i386: Remove f{max,min} assembly implementations

The sNaN handling on i386 was not properly implemented or tested due to
ABI and compiler constraints [1] [2], and although GCC has an open bug
to try to fix at least the sNaN in the function call arguments [3], it
will most likely never be fixed.

To simplify the fix or the order signed zeros and make f{fmin,fmax} behave
semantically equal to the rest of the f{min,max}* function, this patch
removes all i386 assembly optimizations.  The f{min,max} functions should
not be hotspots in any meaningful code people are running on i386 nowadays.

Checked on i686-linux-gnu.

[1] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=57484#c11
[2] https://sourceware.org/git/?p=glibc.git;a=commitdiff;h=5aa4a1a1fd742479818a668d42d91ca9ec4a6318
[3] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=56831

Reviewed-by: Wilco Dijkstra  <Wilco.Dijkstra@arm.com>

diff --git a/sysdeps/i386/fpu/s_fmax.S b/sysdeps/i386/fpu/s_fmax.S
deleted file mode 100644 (file)
index e0e8bf9..0000000
--- a/sysdeps/i386/fpu/s_fmax.S
+++ /dev/null
@@ -1,43 +0,0 @@
-/* Compute maximum of two numbers, regarding NaN as missing argument.
-   Copyright (C) 1997-2026 Free Software Foundation, Inc.
-   This file is part of the GNU C Library.
-
-   The GNU C Library is free software; you can redistribute it and/or
-   modify it under the terms of the GNU Lesser General Public
-   License as published by the Free Software Foundation; either
-   version 2.1 of the License, or (at your option) any later version.
-
-   The GNU C Library is distributed in the hope that it will be useful,
-   but WITHOUT ANY WARRANTY; without even the implied warranty of
-   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-   Lesser General Public License for more details.
-
-   You should have received a copy of the GNU Lesser General Public
-   License along with the GNU C Library; if not, see
-   <https://www.gnu.org/licenses/>.  */
-
-#include <sysdep.h>
-#include <libm-alias-double.h>
-
-       .text
-ENTRY(__fmax)
-       fldl    12(%esp)        // y
-       fxam
-       fnstsw
-       fldl    4(%esp)         // y : x
-
-       andb    $0x45, %ah
-       cmpb    $0x01, %ah
-       je      1f              // y == NaN
-
-       fucom   %st(1)
-       fnstsw
-       sahf
-       jnc     1f
-
-       fxch    %st(1)
-1:     fstp    %st(1)
-
-       ret
-END(__fmax)
-libm_alias_double (__fmax, fmax)

diff --git a/sysdeps/i386/fpu/s_fmaxf.S b/sysdeps/i386/fpu/s_fmaxf.S
deleted file mode 100644 (file)
index 2d4b708..0000000
--- a/sysdeps/i386/fpu/s_fmaxf.S
+++ /dev/null
@@ -1,43 +0,0 @@
-/* Compute maximum of two numbers, regarding NaN as missing argument.
-   Copyright (C) 1997-2026 Free Software Foundation, Inc.
-   This file is part of the GNU C Library.
-
-   The GNU C Library is free software; you can redistribute it and/or
-   modify it under the terms of the GNU Lesser General Public
-   License as published by the Free Software Foundation; either
-   version 2.1 of the License, or (at your option) any later version.
-
-   The GNU C Library is distributed in the hope that it will be useful,
-   but WITHOUT ANY WARRANTY; without even the implied warranty of
-   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-   Lesser General Public License for more details.
-
-   You should have received a copy of the GNU Lesser General Public
-   License along with the GNU C Library; if not, see
-   <https://www.gnu.org/licenses/>.  */
-
-#include <sysdep.h>
-#include <libm-alias-float.h>
-
-       .text
-ENTRY(__fmaxf)
-       flds    8(%esp)         // y
-       fxam
-       fnstsw
-       flds    4(%esp)         // y : x
-
-       andb    $0x45, %ah
-       cmpb    $0x01, %ah
-       je      1f              // y == NaN
-
-       fucom   %st(1)
-       fnstsw
-       sahf
-       jnc     1f
-
-       fxch    %st(1)
-1:     fstp    %st(1)
-
-       ret
-END(__fmaxf)
-libm_alias_float (__fmax, fmax)

diff --git a/sysdeps/i386/fpu/s_fmaxl.S b/sysdeps/i386/fpu/s_fmaxl.S
deleted file mode 100644 (file)
index adfafdb..0000000
--- a/sysdeps/i386/fpu/s_fmaxl.S
+++ /dev/null
@@ -1,71 +0,0 @@
-/* Compute maximum of two numbers, regarding NaN as missing argument.
-   Copyright (C) 1997-2026 Free Software Foundation, Inc.
-   This file is part of the GNU C Library.
-
-   The GNU C Library is free software; you can redistribute it and/or
-   modify it under the terms of the GNU Lesser General Public
-   License as published by the Free Software Foundation; either
-   version 2.1 of the License, or (at your option) any later version.
-
-   The GNU C Library is distributed in the hope that it will be useful,
-   but WITHOUT ANY WARRANTY; without even the implied warranty of
-   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-   Lesser General Public License for more details.
-
-   You should have received a copy of the GNU Lesser General Public
-   License along with the GNU C Library; if not, see
-   <https://www.gnu.org/licenses/>.  */
-
-#include <libm-alias-ldouble.h>
-#include <sysdep.h>
-
-       .text
-ENTRY(__fmaxl)
-       fldt    16(%esp)        // y
-       fxam
-       fnstsw
-       fldt    4(%esp)         // y : x
-
-       andb    $0x45, %ah
-       cmpb    $0x01, %ah
-       je      2f              // y == NaN
-
-       fxam
-       fnstsw
-       andb    $0x45, %ah
-       cmpb    $0x01, %ah
-       je      3f              // x == NaN
-
-       fucom   %st(1)
-       fnstsw
-       sahf
-       jnc     1f
-
-       fxch    %st(1)
-1:     fstp    %st(1)
-
-       ret
-
-2:     // st(1) is a NaN; st(0) may or may not be.
-       fxam
-       fnstsw
-       andb    $0x45, %ah
-       cmpb    $0x01, %ah
-       je      4f
-       // st(1) is a NaN; st(0) is not.  Test if st(1) is signaling.
-       testb   $0x40, 23(%esp)
-       jz      4f
-       fstp    %st(1)
-       ret
-
-3:     // st(0) is a NaN; st(1) is not.  Test if st(0) is signaling.
-       testb   $0x40, 11(%esp)
-       jz      4f
-       fstp    %st(0)
-       ret
-
-4:     // Both arguments are NaNs, or one is a signaling NaN.
-       faddp
-       ret
-END(__fmaxl)
-libm_alias_ldouble (__fmax, fmax)

diff --git a/sysdeps/i386/fpu/s_fmin.S b/sysdeps/i386/fpu/s_fmin.S
deleted file mode 100644 (file)
index cd1e2ca..0000000
--- a/sysdeps/i386/fpu/s_fmin.S
+++ /dev/null
@@ -1,43 +0,0 @@
-/* Compute minimum of two numbers, regarding NaN as missing argument.
-   Copyright (C) 1997-2026 Free Software Foundation, Inc.
-   This file is part of the GNU C Library.
-
-   The GNU C Library is free software; you can redistribute it and/or
-   modify it under the terms of the GNU Lesser General Public
-   License as published by the Free Software Foundation; either
-   version 2.1 of the License, or (at your option) any later version.
-
-   The GNU C Library is distributed in the hope that it will be useful,
-   but WITHOUT ANY WARRANTY; without even the implied warranty of
-   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-   Lesser General Public License for more details.
-
-   You should have received a copy of the GNU Lesser General Public
-   License along with the GNU C Library; if not, see
-   <https://www.gnu.org/licenses/>.  */
-
-#include <sysdep.h>
-#include <libm-alias-double.h>
-
-       .text
-ENTRY(__fmin)
-       fldl    4(%esp)         // x
-       fldl    12(%esp)        // x : y
-
-       fxam
-       fnstsw
-       andb    $0x45, %ah
-       cmpb    $0x01, %ah
-       je      1f              // y == NaN
-
-       fucom   %st(1)
-       fnstsw
-       sahf
-       jc      2f
-
-1:     fxch    %st(1)
-2:     fstp    %st(1)
-
-       ret
-END(__fmin)
-libm_alias_double (__fmin, fmin)

diff --git a/sysdeps/i386/fpu/s_fminf.S b/sysdeps/i386/fpu/s_fminf.S
deleted file mode 100644 (file)
index d2a6c8f..0000000
--- a/sysdeps/i386/fpu/s_fminf.S
+++ /dev/null
@@ -1,43 +0,0 @@
-/* Compute minimum of two numbers, regarding NaN as missing argument.
-   Copyright (C) 1997-2026 Free Software Foundation, Inc.
-   This file is part of the GNU C Library.
-
-   The GNU C Library is free software; you can redistribute it and/or
-   modify it under the terms of the GNU Lesser General Public
-   License as published by the Free Software Foundation; either
-   version 2.1 of the License, or (at your option) any later version.
-
-   The GNU C Library is distributed in the hope that it will be useful,
-   but WITHOUT ANY WARRANTY; without even the implied warranty of
-   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-   Lesser General Public License for more details.
-
-   You should have received a copy of the GNU Lesser General Public
-   License along with the GNU C Library; if not, see
-   <https://www.gnu.org/licenses/>.  */
-
-#include <sysdep.h>
-#include <libm-alias-float.h>
-
-       .text
-ENTRY(__fminf)
-       flds    4(%esp)         // x
-       flds    8(%esp)         // x : y
-
-       fxam
-       fnstsw
-       andb    $0x45, %ah
-       cmpb    $0x01, %ah
-       je      1f              // y == NaN
-
-       fucom   %st(1)
-       fnstsw
-       sahf
-       jc      2f
-
-1:     fxch    %st(1)
-2:     fstp    %st(1)
-
-       ret
-END(__fminf)
-libm_alias_float (__fmin, fmin)

diff --git a/sysdeps/i386/fpu/s_fminl.S b/sysdeps/i386/fpu/s_fminl.S
deleted file mode 100644 (file)
index 7eaad28..0000000
--- a/sysdeps/i386/fpu/s_fminl.S
+++ /dev/null
@@ -1,71 +0,0 @@
-/* Compute minimum of two numbers, regarding NaN as missing argument.
-   Copyright (C) 1997-2026 Free Software Foundation, Inc.
-   This file is part of the GNU C Library.
-
-   The GNU C Library is free software; you can redistribute it and/or
-   modify it under the terms of the GNU Lesser General Public
-   License as published by the Free Software Foundation; either
-   version 2.1 of the License, or (at your option) any later version.
-
-   The GNU C Library is distributed in the hope that it will be useful,
-   but WITHOUT ANY WARRANTY; without even the implied warranty of
-   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-   Lesser General Public License for more details.
-
-   You should have received a copy of the GNU Lesser General Public
-   License along with the GNU C Library; if not, see
-   <https://www.gnu.org/licenses/>.  */
-
-#include <libm-alias-ldouble.h>
-#include <sysdep.h>
-
-       .text
-ENTRY(__fminl)
-       fldt    16(%esp)        // y
-       fxam
-       fnstsw
-       fldt    4(%esp)         // y : x
-
-       andb    $0x45, %ah
-       cmpb    $0x01, %ah
-       je      2f              // y == NaN
-
-       fxam
-       fnstsw
-       andb    $0x45, %ah
-       cmpb    $0x01, %ah
-       je      3f              // x == NaN
-
-       fucom   %st(1)
-       fnstsw
-       sahf
-       jc      1f
-
-       fxch    %st(1)
-1:     fstp    %st(1)
-
-       ret
-
-2:     // st(1) is a NaN; st(0) may or may not be.
-       fxam
-       fnstsw
-       andb    $0x45, %ah
-       cmpb    $0x01, %ah
-       je      4f
-       // st(1) is a NaN; st(0) is not.  Test if st(1) is signaling.
-       testb   $0x40, 23(%esp)
-       jz      4f
-       fstp    %st(1)
-       ret
-
-3:     // st(0) is a NaN; st(1) is not.  Test if st(0) is signaling.
-       testb   $0x40, 11(%esp)
-       jz      4f
-       fstp    %st(0)
-       ret
-
-4:     // Both arguments are NaNs, or one is a signaling NaN.
-       faddp
-       ret
-END(__fminl)
-libm_alias_ldouble (__fmin, fmin)

diff --git a/sysdeps/i386/i686/fpu/s_fmax.S b/sysdeps/i386/i686/fpu/s_fmax.S
deleted file mode 100644 (file)
index 0e36a60..0000000
--- a/sysdeps/i386/i686/fpu/s_fmax.S
+++ /dev/null
@@ -1,39 +0,0 @@
-/* Compute maximum of two numbers, regarding NaN as missing argument.
-   Copyright (C) 1997-2026 Free Software Foundation, Inc.
-   This file is part of the GNU C Library.
-
-   The GNU C Library is free software; you can redistribute it and/or
-   modify it under the terms of the GNU Lesser General Public
-   License as published by the Free Software Foundation; either
-   version 2.1 of the License, or (at your option) any later version.
-
-   The GNU C Library is distributed in the hope that it will be useful,
-   but WITHOUT ANY WARRANTY; without even the implied warranty of
-   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-   Lesser General Public License for more details.
-
-   You should have received a copy of the GNU Lesser General Public
-   License along with the GNU C Library; if not, see
-   <https://www.gnu.org/licenses/>.  */
-
-#include <sysdep.h>
-#include <libm-alias-double.h>
-
-       .text
-ENTRY(__fmax)
-       fldl    4(%esp)         // x
-       fldl    12(%esp)        // x : y
-
-       fucomi  %st(0), %st
-       fcmovu  %st(1), %st     // now %st contains y if not NaN, x otherwise
-
-       fxch
-
-       fucomi  %st(1), %st
-       fcmovb  %st(1), %st
-
-       fstp    %st(1)
-
-       ret
-END(__fmax)
-libm_alias_double (__fmax, fmax)

diff --git a/sysdeps/i386/i686/fpu/s_fmaxf.S b/sysdeps/i386/i686/fpu/s_fmaxf.S
deleted file mode 100644 (file)
index 33a1aa6..0000000
--- a/sysdeps/i386/i686/fpu/s_fmaxf.S
+++ /dev/null
@@ -1,39 +0,0 @@
-/* Compute maximum of two numbers, regarding NaN as missing argument.
-   Copyright (C) 1997-2026 Free Software Foundation, Inc.
-   This file is part of the GNU C Library.
-
-   The GNU C Library is free software; you can redistribute it and/or
-   modify it under the terms of the GNU Lesser General Public
-   License as published by the Free Software Foundation; either
-   version 2.1 of the License, or (at your option) any later version.
-
-   The GNU C Library is distributed in the hope that it will be useful,
-   but WITHOUT ANY WARRANTY; without even the implied warranty of
-   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-   Lesser General Public License for more details.
-
-   You should have received a copy of the GNU Lesser General Public
-   License along with the GNU C Library; if not, see
-   <https://www.gnu.org/licenses/>.  */
-
-#include <sysdep.h>
-#include <libm-alias-float.h>
-
-       .text
-ENTRY(__fmaxf)
-       flds    4(%esp)         // x
-       flds    8(%esp)         // x : y
-
-       fucomi  %st(0), %st
-       fcmovu  %st(1), %st     // now %st contains y if not NaN, x otherwise
-
-       fxch
-
-       fucomi  %st(1), %st
-       fcmovb  %st(1), %st
-
-       fstp    %st(1)
-
-       ret
-END(__fmaxf)
-libm_alias_float (__fmax, fmax)

diff --git a/sysdeps/i386/i686/fpu/s_fmaxl.S b/sysdeps/i386/i686/fpu/s_fmaxl.S
deleted file mode 100644 (file)
index c1b191b..0000000
--- a/sysdeps/i386/i686/fpu/s_fmaxl.S
+++ /dev/null
@@ -1,58 +0,0 @@
-/* Compute maximum of two numbers, regarding NaN as missing argument.
-   Copyright (C) 1997-2026 Free Software Foundation, Inc.
-   This file is part of the GNU C Library.
-
-   The GNU C Library is free software; you can redistribute it and/or
-   modify it under the terms of the GNU Lesser General Public
-   License as published by the Free Software Foundation; either
-   version 2.1 of the License, or (at your option) any later version.
-
-   The GNU C Library is distributed in the hope that it will be useful,
-   but WITHOUT ANY WARRANTY; without even the implied warranty of
-   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-   Lesser General Public License for more details.
-
-   You should have received a copy of the GNU Lesser General Public
-   License along with the GNU C Library; if not, see
-   <https://www.gnu.org/licenses/>.  */
-
-#include <sysdep.h>
-#include <libm-alias-ldouble.h>
-
-       .text
-ENTRY(__fmaxl)
-       fldt    4(%esp)         // x
-       fldt    16(%esp)        // x : y
-
-       fucomi  %st(1), %st
-       jp      2f
-       fcmovb  %st(1), %st
-
-       fstp    %st(1)
-
-       ret
-
-2:     // Unordered.
-       fucomi  %st(0), %st
-       jp      3f
-       // st(1) is a NaN; st(0) is not.  Test if st(1) is signaling.
-       testb   $0x40, 11(%esp)
-       jz      4f
-       fstp    %st(1)
-       ret
-
-3:     // st(0) is a NaN; st(1) may or may not be.
-       fxch
-       fucomi  %st(0), %st
-       jp      4f
-       // st(1) is a NaN; st(0) is not.  Test if st(1) is signaling.
-       testb   $0x40, 23(%esp)
-       jz      4f
-       fstp    %st(1)
-       ret
-
-4:     // Both arguments are NaNs, or one is a signaling NaN.
-       faddp
-       ret
-END(__fmaxl)
-libm_alias_ldouble (__fmax, fmax)

diff --git a/sysdeps/i386/i686/fpu/s_fmin.S b/sysdeps/i386/i686/fpu/s_fmin.S
deleted file mode 100644 (file)
index ef4e54d..0000000
--- a/sysdeps/i386/i686/fpu/s_fmin.S
+++ /dev/null
@@ -1,37 +0,0 @@
-/* Compute minimum of two numbers, regarding NaN as missing argument.
-   Copyright (C) 1997-2026 Free Software Foundation, Inc.
-   This file is part of the GNU C Library.
-
-   The GNU C Library is free software; you can redistribute it and/or
-   modify it under the terms of the GNU Lesser General Public
-   License as published by the Free Software Foundation; either
-   version 2.1 of the License, or (at your option) any later version.
-
-   The GNU C Library is distributed in the hope that it will be useful,
-   but WITHOUT ANY WARRANTY; without even the implied warranty of
-   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-   Lesser General Public License for more details.
-
-   You should have received a copy of the GNU Lesser General Public
-   License along with the GNU C Library; if not, see
-   <https://www.gnu.org/licenses/>.  */
-
-#include <sysdep.h>
-#include <libm-alias-double.h>
-
-       .text
-ENTRY(__fmin)
-       fldl    4(%esp)         // x
-       fldl    12(%esp)        // x : y
-
-       fucomi  %st(0), %st
-       fcmovu  %st(1), %st     // now %st contains y if not NaN, x otherwise
-
-       fucomi  %st(1), %st
-       fcmovnb %st(1), %st
-
-       fstp    %st(1)
-
-       ret
-END(__fmin)
-libm_alias_double (__fmin, fmin)

diff --git a/sysdeps/i386/i686/fpu/s_fminf.S b/sysdeps/i386/i686/fpu/s_fminf.S
deleted file mode 100644 (file)
index eaa680e..0000000
--- a/sysdeps/i386/i686/fpu/s_fminf.S
+++ /dev/null
@@ -1,37 +0,0 @@
-/* Compute minimum of two numbers, regarding NaN as missing argument.
-   Copyright (C) 1997-2026 Free Software Foundation, Inc.
-   This file is part of the GNU C Library.
-
-   The GNU C Library is free software; you can redistribute it and/or
-   modify it under the terms of the GNU Lesser General Public
-   License as published by the Free Software Foundation; either
-   version 2.1 of the License, or (at your option) any later version.
-
-   The GNU C Library is distributed in the hope that it will be useful,
-   but WITHOUT ANY WARRANTY; without even the implied warranty of
-   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-   Lesser General Public License for more details.
-
-   You should have received a copy of the GNU Lesser General Public
-   License along with the GNU C Library; if not, see
-   <https://www.gnu.org/licenses/>.  */
-
-#include <sysdep.h>
-#include <libm-alias-float.h>
-
-       .text
-ENTRY(__fminf)
-       flds    4(%esp)         // x
-       flds    8(%esp)         // x : y
-
-       fucomi  %st(0), %st
-       fcmovu  %st(1), %st     // now %st contains y if not NaN, x otherwise
-
-       fucomi  %st(1), %st
-       fcmovnb %st(1), %st
-
-       fstp    %st(1)
-
-       ret
-END(__fminf)
-libm_alias_float (__fmin, fmin)

diff --git a/sysdeps/i386/i686/fpu/s_fminl.S b/sysdeps/i386/i686/fpu/s_fminl.S
deleted file mode 100644 (file)
index a6cc6ca..0000000
--- a/sysdeps/i386/i686/fpu/s_fminl.S
+++ /dev/null
@@ -1,58 +0,0 @@
-/* Compute minimum of two numbers, regarding NaN as missing argument.
-   Copyright (C) 1997-2026 Free Software Foundation, Inc.
-   This file is part of the GNU C Library.
-
-   The GNU C Library is free software; you can redistribute it and/or
-   modify it under the terms of the GNU Lesser General Public
-   License as published by the Free Software Foundation; either
-   version 2.1 of the License, or (at your option) any later version.
-
-   The GNU C Library is distributed in the hope that it will be useful,
-   but WITHOUT ANY WARRANTY; without even the implied warranty of
-   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-   Lesser General Public License for more details.
-
-   You should have received a copy of the GNU Lesser General Public
-   License along with the GNU C Library; if not, see
-   <https://www.gnu.org/licenses/>.  */
-
-#include <libm-alias-ldouble.h>
-#include <sysdep.h>
-
-       .text
-ENTRY(__fminl)
-       fldt    4(%esp)         // x
-       fldt    16(%esp)        // x : y
-
-       fucomi  %st(1), %st
-       jp      2f
-       fcmovnb %st(1), %st
-
-       fstp    %st(1)
-
-       ret
-
-2:     // Unordered.
-       fucomi  %st(0), %st
-       jp      3f
-       // st(1) is a NaN; st(0) is not.  Test if st(1) is signaling.
-       testb   $0x40, 11(%esp)
-       jz      4f
-       fstp    %st(1)
-       ret
-
-3:     // st(0) is a NaN; st(1) may or may not be.
-       fxch
-       fucomi  %st(0), %st
-       jp      4f
-       // st(1) is a NaN; st(0) is not.  Test if st(1) is signaling.
-       testb   $0x40, 23(%esp)
-       jz      4f
-       fstp    %st(1)
-       ret
-
-4:     // Both arguments are NaNs, or one is a signaling NaN.
-       faddp
-       ret
-END(__fminl)
-libm_alias_ldouble (__fmin, fmin)