diff options
Diffstat (limited to 'sysdeps/x86_64/fpu/e_exp2l.S')
| -rw-r--r-- | sysdeps/x86_64/fpu/e_exp2l.S | 25 |
1 files changed, 24 insertions, 1 deletions
diff --git a/sysdeps/x86_64/fpu/e_exp2l.S b/sysdeps/x86_64/fpu/e_exp2l.S index 7d42a932db..d634ad38f8 100644 --- a/sysdeps/x86_64/fpu/e_exp2l.S +++ b/sysdeps/x86_64/fpu/e_exp2l.S @@ -7,6 +7,20 @@ #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##(%rip) +#else +# define MO(op) op +#endif + + .text ENTRY(__ieee754_exp2l) fldt 8(%rsp) /* I added the following ugly construct because exp(+-Inf) resulted @@ -36,7 +50,16 @@ 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) + fucomip %st(1), %st + fstp %st + jnc 4f + fld %st + fmul %st + fstp %st +4: ret 1: testl $0x200, %eax /* Test sign. */ jz 2f /* If positive, jump. */ |