nasty kludge for msabi

configure.ac

@@ -29,7 +29,14 @@ if test "x$enable_x86_64" = "xyes"; then
   AC_DEFINE([XPAR_X86_64], [1], [Enable x86_64 platform specific code.])
   AM_CONDITIONAL([XPAR_X86_64], [true])
   AX_PROG_NASM
-  AX_GCC_FUNC_ATTRIBUTE([sysv_abi])
+
+  # Check if the target platform is Windows specifically.
+  # It needs a large amount of nasty kludges to work.
+  case "$target_os" in
+    *cygwin* | *mingw* | *windows*)
+      AC_DEFINE([XPAR_WINDOWS], [1], [Set if compiling on Windows.])
+      ;;
+  esac
 else
   AM_CONDITIONAL([XPAR_X86_64], [false])
 fi

crc32c.c

@@ -90,23 +90,21 @@ u32 crc32c_tabular(u32 crc, u8 * data, sz length) {
 }
 
 #if defined(XPAR_X86_64)
-  #ifdef HAVE_FUNC_ATTRIBUTE_SYSV_ABI
-    #define EXTERNAL_ABI __attribute__((sysv_abi))
-  #else
-    #define EXTERNAL_ABI
-  #endif
-
   typedef u32 (*crc32c_func)(u32, u8 *, sz);
-  extern EXTERNAL_ABI int crc32c_x86_64_cpuflags(void);
-  extern EXTERNAL_ABI u32 crc32c_small_x86_64_sse42(u32, u8 *, sz);
+  extern int crc32c_x86_64_cpuflags(void);
+  extern u32 crc32c_small_x86_64_sse42(u32, u8 *, sz);
 #endif
 
 u32 crc32c(u8 * data, sz length) {
 #if defined(XPAR_X86_64)
   static int cpuflags = -1;
   if (cpuflags == -1) cpuflags = crc32c_x86_64_cpuflags();
   if (cpuflags & 1)
+  #if defined(XPAR_WINDOWS)
+    return crc32c_small_x86_64_sse42_msabi(0xFFFFFFFFL, data, length) ^ 0xFFFFFFFFL;
+  #else
     return crc32c_small_x86_64_sse42(0xFFFFFFFFL, data, length) ^ 0xFFFFFFFFL;
+  #endif
   else
     return crc32c_tabular(0xFFFFFFFFL, data, length) ^ 0xFFFFFFFFL;
 #else

m4/ax_prog_nasm.m4

@@ -6,10 +6,10 @@ AC_DEFUN([AX_PROG_NASM],[
 AC_CHECK_PROGS(NASM, [nasm nasmw yasm])
 test -z "$NASM" && AC_MSG_ERROR([no nasm (Netwide Assembler) found])
 
-AC_MSG_CHECKING([for object file format of host system])
-case "$host_os" in
+AC_MSG_CHECKING([for object file format of target system])
+case "$target_os" in
   cygwin* | mingw* | pw32* | interix*)
-    case "$host_cpu" in
+    case "$target_cpu" in
       x86_64 | amd64)
         objfmt='Win64-COFF'
         ;;
@@ -31,7 +31,7 @@ case "$host_os" in
     objfmt='a.out'
   ;;
   linux*)
-    case "$host_cpu" in
+    case "$target_cpu" in
       x86_64 | amd64)
         objfmt='ELF64'
         ;;
@@ -44,7 +44,7 @@ case "$host_os" in
     if echo __ELF__ | $CC -E - | grep __ELF__ > /dev/null; then
       objfmt='BSD-a.out'
     else
-      case "$host_cpu" in
+      case "$target_cpu" in
         x86_64 | amd64)
           objfmt='ELF64'
           ;;
@@ -55,7 +55,7 @@ case "$host_os" in
     fi
   ;;
   solaris* | sunos* | sysv* | sco*)
-    case "$host_cpu" in
+    case "$target_cpu" in
       x86_64 | amd64)
         objfmt='ELF64'
         ;;
@@ -65,7 +65,7 @@ case "$host_os" in
     esac
   ;;
   darwin* | rhapsody* | nextstep* | openstep* | macos*)
-    case "$host_cpu" in
+    case "$target_cpu" in
       x86_64 | amd64)
         objfmt='Mach-O64'
         ;;
@@ -82,7 +82,7 @@ esac
 AC_MSG_RESULT([$objfmt])
 if test "$objfmt" = 'ELF ?'; then
   objfmt='ELF'
-  AC_MSG_WARN([unexpected host system. assumed that the format is $objfmt.])
+  AC_MSG_WARN([unexpected target system. assumed that the format is $objfmt.])
 fi
 
 AC_MSG_CHECKING([for object file format specifier (NAFLAGS) ])

xpar-x86_64.asm

@@ -102,16 +102,26 @@ crc32c_small_x86_64_sse42:
 .done:
   retq
 
-; Some *cough* compilers use leading underscores. Please them.
-; Is there a better solution?
-
+; clang bug workaround for MacOS
 global _crc32c_x86_64_cpuflags
 global _crc32c_small_x86_64_sse42
 _crc32c_x86_64_cpuflags:
   jmp crc32c_x86_64_cpuflags
 _crc32c_small_x86_64_sse42:
   jmp crc32c_small_x86_64_sse42
 
+; clang bug workaround for Windows
+global crc32c_small_x86_64_sse42_msabi
+crc32c_small_x86_64_sse42_msabi:
+  push rdi
+  mov rdi, rcx
+  push rsi
+  mov rsi, rdx
+  mov rdx, r8
+  call crc32c_small_x86_64_sse42
+  pop rsi
+  pop rdi
+  ret
 
 ; Need .GNU-stack to mark the stack as non-executable on ELF targets.
 %ifdef ELF