blob: a3f3067fb7571280fb2b78493ce9fd179d102b88 [file] [log] [blame]
lh9ed821d2023-04-07 01:36:19 -07001GLIBC_PROVIDES dnl See aclocal.m4 in the top level source directory.
2# Local configure fragment for sysdeps/i386.
3
4# We no longer support i386 since it lacks the atomic instructions
5# required to implement NPTL threading.
6if test "$config_machine" = i386; then
7 AC_MSG_ERROR([
8*** ERROR: Support for i386 is deprecated.
9*** Please use host i786, i686, i585 or i486.
10*** For example: /src/glibc/configure --host=i686-pc-linux-gnu ..."])
11fi
12
13# The GNU C Library can't be built for i386. There are several reasons for
14# this restriction. The primary reason is that i386 lacks the atomic
15# operations required to support the current NPTL implementation. While it is
16# possible that such atomic operations could be emulated in the kernel to date
17# no such work has been done to enable this. Even with NPTL disabled you still
18# have no atomic.h implementation. Given the declining use of i386 we disable
19# support for building with `-march=i386' or `-mcpu=i386.' We don't explicitly
20# check for i386, instead we make sure the compiler has support for inlining
21# the builtin __sync_val_compare_and_swap. If it does then we should have no
22# problem building for i386.
23LIBC_COMPILER_BUILTIN_INLINED(
24 [__sync_val_compare_and_swap],
25 [int a, b, c; __sync_val_compare_and_swap (&a, b, c);],
26 [-O0],
27 [libc_cv_unsupported_i386=no],
28 [AC_MSG_ERROR([
29*** Building with -march=i386/-mcpu=i386 is not supported.
30*** Please use host i786, i686, i586, or i486.
31*** For example: /source/glibc/configure CFLAGS='-O2 -march=i686' ...])])
32
33AC_CHECK_HEADER([cpuid.h], ,
34 [AC_MSG_ERROR([gcc must provide the <cpuid.h> header])],
35 [/* No default includes. */])
36
37dnl Check if -msse4 works.
38AC_CACHE_CHECK(for SSE4 support, libc_cv_cc_sse4, [dnl
39LIBC_TRY_CC_OPTION([-msse4], [libc_cv_cc_sse4=yes], [libc_cv_cc_sse4=no])
40])
41if test $libc_cv_cc_sse4 = yes; then
42 AC_DEFINE(HAVE_SSE4_SUPPORT)
43fi
44LIBC_CONFIG_VAR([config-cflags-sse4], [$libc_cv_cc_sse4])
45
46dnl Check if -Wa,-mtune=i686 works.
47AC_CACHE_CHECK(for assembler -mtune=i686 support, libc_cv_as_i686, [dnl
48LIBC_TRY_CC_OPTION([-Wa,-mtune=i686],
49 [libc_cv_as_i686=yes],
50 [libc_cv_as_i686=no])
51])
52LIBC_CONFIG_VAR([config-asflags-i686], [$libc_cv_as_i686])
53
54dnl Check if -mavx works.
55AC_CACHE_CHECK(for AVX support, libc_cv_cc_avx, [dnl
56LIBC_TRY_CC_OPTION([-mavx], [libc_cv_cc_avx=yes], [libc_cv_cc_avx=no])
57])
58if test $libc_cv_cc_avx = yes; then
59 AC_DEFINE(HAVE_AVX_SUPPORT)
60fi
61LIBC_CONFIG_VAR([config-cflags-avx], [$libc_cv_cc_avx])
62
63dnl Check if -msse2avx works.
64AC_CACHE_CHECK(for AVX encoding of SSE instructions, libc_cv_cc_sse2avx, [dnl
65LIBC_TRY_CC_OPTION([-msse2avx],
66 [libc_cv_cc_sse2avx=yes],
67 [libc_cv_cc_sse2avx=no])
68])
69if test $libc_cv_cc_sse2avx = yes; then
70 AC_DEFINE(HAVE_SSE2AVX_SUPPORT)
71fi
72LIBC_CONFIG_VAR([config-cflags-sse2avx], [$libc_cv_cc_sse2avx])
73
74dnl Check if -mfma4 works.
75AC_CACHE_CHECK(for FMA4 support, libc_cv_cc_fma4, [dnl
76LIBC_TRY_CC_OPTION([-mfma4], [libc_cv_cc_fma4=yes], [libc_cv_cc_fma4=no])
77])
78if test $libc_cv_cc_fma4 = yes; then
79 AC_DEFINE(HAVE_FMA4_SUPPORT)
80fi
81LIBC_CONFIG_VAR([have-mfma4], [$libc_cv_cc_fma4])
82
83dnl Check if -mno-vzeroupper works.
84AC_CACHE_CHECK(for -mno-vzeroupper support, libc_cv_cc_novzeroupper, [dnl
85LIBC_TRY_CC_OPTION([-mno-vzeroupper],
86 [libc_cv_cc_novzeroupper=yes],
87 [libc_cv_cc_novzeroupper=no])
88])
89LIBC_CONFIG_VAR([config-cflags-novzeroupper], [$libc_cv_cc_novzeroupper])
90
91dnl Check whether asm supports Intel MPX
92AC_CACHE_CHECK(for Intel MPX support, libc_cv_asm_mpx, [dnl
93cat > conftest.s <<\EOF
94 bndmov %bnd0,(%esp)
95EOF
96if AC_TRY_COMMAND(${CC-cc} -c $ASFLAGS conftest.s 1>&AS_MESSAGE_LOG_FD); then
97 libc_cv_asm_mpx=yes
98else
99 libc_cv_asm_mpx=no
100fi
101rm -f conftest*])
102if test $libc_cv_asm_mpx == yes; then
103 AC_DEFINE(HAVE_MPX_SUPPORT)
104fi
105
106dnl Check if -mavx2 works.
107AC_CACHE_CHECK(for AVX2 support, libc_cv_cc_avx2, [dnl
108LIBC_TRY_CC_OPTION([-mavx2], [libc_cv_cc_avx2=yes], [libc_cv_cc_avx2=no])
109])
110if test $libc_cv_cc_avx2 = yes; then
111 AC_DEFINE(HAVE_AVX2_SUPPORT)
112fi
113LIBC_CONFIG_VAR([config-cflags-avx2], [$libc_cv_cc_avx2])
114
115AC_DEFINE(USE_REGPARMS)
116
117dnl It is always possible to access static and hidden symbols in an
118dnl position independent way.
119AC_DEFINE(PI_STATIC_AND_HIDDEN)