diff options
Diffstat (limited to 'sysdeps/i386/fpu/e_exp2l.S')
| -rw-r--r-- | sysdeps/i386/fpu/e_exp2l.S | 29 |
1 files changed, 28 insertions, 1 deletions
diff --git a/sysdeps/i386/fpu/e_exp2l.S b/sysdeps/i386/fpu/e_exp2l.S index 2bf9a25727..9a5ff95a6c 100644 --- a/sysdeps/i386/fpu/e_exp2l.S +++ b/sysdeps/i386/fpu/e_exp2l.S @@ -6,7 +6,24 @@ #include <machine/asm.h> + .section .rodata.cst16,"aM",@progbits,16 + .p2align 4 + .type ldbl_min,@object +ldbl_min: .byte 0, 0, 0, 0, 0, 0, 0, 0x80, 0x1, 0 + .byte 0, 0, 0, 0, 0, 0 + ASM_SIZE_DIRECTIVE(ldbl_min) + +#ifdef PIC +# define MO(op) op##@GOTOFF(%ecx) +#else +# define MO(op) op +#endif + + .text ENTRY(__ieee754_exp2l) +#ifdef PIC + LOAD_PIC_REG (cx) +#endif fldt 4(%esp) /* I added the following ugly construct because exp(+-Inf) resulted in NaN. The ugliness results from the bright minds at Intel. @@ -35,7 +52,17 @@ ENTRY(__ieee754_exp2l) faddp /* 2^(fract(x)) */ fscale /* e^x */ fstp %st(1) - ret + /* Ensure underflow for tiny result. */ + fldt MO(ldbl_min) + fld %st(1) + fucompp + fnstsw + sahf + jnc 4f + fld %st + fmul %st + fstp %st +4: ret 1: testl $0x200, %eax /* Test sign. */ jz 2f /* If positive, jump. */ |