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Jit64: Clean up the test_bit variable 

Using shifts and bit tests makes the code unnecessarily annoying to
reason about. I'm replacing it with subtracting from 3 to translate the
bit order from the PowerPC format to the usual format.
This commit is contained in:
JosJuice 2024-05-26 09:04:25 +02:00
parent 8167a046ef
commit e88e641bc0
1 changed files with 25 additions and 18 deletions
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43
Source/Core/Core/PowerPC/Jit64/Jit_Integer.cpp
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@ -16,6 +16,7 @@
#include "Common/x64Emitter.h"
#include "Core/CoreTiming.h"
#include "Core/PowerPC/ConditionRegister.h"
#include "Core/PowerPC/Interpreter/ExceptionUtils.h"
#include "Core/PowerPC/Interpreter/Interpreter.h"
#include "Core/PowerPC/Jit64/RegCache/JitRegCache.h"
@ -453,32 +454,31 @@ void Jit64::DoMergedBranchCondition()
js.downcountAmount++;
js.skipInstructions = 1;
const UGeckoInstruction& next = js.op[1].inst;
int test_bit = 8 >> (next.BI & 3);
int test_bit = 3 - (next.BI & 3);
bool condition = !!(next.BO & BO_BRANCH_IF_TRUE);
const u32 nextPC = js.op[1].address;
ASSERT(gpr.IsAllUnlocked());
FixupBranch pDontBranch;
if (test_bit & 8)
switch (test_bit)
{
case PowerPC::CR_LT_BIT:
// Test < 0, so jump over if >= 0.
pDontBranch = J_CC(condition ? CC_GE : CC_L, Jump::Near);
}
else if (test_bit & 4)
{
break;
case PowerPC::CR_GT_BIT:
// Test > 0, so jump over if <= 0.
pDontBranch = J_CC(condition ? CC_LE : CC_G, Jump::Near);
}
else if (test_bit & 2)
{
break;
case PowerPC::CR_EQ_BIT:
// Test = 0, so jump over if != 0.
pDontBranch = J_CC(condition ? CC_NE : CC_E, Jump::Near);
}
else
{
break;
case PowerPC::CR_SO_BIT:
// SO bit, do not branch (we don't emulate SO for cmp).
pDontBranch = J(Jump::Near);
break;
}
{
@ -516,21 +516,28 @@ void Jit64::DoMergedBranchImmediate(s64 val)
js.downcountAmount++;
js.skipInstructions = 1;
const UGeckoInstruction& next = js.op[1].inst;
int test_bit = 8 >> (next.BI & 3);
int test_bit = 3 - (next.BI & 3);
bool condition = !!(next.BO & BO_BRANCH_IF_TRUE);
const u32 nextPC = js.op[1].address;
ASSERT(gpr.IsAllUnlocked());
bool branch;
if (test_bit & 8)
bool branch = false;
switch (test_bit)
{
case PowerPC::CR_LT_BIT:
branch = condition ? val < 0 : val >= 0;
else if (test_bit & 4)
break;
case PowerPC::CR_GT_BIT:
branch = condition ? val > 0 : val <= 0;
else if (test_bit & 2)
break;
case PowerPC::CR_EQ_BIT:
branch = condition ? val == 0 : val != 0;
else // SO bit, do not branch (we don't emulate SO for cmp).
branch = false;
break;
case PowerPC::CR_SO_BIT:
// SO bit, do not branch (we don't emulate SO for cmp).
break;
}
if (branch)
{