Reverse shift with negated distance

This commit is contained in:
drmortalwombat 2024-11-21 22:02:25 +01:00
parent d3e7a991a4
commit e1736c8214

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@ -6358,6 +6358,20 @@ static bool ispow2(int64 v)
return 0; return 0;
} }
static int binlog(int64 n)
{
int k = -1;
while (n)
{
n >>= 1;
k++;
}
return k;
}
void InterCodeBasicBlock::CheckValueUsage(InterInstruction * ins, const GrowingInstructionPtrArray& tvalue, const GrowingVariableArray& staticVars, const GrowingInterCodeProcedurePtrArray& staticProcs, FastNumberSet& fsingle) void InterCodeBasicBlock::CheckValueUsage(InterInstruction * ins, const GrowingInstructionPtrArray& tvalue, const GrowingVariableArray& staticVars, const GrowingInterCodeProcedurePtrArray& staticProcs, FastNumberSet& fsingle)
{ {
switch (ins->mCode) switch (ins->mCode)
@ -20552,6 +20566,61 @@ bool InterCodeBasicBlock::PeepholeReplaceOptimization(const GrowingVariableArray
} }
} }
} }
#endif
#if 1
if (i + 1 < mInstructions.Size())
{
if (mInstructions[i + 0]->mCode == IC_BINARY_OPERATOR && mInstructions[i + 0]->mOperator == IA_SUB &&
mInstructions[i + 1]->mCode == IC_BINARY_OPERATOR && mInstructions[i + 1]->mOperator == IA_SHL &&
mInstructions[i + 1]->mSrc[0].mTemp == mInstructions[i + 0]->mDst.mTemp && mInstructions[i + 1]->mSrc[0].mFinal && mInstructions[i + 1]->mSrc[0].IsUByte() &&
mInstructions[i + 1]->mSrc[1].mTemp < 0 && ispow2(mInstructions[i + 1]->mSrc[1].mIntConst))
{
int64 k = binlog(mInstructions[i + 1]->mSrc[1].mIntConst);
if (mInstructions[i + 0]->mSrc[0].mTemp >= 0 && mInstructions[i + 0]->mSrc[1].mTemp < 0)
{
int64 s = mInstructions[i + 0]->mSrc[1].mIntConst;
mInstructions[i + 0]->mSrc[1] = mInstructions[i + 0]->mSrc[0];
mInstructions[i + 0]->mSrc[0].mTemp = -1;
mInstructions[i + 0]->mSrc[0].mIntConst = mInstructions[i + 0]->mSrc[1].mRange.mMinValue;
mInstructions[i + 0]->mDst.mRange.SetLimit(0, mInstructions[i + 0]->mSrc[1].mRange.mMaxValue - mInstructions[i + 0]->mSrc[0].mIntConst);
mInstructions[i + 1]->mOperator = IA_SHR;
mInstructions[i + 1]->mSrc[0] = mInstructions[i + 0]->mDst;
int64 d = s - mInstructions[i + 0]->mSrc[0].mIntConst;
if (d < 0)
mInstructions[i + 1]->mSrc[1].mIntConst >>= -d;
else
mInstructions[i + 1]->mSrc[1].mIntConst <<= d;
changed = true;
}
}
if (mInstructions[i + 0]->mCode == IC_BINARY_OPERATOR && mInstructions[i + 0]->mOperator == IA_SUB &&
mInstructions[i + 1]->mCode == IC_BINARY_OPERATOR && mInstructions[i + 1]->mOperator == IA_SHR &&
mInstructions[i + 1]->mSrc[0].mTemp == mInstructions[i + 0]->mDst.mTemp && mInstructions[i + 1]->mSrc[0].mFinal && mInstructions[i + 1]->mSrc[0].IsUByte() &&
mInstructions[i + 1]->mSrc[1].mTemp < 0 && ispow2(mInstructions[i + 1]->mSrc[1].mIntConst))
{
int64 k = binlog(mInstructions[i + 1]->mSrc[1].mIntConst);
if (mInstructions[i + 0]->mSrc[0].mTemp >= 0 && mInstructions[i + 0]->mSrc[1].mTemp < 0)
{
int64 s = mInstructions[i + 0]->mSrc[1].mIntConst;
mInstructions[i + 0]->mSrc[1] = mInstructions[i + 0]->mSrc[0];
mInstructions[i + 0]->mSrc[0].mTemp = -1;
mInstructions[i + 0]->mSrc[0].mIntConst = mInstructions[i + 0]->mSrc[1].mRange.mMinValue;
mInstructions[i + 0]->mDst.mRange.SetLimit(0, mInstructions[i + 0]->mSrc[1].mRange.mMaxValue - mInstructions[i + 0]->mSrc[0].mIntConst);
mInstructions[i + 1]->mOperator = IA_SHL;
mInstructions[i + 1]->mSrc[0] = mInstructions[i + 0]->mDst;
int64 d = s - mInstructions[i + 0]->mSrc[0].mIntConst;
if (d < 0)
mInstructions[i + 1]->mSrc[1].mIntConst <<= -d;
else
mInstructions[i + 1]->mSrc[1].mIntConst >>= d;
changed = true;
}
}
}
#endif #endif
} }
@ -22927,7 +22996,7 @@ void InterCodeProcedure::Close(void)
{ {
GrowingTypeArray tstack(IT_NONE); GrowingTypeArray tstack(IT_NONE);
CheckFunc = !strcmp(mIdent->mString, "main"); CheckFunc = !strcmp(mIdent->mString, "test");
CheckCase = false; CheckCase = false;
mEntryBlock = mBlocks[0]; mEntryBlock = mBlocks[0];