From 532fc08102d62c04d55f5b8aac00bd9e7e12ff4b Mon Sep 17 00:00:00 2001 From: "Erlend E. Aasland" Date: Mon, 4 Nov 2024 21:48:09 +0100 Subject: [PATCH] gh-89640: Hardcode WASM float word ordering as little endian (#126387) --- ...4-11-04-09-42-04.gh-issue-89640.QBv05o.rst | 1 + configure | 47 ++++++++----------- configure.ac | 42 ++++++++--------- pyconfig.h.in | 4 -- 4 files changed, 41 insertions(+), 53 deletions(-) create mode 100644 Misc/NEWS.d/next/Build/2024-11-04-09-42-04.gh-issue-89640.QBv05o.rst diff --git a/Misc/NEWS.d/next/Build/2024-11-04-09-42-04.gh-issue-89640.QBv05o.rst b/Misc/NEWS.d/next/Build/2024-11-04-09-42-04.gh-issue-89640.QBv05o.rst new file mode 100644 index 00000000000000..4fa44a1d6493b4 --- /dev/null +++ b/Misc/NEWS.d/next/Build/2024-11-04-09-42-04.gh-issue-89640.QBv05o.rst @@ -0,0 +1 @@ +Hard-code float word ordering as little endian on WASM. diff --git a/configure b/configure index 1097747e055179..e529527214da29 100755 --- a/configure +++ b/configure @@ -24227,41 +24227,34 @@ printf "%s\n" "$ax_cv_c_float_words_bigendian" >&6; } case $ax_cv_c_float_words_bigendian in yes) -printf "%s\n" "#define FLOAT_WORDS_BIGENDIAN 1" >>confdefs.h +printf "%s\n" "#define DOUBLE_IS_BIG_ENDIAN_IEEE754 1" >>confdefs.h ;; no) - ;; - *) - as_fn_error $? " - -Unknown float word ordering. You need to manually preset -ax_cv_c_float_words_bigendian=no (or yes) according to your system. - - " "$LINENO" 5 ;; -esac +printf "%s\n" "#define DOUBLE_IS_LITTLE_ENDIAN_IEEE754 1" >>confdefs.h + ;; + *) + case $host_cpu in #( + *arm*) : + # Some ARM platforms use a mixed-endian representation for + # doubles. While Python doesn't currently have full support + # for these platforms (see e.g., issue 1762561), we can at + # least make sure that float <-> string conversions work. + # FLOAT_WORDS_BIGENDIAN doesn't actually detect this case, + # but if it's not big or little, then it must be this? -if test "$ax_cv_c_float_words_bigendian" = "yes" -then - -printf "%s\n" "#define DOUBLE_IS_BIG_ENDIAN_IEEE754 1" >>confdefs.h - -elif test "$ax_cv_c_float_words_bigendian" = "no" -then +printf "%s\n" "#define DOUBLE_IS_ARM_MIXED_ENDIAN_IEEE754 1" >>confdefs.h + ;; #( + wasm*) : printf "%s\n" "#define DOUBLE_IS_LITTLE_ENDIAN_IEEE754 1" >>confdefs.h + ;; #( + *) : + ;; +esac ;; +esac -else - # Some ARM platforms use a mixed-endian representation for doubles. - # While Python doesn't currently have full support for these platforms - # (see e.g., issue 1762561), we can at least make sure that float <-> string - # conversions work. - # FLOAT_WORDS_BIGENDIAN doesn't actually detect this case, but if it's not big - # or little, then it must be this? - -printf "%s\n" "#define DOUBLE_IS_ARM_MIXED_ENDIAN_IEEE754 1" >>confdefs.h -fi # The short float repr introduced in Python 3.1 requires the # correctly-rounded string <-> double conversion functions from diff --git a/configure.ac b/configure.ac index 6d514705e91ce5..bc67a0596ac2b4 100644 --- a/configure.ac +++ b/configure.ac @@ -5946,28 +5946,26 @@ AS_VAR_IF([ac_cv_gcc_asm_for_x64], [yes], [ # * Check for various properties of floating point * # ************************************************** -AX_C_FLOAT_WORDS_BIGENDIAN -if test "$ax_cv_c_float_words_bigendian" = "yes" -then - AC_DEFINE([DOUBLE_IS_BIG_ENDIAN_IEEE754], [1], - [Define if C doubles are 64-bit IEEE 754 binary format, stored - with the most significant byte first]) -elif test "$ax_cv_c_float_words_bigendian" = "no" -then - AC_DEFINE([DOUBLE_IS_LITTLE_ENDIAN_IEEE754], [1], - [Define if C doubles are 64-bit IEEE 754 binary format, stored - with the least significant byte first]) -else - # Some ARM platforms use a mixed-endian representation for doubles. - # While Python doesn't currently have full support for these platforms - # (see e.g., issue 1762561), we can at least make sure that float <-> string - # conversions work. - # FLOAT_WORDS_BIGENDIAN doesn't actually detect this case, but if it's not big - # or little, then it must be this? - AC_DEFINE([DOUBLE_IS_ARM_MIXED_ENDIAN_IEEE754], [1], - [Define if C doubles are 64-bit IEEE 754 binary format, stored - in ARM mixed-endian order (byte order 45670123)]) -fi +AX_C_FLOAT_WORDS_BIGENDIAN( + [AC_DEFINE([DOUBLE_IS_BIG_ENDIAN_IEEE754], [1], + [Define if C doubles are 64-bit IEEE 754 binary format, + stored with the most significant byte first])], + [AC_DEFINE([DOUBLE_IS_LITTLE_ENDIAN_IEEE754], [1], + [Define if C doubles are 64-bit IEEE 754 binary format, + stored with the least significant byte first])], + [AS_CASE([$host_cpu], + [*arm*], [# Some ARM platforms use a mixed-endian representation for + # doubles. While Python doesn't currently have full support + # for these platforms (see e.g., issue 1762561), we can at + # least make sure that float <-> string conversions work. + # FLOAT_WORDS_BIGENDIAN doesn't actually detect this case, + # but if it's not big or little, then it must be this? + AC_DEFINE([DOUBLE_IS_ARM_MIXED_ENDIAN_IEEE754], [1], + [Define if C doubles are 64-bit IEEE 754 binary format, + stored in ARM mixed-endian order (byte order 45670123)])], + [wasm*], [AC_DEFINE([DOUBLE_IS_LITTLE_ENDIAN_IEEE754], [1], + [Define if C doubles are 64-bit IEEE 754 binary format, + stored with the least significant byte first])])]) # The short float repr introduced in Python 3.1 requires the # correctly-rounded string <-> double conversion functions from diff --git a/pyconfig.h.in b/pyconfig.h.in index fcb8a965b1e476..924d86627b0e9b 100644 --- a/pyconfig.h.in +++ b/pyconfig.h.in @@ -47,10 +47,6 @@ /* Define if --enable-ipv6 is specified */ #undef ENABLE_IPV6 -/* Define to 1 if your system stores words within floats with the most - significant word first */ -#undef FLOAT_WORDS_BIGENDIAN - /* Define if getpgrp() must be called as getpgrp(0). */ #undef GETPGRP_HAVE_ARG