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Merge pull request #12249 from Sintendo/frsqrte-nit

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PowerPC: Negate m_dec values in frsqrte table
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Tilka 2023-10-28 02:15:05 +01:00 committed by GitHub
commit 9bea807732
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3 changed files with 14 additions and 15 deletions
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18
Source/Core/Common/FloatUtils.cpp
View file

@ -74,14 +74,14 @@ u32 ClassifyFloat(float fvalue)
}
const std::array<BaseAndDec, 32> frsqrte_expected = {{
{0x1a7e800, 0x568}, {0x17cb800, 0x4f3}, {0x1552800, 0x48d}, {0x130c000, 0x435},
{0x10f2000, 0x3e7}, {0x0eff000, 0x3a2}, {0x0d2e000, 0x365}, {0x0b7c000, 0x32e},
{0x09e5000, 0x2fc}, {0x0867000, 0x2d0}, {0x06ff000, 0x2a8}, {0x05ab800, 0x283},
{0x046a000, 0x261}, {0x0339800, 0x243}, {0x0218800, 0x226}, {0x0105800, 0x20b},
{0x3ffa000, 0x7a4}, {0x3c29000, 0x700}, {0x38aa000, 0x670}, {0x3572000, 0x5f2},
{0x3279000, 0x584}, {0x2fb7000, 0x524}, {0x2d26000, 0x4cc}, {0x2ac0000, 0x47e},
{0x2881000, 0x43a}, {0x2665000, 0x3fa}, {0x2468000, 0x3c2}, {0x2287000, 0x38e},
{0x20c1000, 0x35e}, {0x1f12000, 0x332}, {0x1d79000, 0x30a}, {0x1bf4000, 0x2e6},
{0x1a7e800, -0x568}, {0x17cb800, -0x4f3}, {0x1552800, -0x48d}, {0x130c000, -0x435},
{0x10f2000, -0x3e7}, {0x0eff000, -0x3a2}, {0x0d2e000, -0x365}, {0x0b7c000, -0x32e},
{0x09e5000, -0x2fc}, {0x0867000, -0x2d0}, {0x06ff000, -0x2a8}, {0x05ab800, -0x283},
{0x046a000, -0x261}, {0x0339800, -0x243}, {0x0218800, -0x226}, {0x0105800, -0x20b},
{0x3ffa000, -0x7a4}, {0x3c29000, -0x700}, {0x38aa000, -0x670}, {0x3572000, -0x5f2},
{0x3279000, -0x584}, {0x2fb7000, -0x524}, {0x2d26000, -0x4cc}, {0x2ac0000, -0x47e},
{0x2881000, -0x43a}, {0x2665000, -0x3fa}, {0x2468000, -0x3c2}, {0x2287000, -0x38e},
{0x20c1000, -0x35e}, {0x1f12000, -0x332}, {0x1d79000, -0x30a}, {0x1bf4000, -0x2e6},
}};
double ApproximateReciprocalSquareRoot(double val)
@ -134,7 +134,7 @@ double ApproximateReciprocalSquareRoot(double val)
const int i = static_cast<int>((exponent_lsb | mantissa) >> 37);
const auto& entry = frsqrte_expected[i / 2048];
integral |= static_cast<s64>(entry.m_base - entry.m_dec * (i % 2048)) << 26;
integral |= static_cast<s64>(entry.m_base + entry.m_dec * (i % 2048)) << 26;
return BitCast<double>(integral);
}

9
Source/Core/Core/PowerPC/Jit64Common/Jit64AsmCommon.cpp
View file

@ -150,14 +150,13 @@ void CommonAsmRoutines::GenFrsqrte()
AND(32, R(RSCRATCH), Imm32(0x7FF));
IMUL(32, RSCRATCH,
MComplex(RSCRATCH2, RSCRATCH_EXTRA, SCALE_8, offsetof(Common::BaseAndDec, m_dec)));
MOV(32, R(RSCRATCH_EXTRA),
ADD(32, R(RSCRATCH),
MComplex(RSCRATCH2, RSCRATCH_EXTRA, SCALE_8, offsetof(Common::BaseAndDec, m_base)));
SUB(32, R(RSCRATCH_EXTRA), R(RSCRATCH));
SHL(64, R(RSCRATCH_EXTRA), Imm8(26));
SHL(64, R(RSCRATCH), Imm8(26));
POP(RSCRATCH2);
OR(64, R(RSCRATCH2), R(RSCRATCH_EXTRA)); // vali |= (s64)(frsqrte_expected_base[index] -
// frsqrte_expected_dec[index] * (i % 2048)) << 26;
OR(64, R(RSCRATCH2), R(RSCRATCH)); // vali |= (s64)(frsqrte_expected_base[index] +
// frsqrte_expected_dec[index] * (i % 2048)) << 26;
MOVQ_xmm(XMM0, R(RSCRATCH2));
RET();

2
Source/Core/Core/PowerPC/JitArm64/JitAsm.cpp
View file

@ -347,7 +347,7 @@ void JitArm64::GenerateFrsqrte()
LDP(IndexType::Signed, ARM64Reg::W1, ARM64Reg::W2, ARM64Reg::X2, 0);
UBFX(ARM64Reg::X3, ARM64Reg::X3, 37, 11);
AND(ARM64Reg::X0, ARM64Reg::X0, LogicalImm(Common::DOUBLE_SIGN | Common::DOUBLE_EXP, 64));
MSUB(ARM64Reg::W3, ARM64Reg::W3, ARM64Reg::W2, ARM64Reg::W1);
MADD(ARM64Reg::W3, ARM64Reg::W3, ARM64Reg::W2, ARM64Reg::W1);
ORR(ARM64Reg::X0, ARM64Reg::X0, ARM64Reg::X3, ArithOption(ARM64Reg::X3, ShiftType::LSL, 26));
RET();