diff options
author | Arne Juul <arnej@verizonmedia.com> | 2021-03-02 12:26:27 +0000 |
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committer | Arne Juul <arnej@verizonmedia.com> | 2021-03-02 15:18:24 +0000 |
commit | 433fb61148345f8f187235f0875dbc10c0bfadeb (patch) | |
tree | 3aee7c7bb0ad8f13da3f065aa85c811e69639a78 /vespalib/src/tests/util | |
parent | ed789e176193da5e700c8e5014cc4ded391edbda (diff) |
better NaN support for BrainFloat16
Diffstat (limited to 'vespalib/src/tests/util')
-rw-r--r-- | vespalib/src/tests/util/brain_float16/brain_float16_test.cpp | 70 |
1 files changed, 60 insertions, 10 deletions
diff --git a/vespalib/src/tests/util/brain_float16/brain_float16_test.cpp b/vespalib/src/tests/util/brain_float16/brain_float16_test.cpp index 4b7b0ee7897..6de41b3e038 100644 --- a/vespalib/src/tests/util/brain_float16/brain_float16_test.cpp +++ b/vespalib/src/tests/util/brain_float16/brain_float16_test.cpp @@ -4,6 +4,8 @@ #include <vespa/vespalib/gtest/gtest.h> #include <stdio.h> #include <cmath> +#include <cmath> +#include <cfenv> using namespace vespalib; @@ -57,25 +59,73 @@ TEST(BrainFloat16Test, traits_check) { EXPECT_TRUE(std::has_unique_object_representations<BrainFloat16>::value); } +static std::string hexdump(const void *p, size_t sz) { + char tmpbuf[10]; + if (sz == 2) { + uint16_t bits; + memcpy(&bits, p, sz); + snprintf(tmpbuf, 10, "%04x", bits); + } else if (sz == 4) { + uint32_t bits; + memcpy(&bits, p, sz); + snprintf(tmpbuf, 10, "%08x", bits); + } else { + abort(); + } + return tmpbuf; +} +#define HEX_DUMP(arg) hexdump(&arg, sizeof(arg)).c_str() + TEST(BrainFloat16Test, check_special_values) { + // we should not need to support HW without normal float support: + EXPECT_TRUE(std::numeric_limits<float>::has_quiet_NaN); + EXPECT_TRUE(std::numeric_limits<float>::has_signaling_NaN); + EXPECT_TRUE(std::numeric_limits<BrainFloat16>::has_quiet_NaN); + EXPECT_TRUE(std::numeric_limits<BrainFloat16>::has_signaling_NaN); + std::feclearexcept(FE_ALL_EXCEPT); + EXPECT_TRUE(std::fetestexcept(FE_INVALID) == 0); float f_inf = std::numeric_limits<float>::infinity(); float f_neg = -f_inf; - float f_nan = std::numeric_limits<float>::quiet_NaN(); - BrainFloat16 b_inf = f_inf; - BrainFloat16 b_neg = f_neg; - BrainFloat16 b_nan = f_nan; + float f_qnan = std::numeric_limits<float>::quiet_NaN(); + float f_snan = std::numeric_limits<float>::signaling_NaN(); + BrainFloat16 b_inf = std::numeric_limits<BrainFloat16>::infinity(); + BrainFloat16 b_qnan = std::numeric_limits<BrainFloat16>::quiet_NaN(); + BrainFloat16 b_snan = std::numeric_limits<BrainFloat16>::signaling_NaN(); + BrainFloat16 b_from_f_inf = f_inf; + BrainFloat16 b_from_f_neg = f_neg; + BrainFloat16 b_from_f_qnan = f_qnan; + BrainFloat16 b_from_f_snan = f_snan; + EXPECT_EQ(sizeof(b_inf), 2); + EXPECT_EQ(memcmp(&b_inf, &b_from_f_inf, sizeof(BrainFloat16)), 0); + EXPECT_EQ(memcmp(&b_qnan, &b_from_f_qnan, sizeof(BrainFloat16)), 0); + EXPECT_EQ(memcmp(&b_snan, &b_from_f_snan, sizeof(BrainFloat16)), 0); + printf("+inf float is '%s' / bf16 is '%s'\n", HEX_DUMP(f_inf), HEX_DUMP(b_from_f_inf)); + printf("-inf float is '%s' / bf16 is '%s'\n", HEX_DUMP(f_neg), HEX_DUMP(b_from_f_neg)); + printf("qNaN float is '%s' / bf16 is '%s'\n", HEX_DUMP(f_qnan), HEX_DUMP(b_from_f_qnan)); + printf("sNan float is '%s' / bf16 is '%s'\n", HEX_DUMP(f_snan), HEX_DUMP(b_from_f_snan)); double d_inf = b_inf; - double d_neg = b_neg; - double d_nan = b_nan; + double d_neg = b_from_f_neg; + double d_qnan = b_qnan; + EXPECT_TRUE(std::fetestexcept(FE_INVALID) == 0); + // float->double conversion of signaling NaN: + double d_snan = b_snan; + EXPECT_TRUE(std::fetestexcept(FE_INVALID) != 0); + std::feclearexcept(FE_ALL_EXCEPT); + EXPECT_TRUE(std::fetestexcept(FE_INVALID) == 0); EXPECT_EQ(d_inf, std::numeric_limits<double>::infinity()); EXPECT_EQ(d_neg, -std::numeric_limits<double>::infinity()); - EXPECT_TRUE(std::isnan(d_nan)); + EXPECT_TRUE(std::isnan(d_qnan)); + EXPECT_TRUE(std::isnan(d_snan)); float f_from_b_inf = b_inf; - float f_from_b_neg = b_neg; - float f_from_b_nan = b_nan; + float f_from_b_neg = b_from_f_neg; + float f_from_b_qnan = b_qnan; + float f_from_b_snan = b_snan; EXPECT_EQ(memcmp(&f_inf, &f_from_b_inf, sizeof(float)), 0); EXPECT_EQ(memcmp(&f_neg, &f_from_b_neg, sizeof(float)), 0); - EXPECT_EQ(memcmp(&f_nan, &f_from_b_nan, sizeof(float)), 0); + EXPECT_EQ(memcmp(&f_qnan, &f_from_b_qnan, sizeof(float)), 0); + EXPECT_EQ(memcmp(&f_snan, &f_from_b_snan, sizeof(float)), 0); + // none of the BF16 operations should trigger FPE: + EXPECT_TRUE(std::fetestexcept(FE_INVALID) == 0); } GTEST_MAIN_RUN_ALL_TESTS() |