dolphin-emu/archived-hwtests
1
0
Fork 0
mirror of https://github.com/dolphin-emu/hwtests.git synced 2026-01-31 01:05:17 +01:00
Code Issues Packages Projects Releases Wiki Activity

cputest_ni: Add tests for subnormals that get rounded to normals

Browse Source 
I wrote these two tests because I wanted to test if the behavior I
implemented in https://github.com/dolphin-emu/dolphin/pull/10959 should
affect the results of arithmetic operations in addition to frsp. It
turned out that Dolphin was already correctly emulating these two tests
(I frankly don't understand how in the float case), but I figured I
would submit the tests regardless. If nothing else, it's good for
documenting what the real hardware is doing.
This commit is contained in:
JosJuice
2022-08-06 19:00:19 +02:00
parent ca5f8a9b1a
commit 60b9e0c2dc
1 changed files with 22 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

22
cputest/ni.cpp
View File

@@ -12,6 +12,12 @@ static const double product = Common::BitCast<double>(0x3ccfffffffffffffULL);
static const double smallest_normal = Common::BitCast<double>(0x0010000000000000ULL);
static const double divisor = Common::BitCast<double>(0x4330000000000000ULL);
static const double one_minus_ulp = Common::BitCast<double>(0x3fefffffffffffffULL);
static const float zero_single = Common::BitCast<float>(0);
static const float smallest_normal_single = Common::BitCast<float>(0x00800000);
static const float one_minus_ulp_single = Common::BitCast<float>(0x3f7fffff);
// Test of the Non-IEEE bit in FPSCR
static void NiTest()
{
@@ -49,6 +55,22 @@ static void NiTest()
" got 0x{:016x}\n"
"expected 0x{:016x}",
ni, div_result, div_expected);
const u64 mul2_expected = Common::BitCast<u64>(outputs_expected_flushed ? zero : smallest_normal);
const u64 mul2_result = Common::BitCast<u64>(smallest_normal * one_minus_ulp);
DO_TEST(mul2_result == mul2_expected,
"Multiply smallest normal by 1 minus ULP (NI={}):\n"
" got 0x{:016x}\n"
"expected 0x{:016x}",
ni, mul2_result, mul2_expected);
const u32 mul3_expected = Common::BitCast<u32>(outputs_expected_flushed ? zero_single : smallest_normal_single);
const u32 mul3_result = Common::BitCast<u32>(smallest_normal_single * one_minus_ulp_single);
DO_TEST(mul3_result == mul3_expected,
"Multiply smallest normal single by 1 minus ULP (NI={}):\n"
" got 0x{:08x}\n"
"expected 0x{:08x}",
ni, mul3_result, mul3_expected);
}
END_TEST();