From 1940f0ec28f08c0ac72c1413d9706fb82eabe6ad Mon Sep 17 00:00:00 2001
From: Jia Tan <jiat0218@gmail.com>
Date: Mon, 22 Jan 2024 21:36:09 +0800
Subject: [PATCH] liblzma: Omit CRC tables when not needed with ARM64
 optimizations.

This is similar to the existing x86-64 CLMUL conditions to omit the
tables. They were slightly refactored to improve readability.
---
 src/liblzma/check/crc32_table.c | 18 +++++++++++++++---
 src/liblzma/check/crc64_table.c |  7 ++++++-
 src/liblzma/check/crc_common.h  |  5 ++++-
 3 files changed, 25 insertions(+), 5 deletions(-)

diff --git a/src/liblzma/check/crc32_table.c b/src/liblzma/check/crc32_table.c
index e53b63c9..41a80dcb 100644
--- a/src/liblzma/check/crc32_table.c
+++ b/src/liblzma/check/crc32_table.c
@@ -13,11 +13,23 @@
 #include "common.h"
 
 
-// FIXME: Compared to crc32_fast.c this has to check for __x86_64__ too
+// FIXME: Compared to crc_common.h this has to check for __x86_64__ too
 // so that in 32-bit builds crc32_x86.S won't break due to a missing table.
-#if !defined(HAVE_ENCODERS) && ((defined(__x86_64__) && defined(__SSSE3__) \
+#if (defined(__x86_64__) && defined(__SSSE3__) \
 			&& defined(__SSE4_1__) && defined(__PCLMUL__)) \
-			|| (defined(__e2k__) && __iset__ >= 6))
+		|| (defined(__e2k__) && __iset__ >= 6)
+#	define X86_CLMUL_NO_TABLE 1
+#endif
+
+#if defined(HAVE_ARM64_CRC32) \
+		&& !defined(WORDS_BIGENDIAN) \
+		&& defined(__ARM_FEATURE_CRC32)
+#	define ARM64_CRC32_NO_TABLE 1
+#endif
+
+
+#if !defined(HAVE_ENCODERS) && (defined(X86_CLMUL_NO_TABLE) \
+		|| defined(ARM64_CRC32_NO_TABLE_))
 // No table needed. Use a typedef to avoid an empty translation unit.
 typedef void lzma_crc32_dummy;
 
diff --git a/src/liblzma/check/crc64_table.c b/src/liblzma/check/crc64_table.c
index 688e527b..0ae9dda8 100644
--- a/src/liblzma/check/crc64_table.c
+++ b/src/liblzma/check/crc64_table.c
@@ -13,11 +13,16 @@
 #include "common.h"
 
 
-// FIXME: Compared to crc64_fast.c this has to check for __x86_64__ too
+// FIXME: Compared to crc_common.h this has to check for __x86_64__ too
 // so that in 32-bit builds crc64_x86.S won't break due to a missing table.
 #if (defined(__x86_64__) && defined(__SSSE3__) \
 			&& defined(__SSE4_1__) && defined(__PCLMUL__)) \
 		|| (defined(__e2k__) && __iset__ >= 6)
+#	define X86_CLMUL_NO_TABLE 1
+#endif
+
+
+#ifdef X86_CLMUL_NO_TABLE
 // No table needed. Use a typedef to avoid an empty translation unit.
 typedef void lzma_crc64_dummy;
 
diff --git a/src/liblzma/check/crc_common.h b/src/liblzma/check/crc_common.h
index 35f60d95..123d7db0 100644
--- a/src/liblzma/check/crc_common.h
+++ b/src/liblzma/check/crc_common.h
@@ -75,6 +75,9 @@
 // ARM64 CRC32 instruction is only useful for CRC32. Currently, only
 // little endian is supported since we were unable to test on a big
 // endian machine.
+//
+// NOTE: Keep this and the next check in sync with the macro
+//       ARM64_CRC32_NO_TABLE in crc32_table.c
 #if defined(HAVE_ARM64_CRC32) && !defined(WORDS_BIGENDIAN)
 // Allow ARM64 CRC32 instruction without a runtime check if
 // __ARM_FEATURE_CRC32 is defined. GCC and Clang only define this if the
@@ -94,7 +97,7 @@
 // generic version can be omitted. Note that this doesn't work with MSVC
 // as I don't know how to detect the features here.
 //
-// NOTE: Keep this this in sync with crc32_table.c.
+// NOTE: Keep this in sync with the CLMUL_NO_TABLE macro in crc32_table.c.
 #	if (defined(__SSSE3__) && defined(__SSE4_1__) && defined(__PCLMUL__)) \
 		|| (defined(__e2k__) && __iset__ >= 6)
 #		define CRC32_ARCH_OPTIMIZED 1