[Libclc-dev] [PATCH 1/1] fmod: Port from amd_builtins

Jan Vesely via Libclc-dev libclc-dev at lists.llvm.org
Fri Mar 30 08:03:30 PDT 2018


On Sun, 2018-03-18 at 15:16 -0400, Jan Vesely wrote:
> Uses only denormal path for fp32.
> Passes CTS on carrizo and turks.
> 
> Signed-off-by: Jan Vesely <jan.vesely at rutgers.edu>
> ---
>  generic/include/clc/math/fmod.h   |   4 +-
>  generic/include/clc/math/fmod.inc |   1 -
>  generic/include/math/clc_fmod.h   |   4 +
>  generic/lib/SOURCES               |   1 +
>  generic/lib/math/clc_fmod.cl      | 184 ++++++++++++++++++++++++++++++++++++++
>  generic/lib/math/fmod.cl          |  14 +--
>  6 files changed, 196 insertions(+), 12 deletions(-)
>  delete mode 100644 generic/include/clc/math/fmod.inc
>  create mode 100644 generic/include/math/clc_fmod.h
>  create mode 100644 generic/lib/math/clc_fmod.cl
> 
> diff --git a/generic/include/clc/math/fmod.h b/generic/include/clc/math/fmod.h
> index 4906867..443eaf3 100644
> --- a/generic/include/clc/math/fmod.h
> +++ b/generic/include/clc/math/fmod.h
> @@ -1,2 +1,4 @@
> -#define __CLC_BODY <clc/math/fmod.inc>
> +#define __CLC_FUNCTION fmod
> +#define __CLC_BODY <clc/math/binary_decl_tt.inc>
>  #include <clc/math/gentype.inc>
> +#undef __CLC_FUNCTION
> diff --git a/generic/include/clc/math/fmod.inc b/generic/include/clc/math/fmod.inc
> deleted file mode 100644
> index 39d9153..0000000
> --- a/generic/include/clc/math/fmod.inc
> +++ /dev/null
> @@ -1 +0,0 @@
> -_CLC_OVERLOAD _CLC_DECL __CLC_GENTYPE fmod(__CLC_GENTYPE a, __CLC_GENTYPE b);
> diff --git a/generic/include/math/clc_fmod.h b/generic/include/math/clc_fmod.h
> new file mode 100644
> index 0000000..0409785
> --- /dev/null
> +++ b/generic/include/math/clc_fmod.h
> @@ -0,0 +1,4 @@
> +#define __CLC_FUNCTION __clc_fmod
> +#define __CLC_BODY <clc/math/binary_decl_tt.inc>
> +#include <clc/math/gentype.inc>
> +#undef __CLC_FUNCTION
> diff --git a/generic/lib/SOURCES b/generic/lib/SOURCES
> index 843d44d..dfa9d0c 100644
> --- a/generic/lib/SOURCES
> +++ b/generic/lib/SOURCES
> @@ -103,6 +103,7 @@ math/fdim.cl
>  math/fma.cl
>  math/fmax.cl
>  math/fmin.cl
> +math/clc_fmod.cl
>  math/fmod.cl
>  math/fract.cl
>  math/frexp.cl
> diff --git a/generic/lib/math/clc_fmod.cl b/generic/lib/math/clc_fmod.cl
> new file mode 100644
> index 0000000..a45c2b4
> --- /dev/null
> +++ b/generic/lib/math/clc_fmod.cl
> @@ -0,0 +1,184 @@
> +/*
> + * Copyright (c) 2014 Advanced Micro Devices, Inc.
> + *
> + * Permission is hereby granted, free of charge, to any person obtaining a copy
> + * of this software and associated documentation files (the "Software"), to deal
> + * in the Software without restriction, including without limitation the rights
> + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
> + * copies of the Software, and to permit persons to whom the Software is
> + * furnished to do so, subject to the following conditions:
> + *
> + * The above copyright notice and this permission notice shall be included in
> + * all copies or substantial portions of the Software.
> + *
> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
> + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
> + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
> + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
> + * THE SOFTWARE.
> + */
> +
> +#include <clc/clc.h>
> +
> +#include <math/clc_remainder.h>
> +#include "../clcmacro.h"
> +#include "config.h"
> +#include "math.h"
> +
> +_CLC_DEF _CLC_OVERLOAD float __clc_fmod(float x, float y)
> +{
> +    int ux = as_int(x);
> +    int ax = ux & EXSIGNBIT_SP32;
> +    float xa = as_float(ax);
> +    int sx = ux ^ ax;
> +    int ex = ax >> EXPSHIFTBITS_SP32;
> +
> +    int uy = as_int(y);
> +    int ay = uy & EXSIGNBIT_SP32;
> +    float ya = as_float(ay);
> +    int ey = ay >> EXPSHIFTBITS_SP32;
> +
> +    float xr = as_float(0x3f800000 | (ax & 0x007fffff));
> +    float yr = as_float(0x3f800000 | (ay & 0x007fffff));
> +    int c;
> +    int k = ex - ey;
> +
> +    while (k > 0) {
> +        c = xr >= yr;
> +        xr -= c ? yr : 0.0f;
> +        xr += xr;
> +	--k;
> +    }
> +
> +    c = xr >= yr;
> +    xr -= c ? yr : 0.0f;
> +
> +    int lt = ex < ey;
> +
> +    xr = lt ? xa : xr;
> +    yr = lt ? ya : yr;
> +
> +
> +    float s = as_float(ey << EXPSHIFTBITS_SP32);
> +    xr *= lt ? 1.0f : s;
> +
> +    c = ax == ay;
> +    xr = c ? 0.0f : xr;
> +
> +    xr = as_float(sx ^ as_int(xr));
> +
> +    c = ax > PINFBITPATT_SP32 | ay > PINFBITPATT_SP32 | ax == PINFBITPATT_SP32 | ay == 0;
> +    xr = c ? as_float(QNANBITPATT_SP32) : xr;
> +
> +    return xr;
> +
> +}
> +_CLC_BINARY_VECTORIZE(_CLC_DEF _CLC_OVERLOAD, float, __clc_fmod, float, float);
> +
> +#ifdef cl_khr_fp64
> +_CLC_DEF _CLC_OVERLOAD double __clc_fmod(double x, double y)
> +{
> +    ulong ux = as_ulong(x);
> +    ulong ax = ux & ~SIGNBIT_DP64;
> +    ulong xsgn = ux ^ ax;
> +    double dx = as_double(ax);
> +    int xexp = convert_int(ax >> EXPSHIFTBITS_DP64);
> +    int xexp1 = 11 - (int) clz(ax & MANTBITS_DP64);
> +    xexp1 = xexp < 1 ? xexp1 : xexp;
> +
> +    ulong uy = as_ulong(y);
> +    ulong ay = uy & ~SIGNBIT_DP64;
> +    double dy = as_double(ay);
> +    int yexp = convert_int(ay >> EXPSHIFTBITS_DP64);
> +    int yexp1 = 11 - (int) clz(ay & MANTBITS_DP64);
> +    yexp1 = yexp < 1 ? yexp1 : yexp;
> +
> +    // First assume |x| > |y|
> +
> +    // Set ntimes to the number of times we need to do a
> +    // partial remainder. If the exponent of x is an exact multiple
> +    // of 53 larger than the exponent of y, and the mantissa of x is
> +    // less than the mantissa of y, ntimes will be one too large
> +    // but it doesn't matter - it just means that we'll go round
> +    // the loop below one extra time.
> +    int ntimes = max(0, (xexp1 - yexp1) / 53);
> +    double w =  ldexp(dy, ntimes * 53);
> +    w = ntimes == 0 ? dy : w;
> +    double scale = ntimes == 0 ? 1.0 : 0x1.0p-53;
> +
> +    // Each time round the loop we compute a partial remainder.
> +    // This is done by subtracting a large multiple of w
> +    // from x each time, where w is a scaled up version of y.
> +    // The subtraction must be performed exactly in quad
> +    // precision, though the result at each stage can
> +    // fit exactly in a double precision number.
> +    int i;
> +    double t, v, p, pp;
> +
> +    for (i = 0; i < ntimes; i++) {
> +        // Compute integral multiplier
> +        t = trunc(dx / w);
> +
> +        // Compute w * t in quad precision
> +        p = w * t;
> +        pp = fma(w, t, -p);
> +
> +        // Subtract w * t from dx
> +        v = dx - p;
> +        dx = v + (((dx - v) - p) - pp);
> +
> +        // If t was one too large, dx will be negative. Add back one w.
> +        dx += dx < 0.0 ? w : 0.0;
> +
> +        // Scale w down by 2^(-53) for the next iteration
> +        w *= scale;
> +    }
> +
> +    // One more time
> +    // Variable todd says whether the integer t is odd or not
> +    t = floor(dx / w);
> +    long lt = (long)t;
> +    int todd = lt & 1;
> +
> +    p = w * t;
> +    pp = fma(w, t, -p);
> +    v = dx - p;
> +    dx = v + (((dx - v) - p) - pp);
> +    i = dx < 0.0;
> +    todd ^= i;
> +    dx += i ? w : 0.0;
> +
> +    // At this point, dx lies in the range [0,dy)
> +    double ret = as_double(xsgn ^ as_ulong(dx));
> +    dx = as_double(ax);
> +
> +    // Now handle |x| == |y|
> +    int c = dx == dy;
> +    t = as_double(xsgn);
> +    ret = c ? t : ret;
> +
> +    // Next, handle |x| < |y|
> +    c = dx < dy;
> +    ret = c ? x : ret;
> +
> +    // We don't need anything special for |x| == 0
> +
> +    // |y| is 0
> +    c = dy == 0.0;
> +    ret = c ? as_double(QNANBITPATT_DP64) : ret;
> +
> +    // y is +-Inf, NaN
> +    c = yexp > BIASEDEMAX_DP64;
> +    t = y == y ? x : y;
> +    ret = c ? t : ret;
> +
> +    // x is +=Inf, NaN
> +    c = xexp > BIASEDEMAX_DP64;
> +    ret = c ? as_double(QNANBITPATT_DP64) : ret;
> +
> +    return ret;
> +}
> +_CLC_BINARY_VECTORIZE(_CLC_DEF _CLC_OVERLOAD, double, __clc_fmod, double, double);
> +#endif
> diff --git a/generic/lib/math/fmod.cl b/generic/lib/math/fmod.cl
> index f9a4e31..fac3fc6 100644
> --- a/generic/lib/math/fmod.cl
> +++ b/generic/lib/math/fmod.cl
> @@ -1,12 +1,6 @@
>  #include <clc/clc.h>
> -#include "../clcmacro.h"
> +#include <math/clc_fmod.h>
>  
> -_CLC_DEFINE_BINARY_BUILTIN(float, fmod, __builtin_fmodf, float, float)
> -
> -#ifdef cl_khr_fp64
> -
> -#pragma OPENCL EXTENSION cl_khr_fp64 : enable
> -
> -_CLC_DEFINE_BINARY_BUILTIN(double, fmod, __builtin_fmod, double, double)
> -
> -#endif
> +#define __CLC_FUNC fmod
> +#define __CLC_BODY <clc_sw_binary.inc>
> +#include <clc/math/gentype.inc>

ping.

Jan
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