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| author | Joseph Myers <joseph@codesourcery.com> | 2015-05-14 23:38:07 +0000 |
|---|---|---|
| committer | Joseph Myers <joseph@codesourcery.com> | 2015-05-14 23:38:07 +0000 |
| commit | 0b7a5f920163d03806d7c5d9d1c83b16942c9496 (patch) | |
| tree | a108347db6f5f094bf917214f562b9a3a7ae8b04 /sysdeps/i386 | |
| parent | 95b07fbcc702a83b421cb5d0488ba2817d3123c1 (diff) | |
| download | glibc-0b7a5f920163d03806d7c5d9d1c83b16942c9496.zip glibc-0b7a5f920163d03806d7c5d9d1c83b16942c9496.tar.gz glibc-0b7a5f920163d03806d7c5d9d1c83b16942c9496.tar.bz2 | |
Fix log1p missing underflows (bug 16339).
Similar to various other bugs in this area, some log1p implementations
do not raise the underflow exception for subnormal arguments, when the
result is tiny and inexact. This patch forces the exception in a
similar way to previous fixes. (The ldbl-128ibm implementation
doesn't currently need any change as it already generates this
exception, albeit through code that would generate spurious exceptions
in other cases; special code for this issue will only be needed there
when fixing the spurious exceptions.)
Tested for x86_64, x86, powerpc and mips64.
[BZ #16339]
* sysdeps/i386/fpu/s_log1p.S (dbl_min): New object.
(__log1p): Force underflow exception for results with small
absolute value.
* sysdeps/i386/fpu/s_log1pf.S (flt_min): New object.
(__log1pf): Force underflow exception for results with small
absolute value.
* sysdeps/ieee754/dbl-64/s_log1p.c: Include <float.h>.
(__log1p): Force underflow exception for results with small
absolute value.
* sysdeps/ieee754/flt-32/s_log1pf.c: Include <float.h>.
(__log1pf): Force underflow exception for results with small
absolute value.
* sysdeps/ieee754/ldbl-128/s_log1pl.c: Include <float.h>.
(__log1pl): Force underflow exception for results with small
absolute value.
* math/auto-libm-test-in: Do not allow missing underflow
exceptions from log1p.
* math/auto-libm-test-out: Regenerated.
Diffstat (limited to 'sysdeps/i386')
| -rw-r--r-- | sysdeps/i386/fpu/s_log1p.S | 27 | ||||
| -rw-r--r-- | sysdeps/i386/fpu/s_log1pf.S | 27 |
2 files changed, 52 insertions, 2 deletions
diff --git a/sysdeps/i386/fpu/s_log1p.S b/sysdeps/i386/fpu/s_log1p.S index 8624249..c2559a3 100644 --- a/sysdeps/i386/fpu/s_log1p.S +++ b/sysdeps/i386/fpu/s_log1p.S @@ -17,6 +17,13 @@ RCSID("$NetBSD: s_log1p.S,v 1.7 1995/05/09 00:10:58 jtc Exp $") limit: .double 0.29 one: .double 1.0 + .section .rodata.cst8,"aM",@progbits,8 + + .p2align 3 + .type dbl_min,@object +dbl_min: .byte 0, 0, 0, 0, 0, 0, 0x10, 0 + ASM_SIZE_DIRECTIVE(dbl_min) + /* * Use the fyl2xp1 function when the argument is in the range -0.29 to 0.29, * otherwise fyl2x with the needed extra computation. @@ -55,7 +62,25 @@ ENTRY(__log1p) ret 2: fyl2xp1 - ret +#ifdef PIC + fldl dbl_min@GOTOFF(%edx) +#else + fldl dbl_min +#endif + fld %st(1) + fabs + fucompp + fnstsw + sahf + jnc 1f + subl $8, %esp + cfi_adjust_cfa_offset (8) + fld %st(0) + fmul %st(0) + fstpl (%esp) + addl $8, %esp + cfi_adjust_cfa_offset (-8) +1: ret 3: jp 4b // in case x is ħInf fstp %st(1) diff --git a/sysdeps/i386/fpu/s_log1pf.S b/sysdeps/i386/fpu/s_log1pf.S index b071e73..8fca22e 100644 --- a/sysdeps/i386/fpu/s_log1pf.S +++ b/sysdeps/i386/fpu/s_log1pf.S @@ -17,6 +17,13 @@ RCSID("$NetBSD: s_log1pf.S,v 1.4 1995/05/09 00:13:05 jtc Exp $") limit: .float 0.29 one: .float 1.0 + .section .rodata.cst4,"aM",@progbits,4 + + .p2align 2 + .type flt_min,@object +flt_min: .byte 0, 0, 0x80, 0 + ASM_SIZE_DIRECTIVE(flt_min) + /* * Use the fyl2xp1 function when the argument is in the range -0.29 to 0.29, * otherwise fyl2x with the needed extra computation. @@ -55,7 +62,25 @@ ENTRY(__log1pf) ret 2: fyl2xp1 - ret +#ifdef PIC + flds flt_min@GOTOFF(%edx) +#else + flds flt_min +#endif + fld %st(1) + fabs + fucompp + fnstsw + sahf + jnc 1f + subl $4, %esp + cfi_adjust_cfa_offset (4) + fld %st(0) + fmul %st(0) + fstps (%esp) + addl $4, %esp + cfi_adjust_cfa_offset (-4) +1: ret 3: jp 4b // in case x is ħInf fstp %st(1) |