src/intel/compiler/test_vf_float_conversions.cpp

   1 /*
   2  * Copyright © 2014 Intel Corporation
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a
   5  * copy of this software and associated documentation files (the "Software"),
   6  * to deal in the Software without restriction, including without limitation
   7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   8  * and/or sell copies of the Software, and to permit persons to whom the
   9  * Software is furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice (including the next
  12  * paragraph) shall be included in all copies or substantial portions of the
  13  * Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  18  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  20  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
  21  * IN THE SOFTWARE.
  22  */
  23
  24 #include <gtest/gtest.h>
  25 #include <math.h>
  26 #include "brw_reg.h"
  27
  28 class vf_float_conversion_test : public ::testing::Test {
  29    virtual void SetUp();
  30
  31 public:
  32    float vf_to_float[128];
  33 };
  34
  35 void vf_float_conversion_test::SetUp() {
  36    /* 0 is special cased. */
  37    vf_to_float[0] = 0.0;
  38
  39    for (int vf = 1; vf < 128; vf++) {
  40       int ebits = (vf >> 4) & 0x7;
  41       int mbits = vf & 0xf;
  42
  43       float x = 1.0f + mbits / 16.0f;
  44       int exp = ebits - 3;
  45
  46       vf_to_float[vf] = ldexpf(x, exp);
  47    }
  48 }
  49
  50 union fu {
  51    float f;
  52    unsigned u;
  53 };
  54
  55 static unsigned
  56 f2u(float f)
  57 {
  58    union fu fu;
  59    fu.f = f;
  60    return fu.u;
  61 }
  62
  63 TEST_F(vf_float_conversion_test, test_vf_to_float)
  64 {
  65    for (int vf = 0; vf < 256; vf++) {
  66       float expected = vf_to_float[vf % 128];
  67       if (vf > 127)
  68          expected = -expected;
  69
  70       EXPECT_EQ(f2u(expected), f2u(brw_vf_to_float(vf)));
  71    }
  72 }
  73
  74 TEST_F(vf_float_conversion_test, test_float_to_vf)
  75 {
  76    for (int vf = 0; vf < 256; vf++) {
  77       float f = vf_to_float[vf % 128];
  78       if (vf > 127)
  79          f = -f;
  80
  81       EXPECT_EQ(vf, brw_float_to_vf(f));
  82    }
  83 }
  84
  85 TEST_F(vf_float_conversion_test, test_special_case_0)
  86 {
  87    /* ±0.0f are special cased to the VFs that would otherwise correspond
  88     * to ±0.125f. Make sure we can't convert these values to VF.
  89     */
  90    EXPECT_EQ(brw_float_to_vf(+0.125f), -1);
  91    EXPECT_EQ(brw_float_to_vf(-0.125f), -1);
  92
  93    EXPECT_EQ(f2u(brw_vf_to_float(brw_float_to_vf(+0.0f))), f2u(+0.0f));
  94    EXPECT_EQ(f2u(brw_vf_to_float(brw_float_to_vf(-0.0f))), f2u(-0.0f));
  95 }
  96
  97 TEST_F(vf_float_conversion_test, test_nonrepresentable_float_input)
  98 {
  99    EXPECT_EQ(brw_float_to_vf(+32.0f), -1);
 100    EXPECT_EQ(brw_float_to_vf(-32.0f), -1);
 101
 102    EXPECT_EQ(brw_float_to_vf(+16.5f), -1);
 103    EXPECT_EQ(brw_float_to_vf(-16.5f), -1);
 104
 105    EXPECT_EQ(brw_float_to_vf(+8.25f), -1);
 106    EXPECT_EQ(brw_float_to_vf(-8.25f), -1);
 107
 108    EXPECT_EQ(brw_float_to_vf(+4.125f), -1);
 109    EXPECT_EQ(brw_float_to_vf(-4.125f), -1);
 110 }