Move UNALIGNED_OK detection to compile time instead of configure time.

.github/workflows/cmake.yml

@@ -41,21 +41,20 @@ jobs:
             cmake-args: -DZLIB_COMPAT=ON -DZLIB_SYMBOL_PREFIX=zTest_
             codecov: ubuntu_gcc_compat_sprefix
 
-          - name: Ubuntu GCC OSB -O1 No Unaligned64 UBSAN
+          - name: Ubuntu GCC OSB -O1 UBSAN
             os: ubuntu-latest
             compiler: gcc
             cxx-compiler: g++
-            cmake-args: -DWITH_UNALIGNED=ON -DUNALIGNED64_OK=OFF -DWITH_SANITIZER=Undefined
+            cmake-args: -DWITH_SANITIZER=Undefined
             build-dir: ../build
             build-src-dir: ../zlib-ng
             codecov: ubuntu_gcc_osb
             cflags: -O1 -g3
 
-          - name: Ubuntu GCC -O3 No Unaligned
+          - name: Ubuntu GCC -O3
             os: ubuntu-latest
             compiler: gcc
             cxx-compiler: g++
-            cmake-args: -DWITH_UNALIGNED=OFF
             codecov: ubuntu_gcc_o3
             cflags: -O3
 

CMakeLists.txt

@@ -87,7 +87,6 @@ option(WITH_MAINTAINER_WARNINGS "Build with project maintainer warnings" OFF)
 option(WITH_CODE_COVERAGE "Enable code coverage reporting" OFF)
 option(WITH_INFLATE_STRICT "Build with strict inflate distance checking" OFF)
 option(WITH_INFLATE_ALLOW_INVALID_DIST "Build with zero fill for inflate invalid distances" OFF)
-option(WITH_UNALIGNED "Support unaligned reads on platforms that support it" ON)
 
 set(ZLIB_SYMBOL_PREFIX "" CACHE STRING "Give this prefix to all publicly exported symbols.
 Useful when embedding into a larger library.
@@ -138,7 +137,6 @@ mark_as_advanced(FORCE
     WITH_POWER8
     WITH_INFLATE_STRICT
     WITH_INFLATE_ALLOW_INVALID_DIST
-    WITH_UNALIGNED
     INSTALL_UTILS
     )
 
@@ -249,46 +247,6 @@ else()
     endif()
 endif()
 
-# Set architecture alignment requirements
-if(WITH_UNALIGNED)
-    if((BASEARCH_ARM_FOUND AND NOT "${ARCH}" MATCHES "armv[2-7]") OR (BASEARCH_PPC_FOUND AND "${ARCH}" MATCHES "powerpc64le") OR BASEARCH_X86_FOUND)
-        if(NOT DEFINED UNALIGNED_OK)
-            set(UNALIGNED_OK TRUE)
-        endif()
-    endif()
-    if(UNALIGNED_OK)
-        add_definitions(-DUNALIGNED_OK)
-        message(STATUS "Architecture supports unaligned reads")
-    endif()
-    if(BASEARCH_ARM_FOUND)
-        if(NOT DEFINED UNALIGNED64_OK)
-            if("${ARCH}" MATCHES "armv[2-7]")
-                set(UNALIGNED64_OK FALSE)
-            elseif("${ARCH}" MATCHES "(arm(v[8-9])?|aarch64)")
-                set(UNALIGNED64_OK TRUE)
-            endif()
-        endif()
-    endif()
-    if(BASEARCH_PPC_FOUND)
-        if(NOT DEFINED UNALIGNED64_OK)
-            if("${ARCH}" MATCHES "powerpc64le")
-                set(UNALIGNED64_OK TRUE)
-            endif()
-        endif()
-    endif()
-    if(BASEARCH_X86_FOUND)
-        if(NOT DEFINED UNALIGNED64_OK)
-            set(UNALIGNED64_OK TRUE)
-        endif()
-    endif()
-    if(UNALIGNED64_OK)
-        add_definitions(-DUNALIGNED64_OK)
-        message(STATUS "Architecture supports unaligned reads of > 4 bytes")
-    endif()
-else()
-    message(STATUS "Unaligned reads manually disabled")
-endif()
-
 # Apply warning compiler flags
 if(WITH_MAINTAINER_WARNINGS)
     add_compile_options(${WARNFLAGS} ${WARNFLAGS_MAINTAINER} ${WARNFLAGS_DISABLE})
@@ -1459,8 +1417,6 @@ add_feature_info(WITH_MAINTAINER_WARNINGS WITH_MAINTAINER_WARNINGS "Build with p
 add_feature_info(WITH_CODE_COVERAGE WITH_CODE_COVERAGE "Enable code coverage reporting")
 add_feature_info(WITH_INFLATE_STRICT WITH_INFLATE_STRICT "Build with strict inflate distance checking")
 add_feature_info(WITH_INFLATE_ALLOW_INVALID_DIST WITH_INFLATE_ALLOW_INVALID_DIST "Build with zero fill for inflate invalid distances")
-add_feature_info(WITH_UNALIGNED UNALIGNED_OK "Support unaligned reads on platforms that support it")
-add_feature_info(WITH_UNALIGNED64 UNALIGNED64_OK "Support unaligned 64-bit reads on platforms that support it")
 
 if(BASEARCH_ARM_FOUND)
     add_feature_info(WITH_ACLE WITH_ACLE "Build with ACLE")

README.md

@@ -194,7 +194,6 @@ Advanced Build Options
 | CMake                           | configure             | Description                                                         | Default                |
 |:--------------------------------|:----------------------|:--------------------------------------------------------------------|------------------------|
 | ZLIB_DUAL_LINK                  |                       | Dual link tests with system zlib                                    | OFF                    |
-| UNALIGNED_OK                    |                       | Allow unaligned reads                                               | ON (x86, arm)          |
 | FORCE_SSE2                      | --force-sse2          | Skip runtime check for SSE2 instructions (Always on for x86_64)     | OFF (x86)              |
 | FORCE_TZCNT                     | --force-tzcnt         | Skip runtime check for TZCNT instructions                           | OFF                    |
 | WITH_AVX2                       |                       | Build with AVX2 intrinsics                                          | ON                     |
@@ -212,7 +211,6 @@ Advanced Build Options
 | WITH_CRC32_VX                   | --without-crc32-vx    | Build with vectorized CRC32 on IBM Z                                | ON                     |
 | WITH_DFLTCC_DEFLATE             | --with-dfltcc-deflate | Build with DFLTCC intrinsics for compression on IBM Z               | OFF                    |
 | WITH_DFLTCC_INFLATE             | --with-dfltcc-inflate | Build with DFLTCC intrinsics for decompression on IBM Z             | OFF                    |
-| WITH_UNALIGNED                  |                       | Allow optimizations that use unaligned reads if safe on current arch| ON                     |
 | WITH_INFLATE_STRICT             |                       | Build with strict inflate distance checking                         | OFF                    |
 | WITH_INFLATE_ALLOW_INVALID_DIST |                       | Build with zero fill for inflate invalid distances                  | OFF                    |
 | INSTALL_UTILS                   |                       | Copy minigzip and minideflate during install                        | OFF                    |

arch/x86/compare256_avx2.c

@@ -14,7 +14,7 @@
 #  include <nmmintrin.h>
 #endif
 
-/* UNALIGNED_OK, AVX2 intrinsic comparison */
+/* AVX2 unaligned intrinsic comparison */
 static inline uint32_t compare256_unaligned_avx2_static(const uint8_t *src0, const uint8_t *src1) {
     uint32_t len = 0;
 

compare256.c

@@ -56,7 +56,7 @@ Z_INTERNAL uint32_t compare256_c(const uint8_t *src0, const uint8_t *src1) {
 #include "match_tpl.h"
 
 #ifdef UNALIGNED_OK
-/* UNALIGNED_OK, 16-bit integer comparison */
+/* 16-bit unaligned integer comparison */
 static inline uint32_t compare256_unaligned_16_static(const uint8_t *src0, const uint8_t *src1) {
     uint32_t len = 0;
 
@@ -94,7 +94,7 @@ Z_INTERNAL uint32_t compare256_unaligned_16(const uint8_t *src0, const uint8_t *
 #include "match_tpl.h"
 
 #ifdef HAVE_BUILTIN_CTZ
-/* UNALIGNED_OK, 32-bit integer comparison */
+/* 32-bit unaligned integer comparison */
 static inline uint32_t compare256_unaligned_32_static(const uint8_t *src0, const uint8_t *src1) {
     uint32_t len = 0;
 

configure

@@ -1481,9 +1481,6 @@ case "${ARCH}" in
     i386 | i486 | i586 | i686 |x86_64)
         ARCHDIR=arch/x86
 
-        CFLAGS="${CFLAGS} -DUNALIGNED_OK -DUNALIGNED64_OK"
-        SFLAGS="${SFLAGS} -DUNALIGNED_OK -DUNALIGNED64_OK"
-
         # Enable arch-specific optimizations
         if test $without_optimizations -eq 0; then
             CFLAGS="${CFLAGS} -DX86_FEATURES"
@@ -1704,9 +1701,6 @@ EOF
                 fi
             ;;
             armv6l | armv6hl)
-                CFLAGS="${CFLAGS} -DUNALIGNED_OK"
-                SFLAGS="${SFLAGS} -DUNALIGNED_OK"
-
                 if test $without_optimizations -eq 0; then
                     if test $buildacle -eq 1; then
                         echo ACLE support not available
@@ -1718,9 +1712,6 @@ EOF
                 fi
             ;;
             arm | armv7*)
-                CFLAGS="${CFLAGS} -DUNALIGNED_OK"
-                SFLAGS="${SFLAGS} -DUNALIGNED_OK"
-
                 if test $without_optimizations -eq 0; then
                     if test $buildacle -eq 1; then
                         echo ACLE support not available
@@ -1745,9 +1736,6 @@ EOF
                 fi
             ;;
             armv8-a | armv8-a+simd)
-                CFLAGS="${CFLAGS} -DUNALIGNED_OK -DUNALIGNED64_OK"
-                SFLAGS="${SFLAGS} -DUNALIGNED_OK -DUNALIGNED64_OK"
-
                 if test $without_optimizations -eq 0; then
                     if test $buildacle -eq 1; then
                         echo ACLE support not available
@@ -1772,9 +1760,6 @@ EOF
                 fi
             ;;
             armv8-a+crc | armv8-a+crc+simd | armv8.[1234]-a | armv8.[1234]-a+simd)
-                CFLAGS="${CFLAGS} -DUNALIGNED_OK -DUNALIGNED64_OK"
-                SFLAGS="${SFLAGS} -DUNALIGNED_OK -DUNALIGNED64_OK"
-
                 acleflag="-march=${ARCH}"
 
                 if test $without_optimizations -eq 0; then
@@ -1869,9 +1854,6 @@ EOF
 
         neonflag="-march=${ARCH}"
         acleflag="-march=${ARCH}"
-
-        CFLAGS="${CFLAGS} -DUNALIGNED_OK -DUNALIGNED64_OK"
-        SFLAGS="${SFLAGS} -DUNALIGNED_OK -DUNALIGNED64_OK"
     ;;
     powerpc*)
         case "${ARCH}" in
@@ -1883,8 +1865,6 @@ EOF
             ;;
             powerpc64le)
                 [ ! -z $CROSS_PREFIX ] && QEMU_ARCH=ppc64le
-                CFLAGS="${CFLAGS} -DUNALIGNED_OK -DUNALIGNED64_OK"
-                SFLAGS="${SFLAGS} -DUNALIGNED_OK -DUNALIGNED64_OK"
             ;;
         esac
 

win32/Makefile.a64

@@ -30,8 +30,6 @@ WFLAGS  = \
 	-D_CRT_NONSTDC_NO_DEPRECATE \
 	-DARM_NEON_HASLD4 \
 	-DARM_FEATURES \
-	-DUNALIGNED_OK \
-	-DUNALIGNED64_OK \
 	#
 LDFLAGS = -nologo -debug -incremental:no -opt:ref -manifest
 ARFLAGS = -nologo

win32/Makefile.arm

@@ -30,7 +30,6 @@ WFLAGS  = \
 	-D_CRT_NONSTDC_NO_DEPRECATE \
 	-DARM_FEATURES \
 	-DARM_NEON_HASLD4 \
-	-DUNALIGNED_OK \
 	#
 LDFLAGS = -nologo -debug -incremental:no -opt:ref -manifest
 ARFLAGS = -nologo

win32/Makefile.msc

@@ -35,8 +35,6 @@ WFLAGS  = \
 	-DX86_AVX2 \
 	-DX86_AVX_CHUNKSET \
 	-DX86_SSE2_CHUNKSET \
-	-DUNALIGNED_OK \
-	-DUNALIGNED64_OK \
 	#
 LDFLAGS = -nologo -debug -incremental:no -opt:ref -manifest
 ARFLAGS = -nologo

zbuild.h

@@ -194,6 +194,28 @@
 #  define Tracecv(c, x)
 #endif
 
+#if defined(__x86_64__) || defined(_M_X64) || defined(__amd64__) || defined(_M_AMD64)
+#  define UNALIGNED_OK
+#  define UNALIGNED64_OK
+#elif defined(__i386__) || defined(__i486__) || defined(__i586__) || \
+      defined(__i686__) || defined(_X86_) || defined(_M_IX86)
+#  define UNALIGNED_OK
+#elif defined(__aarch64__) || defined(_M_ARM64)
+#  if (defined(__GNUC__) && defined(__ARM_FEATURE_UNALIGNED)) || !defined(__GNUC__)
+#    define UNALIGNED_OK
+#    define UNALIGNED64_OK
+#  endif
+#elif defined(__arm__) || (_M_ARM >= 7)
+#  if (defined(__GNUC__) && defined(__ARM_FEATURE_UNALIGNED)) || !defined(__GNUC__)
+#    define UNALIGNED_OK
+#  endif
+#elif defined(__powerpc64__) || defined(__ppc64__)
+#  if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
+#    define UNALIGNED_OK
+#    define UNALIGNED64_OK
+#  endif
+#endif
+
 /* Force compiler to emit unaligned memory accesses if unaligned access is supported
    on the architecture, otherwise don't assume unaligned access is supported. Older
    compilers don't optimize memcpy and memcmp calls to unaligned access instructions