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authorLukas Larsson <[email protected]>2012-08-24 12:02:58 +0200
committerLukas Larsson <[email protected]>2012-08-24 12:02:58 +0200
commit0342137176c653c51cc3a78781888cfca8568650 (patch)
treeb3f2b462589a7d574a80e4557a8a05a222184a3e /erts
parentdd12380a68f4692c1aba2e972b84de89f3df46df (diff)
parent85283dc19ceea2905ff39aa0615d1a99d7aea16c (diff)
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Merge branch 'msp/double_middle_endian/OTP-10209' into maint
* msp/double_middle_endian/OTP-10209: Configure now assumed normal doubles Revise the autoconf tests for double middle endianness. Add test for floating-point output to float_SUITE. Unbreak floating point on middle-endian machines.
Diffstat (limited to 'erts')
-rw-r--r--erts/aclocal.m4106
-rw-r--r--erts/configure.in1
-rw-r--r--erts/emulator/beam/erl_bits.c10
-rw-r--r--erts/emulator/test/float_SUITE.erl9
4 files changed, 124 insertions, 2 deletions
diff --git a/erts/aclocal.m4 b/erts/aclocal.m4
index 339a15a2bb..a76594d86f 100644
--- a/erts/aclocal.m4
+++ b/erts/aclocal.m4
@@ -59,6 +59,7 @@ AC_ARG_VAR(erl_xcomp_isysroot, [Absolute cross system root include path (only us
dnl Cross compilation variables
AC_ARG_VAR(erl_xcomp_bigendian, [big endian system: yes|no (only used when cross compiling)])
+AC_ARG_VAR(erl_xcomp_double_middle_endian, [double-middle-endian system: yes|no (only used when cross compiling)])
AC_ARG_VAR(erl_xcomp_linux_clock_gettime_correction, [clock_gettime() can be used for time correction: yes|no (only used when cross compiling)])
AC_ARG_VAR(erl_xcomp_linux_nptl, [have Native POSIX Thread Library: yes|no (only used when cross compiling)])
AC_ARG_VAR(erl_xcomp_linux_usable_sigusrx, [SIGUSR1 and SIGUSR2 can be used: yes|no (only used when cross compiling)])
@@ -606,6 +607,103 @@ ifelse([$5], , , [$5
fi
])
+dnl ----------------------------------------------------------------------
+dnl
+dnl AC_DOUBLE_MIDDLE_ENDIAN
+dnl
+dnl Checks whether doubles are represented in "middle-endian" format.
+dnl Sets ac_cv_double_middle_endian={no,yes,unknown} accordingly,
+dnl as well as DOUBLE_MIDDLE_ENDIAN.
+dnl
+dnl
+
+AC_DEFUN([AC_C_DOUBLE_MIDDLE_ENDIAN],
+[AC_CACHE_CHECK(whether double word ordering is middle-endian, ac_cv_c_double_middle_endian,
+[# It does not; compile a test program.
+AC_RUN_IFELSE(
+[AC_LANG_SOURCE([[#include <stdlib.h>
+
+int
+main(void)
+{
+ int i = 0;
+ int zero = 0;
+ int bigendian;
+ int zero_index = 0;
+
+ union
+ {
+ long int l;
+ char c[sizeof (long int)];
+ } u;
+
+ /* we'll use the one with 32-bit words */
+ union
+ {
+ double d;
+ unsigned int c[2];
+ } vint;
+
+ union
+ {
+ double d;
+ unsigned long c[2];
+ } vlong;
+
+ union
+ {
+ double d;
+ unsigned short c[2];
+ } vshort;
+
+
+ /* Are we little or big endian? From Harbison&Steele. */
+ u.l = 1;
+ bigendian = (u.c[sizeof (long int) - 1] == 1);
+
+ zero_index = bigendian ? 1 : 0;
+
+ vint.d = 1.0;
+ vlong.d = 1.0;
+ vshort.d = 1.0;
+
+ if (sizeof(unsigned int) == 4)
+ {
+ if (vint.c[zero_index] != 0)
+ zero = 1;
+ }
+ else if (sizeof(unsigned long) == 4)
+ {
+ if (vlong.c[zero_index] != 0)
+ zero = 1;
+ }
+ else if (sizeof(unsigned short) == 4)
+ {
+ if (vshort.c[zero_index] != 0)
+ zero = 1;
+ }
+
+ exit (zero);
+}
+]])],
+ [ac_cv_c_double_middle_endian=no],
+ [ac_cv_c_double_middle_endian=yes],
+ [ac_cv_c_double_middle=unknown])])
+case $ac_cv_c_double_middle_endian in
+ yes)
+ m4_default([$1],
+ [AC_DEFINE([DOUBLE_MIDDLE_ENDIAN], 1,
+ [Define to 1 if your processor stores the words in a double in
+ middle-endian format (like some ARMs).])]) ;;
+ no)
+ $2 ;;
+ *)
+ m4_default([$3],
+ [AC_MSG_WARN([unknown double endianness
+presetting ac_cv_c_double_middle_endian=no (or yes) will help])]) ;;
+esac
+])# AC_C_DOUBLE_MIDDLE_ENDIAN
+
dnl ----------------------------------------------------------------------
dnl
@@ -1337,6 +1435,14 @@ if test "$ac_cv_c_bigendian" = "yes"; then
AC_DEFINE(ETHR_BIGENDIAN, 1, [Define if bigendian])
fi
+case X$erl_xcomp_double_middle_endian in
+ X) ;;
+ Xyes|Xno|Xunknown) ac_cv_c_double_middle_endian=$erl_xcomp_double_middle_endian;;
+ *) AC_MSG_ERROR([Bad erl_xcomp_double_middle_endian value: $erl_xcomp_double_middle_endian]);;
+esac
+
+AC_C_DOUBLE_MIDDLE_ENDIAN
+
AC_ARG_ENABLE(native-ethr-impls,
AS_HELP_STRING([--disable-native-ethr-impls],
[disable native ethread implementations]),
diff --git a/erts/configure.in b/erts/configure.in
index b3289bf84c..e576bd7755 100644
--- a/erts/configure.in
+++ b/erts/configure.in
@@ -1730,6 +1730,7 @@ case X$erl_xcomp_bigendian in
esac
AC_C_BIGENDIAN
+AC_C_DOUBLE_MIDDLE_ENDIAN
dnl fdatasync syscall (Unix only)
AC_CHECK_FUNCS([fdatasync])
diff --git a/erts/emulator/beam/erl_bits.c b/erts/emulator/beam/erl_bits.c
index 6f7309f493..b7c82935ff 100644
--- a/erts/emulator/beam/erl_bits.c
+++ b/erts/emulator/beam/erl_bits.c
@@ -1005,8 +1005,13 @@ erts_new_bs_put_float(Process *c_p, Eterm arg, Uint num_bits, int flags)
if (is_float(arg)) {
FloatDef *fdp = (FloatDef*)(float_val(arg) + 1);
+#ifdef DOUBLE_MIDDLE_ENDIAN
+ a = fdp->fw[1];
+ b = fdp->fw[0];
+#else
a = fdp->fw[0];
b = fdp->fw[1];
+#endif
} else if (is_small(arg)) {
u.f64 = (double) signed_val(arg);
a = u.i32[0];
@@ -1015,8 +1020,13 @@ erts_new_bs_put_float(Process *c_p, Eterm arg, Uint num_bits, int flags)
if (big_to_double(arg, &u.f64) < 0) {
return 0;
}
+#ifdef DOUBLE_MIDDLE_ENDIAN
+ a = u.i32[1];
+ b = u.i32[0];
+#else
a = u.i32[0];
b = u.i32[1];
+#endif
} else {
return 0;
}
diff --git a/erts/emulator/test/float_SUITE.erl b/erts/emulator/test/float_SUITE.erl
index 8e6923ce9f..abe01bf5ec 100644
--- a/erts/emulator/test/float_SUITE.erl
+++ b/erts/emulator/test/float_SUITE.erl
@@ -25,7 +25,7 @@
init_per_group/2,end_per_group/2,
init_per_testcase/2,end_per_testcase/2,
fpe/1,fp_drv/1,fp_drv_thread/1,denormalized/1,match/1,
- bad_float_unpack/1,cmp_zero/1, cmp_integer/1, cmp_bignum/1]).
+ bad_float_unpack/1, write/1, cmp_zero/1, cmp_integer/1, cmp_bignum/1]).
-export([otp_7178/1]).
-export([hidden_inf/1]).
@@ -42,7 +42,7 @@ suite() -> [{ct_hooks,[ts_install_cth]}].
all() ->
[fpe, fp_drv, fp_drv_thread, otp_7178, denormalized,
- match, bad_float_unpack, {group, comparison}
+ match, bad_float_unpack, write, {group, comparison}
,hidden_inf
].
@@ -190,6 +190,11 @@ bad_float_unpack(Config) when is_list(Config) ->
bad_float_unpack_match(<<F:64/float>>) -> F;
bad_float_unpack_match(<<I:64/integer-signed>>) -> I.
+%% Exposes endianness issues.
+
+write(Config) when is_list(Config) ->
+ "1.0" = io_lib:write(1.0).
+
cmp_zero(_Config) ->
cmp(0.5e-323,0).