From 01189b083b8ce54fc568fd2ab0dd433d869ede0e Mon Sep 17 00:00:00 2001 From: Joseph Myers Date: Thu, 5 Nov 2015 21:56:31 +0000 Subject: 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. --- sysdeps/i386/fpu/e_log.S | 8 +++++++- sysdeps/i386/fpu/e_logf.S | 8 +++++++- sysdeps/i386/fpu/e_logl.S | 8 +++++++- sysdeps/i386/i686/fpu/e_logl.S | 8 +++++++- sysdeps/x86_64/fpu/e_log10l.S | 8 +++++++- sysdeps/x86_64/fpu/e_log2l.S | 8 +++++++- sysdeps/x86_64/fpu/e_logl.S | 8 +++++++- 7 files changed, 49 insertions(+), 7 deletions(-) (limited to 'sysdeps') diff --git a/sysdeps/i386/fpu/e_log.S b/sysdeps/i386/fpu/e_log.S index 3fa32aa..335df22 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 ca83d39..de967a3 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 828e98a..7a6d370 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 0ccc8fc..e9ecbcd 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 2607ad1..8fa6164 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 c12906d..a063255 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 047b8db..dbe6fd5 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) -- cgit v1.1