diff options
| author | Joseph Myers <joseph@codesourcery.com> | 2012-07-06 11:17:41 +0000 |
|---|---|---|
| committer | Joseph Myers <joseph@codesourcery.com> | 2012-07-06 11:17:41 +0000 |
| commit | f17ac40d7cb8e8c462476b6ab703262f6b8f6da8 (patch) | |
| tree | b06be367df1701da97deb44092ddf8707d2e8db2 /sysdeps/i386/fpu/s_expm1.S | |
| parent | fb21f89b75d0152aa42efb6b620843799a4cd76b (diff) | |
| download | glibc-f17ac40d7cb8e8c462476b6ab703262f6b8f6da8.tar.gz glibc-f17ac40d7cb8e8c462476b6ab703262f6b8f6da8.tar.xz glibc-f17ac40d7cb8e8c462476b6ab703262f6b8f6da8.zip | |
Fix expm1 spurious underflow exceptions (bug 6778).
Diffstat (limited to 'sysdeps/i386/fpu/s_expm1.S')
| -rw-r--r-- | sysdeps/i386/fpu/s_expm1.S | 24 |
1 files changed, 17 insertions, 7 deletions
diff --git a/sysdeps/i386/fpu/s_expm1.S b/sysdeps/i386/fpu/s_expm1.S index 9883f9b353..d2754de911 100644 --- a/sysdeps/i386/fpu/s_expm1.S +++ b/sysdeps/i386/fpu/s_expm1.S @@ -51,19 +51,31 @@ ENTRY(__expm1) jae HIDDEN_JUMPTARGET (__exp) fldl 4(%esp) // x - fxam // Is NaN or +-Inf? + fxam // Is NaN, +-Inf or +-0? + xorb $0x80, %ah + cmpl $0xc043, %eax // is num <= -38.0? fstsw %ax movb $0x45, %ch + jb 4f + + // Below -38.0 (may be -NaN or -Inf). + andb %ah, %ch +#ifdef PIC + LOAD_PIC_REG (dx) +#endif + cmpb $0x01, %ch + je 5f // If -NaN, jump. + jmp 2f // -large, possibly -Inf. + +4: // In range -38.0 to 704.0 (may be +-0 but not NaN or +-Inf). andb %ah, %ch cmpb $0x40, %ch je 3f // If +-0, jump. #ifdef PIC LOAD_PIC_REG (dx) #endif - cmpb $0x05, %ch - je 2f // If +-Inf, jump. - fldt MO(l2e) // log2(e) : x +5: fldt MO(l2e) // log2(e) : x fmulp // log2(e)*x fld %st // log2(e)*x : log2(e)*x frndint // int(log2(e)*x) : log2(e)*x @@ -79,9 +91,7 @@ ENTRY(__expm1) fsubrp %st, %st(1) // 2^(log2(e)*x) ret -2: testl $0x200, %eax // Test sign. - jz 3f // If positive, jump. - fstp %st +2: fstp %st fldl MO(minus1) // Set result to -1.0. 3: ret END(__expm1) |