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u128: StickyLogicalShiftRight requires special-casing for amount == 64

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In this case (128 - amount) == 64, and this invokes undefined behaviour
This commit is contained in:
MerryMage 2018-07-23 20:21:33 +01:00
parent 49c7edf7c6
commit 76b07d6646
2 changed files with 29 additions and 0 deletions
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10
src/common/u128.cpp
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@ -112,6 +112,16 @@ u128 StickyLogicalShiftRight(u128 operand, int amount) {
return result;
}
if (amount == 64) {
u128 result;
result.lower = operand.upper;
// Sticky bit
if (operand.lower != 0) {
result.lower |= 1;
}
return result;
}
if (amount < 128) {
u128 result;
result.lower = operand.upper >> (amount - 64);

19
tests/A64/a64.cpp
View file

@ -371,3 +371,22 @@ TEST_CASE("A64: FNMSUB 2", "[a64]") {
REQUIRE(jit.GetVector(14) == Vector{0x0000000080045284, 0x0000000000000000});
}
TEST_CASE("A64: FMADD", "[a64]") {
TestEnv env;
Dynarmic::A64::Jit jit{Dynarmic::A64::UserConfig{&env}};
env.code_mem[0] = 0x1f5e0e4a; // FMADD D10, D18, D30, D3
env.code_mem[1] = 0x14000000; // B .
jit.SetPC(0);
jit.SetVector(18, {0x8000007600800000, 0x7ff812347f800000});
jit.SetVector(30, {0xff984a3700000000, 0xe73a513480800000});
jit.SetVector(3, {0x3f000000ff7fffff, 0x8139843780000000});
jit.SetFpcr(0x00400000);
env.ticks_left = 2;
jit.Run();
REQUIRE(jit.GetVector(10) == Vector{0x3f059921bf0dbfff, 0x0000000000000000});
}