diff options
| -rw-r--r-- | ChangeLog | 6 | ||||
| -rw-r--r-- | math/test-misc.c | 37 | ||||
| -rw-r--r-- | sysdeps/i386/fpu/s_frexpl.S | 20 |
3 files changed, 63 insertions, 0 deletions
@@ -1,3 +1,9 @@ +2000-12-03 Ulrich Drepper <drepper@redhat.com> + + * math/test-misc.c (main): Add tests for frexp. + Reported by Fred J. Tydeman <tydeman@tybor.com>. + * sysdeps/i386/fpu/s_frexpl.S: Don't overflow during the computation. + 2000-12-02 H.J. Lu <hjl@gnu.org> * locale/lc-time.c (_nl_init_era_entries): Pass L'\0' instead of diff --git a/math/test-misc.c b/math/test-misc.c index 515277f..c0b8d0f 100644 --- a/math/test-misc.c +++ b/math/test-misc.c @@ -39,6 +39,43 @@ main (void) result = 1; } } + +# if __GNUC__ >= 3 || __GNUC_MINOR__ >= 96 + { + long double x = LDBL_MAX / ldexpl (1.0L, LDBL_MANT_DIG + 1); + long double m; + int i; + +# if LDBL_MANT_DIG == 64 + m = 0xf.fffffffffffffffp-4L; +# else +# error "Please adjust" +# endif + + for (i = 0; i < LDBL_MANT_DIG + 1; ++i, x *= 2.0L) + { + long double r; + int e; + + printf ("2^%d: ", LDBL_MAX_EXP - (LDBL_MANT_DIG + 1) + i); + + r = frexpl (x, &e); + if (r != m) + { + printf ("mantissa incorrect: %.20La\n", r); + result = 1; + continue; + } + if (e != LDBL_MAX_EXP - (LDBL_MANT_DIG + 1) + i) + { + printf ("exponent wrong %d (%.20Lg)\n", e, x); + result = 1; + continue; + } + puts ("ok"); + } + } +# endif #endif { diff --git a/sysdeps/i386/fpu/s_frexpl.S b/sysdeps/i386/fpu/s_frexpl.S index cb943f7..2645d22 100644 --- a/sysdeps/i386/fpu/s_frexpl.S +++ b/sysdeps/i386/fpu/s_frexpl.S @@ -32,6 +32,12 @@ ASM_TYPE_DIRECTIVE(two64,@object) two64: .byte 0, 0, 0, 0, 0, 0, 0xf0, 0x43 ASM_SIZE_DIRECTIVE(two64) + /* The following is LDBL_MAX / ldexp (1.0, 64), the largest + number we can handle the normal way. */ + ASM_TYPE_DIRECTIVE(largest,@object) +largest: + .byte 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xbe, 0x7f, 0, 0 + ASM_SIZE_DIRECTIVE(largest) #ifdef PIC #define MO(op) op##@GOTOFF(%edx) @@ -63,12 +69,16 @@ ENTRY (BP_SYM (__frexpl)) cmpl $0, %eax je 2f + cmpl $0x7fbe, %eax + ja 4f + fldt VAL0(%esp) #ifdef PIC call 3f 3: popl %edx addl $_GLOBAL_OFFSET_TABLE_+[.-3b], %edx #endif + fmull MO(two64) /* It's not necessary to use a 80bit factor */ movl $-64, %ecx fstpt VAL0(%esp) @@ -92,5 +102,15 @@ ENTRY (BP_SYM (__frexpl)) LEAVE ret + +4: movl VAL2(%esp), %ecx + movl %ecx, %edx + andl $0x7fff, %ecx + + andl $0x8000, %edx + subl $16382, %ecx + orl $0x3ffe, %edx + movl %edx, VAL2(%esp) + jmp 1b END (BP_SYM (__frexpl)) weak_alias (BP_SYM (__frexpl), BP_SYM (frexpl)) |