From: Joseph Myers Date: Thu, 5 Nov 2015 21:56:31 +0000 (+0000) Subject: Fix i386/x86_64 log* (1) zero sign for -ffinite-math-only (bug 19213). X-Git-Tag: glibc-2.23~219 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=01189b083b8ce54fc568fd2ab0dd433d869ede0e;p=thirdparty%2Fglibc.git Fix i386/x86_64 log* (1) zero sign for -ffinite-math-only (bug 19213). For the -ffinite-math-only versions of various x86_64 and x86 log* functions, a zero result from log* (1) is returned with incorrect sign in round-downward mode. This patch fixes this in a similar way to the previous fixes for the non-*_finite versions of the functions. Tested for x86_64 and x86 (including an i586 build), together with a patch that will be applied separately to enable the main libm-test.inc tests for the finite-math-only functions. [BZ #19213] * sysdeps/i386/fpu/e_log.S (__log_finite): Ensure +0 is always returned for argument 1. * sysdeps/i386/fpu/e_logf.S (__logf_finite): Likewise. * sysdeps/i386/fpu/e_logl.S (__logl_finite): Likewise. * sysdeps/i386/i686/fpu/e_logl.S (__logl_finite): Likewise. * sysdeps/x86_64/fpu/e_log10l.S (__log10l_finite): Likewise. * sysdeps/x86_64/fpu/e_log2l.S (__log2l_finite): Likewise. * sysdeps/x86_64/fpu/e_logl.S (__logl_finite): Likewise. --- diff --git a/ChangeLog b/ChangeLog index 9c78a117221..95dae4bafa4 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,5 +1,15 @@ 2015-11-05 Joseph Myers + [BZ #19213] + * sysdeps/i386/fpu/e_log.S (__log_finite): Ensure +0 is always + returned for argument 1. + * sysdeps/i386/fpu/e_logf.S (__logf_finite): Likewise. + * sysdeps/i386/fpu/e_logl.S (__logl_finite): Likewise. + * sysdeps/i386/i686/fpu/e_logl.S (__logl_finite): Likewise. + * sysdeps/x86_64/fpu/e_log10l.S (__log10l_finite): Likewise. + * sysdeps/x86_64/fpu/e_log2l.S (__log2l_finite): Likewise. + * sysdeps/x86_64/fpu/e_logl.S (__logl_finite): Likewise. + [BZ #19211] * math/bits/math-finite.h (lgamma): Set signgam if [__USE_MISC || __USE_XOPEN], not if [!__USE_ISOC99]. diff --git a/NEWS b/NEWS index b462e85ddcc..4e419980fe3 100644 --- a/NEWS +++ b/NEWS @@ -22,7 +22,7 @@ Version 2.23 19003, 19007, 19012, 19016, 19018, 19032, 19046, 19048, 19049, 19050, 19059, 19071, 19074, 19076, 19077, 19078, 19079, 19085, 19086, 19088, 19094, 19095, 19124, 19125, 19129, 19134, 19137, 19156, 19174, 19181, - 19189, 19201, 19205, 19209, 19211, 19212. + 19189, 19201, 19205, 19209, 19211, 19212, 19213. * A defect in the malloc implementation, present since glibc 2.15 (2012) or glibc 2.10 via --enable-experimental-malloc (2009), could result in the diff --git a/sysdeps/i386/fpu/e_log.S b/sysdeps/i386/fpu/e_log.S index 3fa32aad3c0..335df225771 100644 --- a/sysdeps/i386/fpu/e_log.S +++ b/sysdeps/i386/fpu/e_log.S @@ -80,7 +80,13 @@ ENTRY(__log_finite) fnstsw // x-1 : x : log(2) andb $0x45, %ah jz 2b - fstp %st(1) // x-1 : log(2) + fxam + fnstsw + andb $0x45, %ah + cmpb $0x40, %ah + jne 6f + fabs // log(1) is +0 in all rounding modes. +6: fstp %st(1) // x-1 : log(2) fyl2xp1 // log(x) ret END(__log_finite) diff --git a/sysdeps/i386/fpu/e_logf.S b/sysdeps/i386/fpu/e_logf.S index ca83d39cef3..de967a31f5a 100644 --- a/sysdeps/i386/fpu/e_logf.S +++ b/sysdeps/i386/fpu/e_logf.S @@ -81,7 +81,13 @@ ENTRY(__logf_finite) fnstsw // x-1 : x : log(2) andb $0x45, %ah jz 2b - fstp %st(1) // x-1 : log(2) + fxam + fnstsw + andb $0x45, %ah + cmpb $0x40, %ah + jne 6f + fabs // log(1) is +0 in all rounding modes. +6: fstp %st(1) // x-1 : log(2) fyl2xp1 // log(x) ret END(__logf_finite) diff --git a/sysdeps/i386/fpu/e_logl.S b/sysdeps/i386/fpu/e_logl.S index 828e98aa8d7..7a6d370e8fc 100644 --- a/sysdeps/i386/fpu/e_logl.S +++ b/sysdeps/i386/fpu/e_logl.S @@ -84,7 +84,13 @@ ENTRY(__logl_finite) fnstsw // x-1 : x : log(2) andb $0x45, %ah jz 2b - fstp %st(1) // x-1 : log(2) + fxam + fnstsw + andb $0x45, %ah + cmpb $0x40, %ah + jne 7f + fabs // log(1) is +0 in all rounding modes. +7: fstp %st(1) // x-1 : log(2) fyl2xp1 // log(x) ret END(__logl_finite) diff --git a/sysdeps/i386/i686/fpu/e_logl.S b/sysdeps/i386/i686/fpu/e_logl.S index 0ccc8fc71e3..e9ecbcd472e 100644 --- a/sysdeps/i386/i686/fpu/e_logl.S +++ b/sysdeps/i386/i686/fpu/e_logl.S @@ -81,7 +81,13 @@ ENTRY(__logl_finite) fcomip %st(1) // |x-1| : x-1 : x : log(2) fstp %st(0) // x-1 : x : log(2) jc 2b - fstp %st(1) // x-1 : log(2) + fxam + fnstsw + andb $0x45, %ah + cmpb $0x40, %ah + jne 6f + fabs // log(1) is +0 in all rounding modes. +6: fstp %st(1) // x-1 : log(2) fyl2xp1 // log(x) ret END(__logl_finite) diff --git a/sysdeps/x86_64/fpu/e_log10l.S b/sysdeps/x86_64/fpu/e_log10l.S index 2607ad199b8..8fa61644c1f 100644 --- a/sysdeps/x86_64/fpu/e_log10l.S +++ b/sysdeps/x86_64/fpu/e_log10l.S @@ -79,7 +79,13 @@ ENTRY(__log10l_finite) fnstsw // x-1 : x : log10(2) andb $0x45, %ah jz 2b - fstp %st(1) // x-1 : log10(2) + fxam + fnstsw + andb $0x45, %ah + cmpb $0x40, %ah + jne 6f + fabs // log10(1) is +0 in all rounding modes. +6: fstp %st(1) // x-1 : log10(2) fyl2xp1 // log10(x) ret END(__log10l_finite) diff --git a/sysdeps/x86_64/fpu/e_log2l.S b/sysdeps/x86_64/fpu/e_log2l.S index c12906d456c..a063255dddf 100644 --- a/sysdeps/x86_64/fpu/e_log2l.S +++ b/sysdeps/x86_64/fpu/e_log2l.S @@ -78,7 +78,13 @@ ENTRY(__log2l_finite) fnstsw // x-1 : x : 1 andb $0x45, %ah jz 2b - fstp %st(1) // x-1 : 1 + fxam + fnstsw + andb $0x45, %ah + cmpb $0x40, %ah + jne 6f + fabs // log2(1) is +0 in all rounding modes. +6: fstp %st(1) // x-1 : 1 fyl2xp1 // log(x) ret END (__log2l_finite) diff --git a/sysdeps/x86_64/fpu/e_logl.S b/sysdeps/x86_64/fpu/e_logl.S index 047b8db88ae..dbe6fd59dc7 100644 --- a/sysdeps/x86_64/fpu/e_logl.S +++ b/sysdeps/x86_64/fpu/e_logl.S @@ -81,7 +81,13 @@ ENTRY(__logl_finite) fnstsw // x-1 : x : log(2) andb $0x45, %ah jz 2b - fstp %st(1) // x-1 : log(2) + fxam + fnstsw + andb $0x45, %ah + cmpb $0x40, %ah + jne 7f + fabs // log(1) is +0 in all rounding modes. +7: fstp %st(1) // x-1 : log(2) fyl2xp1 // log(x) ret END (__logl_finite)