[Libclc-dev] [PATCH 2/4] pown: Port from amd_builtins

Jan Vesely via Libclc-dev libclc-dev at lists.llvm.org
Wed Jan 17 09:47:32 PST 2018


Passes piglit on turks and carrizo
fp64 passes CTS on carrizo

v2: fix formatting
    check fp32 denormal support at runtime

Signed-off-by: Jan Vesely <jan.vesely at rutgers.edu>
---
 generic/include/clc/math/pown.h   |  27 +--
 generic/include/clc/math/pown.inc |   1 +
 generic/include/math/clc_pown.h   |   3 +
 generic/include/math/clc_pown.inc |   1 +
 generic/lib/SOURCES               |   1 +
 generic/lib/math/clc_pown.cl      | 380 ++++++++++++++++++++++++++++++++++++++
 generic/lib/math/pown.cl          |  10 +-
 generic/lib/math/pown.inc         |   3 +
 8 files changed, 395 insertions(+), 31 deletions(-)
 create mode 100644 generic/include/clc/math/pown.inc
 create mode 100644 generic/include/math/clc_pown.h
 create mode 100644 generic/include/math/clc_pown.inc
 create mode 100644 generic/lib/math/clc_pown.cl
 create mode 100644 generic/lib/math/pown.inc

diff --git a/generic/include/clc/math/pown.h b/generic/include/clc/math/pown.h
index bdbf50c..2ed8a6e 100644
--- a/generic/include/clc/math/pown.h
+++ b/generic/include/clc/math/pown.h
@@ -1,24 +1,3 @@
-#define _CLC_POWN_INTRINSIC "llvm.powi"
-
-#define _CLC_POWN_DECL(GENTYPE, INTTYPE) \
-  _CLC_OVERLOAD _CLC_DECL GENTYPE pown(GENTYPE x, INTTYPE y);
-
-#define _CLC_VECTOR_POWN_DECL(GENTYPE, INTTYPE) \
-  _CLC_POWN_DECL(GENTYPE##2, INTTYPE##2)  \
-  _CLC_POWN_DECL(GENTYPE##3, INTTYPE##3)  \
-  _CLC_POWN_DECL(GENTYPE##4, INTTYPE##4)  \
-  _CLC_POWN_DECL(GENTYPE##8, INTTYPE##8)  \
-  _CLC_POWN_DECL(GENTYPE##16, INTTYPE##16)
-
-_CLC_OVERLOAD float pown(float x, int y) __asm(_CLC_POWN_INTRINSIC ".f32");
-
-_CLC_VECTOR_POWN_DECL(float, int)
-
-#ifdef cl_khr_fp64
-_CLC_OVERLOAD double pown(double x, int y) __asm(_CLC_POWN_INTRINSIC ".f64");
-_CLC_VECTOR_POWN_DECL(double, int)
-#endif
-
-#undef _CLC_POWN_INTRINSIC
-#undef _CLC_POWN_DECL
-#undef _CLC_VECTOR_POWN_DECL
+#define __CLC_BODY <clc/math/pown.inc>
+#include <clc/math/gentype.inc>
+#undef __CLC_BODY
diff --git a/generic/include/clc/math/pown.inc b/generic/include/clc/math/pown.inc
new file mode 100644
index 0000000..cf0be4c
--- /dev/null
+++ b/generic/include/clc/math/pown.inc
@@ -0,0 +1 @@
+_CLC_OVERLOAD _CLC_DECL __CLC_GENTYPE pown(__CLC_GENTYPE a, __CLC_INTN b);
diff --git a/generic/include/math/clc_pown.h b/generic/include/math/clc_pown.h
new file mode 100644
index 0000000..222c1dd
--- /dev/null
+++ b/generic/include/math/clc_pown.h
@@ -0,0 +1,3 @@
+#define __CLC_BODY <math/clc_pown.inc>
+#include <clc/math/gentype.inc>
+#undef __CLC_BODY
diff --git a/generic/include/math/clc_pown.inc b/generic/include/math/clc_pown.inc
new file mode 100644
index 0000000..168cd8e
--- /dev/null
+++ b/generic/include/math/clc_pown.inc
@@ -0,0 +1 @@
+_CLC_OVERLOAD _CLC_DECL __CLC_GENTYPE __clc_pown(__CLC_GENTYPE a, __CLC_INTN b);
diff --git a/generic/lib/SOURCES b/generic/lib/SOURCES
index 063552f..4636259 100644
--- a/generic/lib/SOURCES
+++ b/generic/lib/SOURCES
@@ -140,6 +140,7 @@ math/clc_nextafter.cl
 math/nextafter.cl
 math/clc_pow.cl
 math/pow.cl
+math/clc_pown.cl
 math/pown.cl
 math/sin.cl
 math/sincos.cl
diff --git a/generic/lib/math/clc_pown.cl b/generic/lib/math/clc_pown.cl
new file mode 100644
index 0000000..f5b36b3
--- /dev/null
+++ b/generic/lib/math/clc_pown.cl
@@ -0,0 +1,380 @@
+/*
+ * 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 "config.h"
+#include "math.h"
+#include "tables.h"
+#include "../clcmacro.h"
+
+// compute pow using log and exp
+// x^y = exp(y * log(x))
+//
+// we take care not to lose precision in the intermediate steps
+//
+// When computing log, calculate it in splits,
+//
+// r = f * (p_invead + p_inv_tail)
+// r = rh + rt
+//
+// calculate log polynomial using r, in end addition, do
+// poly = poly + ((rh-r) + rt)
+//
+// lth = -r
+// ltt = ((xexp * log2_t) - poly) + logT
+// lt = lth + ltt
+//
+// lh = (xexp * log2_h) + logH
+// l = lh + lt
+//
+// Calculate final log answer as gh and gt,
+// gh = l & higher-half bits
+// gt = (((ltt - (lt - lth)) + ((lh - l) + lt)) + (l - gh))
+//
+// yh = y & higher-half bits
+// yt = y - yh
+//
+// Before entering computation of exp,
+// vs = ((yt*gt + yt*gh) + yh*gt)
+// v = vs + yh*gh
+// vt = ((yh*gh - v) + vs)
+//
+// In calculation of exp, add vt to r that is used for poly
+// At the end of exp, do
+// ((((expT * poly) + expT) + expH*poly) + expH)
+
+_CLC_DEF _CLC_OVERLOAD float __clc_pown(float x, int ny)
+{
+    float y = (float)ny;
+
+    int ix = as_int(x);
+    int ax = ix & EXSIGNBIT_SP32;
+    int xpos = ix == ax;
+
+    int iy = as_int(y);
+    int ay = iy & EXSIGNBIT_SP32;
+    int ypos = iy == ay;
+
+    // Extra precise log calculation
+    // First handle case that x is close to 1
+    float r = 1.0f - as_float(ax);
+    int near1 = fabs(r) < 0x1.0p-4f;
+    float r2 = r*r;
+
+    // Coefficients are just 1/3, 1/4, 1/5 and 1/6
+    float poly = mad(r,
+                     mad(r,
+                         mad(r,
+                             mad(r, 0x1.24924ap-3f, 0x1.555556p-3f),
+                             0x1.99999ap-3f),
+                         0x1.000000p-2f),
+                     0x1.555556p-2f);
+
+    poly *= r2*r;
+
+    float lth_near1 = -r2 * 0.5f;
+    float ltt_near1 = -poly;
+    float lt_near1 = lth_near1 + ltt_near1;
+    float lh_near1 = -r;
+    float l_near1 = lh_near1 + lt_near1;
+
+    // Computations for x not near 1
+    int m = (int)(ax >> EXPSHIFTBITS_SP32) - EXPBIAS_SP32;
+    float mf = (float)m;
+    int ixs = as_int(as_float(ax | 0x3f800000) - 1.0f);
+    float mfs = (float)((ixs >> EXPSHIFTBITS_SP32) - 253);
+    int c = m == -127;
+    int ixn = c ? ixs : ax;
+    float mfn = c ? mfs : mf;
+
+    int indx = (ixn & 0x007f0000) + ((ixn & 0x00008000) << 1);
+
+    // F - Y
+    float f = as_float(0x3f000000 | indx) - as_float(0x3f000000 | (ixn & MANTBITS_SP32));
+
+    indx = indx >> 16;
+    float2 tv = USE_TABLE(log_inv_tbl_ep, indx);
+    float rh = f * tv.s0;
+    float rt = f * tv.s1;
+    r = rh + rt;
+
+    poly = mad(r, mad(r, 0x1.0p-2f, 0x1.555556p-2f), 0x1.0p-1f) * (r*r);
+    poly += (rh - r) + rt;
+
+    const float LOG2_HEAD = 0x1.62e000p-1f;  // 0.693115234
+    const float LOG2_TAIL = 0x1.0bfbe8p-15f; // 0.0000319461833
+    tv = USE_TABLE(loge_tbl, indx);
+    float lth = -r;
+    float ltt = mad(mfn, LOG2_TAIL, -poly) + tv.s1;
+    float lt = lth + ltt;
+    float lh = mad(mfn, LOG2_HEAD, tv.s0);
+    float l = lh + lt;
+
+    // Select near 1 or not
+    lth = near1 ? lth_near1 : lth;
+    ltt = near1 ? ltt_near1 : ltt;
+    lt = near1 ? lt_near1 : lt;
+    lh = near1 ? lh_near1 : lh;
+    l = near1 ? l_near1 : l;
+
+    float gh = as_float(as_int(l) & 0xfffff000);
+    float gt = ((ltt - (lt - lth)) + ((lh - l) + lt)) + (l - gh);
+
+    float yh = as_float(iy & 0xfffff000);
+
+    float yt = (float)(ny - (int)yh);
+
+    float ylogx_s = mad(gt, yh, mad(gh, yt, yt*gt));
+    float ylogx = mad(yh, gh, ylogx_s);
+    float ylogx_t = mad(yh, gh, -ylogx) + ylogx_s;
+
+    // Extra precise exp of ylogx
+    const float R_64_BY_LOG2 = 0x1.715476p+6f; // 64/log2 : 92.332482616893657
+    int n = convert_int(ylogx * R_64_BY_LOG2);
+    float nf = (float) n;
+
+    int j = n & 0x3f;
+    m = n >> 6;
+    int m2 = m << EXPSHIFTBITS_SP32;
+
+    const float R_LOG2_BY_64_LD = 0x1.620000p-7f;  // log2/64 lead: 0.0108032227
+    const float R_LOG2_BY_64_TL = 0x1.c85fdep-16f; // log2/64 tail: 0.0000272020388
+    r = mad(nf, -R_LOG2_BY_64_TL, mad(nf, -R_LOG2_BY_64_LD, ylogx)) + ylogx_t;
+
+    // Truncated Taylor series for e^r
+    poly = mad(mad(mad(r, 0x1.555556p-5f, 0x1.555556p-3f), r, 0x1.000000p-1f), r*r, r);
+
+    tv = USE_TABLE(exp_tbl_ep, j);
+
+    float expylogx = mad(tv.s0, poly, mad(tv.s1, poly, tv.s1)) + tv.s0;
+    float sexpylogx;
+    if (!__clc_fp32_subnormals_supported()) {
+		int explg = ((as_uint(expylogx) & EXPBITS_SP32 >> 23) - 127);
+		m = (23-(m + 149)) == 0 ? 1: m;
+		uint mantissa =  ((as_uint(expylogx) & MANTBITS_SP32)|IMPBIT_SP32) >> (23-(m + 149));
+		sexpylogx = as_float(mantissa);
+    } else {
+		sexpylogx = expylogx * as_float(0x1 << (m + 149));
+    }
+
+
+    float texpylogx = as_float(as_int(expylogx) + m2);
+    expylogx = m < -125 ? sexpylogx : texpylogx;
+
+    // Result is +-Inf if (ylogx + ylogx_t) > 128*log2
+    expylogx = ((ylogx > 0x1.62e430p+6f) | (ylogx == 0x1.62e430p+6f & ylogx_t > -0x1.05c610p-22f)) ? as_float(PINFBITPATT_SP32) : expylogx;
+
+    // Result is 0 if ylogx < -149*log2
+    expylogx = ylogx <  -0x1.9d1da0p+6f ? 0.0f : expylogx;
+
+    // Classify y:
+    //   inty = 0 means not an integer.
+    //   inty = 1 means odd integer.
+    //   inty = 2 means even integer.
+
+    int inty = 2 - (ny & 1);
+
+    float signval = as_float((as_uint(expylogx) ^ SIGNBIT_SP32));
+    expylogx = ((inty == 1) & !xpos) ? signval : expylogx;
+    int ret = as_int(expylogx);
+
+    // Corner case handling
+    int xinf = xpos ? PINFBITPATT_SP32 : NINFBITPATT_SP32;
+    ret = ((ax == 0) & !ypos & (inty == 1)) ? xinf : ret;
+    ret = ((ax == 0) & !ypos & (inty == 2)) ? PINFBITPATT_SP32 : ret;
+    ret = ((ax == 0) & ypos & (inty == 2)) ? 0 : ret;
+    int xzero = !xpos ? 0x80000000 : 0L;
+    ret = ((ax == 0) & ypos & (inty == 1)) ? xzero : ret;
+    ret = ((ix == NINFBITPATT_SP32) & !ypos & (inty == 1)) ? 0x80000000 : ret;
+    ret = ((ix == NINFBITPATT_SP32) & !ypos & (inty != 1)) ? 0 : ret;
+    ret = ((ix == NINFBITPATT_SP32) & ypos & (inty == 1)) ? NINFBITPATT_SP32 : ret;
+    ret = ((ix == NINFBITPATT_SP32) & ypos & (inty != 1)) ? PINFBITPATT_SP32 : ret;
+    ret = ((ix == PINFBITPATT_SP32) & !ypos) ? 0 : ret;
+    ret = ((ix == PINFBITPATT_SP32) & ypos) ? PINFBITPATT_SP32 : ret;
+    ret = ax > PINFBITPATT_SP32 ? ix : ret;
+    ret = ny == 0 ? 0x3f800000 : ret;
+
+    return as_float(ret);
+}
+_CLC_BINARY_VECTORIZE(_CLC_DEF _CLC_OVERLOAD, float, __clc_pown, float, int)
+
+#ifdef cl_khr_fp64
+_CLC_DEF _CLC_OVERLOAD double __clc_pown(double x, int ny)
+{
+    const double real_log2_tail = 5.76999904754328540596e-08;
+    const double real_log2_lead = 6.93147122859954833984e-01;
+
+    double y = (double) ny;
+
+    long ux = as_long(x);
+    long ax = ux & (~SIGNBIT_DP64);
+    int xpos = ax == ux;
+
+    long uy = as_long(y);
+    long ay = uy & (~SIGNBIT_DP64);
+    int ypos = ay == uy;
+
+    // Extended precision log
+    double v, vt;
+    {
+        int exp = (int)(ax >> 52) - 1023;
+        int mask_exp_1023 = exp == -1023;
+        double xexp = (double) exp;
+        long mantissa = ax & 0x000FFFFFFFFFFFFFL;
+
+        long temp_ux = as_long(as_double(0x3ff0000000000000L | mantissa) - 1.0);
+        exp = ((temp_ux & 0x7FF0000000000000L) >> 52) - 2045;
+        double xexp1 = (double) exp;
+        long mantissa1 = temp_ux & 0x000FFFFFFFFFFFFFL;
+
+        xexp = mask_exp_1023 ? xexp1 : xexp;
+        mantissa = mask_exp_1023 ? mantissa1 : mantissa;
+
+        long rax = (mantissa & 0x000ff00000000000) + ((mantissa & 0x0000080000000000) << 1);
+        int index = rax >> 44;
+
+        double F = as_double(rax | 0x3FE0000000000000L);
+        double Y = as_double(mantissa | 0x3FE0000000000000L);
+        double f = F - Y;
+        double2 tv = USE_TABLE(log_f_inv_tbl, index);
+        double log_h = tv.s0;
+        double log_t = tv.s1;
+        double f_inv = (log_h + log_t) * f;
+        double r1 = as_double(as_long(f_inv) & 0xfffffffff8000000L);
+        double r2 = fma(-F, r1, f) * (log_h + log_t);
+        double r = r1 + r2;
+
+        double poly = fma(r,
+                          fma(r,
+                              fma(r,
+                                  fma(r, 1.0/7.0, 1.0/6.0),
+                                  1.0/5.0),
+                              1.0/4.0),
+                          1.0/3.0);
+        poly = poly * r * r * r;
+
+        double hr1r1 = 0.5*r1*r1;
+        double poly0h = r1 + hr1r1;
+        double poly0t = r1 - poly0h + hr1r1;
+        poly = fma(r1, r2, fma(0.5*r2, r2, poly)) + r2 + poly0t;
+
+        tv = USE_TABLE(powlog_tbl, index);
+        log_h = tv.s0;
+        log_t = tv.s1;
+
+        double resT_t = fma(xexp, real_log2_tail, + log_t) - poly;
+        double resT = resT_t - poly0h;
+        double resH = fma(xexp, real_log2_lead, log_h);
+        double resT_h = poly0h;
+
+        double H = resT + resH;
+        double H_h = as_double(as_long(H) & 0xfffffffff8000000L);
+        double T = (resH - H + resT) + (resT_t - (resT + resT_h)) + (H - H_h);
+        H = H_h;
+
+        double y_head = as_double(uy & 0xfffffffff8000000L);
+        double y_tail = y - y_head;
+
+        int mask_2_24 = ay > 0x4170000000000000; // 2^24
+        int nyh = convert_int(y_head);
+        int nyt = ny - nyh;
+        double y_tail1 = (double)nyt;
+        y_tail = mask_2_24 ? y_tail1 : y_tail;
+
+        double temp = fma(y_tail, H, fma(y_head, T, y_tail*T));
+        v = fma(y_head, H, temp);
+        vt = fma(y_head, H, -v) + temp;
+    }
+
+    // Now calculate exp of (v,vt)
+
+    double expv;
+    {
+        const double max_exp_arg = 709.782712893384;
+        const double min_exp_arg = -745.1332191019411;
+        const double sixtyfour_by_lnof2 = 92.33248261689366;
+        const double lnof2_by_64_head = 0.010830424260348081;
+        const double lnof2_by_64_tail = -4.359010638708991e-10;
+
+        double temp = v * sixtyfour_by_lnof2;
+        int n = (int)temp;
+        double dn = (double)n;
+        int j = n & 0x0000003f;
+        int m = n >> 6;
+
+        double2 tv = USE_TABLE(two_to_jby64_ep_tbl, j);
+        double f1 = tv.s0;
+        double f2 = tv.s1;
+        double f = f1 + f2;
+
+        double r1 = fma(dn, -lnof2_by_64_head, v);
+        double r2 = dn * lnof2_by_64_tail;
+        double r = (r1 + r2) + vt;
+
+        double q = fma(r,
+                       fma(r,
+                           fma(r,
+                               fma(r, 1.38889490863777199667e-03, 8.33336798434219616221e-03),
+                               4.16666666662260795726e-02),
+                           1.66666666665260878863e-01),
+                       5.00000000000000008883e-01);
+        q = fma(r*r, q, r);
+
+        expv = fma(f, q, f2) + f1;
+	      expv = ldexp(expv, m);
+
+        expv = v > max_exp_arg ? as_double(0x7FF0000000000000L) : expv;
+        expv = v < min_exp_arg ? 0.0 : expv;
+    }
+
+    // See whether y is an integer.
+    // inty = 0 means not an integer.
+    // inty = 1 means odd integer.
+    // inty = 2 means even integer.
+
+    int inty = 2 - (ny & 1);
+
+    expv *= ((inty == 1) & !xpos) ? -1.0 : 1.0;
+
+    long ret = as_long(expv);
+
+    // Now all the edge cases
+    long xinf = xpos ? PINFBITPATT_DP64 : NINFBITPATT_DP64;
+    ret = ((ax == 0L) & !ypos & (inty == 1)) ? xinf : ret;
+    ret = ((ax == 0L) & !ypos & (inty == 2)) ? PINFBITPATT_DP64 : ret;
+    ret = ((ax == 0L) & ypos & (inty == 2)) ? 0L : ret;
+    long xzero = !xpos ? 0x8000000000000000L : 0L;
+    ret = ((ax == 0L) & ypos & (inty == 1)) ? xzero : ret;
+    ret = ((ux == NINFBITPATT_DP64) & !ypos & (inty == 1)) ? 0x8000000000000000L : ret;
+    ret = ((ux == NINFBITPATT_DP64) & !ypos & (inty != 1)) ? 0L : ret;
+    ret = ((ux == NINFBITPATT_DP64) & ypos & (inty == 1)) ? NINFBITPATT_DP64 : ret;
+    ret = ((ux == NINFBITPATT_DP64) & ypos & (inty != 1)) ? PINFBITPATT_DP64 : ret;
+    ret = ((ux == PINFBITPATT_DP64) & !ypos) ? 0L : ret;
+    ret = ((ux == PINFBITPATT_DP64) & ypos) ? PINFBITPATT_DP64 : ret;
+    ret = ax > PINFBITPATT_DP64 ? ux : ret;
+    ret = ny == 0 ? 0x3ff0000000000000L : ret;
+
+    return as_double(ret);
+}
+_CLC_BINARY_VECTORIZE(_CLC_DEF _CLC_OVERLOAD, double, __clc_pown, double, int)
+#endif
diff --git a/generic/lib/math/pown.cl b/generic/lib/math/pown.cl
index f3b27d4..7652cd5 100644
--- a/generic/lib/math/pown.cl
+++ b/generic/lib/math/pown.cl
@@ -1,10 +1,6 @@
 #include <clc/clc.h>
-#include "../clcmacro.h"
 
-_CLC_BINARY_VECTORIZE(_CLC_OVERLOAD _CLC_DEF, float, pown, float, int)
+#include <math/clc_pown.h>
 
-#ifdef cl_khr_fp64
-#pragma OPENCL EXTENSION cl_khr_fp64 : enable
-
-_CLC_BINARY_VECTORIZE(_CLC_OVERLOAD _CLC_DEF, double, pown, double, int)
-#endif
+#define __CLC_BODY <pown.inc>
+#include <clc/math/gentype.inc>
diff --git a/generic/lib/math/pown.inc b/generic/lib/math/pown.inc
new file mode 100644
index 0000000..84729d9
--- /dev/null
+++ b/generic/lib/math/pown.inc
@@ -0,0 +1,3 @@
+_CLC_OVERLOAD _CLC_DEF __CLC_GENTYPE pown(__CLC_GENTYPE x, __CLC_INTN y) {
+  return __clc_pown(x, y);
+}
-- 
2.14.3



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