Apple-2-SW/prog8
1
0
Fork 0
mirror of https://github.com/irmen/prog8.git synced 2025-01-10 20:30:23 +00:00
Code Issues Projects Releases Wiki Activity

IR: Improve codegen for for loops downto 0/1

Browse Source
This commit is contained in:
Irmen de Jong 2024-09-12 22:58:52 +02:00
parent 5986dcdd2f
commit ac0c8a68f6
2 changed files with 86 additions and 44 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

127
codeGenIntermediate/src/prog8/codegen/intermediate/IRCodeGen.kt
View File

@ -487,49 +487,76 @@ class IRCodeGen(
val loopLabel = createLabelName()
val result = mutableListOf<IRCodeChunkBase>()
val toTr = expressionEval.translateExpression(iterable.to)
addToResult(result, toTr, toTr.resultReg, -1)
val fromTr = expressionEval.translateExpression(iterable.from)
addToResult(result, fromTr, fromTr.resultReg, -1)
val labelAfterFor = createLabelName()
val precheckInstruction = if(loopvarDt in SignedDatatypes) {
if(step>0)
IRInstruction(Opcode.BGTSR, loopvarDtIr, fromTr.resultReg, toTr.resultReg, labelSymbol=labelAfterFor)
else
IRInstruction(Opcode.BGTSR, loopvarDtIr, toTr.resultReg, fromTr.resultReg, labelSymbol=labelAfterFor)
} else {
if(step>0)
IRInstruction(Opcode.BGTR, loopvarDtIr, fromTr.resultReg, toTr.resultReg, labelSymbol=labelAfterFor)
else
IRInstruction(Opcode.BGTR, loopvarDtIr, toTr.resultReg, fromTr.resultReg, labelSymbol=labelAfterFor)
}
addInstr(result, precheckInstruction, null)
addInstr(result, IRInstruction(Opcode.STOREM, loopvarDtIr, reg1=fromTr.resultReg, labelSymbol=loopvarSymbol), null)
result += labelFirstChunk(translateNode(forLoop.statements), loopLabel)
if(step==1 || step==-1) {
// if endvalue == loopvar, stop loop, else iterate
if(loopvarDtIr==IRDataType.BYTE && step==-1 && iterable.to.asConstInteger()==0) {
// downto 0 optimization (byte)
val fromTr = expressionEval.translateExpression(iterable.from)
addToResult(result, fromTr, fromTr.resultReg, -1)
addInstr(result, IRInstruction(Opcode.STOREM, loopvarDtIr, reg1=fromTr.resultReg, labelSymbol=loopvarSymbol), null)
result += labelFirstChunk(translateNode(forLoop.statements), loopLabel)
result += addConstMem(loopvarDtIr, null, loopvarSymbol, -1)
result += IRCodeChunk(null, null).also {
it += IRInstruction(Opcode.LOADM, loopvarDtIr, reg1 = fromTr.resultReg, labelSymbol = loopvarSymbol)
it += IRInstruction(Opcode.CMP, loopvarDtIr, reg1=toTr.resultReg, reg2=fromTr.resultReg)
it += IRInstruction(Opcode.BSTEQ, labelSymbol = labelAfterFor)
it += IRInstruction(Opcode.CMPI, loopvarDtIr, reg1 = fromTr.resultReg, immediate = 255)
it += IRInstruction(Opcode.BSTNE, labelSymbol = loopLabel)
}
result += addConstMem(loopvarDtIr, null, loopvarSymbol, step)
addInstr(result, IRInstruction(Opcode.JUMP, labelSymbol = loopLabel), null)
} else {
// ind/dec index, then:
// ascending: if endvalue >= loopvar, iterate
// descending: if loopvar >= endvalue, iterate
result += addConstMem(loopvarDtIr, null, loopvarSymbol, step)
addInstr(result, IRInstruction(Opcode.LOADM, loopvarDtIr, reg1=fromTr.resultReg, labelSymbol = loopvarSymbol), null)
if(step > 0)
addInstr(result, IRInstruction(Opcode.CMP, loopvarDtIr, reg1 = toTr.resultReg, fromTr.resultReg), null)
else
addInstr(result, IRInstruction(Opcode.CMP, loopvarDtIr, reg1 = fromTr.resultReg, toTr.resultReg), null)
addInstr(result, IRInstruction(Opcode.BSTPOS, labelSymbol = loopLabel), null)
}
result += IRCodeChunk(labelAfterFor, null)
else if(step==-1 && iterable.to.asConstInteger()==1) {
// downto 1 optimization (byte and word)
val fromTr = expressionEval.translateExpression(iterable.from)
addToResult(result, fromTr, fromTr.resultReg, -1)
addInstr(result, IRInstruction(Opcode.STOREM, loopvarDtIr, reg1=fromTr.resultReg, labelSymbol=loopvarSymbol), null)
result += labelFirstChunk(translateNode(forLoop.statements), loopLabel)
result += addConstMem(loopvarDtIr, null, loopvarSymbol, -1)
result += IRCodeChunk(null, null).also {
it += IRInstruction(Opcode.LOADM, loopvarDtIr, reg1 = fromTr.resultReg, labelSymbol = loopvarSymbol)
it += IRInstruction(Opcode.BSTNE, labelSymbol = loopLabel)
}
}
else {
val toTr = expressionEval.translateExpression(iterable.to)
addToResult(result, toTr, toTr.resultReg, -1)
val fromTr = expressionEval.translateExpression(iterable.from)
addToResult(result, fromTr, fromTr.resultReg, -1)
val labelAfterFor = createLabelName()
val precheckInstruction = if(loopvarDt in SignedDatatypes) {
if(step>0)
IRInstruction(Opcode.BGTSR, loopvarDtIr, fromTr.resultReg, toTr.resultReg, labelSymbol=labelAfterFor)
else
IRInstruction(Opcode.BGTSR, loopvarDtIr, toTr.resultReg, fromTr.resultReg, labelSymbol=labelAfterFor)
} else {
if(step>0)
IRInstruction(Opcode.BGTR, loopvarDtIr, fromTr.resultReg, toTr.resultReg, labelSymbol=labelAfterFor)
else
IRInstruction(Opcode.BGTR, loopvarDtIr, toTr.resultReg, fromTr.resultReg, labelSymbol=labelAfterFor)
}
addInstr(result, precheckInstruction, null)
addInstr(result, IRInstruction(Opcode.STOREM, loopvarDtIr, reg1=fromTr.resultReg, labelSymbol=loopvarSymbol), null)
result += labelFirstChunk(translateNode(forLoop.statements), loopLabel)
if(step==1 || step==-1) {
// if endvalue == loopvar, stop loop, else iterate
result += IRCodeChunk(null, null).also {
it += IRInstruction(Opcode.LOADM, loopvarDtIr, reg1 = fromTr.resultReg, labelSymbol = loopvarSymbol)
it += IRInstruction(Opcode.CMP, loopvarDtIr, reg1=toTr.resultReg, reg2=fromTr.resultReg)
it += IRInstruction(Opcode.BSTEQ, labelSymbol = labelAfterFor)
}
result += addConstMem(loopvarDtIr, null, loopvarSymbol, step)
addInstr(result, IRInstruction(Opcode.JUMP, labelSymbol = loopLabel), null)
} else {
// ind/dec index, then:
// ascending: if endvalue >= loopvar, iterate
// descending: if loopvar >= endvalue, iterate
result += addConstMem(loopvarDtIr, null, loopvarSymbol, step)
addInstr(result, IRInstruction(Opcode.LOADM, loopvarDtIr, reg1=fromTr.resultReg, labelSymbol = loopvarSymbol), null)
if(step > 0)
addInstr(result, IRInstruction(Opcode.CMP, loopvarDtIr, reg1 = toTr.resultReg, fromTr.resultReg), null)
else
addInstr(result, IRInstruction(Opcode.CMP, loopvarDtIr, reg1 = fromTr.resultReg, toTr.resultReg), null)
addInstr(result, IRInstruction(Opcode.BSTPOS, labelSymbol = loopLabel), null)
}
result += IRCodeChunk(labelAfterFor, null)
}
return result
}
@ -558,9 +585,25 @@ class IRCodeGen(
result += chunk
result += labelFirstChunk(translateNode(forLoop.statements), loopLabel)
val chunk2 = addConstMem(loopvarDtIr, null, loopvarSymbol, iterable.step)
chunk2 += IRInstruction(Opcode.LOADM, loopvarDtIr, reg1 = indexReg, labelSymbol = loopvarSymbol)
chunk2 += IRInstruction(Opcode.CMPI, loopvarDtIr, reg1 = indexReg, immediate = rangeEndExclusiveWrapped)
chunk2 += IRInstruction(Opcode.BSTNE, labelSymbol = loopLabel)
if(loopvarDtIr==IRDataType.BYTE && iterable.step==-1 && iterable.last==0) {
// downto 0 optimization (byte)
if(loopvarDt==DataType.BYTE || iterable.first<=127) {
chunk2 += IRInstruction(Opcode.BSTPOS, labelSymbol = loopLabel)
} else {
chunk2 += IRInstruction(Opcode.LOADM, loopvarDtIr, reg1 = indexReg, labelSymbol = loopvarSymbol)
chunk2 += IRInstruction(Opcode.CMPI, loopvarDtIr, reg1 = indexReg, immediate = rangeEndExclusiveWrapped)
chunk2 += IRInstruction(Opcode.BSTNE, labelSymbol = loopLabel)
}
}
else if(iterable.step==-1 && iterable.last==1) {
// downto 1 optimization (byte and word)
chunk2 += IRInstruction(Opcode.BSTNE, labelSymbol = loopLabel)
} else {
// downto some other value
chunk2 += IRInstruction(Opcode.LOADM, loopvarDtIr, reg1 = indexReg, labelSymbol = loopvarSymbol)
chunk2 += IRInstruction(Opcode.CMPI, loopvarDtIr, reg1 = indexReg, immediate = rangeEndExclusiveWrapped)
chunk2 += IRInstruction(Opcode.BSTNE, labelSymbol = loopLabel)
}
result += chunk2
return result
}

3
docs/source/todo.rst
View File

@ -1,9 +1,8 @@
TODO
====
IR: Improve codegen for for loops downto 0. (BPL if <=127 etc like 6502 codegen?)
callgraph issue? : if a sub contains another sub and it calls that, the outer sub is never removed even if it doesn't get called?
callgraph issue? : there's an odd case that keeps unused subroutines marked as used , they don't get removed. Has to do with declaring string var. ::
%import conv