diff --git a/src/liblzma/check/crc32_fast.c b/src/liblzma/check/crc32_fast.c
index 6982836a..7157e2f4 100644
--- a/src/liblzma/check/crc32_fast.c
+++ b/src/liblzma/check/crc32_fast.c
@@ -15,7 +15,7 @@
 #include "check.h"
 #include "crc_common.h"
 
-#ifdef CRC_CLMUL
+#ifdef CRC_X86_CLMUL
 #	define BUILDING_CRC32_CLMUL
 #	include "crc_x86_clmul.h"
 #endif
@@ -87,7 +87,7 @@ crc32_generic(const uint8_t *buf, size_t size, uint32_t crc)
 #endif
 
 
-#if defined(CRC_GENERIC) && defined(CRC_CLMUL)
+#if defined(CRC_GENERIC) && defined(CRC_ARCH_OPTIMIZED)
 
 //////////////////////////
 // Function dispatching //
@@ -137,7 +137,8 @@ typedef uint32_t (*crc32_func_type)(
 static crc32_func_type
 crc32_resolve(void)
 {
-	return is_clmul_supported() ? &crc32_clmul : &crc32_generic;
+	return is_arch_extension_supported()
+			? &crc32_arch_optimized : &crc32_generic;
 }
 
 #if defined(HAVE_FUNC_ATTRIBUTE_IFUNC) && defined(__clang__)
@@ -193,7 +194,7 @@ lzma_crc32(const uint8_t *buf, size_t size, uint32_t crc)
 extern LZMA_API(uint32_t)
 lzma_crc32(const uint8_t *buf, size_t size, uint32_t crc)
 {
-#if defined(CRC_GENERIC) && defined(CRC_CLMUL)
+#if defined(CRC_GENERIC) && defined(CRC_ARCH_OPTIMIZED)
 	// If CLMUL is available, it is the best for non-tiny inputs,
 	// being over twice as fast as the generic slice-by-four version.
 	// However, for size <= 16 it's different. In the extreme case
@@ -225,8 +226,8 @@ lzma_crc32(const uint8_t *buf, size_t size, uint32_t crc)
 */
 	return crc32_func(buf, size, crc);
 
-#elif defined(CRC_CLMUL)
-	return crc32_clmul(buf, size, crc);
+#elif defined(CRC_ARCH_OPTIMIZED)
+	return crc32_arch_optimized(buf, size, crc);
 
 #else
 	return crc32_generic(buf, size, crc);
diff --git a/src/liblzma/check/crc64_fast.c b/src/liblzma/check/crc64_fast.c
index 46b5c646..4edca1a2 100644
--- a/src/liblzma/check/crc64_fast.c
+++ b/src/liblzma/check/crc64_fast.c
@@ -14,7 +14,7 @@
 #include "check.h"
 #include "crc_common.h"
 
-#ifdef CRC_CLMUL
+#ifdef CRC_X86_CLMUL
 #	define BUILDING_CRC64_CLMUL
 #	include "crc_x86_clmul.h"
 #endif
@@ -82,7 +82,7 @@ crc64_generic(const uint8_t *buf, size_t size, uint64_t crc)
 #endif
 
 
-#if defined(CRC_GENERIC) && defined(CRC_CLMUL)
+#if defined(CRC_GENERIC) && defined(CRC_ARCH_OPTIMIZED)
 
 //////////////////////////
 // Function dispatching //
@@ -102,7 +102,8 @@ typedef uint64_t (*crc64_func_type)(
 static crc64_func_type
 crc64_resolve(void)
 {
-	return is_clmul_supported() ? &crc64_clmul : &crc64_generic;
+	return is_arch_extension_supported()
+			? &crc64_arch_optimized : &crc64_generic;
 }
 
 #if defined(HAVE_FUNC_ATTRIBUTE_IFUNC) && defined(__clang__)
@@ -150,7 +151,7 @@ lzma_crc64(const uint8_t *buf, size_t size, uint64_t crc)
 extern LZMA_API(uint64_t)
 lzma_crc64(const uint8_t *buf, size_t size, uint64_t crc)
 {
-#if defined(CRC_GENERIC) && defined(CRC_CLMUL)
+#if defined(CRC_GENERIC) && defined(CRC_ARCH_OPTIMIZED)
 
 #ifdef CRC_USE_GENERIC_FOR_SMALL_INPUTS
 	if (size <= 16)
@@ -158,14 +159,14 @@ lzma_crc64(const uint8_t *buf, size_t size, uint64_t crc)
 #endif
 	return crc64_func(buf, size, crc);
 
-#elif defined(CRC_CLMUL)
+#elif defined(CRC_ARCH_OPTIMIZED)
 	// If CLMUL is used unconditionally without runtime CPU detection
 	// then omitting the generic version and its 8 KiB lookup table
 	// makes the library smaller.
 	//
 	// FIXME: Lookup table isn't currently omitted on 32-bit x86,
 	// see crc64_table.c.
-	return crc64_clmul(buf, size, crc);
+	return crc64_arch_optimized(buf, size, crc);
 
 #else
 	return crc64_generic(buf, size, crc);
diff --git a/src/liblzma/check/crc_common.h b/src/liblzma/check/crc_common.h
index 372ae4a4..045bc20e 100644
--- a/src/liblzma/check/crc_common.h
+++ b/src/liblzma/check/crc_common.h
@@ -70,7 +70,8 @@
 #endif
 
 #undef CRC_GENERIC
-#undef CRC_CLMUL
+#undef CRC_ARCH_OPTIMIZED
+#undef CRC_X86_CLMUL
 #undef CRC_USE_IFUNC
 #undef CRC_USE_GENERIC_FOR_SMALL_INPUTS
 
@@ -86,12 +87,14 @@
 // NOTE: Keep this this in sync with crc32_table.c.
 #elif (defined(__SSSE3__) && defined(__SSE4_1__) && defined(__PCLMUL__)) \
 		|| (defined(__e2k__) && __iset__ >= 6)
-#	define CRC_CLMUL 1
+#	define CRC_ARCH_OPTIMIZED 1
+#	define CRC_X86_CLMUL 1
 
 // Otherwise build both and detect at runtime which version to use.
 #else
 #	define CRC_GENERIC 1
-#	define CRC_CLMUL 1
+#	define CRC_ARCH_OPTIMIZED 1
+#	define CRC_X86_CLMUL 1
 
 #	ifdef HAVE_FUNC_ATTRIBUTE_IFUNC
 #		define CRC_USE_IFUNC 1
diff --git a/src/liblzma/check/crc_x86_clmul.h b/src/liblzma/check/crc_x86_clmul.h
index 7a47204a..bf3c2397 100644
--- a/src/liblzma/check/crc_x86_clmul.h
+++ b/src/liblzma/check/crc_x86_clmul.h
@@ -3,7 +3,7 @@
 /// \file       crc_x86_clmul.h
 /// \brief      CRC32 and CRC64 implementations using CLMUL instructions.
 ///
-/// crc32_clmul() and crc64_clmul() use 32/64-bit x86 SSSE3, SSE4.1, and
+/// The CRC32 and CRC64 implementations use 32/64-bit x86 SSSE3, SSE4.1, and
 /// CLMUL instructions. This is compatible with Elbrus 2000 (E2K) too.
 ///
 /// They were derived from
@@ -212,7 +212,7 @@ crc_simd_body(const uint8_t *buf, const size_t size, __m128i *v0, __m128i *v1,
 
 /*
 // These functions were used to generate the constants
-// at the top of lzma_crc32_clmul().
+// at the top of crc32_arch_optimized().
 static uint64_t
 calc_lo(uint64_t p, uint64_t a, int n)
 {
@@ -240,7 +240,7 @@ calc_hi(uint64_t p, uint64_t a, int n)
 crc_attr_target
 crc_attr_no_sanitize_address
 static uint32_t
-crc32_clmul(const uint8_t *buf, size_t size, uint32_t crc)
+crc32_arch_optimized(const uint8_t *buf, size_t size, uint32_t crc)
 {
 #ifndef CRC_USE_GENERIC_FOR_SMALL_INPUTS
 	// The code assumes that there is at least one byte of input.
@@ -284,7 +284,7 @@ crc32_clmul(const uint8_t *buf, size_t size, uint32_t crc)
 
 /*
 // These functions were used to generate the constants
-// at the top of lzma_crc64_clmul().
+// at the top of crc64_arch_optimized().
 static uint64_t
 calc_lo(uint64_t poly)
 {
@@ -319,8 +319,9 @@ calc_hi(uint64_t poly, uint64_t a)
 // and CRC32 CLMUL aren't affected by this problem. The problem does not
 // happen in crc_simd_body() either (which is shared with CRC32 CLMUL anyway).
 //
-// NOTE: Another pragma after lzma_crc64_clmul() restores the optimizations.
-// If the #if condition here is updated, the other one must be updated too.
+// NOTE: Another pragma after crc64_arch_optimized() restores
+// the optimizations. If the #if condition here is updated,
+// the other one must be updated too.
 #if defined(_MSC_VER) && !defined(__INTEL_COMPILER) && !defined(__clang__) \
 		&& defined(_M_IX86)
 #	pragma optimize("g", off)
@@ -329,7 +330,7 @@ calc_hi(uint64_t poly, uint64_t a)
 crc_attr_target
 crc_attr_no_sanitize_address
 static uint64_t
-crc64_clmul(const uint8_t *buf, size_t size, uint64_t crc)
+crc64_arch_optimized(const uint8_t *buf, size_t size, uint64_t crc)
 {
 #ifndef CRC_USE_GENERIC_FOR_SMALL_INPUTS
 	// The code assumes that there is at least one byte of input.
@@ -379,8 +380,8 @@ crc64_clmul(const uint8_t *buf, size_t size, uint64_t crc)
 #endif // BUILDING_CRC64_CLMUL
 
 
-// is_clmul_supported() must be inlined in this header file because the
-// ifunc resolver function may not support calling a function in another
+// is_arch_extension_supported() must be inlined in this header file because
+// the ifunc resolver function may not support calling a function in another
 // translation unit. Depending on compiler-toolchain and flags, a call to
 // a function defined in another translation unit could result in a
 // reference to the PLT, which is unsafe to do in an ifunc resolver. The
@@ -389,7 +390,7 @@ crc64_clmul(const uint8_t *buf, size_t size, uint64_t crc)
 // the function body in crc32_resolve() and crc64_resolve(), but this is
 // acceptable because the function results in very few instructions.
 static inline bool
-is_clmul_supported(void)
+is_arch_extension_supported(void)
 {
 	int success = 1;
 	uint32_t r[4]; // eax, ebx, ecx, edx