diff options
Diffstat (limited to 'sysdeps/i386/fpu/e_powl.S')
| -rw-r--r-- | sysdeps/i386/fpu/e_powl.S | 41 |
1 files changed, 30 insertions, 11 deletions
diff --git a/sysdeps/i386/fpu/e_powl.S b/sysdeps/i386/fpu/e_powl.S index 77d2abfaea..51a0c334f0 100644 --- a/sysdeps/i386/fpu/e_powl.S +++ b/sysdeps/i386/fpu/e_powl.S @@ -1,5 +1,5 @@ /* ix87 specific implementation of pow function. - Copyright (C) 1996-2016 Free Software Foundation, Inc. + Copyright (C) 1996-2018 Free Software Foundation, Inc. This file is part of the GNU C Library. Contributed by Ulrich Drepper <drepper@cygnus.com>, 1996. @@ -26,9 +26,9 @@ .type one,@object one: .double 1.0 ASM_SIZE_DIRECTIVE(one) - .type p3,@object -p3: .byte 0, 0, 0, 0, 0, 0, 0x20, 0x40 - ASM_SIZE_DIRECTIVE(p3) + .type p2,@object +p2: .byte 0, 0, 0, 0, 0, 0, 0x10, 0x40 + ASM_SIZE_DIRECTIVE(p2) .type p63,@object p63: .byte 0, 0, 0, 0, 0, 0, 0xe0, 0x43 ASM_SIZE_DIRECTIVE(p63) @@ -146,11 +146,11 @@ ENTRY(__ieee754_powl) jmp 3f 9: /* OK, we have an integer value for y. Unless very small - (we use < 8), use the algorithm for real exponent to avoid + (we use < 4), use the algorithm for real exponent to avoid accumulation of errors. */ fld %st // y : y : x fabs // |y| : y : x - fcompl MO(p3) // y : x + fcompl MO(p2) // y : x fnstsw sahf jnc 3f @@ -201,15 +201,21 @@ ENTRY(__ieee754_powl) fucomp %st(1) // x : y fnstsw sahf - je 31f - fxch // y : x -31: fstp %st(1) + je 33f +31: /* At least one argument NaN, and result should be NaN. */ + faddp + ret +33: jp 31b + /* pow (1, NaN); check if the NaN signaling. */ + testb $0x40, 23(%esp) + jz 31b + fstp %st(1) ret cfi_adjust_cfa_offset (8) 32: addl $8, %esp cfi_adjust_cfa_offset (-8) - fstp %st(1) + faddp ret cfi_adjust_cfa_offset (8) @@ -241,12 +247,24 @@ ENTRY(__ieee754_powl) cfi_adjust_cfa_offset (-36) ret - // pow(x,±0) = 1 + // pow(x,±0) = 1, unless x is sNaN .align ALIGNARG(4) 11: fstp %st(0) // pop y + fldt 4(%esp) // x + fxam + fnstsw + andb $0x45, %ah + cmpb $0x01, %ah + je 112f // x is NaN +111: fstp %st(0) fldl MO(one) ret +112: testb $0x40, 11(%esp) + jnz 111b + fadd %st(0) + ret + // y == ±inf .align ALIGNARG(4) 12: fstp %st(0) // pop y @@ -274,6 +292,7 @@ ENTRY(__ieee754_powl) .align ALIGNARG(4) 13: fldt 4(%esp) // load x == NaN + fadd %st(0) ret cfi_adjust_cfa_offset (8) |