         if (wuffs_base__cpu_arch__have_x86_avx2()) {
           conv3func = &wuffs_private_impl__swizzle_ycc__convert_3_rgbx_x86_avx2;
           break;
@@ -1338,7 +1338,7 @@ wuffs_base__pixel_swizzler__swizzle_ycck(
     upfuncs[1][0] = wuffs_private_impl__swizzle_ycc__upsample_inv_h2v1_triangle;
     upfuncs[1][1] = wuffs_private_impl__swizzle_ycc__upsample_inv_h2v2_triangle;
 
-#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V3)
 #if defined(__GNUC__) && !defined(__clang__)
     // Don't use our AVX2 implementation for GCC (but do use it for clang). For
     // some unknown reason, GCC performs noticably better on the non-SIMD
diff --git a/internal/cgen/statement.go b/internal/cgen/statement.go
index 6e57b662..32a9941a 100644
--- a/internal/cgen/statement.go
+++ b/internal/cgen/statement.go
@@ -275,27 +275,20 @@ func cpuArchCNames(asserts []*a.Node) (caMacro string, caName string, caAttribut
 				caMacro, caName, caAttribute = "ARM_NEON", "arm_neon", ""
 			case t.IDX86SSE42:
 				caMacro, caName, caAttribute =
-					"X86_64", // See the "X86_FAMILY" comment, below.
+					"X86_64_V2",
 					"x86_sse42",
 					"WUFFS_BASE__MAYBE_ATTRIBUTE_TARGET(\"pclmul,popcnt,sse4.2\")"
 			case t.IDX86AVX2:
 				caMacro, caName, caAttribute =
-					"X86_64",
+					"X86_64_V3",
 					"x86_avx2",
 					"WUFFS_BASE__MAYBE_ATTRIBUTE_TARGET(\"pclmul,popcnt,sse4.2,avx2\")"
 			case t.IDX86BMI2:
 				caMacro, caName, caAttribute =
-					"X86_64", // See the "X86_FAMILY" comment, below.
+					"X86_64_V3",
 					"x86_bmi2",
 					"WUFFS_BASE__MAYBE_ATTRIBUTE_TARGET(\"bmi2\")"
 			}
-
-			// "X86_FAMILY" (which covers both 32-bit and 64-bit x86) is
-			// technically correct, instead of "X86_64". But some intrinsics
-			// don't compile in 32-bit mode. It's not worth the hassle to
-			// support 32-bit x86 SIMD, so we gate on "X86_64" instead.
-			//
-			// https://github.com/google/wuffs/issues/145
 		}
 	}
 	return caMacro, caName, caAttribute, nil
diff --git a/release/c/wuffs-unsupported-snapshot.c b/release/c/wuffs-unsupported-snapshot.c
index c6f1dce5..f4e55f01 100644
--- a/release/c/wuffs-unsupported-snapshot.c
+++ b/release/c/wuffs-unsupported-snapshot.c
@@ -100,6 +100,8 @@ extern "C" {
 #if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__ARM_CRC32) ||       \
     defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__ARM_NEON) ||        \
     defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64) ||          \
+    defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V2) ||       \
+    defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V3) ||       \
     defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_FAMILY) ||      \
     defined(WUFFS_PRIVATE_IMPL__HPD__DECIMAL_POINT__RANGE) || \
     defined(WUFFS_PRIVATE_IMPL__HPD__DIGITS_PRECISION) ||     \
@@ -163,6 +165,8 @@ extern "C" {
 #define WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_FAMILY
 #if defined(__x86_64__)
 #define WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64
+#define WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V2
+#define WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V3
 #endif  // defined(__x86_64__)
 #endif  // !defined(__native_client__)
 #endif  // defined(__i386__) || defined(__x86_64__)
@@ -187,6 +191,8 @@ extern "C" {
 #define WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_FAMILY
 #if defined(_M_X64)
 #define WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64
+#define WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V2
+#define WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V3
 #endif  // defined(_M_X64)
 
 #else  // defined(__AVX__) || defined(__clang__)
@@ -21658,7 +21664,7 @@ wuffs_base__magic_number_guess_fourcc(wuffs_base__slice_u8 prefix_data,
 
 // ---------------- Pixel Swizzler
 
-#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V2)
 WUFFS_BASE__MAYBE_ATTRIBUTE_TARGET("pclmul,popcnt,sse4.2")
 static uint64_t  //
 wuffs_private_impl__swizzle_bgrw__bgr__x86_sse42(uint8_t* dst_ptr,
@@ -21693,7 +21699,7 @@ wuffs_private_impl__swizzle_xxxx__y__x86_sse42(uint8_t* dst_ptr,
                                                size_t dst_palette_len,
                                                const uint8_t* src_ptr,
                                                size_t src_len);
-#endif  // defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#endif  // defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V2)
 
 // --------
 
@@ -22529,7 +22535,7 @@ wuffs_private_impl__swizzle_swap_rgb_bgr(uint8_t* dst_ptr,
 }
 
 // ‼ WUFFS MULTI-FILE SECTION +x86_sse42
-#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V2)
 WUFFS_BASE__MAYBE_ATTRIBUTE_TARGET("pclmul,popcnt,sse4.2")
 static uint64_t  //
 wuffs_private_impl__swizzle_swap_rgbx_bgrx__x86_sse42(uint8_t* dst_ptr,
@@ -22573,7 +22579,7 @@ wuffs_private_impl__swizzle_swap_rgbx_bgrx__x86_sse42(uint8_t* dst_ptr,
   }
   return len;
 }
-#endif  // defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#endif  // defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V2)
 // ‼ WUFFS MULTI-FILE SECTION -x86_sse42
 
 static uint64_t  //
@@ -25241,7 +25247,7 @@ wuffs_private_impl__swizzle_bgrw__bgrx(uint8_t* dst_ptr,
 }
 
 // ‼ WUFFS MULTI-FILE SECTION +x86_sse42
-#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V2)
 WUFFS_BASE__MAYBE_ATTRIBUTE_TARGET("pclmul,popcnt,sse4.2")
 static uint64_t  //
 wuffs_private_impl__swizzle_bgrw__bgr__x86_sse42(uint8_t* dst_ptr,
@@ -25347,7 +25353,7 @@ wuffs_private_impl__swizzle_bgrw__rgb__x86_sse42(uint8_t* dst_ptr,
 
   return len;
 }
-#endif  // defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#endif  // defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V2)
 // ‼ WUFFS MULTI-FILE SECTION -x86_sse42
 
 static uint64_t  //
@@ -26105,7 +26111,7 @@ wuffs_private_impl__swizzle_xxxx__index_binary_alpha__src_over(
 }
 
 // ‼ WUFFS MULTI-FILE SECTION +x86_sse42
-#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V2)
 WUFFS_BASE__MAYBE_ATTRIBUTE_TARGET("pclmul,popcnt,sse4.2")
 static uint64_t  //
 wuffs_private_impl__swizzle_xxxx__y__x86_sse42(uint8_t* dst_ptr,
@@ -26152,7 +26158,7 @@ wuffs_private_impl__swizzle_xxxx__y__x86_sse42(uint8_t* dst_ptr,
 
   return len;
 }
-#endif  // defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#endif  // defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V2)
 // ‼ WUFFS MULTI-FILE SECTION -x86_sse42
 
 static uint64_t  //
@@ -26554,7 +26560,7 @@ wuffs_private_impl__pixel_swizzler__prepare__y(
     case WUFFS_BASE__PIXEL_FORMAT__RGBA_PREMUL:
     case WUFFS_BASE__PIXEL_FORMAT__RGBA_BINARY:
     case WUFFS_BASE__PIXEL_FORMAT__RGBX:
-#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V2)
       if (wuffs_base__cpu_arch__have_x86_sse42()) {
         return wuffs_private_impl__swizzle_xxxx__y__x86_sse42;
       }
@@ -27025,7 +27031,7 @@ wuffs_private_impl__pixel_swizzler__prepare__bgr(
     case WUFFS_BASE__PIXEL_FORMAT__BGRA_PREMUL:
     case WUFFS_BASE__PIXEL_FORMAT__BGRA_BINARY:
     case WUFFS_BASE__PIXEL_FORMAT__BGRX:
-#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V2)
       if (wuffs_base__cpu_arch__have_x86_sse42()) {
         return wuffs_private_impl__swizzle_bgrw__bgr__x86_sse42;
       }
@@ -27043,7 +27049,7 @@ wuffs_private_impl__pixel_swizzler__prepare__bgr(
     case WUFFS_BASE__PIXEL_FORMAT__RGBA_PREMUL:
     case WUFFS_BASE__PIXEL_FORMAT__RGBA_BINARY:
     case WUFFS_BASE__PIXEL_FORMAT__RGBX:
-#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V2)
       if (wuffs_base__cpu_arch__have_x86_sse42()) {
         return wuffs_private_impl__swizzle_bgrw__rgb__x86_sse42;
       }
@@ -27132,7 +27138,7 @@ wuffs_private_impl__pixel_swizzler__prepare__bgra_nonpremul(
     case WUFFS_BASE__PIXEL_FORMAT__RGBA_NONPREMUL:
       switch (blend) {
         case WUFFS_BASE__PIXEL_BLEND__SRC:
-#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V2)
           if (wuffs_base__cpu_arch__have_x86_sse42()) {
             return wuffs_private_impl__swizzle_swap_rgbx_bgrx__x86_sse42;
           }
@@ -27327,7 +27333,7 @@ wuffs_private_impl__pixel_swizzler__prepare__bgra_premul(
     case WUFFS_BASE__PIXEL_FORMAT__RGBA_PREMUL:
       switch (blend) {
         case WUFFS_BASE__PIXEL_BLEND__SRC:
-#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V2)
           if (wuffs_base__cpu_arch__have_x86_sse42()) {
             return wuffs_private_impl__swizzle_swap_rgbx_bgrx__x86_sse42;
           }
@@ -27399,7 +27405,7 @@ wuffs_private_impl__pixel_swizzler__prepare__rgb(
     case WUFFS_BASE__PIXEL_FORMAT__BGRA_PREMUL:
     case WUFFS_BASE__PIXEL_FORMAT__BGRA_BINARY:
     case WUFFS_BASE__PIXEL_FORMAT__BGRX:
-#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V2)
       if (wuffs_base__cpu_arch__have_x86_sse42()) {
         return wuffs_private_impl__swizzle_bgrw__rgb__x86_sse42;
       }
@@ -27416,7 +27422,7 @@ wuffs_private_impl__pixel_swizzler__prepare__rgb(
     case WUFFS_BASE__PIXEL_FORMAT__RGBA_PREMUL:
     case WUFFS_BASE__PIXEL_FORMAT__RGBA_BINARY:
     case WUFFS_BASE__PIXEL_FORMAT__RGBX:
-#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V2)
       if (wuffs_base__cpu_arch__have_x86_sse42()) {
         return wuffs_private_impl__swizzle_bgrw__bgr__x86_sse42;
       }
@@ -27455,7 +27461,7 @@ wuffs_private_impl__pixel_swizzler__prepare__rgba_nonpremul(
     case WUFFS_BASE__PIXEL_FORMAT__BGRA_NONPREMUL:
       switch (blend) {
         case WUFFS_BASE__PIXEL_BLEND__SRC:
-#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V2)
           if (wuffs_base__cpu_arch__have_x86_sse42()) {
             return wuffs_private_impl__swizzle_swap_rgbx_bgrx__x86_sse42;
           }
@@ -27571,7 +27577,7 @@ wuffs_private_impl__pixel_swizzler__prepare__rgba_premul(
     case WUFFS_BASE__PIXEL_FORMAT__BGRA_PREMUL:
       switch (blend) {
         case WUFFS_BASE__PIXEL_BLEND__SRC:
-#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V2)
           if (wuffs_base__cpu_arch__have_x86_sse42()) {
             return wuffs_private_impl__swizzle_swap_rgbx_bgrx__x86_sse42;
           }
@@ -27859,7 +27865,7 @@ wuffs_base__pixel_swizzler__swizzle_interleaved_transparent_black(
 
 // --------
 
-#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V3)
 WUFFS_BASE__MAYBE_ATTRIBUTE_TARGET("pclmul,popcnt,sse4.2,avx2")
 static void  //
 wuffs_private_impl__swizzle_ycc__convert_3_bgrx_x86_avx2(
@@ -27896,7 +27902,7 @@ wuffs_private_impl__swizzle_ycc__upsample_inv_h2v2_triangle_x86_avx2(
     bool first_column,
     bool last_column);
 #endif
-#endif  // defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#endif  // defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V3)
 
 // --------
 
@@ -29126,7 +29132,7 @@ wuffs_base__pixel_swizzler__swizzle_ycck(
       case WUFFS_BASE__PIXEL_FORMAT__BGRA_NONPREMUL:
       case WUFFS_BASE__PIXEL_FORMAT__BGRA_PREMUL:
       case WUFFS_BASE__PIXEL_FORMAT__BGRX:
-#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V3)
         if (wuffs_base__cpu_arch__have_x86_avx2()) {
           conv3func = &wuffs_private_impl__swizzle_ycc__convert_3_bgrx_x86_avx2;
           break;
@@ -29137,7 +29143,7 @@ wuffs_base__pixel_swizzler__swizzle_ycck(
       case WUFFS_BASE__PIXEL_FORMAT__RGBA_NONPREMUL:
       case WUFFS_BASE__PIXEL_FORMAT__RGBA_PREMUL:
       case WUFFS_BASE__PIXEL_FORMAT__RGBX:
-#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V3)
         if (wuffs_base__cpu_arch__have_x86_avx2()) {
           conv3func = &wuffs_private_impl__swizzle_ycc__convert_3_rgbx_x86_avx2;
           break;
@@ -29187,7 +29193,7 @@ wuffs_base__pixel_swizzler__swizzle_ycck(
     upfuncs[1][0] = wuffs_private_impl__swizzle_ycc__upsample_inv_h2v1_triangle;
     upfuncs[1][1] = wuffs_private_impl__swizzle_ycc__upsample_inv_h2v2_triangle;
 
-#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V3)
 #if defined(__GNUC__) && !defined(__clang__)
     // Don't use our AVX2 implementation for GCC (but do use it for clang). For
     // some unknown reason, GCC performs noticably better on the non-SIMD
@@ -29239,7 +29245,7 @@ wuffs_base__pixel_swizzler__swizzle_ycck(
 // --------
 
 // ‼ WUFFS MULTI-FILE SECTION +x86_avx2
-#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V3)
 WUFFS_BASE__MAYBE_ATTRIBUTE_TARGET("pclmul,popcnt,sse4.2,avx2")
 static void  //
 wuffs_private_impl__swizzle_ycc__convert_3_bgrx_x86_avx2(
@@ -29864,7 +29870,7 @@ wuffs_private_impl__swizzle_ycc__upsample_inv_h2v2_triangle_x86_avx2(
   return dst_ptr;
 }
 #endif
-#endif  // defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#endif  // defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V3)
 // ‼ WUFFS MULTI-FILE SECTION -x86_avx2
 
 #endif  // !defined(WUFFS_CONFIG__MODULES) ||
@@ -30126,13 +30132,13 @@ wuffs_adler32__hasher__up_arm_neon(
     wuffs_base__slice_u8 a_x);
 #endif  // defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__ARM_NEON)
 
-#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V2)
 WUFFS_BASE__GENERATED_C_CODE
 static wuffs_base__empty_struct
 wuffs_adler32__hasher__up_x86_sse42(
     wuffs_adler32__hasher* self,
     wuffs_base__slice_u8 a_x);
-#endif  // defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#endif  // defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V2)
 
 // ---------------- VTables
 
@@ -30283,7 +30289,7 @@ wuffs_adler32__hasher__update(
 #if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__ARM_NEON)
         wuffs_base__cpu_arch__have_arm_neon() ? &wuffs_adler32__hasher__up_arm_neon :
 #endif
-#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V2)
         wuffs_base__cpu_arch__have_x86_sse42() ? &wuffs_adler32__hasher__up_x86_sse42 :
 #endif
         self->private_impl.choosy_up);
@@ -30513,7 +30519,7 @@ wuffs_adler32__hasher__up_arm_neon(
 // ‼ WUFFS MULTI-FILE SECTION +x86_sse42
 // -------- func adler32.hasher.up_x86_sse42
 
-#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V2)
 WUFFS_BASE__MAYBE_ATTRIBUTE_TARGET("pclmul,popcnt,sse4.2")
 WUFFS_BASE__GENERATED_C_CODE
 static wuffs_base__empty_struct
@@ -30600,7 +30606,7 @@ wuffs_adler32__hasher__up_x86_sse42(
   self->private_impl.f_state = (((v_s2 & 65535u) << 16u) | (v_s1 & 65535u));
   return wuffs_base__make_empty_struct();
 }
-#endif  // defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#endif  // defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V2)
 // ‼ WUFFS MULTI-FILE SECTION -x86_sse42
 
 #endif  // !defined(WUFFS_CONFIG__MODULES) || defined(WUFFS_CONFIG__MODULE__ADLER32)
@@ -36366,13 +36372,13 @@ wuffs_crc32__ieee_hasher__up_arm_crc32(
     wuffs_base__slice_u8 a_x);
 #endif  // defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__ARM_CRC32)
 
-#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V2)
 WUFFS_BASE__GENERATED_C_CODE
 static wuffs_base__empty_struct
 wuffs_crc32__ieee_hasher__up_x86_sse42(
     wuffs_crc32__ieee_hasher* self,
     wuffs_base__slice_u8 a_x);
-#endif  // defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#endif  // defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V2)
 
 // ---------------- VTables
 
@@ -36521,7 +36527,7 @@ wuffs_crc32__ieee_hasher__update(
 #if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__ARM_CRC32)
         wuffs_base__cpu_arch__have_arm_crc32() ? &wuffs_crc32__ieee_hasher__up_arm_crc32 :
 #endif
-#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V2)
         wuffs_base__cpu_arch__have_x86_sse42() ? &wuffs_crc32__ieee_hasher__up_x86_sse42 :
 #endif
         self->private_impl.choosy_up);
@@ -36749,7 +36755,7 @@ wuffs_crc32__ieee_hasher__up_arm_crc32(
 // ‼ WUFFS MULTI-FILE SECTION +x86_sse42
 // -------- func crc32.ieee_hasher.up_x86_sse42
 
-#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V2)
 WUFFS_BASE__MAYBE_ATTRIBUTE_TARGET("pclmul,popcnt,sse4.2")
 WUFFS_BASE__GENERATED_C_CODE
 static wuffs_base__empty_struct
@@ -36875,7 +36881,7 @@ wuffs_crc32__ieee_hasher__up_x86_sse42(
   self->private_impl.f_state = (4294967295u ^ v_s);
   return wuffs_base__make_empty_struct();
 }
-#endif  // defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#endif  // defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V2)
 // ‼ WUFFS MULTI-FILE SECTION -x86_sse42
 
 #endif  // !defined(WUFFS_CONFIG__MODULES) || defined(WUFFS_CONFIG__MODULE__CRC32)
@@ -37201,13 +37207,13 @@ wuffs_crc64__ecma_hasher__up__choosy_default(
     wuffs_crc64__ecma_hasher* self,
     wuffs_base__slice_u8 a_x);
 
-#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V2)
 WUFFS_BASE__GENERATED_C_CODE
 static wuffs_base__empty_struct
 wuffs_crc64__ecma_hasher__up_x86_sse42(
     wuffs_crc64__ecma_hasher* self,
     wuffs_base__slice_u8 a_x);
-#endif  // defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#endif  // defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V2)
 
 // ---------------- VTables
 
@@ -37353,7 +37359,7 @@ wuffs_crc64__ecma_hasher__update(
 
   if (self->private_impl.f_state == 0u) {
     self->private_impl.choosy_up = (
-#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V2)
         wuffs_base__cpu_arch__have_x86_sse42() ? &wuffs_crc64__ecma_hasher__up_x86_sse42 :
 #endif
         self->private_impl.choosy_up);
@@ -37455,7 +37461,7 @@ wuffs_crc64__ecma_hasher__checksum_u64(
 // ‼ WUFFS MULTI-FILE SECTION +x86_sse42
 // -------- func crc64.ecma_hasher.up_x86_sse42
 
-#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V2)
 WUFFS_BASE__MAYBE_ATTRIBUTE_TARGET("pclmul,popcnt,sse4.2")
 WUFFS_BASE__GENERATED_C_CODE
 static wuffs_base__empty_struct
@@ -37583,7 +37589,7 @@ wuffs_crc64__ecma_hasher__up_x86_sse42(
   self->private_impl.f_state = (18446744073709551615u ^ v_s);
   return wuffs_base__make_empty_struct();
 }
-#endif  // defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#endif  // defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V2)
 // ‼ WUFFS MULTI-FILE SECTION -x86_sse42
 
 #endif  // !defined(WUFFS_CONFIG__MODULES) || defined(WUFFS_CONFIG__MODULE__CRC64)
@@ -37722,14 +37728,14 @@ wuffs_deflate__decoder__init_huff(
     uint32_t a_n_codes1,
     uint32_t a_base_symbol);
 
-#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V3)
 WUFFS_BASE__GENERATED_C_CODE
 static wuffs_base__status
 wuffs_deflate__decoder__decode_huffman_bmi2(
     wuffs_deflate__decoder* self,
     wuffs_base__io_buffer* a_dst,
     wuffs_base__io_buffer* a_src);
-#endif  // defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#endif  // defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V3)
 
 WUFFS_BASE__GENERATED_C_CODE
 static wuffs_base__status
@@ -38063,7 +38069,7 @@ wuffs_deflate__decoder__do_transform_io(
     WUFFS_BASE__COROUTINE_SUSPENSION_POINT_0;
 
     self->private_impl.choosy_decode_huffman_fast64 = (
-#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V3)
         wuffs_base__cpu_arch__have_x86_bmi2() ? &wuffs_deflate__decoder__decode_huffman_bmi2 :
 #endif
         self->private_impl.choosy_decode_huffman_fast64);
@@ -38952,7 +38958,7 @@ wuffs_deflate__decoder__init_huff(
 // ‼ WUFFS MULTI-FILE SECTION +x86_bmi2
 // -------- func deflate.decoder.decode_huffman_bmi2
 
-#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V3)
 WUFFS_BASE__MAYBE_ATTRIBUTE_TARGET("bmi2")
 WUFFS_BASE__GENERATED_C_CODE
 static wuffs_base__status
@@ -39160,7 +39166,7 @@ wuffs_deflate__decoder__decode_huffman_bmi2(
 
   return status;
 }
-#endif  // defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#endif  // defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V3)
 // ‼ WUFFS MULTI-FILE SECTION -x86_bmi2
 
 // -------- func deflate.decoder.decode_huffman_fast32
@@ -43910,7 +43916,7 @@ wuffs_jpeg__decoder__decode_idct__choosy_default(
     uint64_t a_dst_stride,
     uint32_t a_q);
 
-#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V3)
 WUFFS_BASE__GENERATED_C_CODE
 static wuffs_base__empty_struct
 wuffs_jpeg__decoder__decode_idct_x86_avx2(
@@ -43918,7 +43924,7 @@ wuffs_jpeg__decoder__decode_idct_x86_avx2(
     wuffs_base__slice_u8 a_dst_buffer,
     uint64_t a_dst_stride,
     uint32_t a_q);
-#endif  // defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#endif  // defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V3)
 
 WUFFS_BASE__GENERATED_C_CODE
 static wuffs_base__status
@@ -45385,7 +45391,7 @@ wuffs_jpeg__decoder__decode_idct__choosy_default(
 // ‼ WUFFS MULTI-FILE SECTION +x86_avx2
 // -------- func jpeg.decoder.decode_idct_x86_avx2
 
-#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V3)
 WUFFS_BASE__MAYBE_ATTRIBUTE_TARGET("pclmul,popcnt,sse4.2,avx2")
 WUFFS_BASE__GENERATED_C_CODE
 static wuffs_base__empty_struct
@@ -45769,7 +45775,7 @@ wuffs_jpeg__decoder__decode_idct_x86_avx2(
   wuffs_base__poke_u64le__no_bounds_check(a_dst_buffer.ptr, v_final7);
   return wuffs_base__make_empty_struct();
 }
-#endif  // defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#endif  // defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V3)
 // ‼ WUFFS MULTI-FILE SECTION -x86_avx2
 
 // -------- func jpeg.decoder.get_quirk
@@ -46118,7 +46124,7 @@ wuffs_jpeg__decoder__do_decode_image_config(
       self->private_impl.f_payload_length = 0u;
     }
     self->private_impl.choosy_decode_idct = (
-#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V3)
         wuffs_base__cpu_arch__have_x86_avx2() ? &wuffs_jpeg__decoder__decode_idct_x86_avx2 :
 #endif
         self->private_impl.choosy_decode_idct);
@@ -60038,40 +60044,40 @@ wuffs_png__decoder__filter_4_distance_4_fallback(
     wuffs_base__slice_u8 a_curr,
     wuffs_base__slice_u8 a_prev);
 
-#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V2)
 WUFFS_BASE__GENERATED_C_CODE
 static wuffs_base__empty_struct
 wuffs_png__decoder__filter_1_distance_4_x86_sse42(
     wuffs_png__decoder* self,
     wuffs_base__slice_u8 a_curr);
-#endif  // defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#endif  // defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V2)
 
-#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V2)
 WUFFS_BASE__GENERATED_C_CODE
 static wuffs_base__empty_struct
 wuffs_png__decoder__filter_3_distance_4_x86_sse42(
     wuffs_png__decoder* self,
     wuffs_base__slice_u8 a_curr,
     wuffs_base__slice_u8 a_prev);
-#endif  // defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#endif  // defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V2)
 
-#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V2)
 WUFFS_BASE__GENERATED_C_CODE
 static wuffs_base__empty_struct
 wuffs_png__decoder__filter_4_distance_3_x86_sse42(
     wuffs_png__decoder* self,
     wuffs_base__slice_u8 a_curr,
     wuffs_base__slice_u8 a_prev);
-#endif  // defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#endif  // defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V2)
 
-#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V2)
 WUFFS_BASE__GENERATED_C_CODE
 static wuffs_base__empty_struct
 wuffs_png__decoder__filter_4_distance_4_x86_sse42(
     wuffs_png__decoder* self,
     wuffs_base__slice_u8 a_curr,
     wuffs_base__slice_u8 a_prev);
-#endif  // defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#endif  // defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V2)
 
 WUFFS_BASE__GENERATED_C_CODE
 static wuffs_base__status
@@ -61390,7 +61396,7 @@ wuffs_png__decoder__filter_4_distance_4_fallback(
 // ‼ WUFFS MULTI-FILE SECTION +x86_sse42
 // -------- func png.decoder.filter_1_distance_4_x86_sse42
 
-#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V2)
 WUFFS_BASE__MAYBE_ATTRIBUTE_TARGET("pclmul,popcnt,sse4.2")
 WUFFS_BASE__GENERATED_C_CODE
 static wuffs_base__empty_struct
@@ -61431,13 +61437,13 @@ wuffs_png__decoder__filter_1_distance_4_x86_sse42(
   }
   return wuffs_base__make_empty_struct();
 }
-#endif  // defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#endif  // defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V2)
 // ‼ WUFFS MULTI-FILE SECTION -x86_sse42
 
 // ‼ WUFFS MULTI-FILE SECTION +x86_sse42
 // -------- func png.decoder.filter_3_distance_4_x86_sse42
 
-#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V2)
 WUFFS_BASE__MAYBE_ATTRIBUTE_TARGET("pclmul,popcnt,sse4.2")
 WUFFS_BASE__GENERATED_C_CODE
 static wuffs_base__empty_struct
@@ -61537,13 +61543,13 @@ wuffs_png__decoder__filter_3_distance_4_x86_sse42(
   }
   return wuffs_base__make_empty_struct();
 }
-#endif  // defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#endif  // defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V2)
 // ‼ WUFFS MULTI-FILE SECTION -x86_sse42
 
 // ‼ WUFFS MULTI-FILE SECTION +x86_sse42
 // -------- func png.decoder.filter_4_distance_3_x86_sse42
 
-#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V2)
 WUFFS_BASE__MAYBE_ATTRIBUTE_TARGET("pclmul,popcnt,sse4.2")
 WUFFS_BASE__GENERATED_C_CODE
 static wuffs_base__empty_struct
@@ -61664,13 +61670,13 @@ wuffs_png__decoder__filter_4_distance_3_x86_sse42(
   }
   return wuffs_base__make_empty_struct();
 }
-#endif  // defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#endif  // defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V2)
 // ‼ WUFFS MULTI-FILE SECTION -x86_sse42
 
 // ‼ WUFFS MULTI-FILE SECTION +x86_sse42
 // -------- func png.decoder.filter_4_distance_4_x86_sse42
 
-#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V2)
 WUFFS_BASE__MAYBE_ATTRIBUTE_TARGET("pclmul,popcnt,sse4.2")
 WUFFS_BASE__GENERATED_C_CODE
 static wuffs_base__empty_struct
@@ -61769,7 +61775,7 @@ wuffs_png__decoder__filter_4_distance_4_x86_sse42(
   }
   return wuffs_base__make_empty_struct();
 }
-#endif  // defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#endif  // defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V2)
 // ‼ WUFFS MULTI-FILE SECTION -x86_sse42
 
 // -------- func png.decoder.get_quirk
@@ -62516,7 +62522,7 @@ wuffs_png__decoder__choose_filter_implementations(
 #if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__ARM_NEON)
         wuffs_base__cpu_arch__have_arm_neon() ? &wuffs_png__decoder__filter_4_distance_3_arm_neon :
 #endif
-#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V2)
         wuffs_base__cpu_arch__have_x86_sse42() ? &wuffs_png__decoder__filter_4_distance_3_x86_sse42 :
 #endif
         &wuffs_png__decoder__filter_4_distance_3_fallback);
@@ -62525,7 +62531,7 @@ wuffs_png__decoder__choose_filter_implementations(
 #if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__ARM_NEON)
         wuffs_base__cpu_arch__have_arm_neon() ? &wuffs_png__decoder__filter_1_distance_4_arm_neon :
 #endif
-#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V2)
         wuffs_base__cpu_arch__have_x86_sse42() ? &wuffs_png__decoder__filter_1_distance_4_x86_sse42 :
 #endif
         &wuffs_png__decoder__filter_1_distance_4_fallback);
@@ -62533,7 +62539,7 @@ wuffs_png__decoder__choose_filter_implementations(
 #if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__ARM_NEON)
         wuffs_base__cpu_arch__have_arm_neon() ? &wuffs_png__decoder__filter_3_distance_4_arm_neon :
 #endif
-#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V2)
         wuffs_base__cpu_arch__have_x86_sse42() ? &wuffs_png__decoder__filter_3_distance_4_x86_sse42 :
 #endif
         &wuffs_png__decoder__filter_3_distance_4_fallback);
@@ -62541,7 +62547,7 @@ wuffs_png__decoder__choose_filter_implementations(
 #if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__ARM_NEON)
         wuffs_base__cpu_arch__have_arm_neon() ? &wuffs_png__decoder__filter_4_distance_4_arm_neon :
 #endif
-#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V2)
         wuffs_base__cpu_arch__have_x86_sse42() ? &wuffs_png__decoder__filter_4_distance_4_x86_sse42 :
 #endif
         &wuffs_png__decoder__filter_4_distance_4_fallback);
diff --git a/test/c/std/jpeg.c b/test/c/std/jpeg.c
index 0ba9509e..3ccccb66 100644
--- a/test/c/std/jpeg.c
+++ b/test/c/std/jpeg.c
@@ -590,7 +590,7 @@ test_wuffs_jpeg_decode_idct() {
     if (f == 0) {
       func_name = "choosy_default";
       func = &wuffs_jpeg__decoder__decode_idct__choosy_default;
-#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64)
+#if defined(WUFFS_PRIVATE_IMPL__CPU_ARCH__X86_64_V3)
     } else if (wuffs_base__cpu_arch__have_x86_avx2()) {
       func_name = "x86_avx2";
       func = &wuffs_jpeg__decoder__decode_idct_x86_avx2;