/* * Public domain. * * Adapted for i686 instructions. */ #include #include .section .rodata.cst8,"aM",@progbits,8 .p2align 3 .type one,@object one: .double 1.0 ASM_SIZE_DIRECTIVE(one) /* It is not important that this constant is precise. It is only a value which is known to be on the safe side for using the fyl2xp1 instruction. */ .type limit,@object limit: .double 0.29 ASM_SIZE_DIRECTIVE(limit) #ifdef PIC # define MO(op) op##@GOTOFF(%edx) #else # define MO(op) op #endif .text ENTRY(__ieee754_logl) fldln2 // log(2) fldt 4(%esp) // x : log(2) fucomi %st jp 3f #ifdef PIC LOAD_PIC_REG (dx) #endif fld %st // x : x : log(2) movzwl 4+8(%esp), %eax cmpl $0xc000, %eax jae 5f // x <= -2, avoid overflow from -LDBL_MAX - 1. fsubl MO(one) // x-1 : x : log(2) 5: fld %st // x-1 : x-1 : x : log(2) fabs // |x-1| : x-1 : x : log(2) fld MO(limit) // 0.29 : |x-1| : x-1 : x : log(2) fcomip %st(1) // |x-1| : x-1 : x : log(2) fstp %st(0) // x-1 : x : log(2) jc 2f fxam fnstsw andb $0x45, %ah cmpb $0x40, %ah jne 4f fabs // log(1) is +0 in all rounding modes. 4: fstp %st(1) // x-1 : log(2) fyl2xp1 // log(x) ret 2: fstp %st(0) // x : log(2) fyl2x // log(x) ret 3: fstp %st(1) fadd %st(0) ret END (__ieee754_logl) ENTRY(__logl_finite) fldln2 // log(2) fldt 4(%esp) // x : log(2) #ifdef PIC LOAD_PIC_REG (dx) #endif fld %st // x : x : log(2) fsubl MO(one) // x-1 : x : log(2) fld %st // x-1 : x-1 : x : log(2) fabs // |x-1| : x-1 : x : log(2) fld MO(limit) // 0.29 : |x-1| : x-1 : x : log(2) fcomip %st(1) // |x-1| : x-1 : x : log(2) fstp %st(0) // x-1 : x : log(2) jc 2b fxam fnstsw andb $0x45, %ah cmpb $0x40, %ah jne 6f fabs // log(1) is +0 in all rounding modes. 6: fstp %st(1) // x-1 : log(2) fyl2xp1 // log(x) ret END(__logl_finite) libm_alias_finite (__logl_finite, __logl)