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Improve and fix 16-bit comparisons

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This commit is contained in:
Karol Stasiak 2019-10-22 13:54:30 +02:00
parent 76044ca429
commit ec96f16482
5 changed files with 107 additions and 13 deletions
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2
CHANGELOG.md
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@ -22,6 +22,8 @@
* Fixed a bug with variable overlapping (#11).
* 8080: Fixed and optimized 16-bit comparisons.
* 8080: Optimized some library functions.
* Optimized certain byte comparisons.

3
docs/lang/operators.md
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@ -161,7 +161,8 @@ Note you cannot mix those operators, so `a <= b < c` is not valid.
* `>`, `<`, `<=`, `>=`: inequality
`byte > byte`
`simple word > simple word`
`simple word > word`
`word > simple word`
`simple long > simple long`
Currently, `>`, `<`, `<=`, `>=` operators perform signed comparison

44
src/main/scala/millfork/compiler/mos/BuiltIns.scala
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@ -724,7 +724,7 @@ object BuiltIns {
val rc = MosExpressionCompiler.compileToAX(ctx, rhs)
(lc, rc, effectiveComparisonType) match {
case (
List(lcl@AssemblyLine0(LDA, Absolute | Immediate | ZeroPage | LongAbsolute, _), lch@AssemblyLine0(LDX, Absolute | Immediate | ZeroPage, _)),
List(lcl@AssemblyLine0(LDA, Absolute | Immediate | ZeroPage | LongAbsolute, _), lch@AssemblyLine0(LDX, Absolute | Immediate | ZeroPage | LongAbsolute, _)),
_,
ComparisonType.NotEqual
) =>
@ -735,7 +735,7 @@ object BuiltIns {
AssemblyLine.relative(BNE, Label(x)))
case (
_,
List(rcl@AssemblyLine0(LDA, Absolute | Immediate | ZeroPage | LongAbsolute, _), rch@AssemblyLine0(LDX, Absolute | Immediate | ZeroPage, _)),
List(rcl@AssemblyLine0(LDA, Absolute | Immediate | ZeroPage | LongAbsolute, _), rch@AssemblyLine0(LDX, Absolute | Immediate | ZeroPage | LongAbsolute, _)),
ComparisonType.NotEqual
) =>
return lc ++ List(
@ -744,7 +744,7 @@ object BuiltIns {
rch.copy(opcode = CPX),
AssemblyLine.relative(BNE, Label(x)))
case (
List(lcl@AssemblyLine0(LDA, Absolute | Immediate | ZeroPage | LongAbsolute, _), lch@AssemblyLine0(LDX, Absolute | Immediate | ZeroPage, _)),
List(lcl@AssemblyLine0(LDA, Absolute | Immediate | ZeroPage | LongAbsolute, _), lch@AssemblyLine0(LDX, Absolute | Immediate | ZeroPage | LongAbsolute, _)),
_,
ComparisonType.Equal
) =>
@ -757,7 +757,7 @@ object BuiltIns {
AssemblyLine.label(skip))
case (
_,
List(rcl@AssemblyLine0(LDA, Absolute | Immediate | ZeroPage | LongAbsolute, _), rch@AssemblyLine0(LDX, Absolute | Immediate | ZeroPage, _)),
List(rcl@AssemblyLine0(LDA, Absolute | Immediate | ZeroPage | LongAbsolute, _), rch@AssemblyLine0(LDX, Absolute | Immediate | ZeroPage | LongAbsolute, _)),
ComparisonType.Equal
) =>
val skip = ctx.nextLabel("cp")
@ -767,6 +767,42 @@ object BuiltIns {
rch.copy(opcode = CPX),
AssemblyLine.relative(BEQ, Label(x)),
AssemblyLine.label(skip))
case (
List(lcl@AssemblyLine0(LDA, Absolute | Immediate | ZeroPage | LongAbsolute, _), lch@AssemblyLine0(LDX, Absolute | Immediate | ZeroPage | LongAbsolute, _)),
List(rcl@AssemblyLine0(LDA, Absolute | Immediate | ZeroPage | LongAbsolute, _), rch@AssemblyLine0(LDX, Absolute | Immediate | ZeroPage | LongAbsolute, _)),
_
) =>
(Nil,
List(lch.copy(opcode = CMP)),
List(lcl.copy(opcode = CMP)),
List(rch.copy(opcode = CMP)),
List(rcl.copy(opcode = CMP)))
case (
_,
List(AssemblyLine0(LDA, Absolute | Immediate | ZeroPage | LongAbsolute, _), AssemblyLine0(LDX, Absolute | Immediate | ZeroPage | LongAbsolute, _)),
_
) =>
if (ctx.options.zpRegisterSize < 2) {
ctx.log.error("Too complex expressions in comparison", lhs.position.orElse(rhs.position))
(Nil, Nil, Nil, Nil, Nil)
} else {
val reg = ctx.env.get[ThingInMemory]("__reg.loword")
return lc ++ List(AssemblyLine.zeropage(STA, reg), AssemblyLine.zeropage(STX, reg, 1)) ++ compileWordComparison(
ctx, effectiveComparisonType, VariableExpression("__reg.loword").pos(lhs.position), rhs, BranchIfTrue(x))
}
case (
List(AssemblyLine0(LDA, Absolute | Immediate | ZeroPage | LongAbsolute, _), AssemblyLine0(LDX, Absolute | Immediate | ZeroPage | LongAbsolute, _)),
_,
_
) =>
if (ctx.options.zpRegisterSize < 2) {
ctx.log.error("Too complex expressions in comparison", lhs.position.orElse(rhs.position))
(Nil, Nil, Nil, Nil, Nil)
} else {
val reg = ctx.env.get[ThingInMemory]("__reg.loword")
return rc ++ List(AssemblyLine.zeropage(STA, reg), AssemblyLine.zeropage(STX, reg, 1)) ++ compileWordComparison(
ctx, effectiveComparisonType, lhs, VariableExpression("__reg.loword").pos(rhs.position), BranchIfTrue(x))
}
case _ =>
// TODO comparing expressions
ctx.log.error("Too complex expressions in comparison", lhs.position.orElse(rhs.position))

23
src/main/scala/millfork/compiler/z80/Z80Comparisons.scala
View File

@ -192,14 +192,21 @@ object Z80Comparisons {
case _ =>
}
val (calculated, useBC) = if (calculateLeft.exists(Z80ExpressionCompiler.changesBC)) {
if (calculateLeft.exists(Z80ExpressionCompiler.changesDE)) {
calculateRight ++ List(ZLine.register(ZOpcode.PUSH, ZRegister.HL)) ++ Z80ExpressionCompiler.fixTsx(ctx, calculateLeft) ++ List(ZLine.register(ZOpcode.POP, ZRegister.BC)) -> false
} else {
calculateRight ++ List(ZLine.ld8(ZRegister.D, ZRegister.H), ZLine.ld8(ZRegister.E, ZRegister.L)) ++ calculateLeft -> false
}
} else {
calculateRight ++ List(ZLine.ld8(ZRegister.B, ZRegister.H), ZLine.ld8(ZRegister.C, ZRegister.L)) ++ calculateLeft -> true
val (calculated, useBC) = calculateRight match {
case List(ZLine0(LD_16, TwoRegisters(ZRegister.HL, ZRegister.IMM_16), c)) =>
(calculateLeft :+ ZLine.ldImm16(ZRegister.BC, c)) -> true
case List(ZLine0(LD_16, TwoRegisters(ZRegister.HL, ZRegister.MEM_ABS_16), c)) if ctx.options.flag(CompilationFlag.EmitZ80Opcodes) =>
(calculateLeft :+ ZLine.ldAbs16(ZRegister.BC, c)) -> true
case _ =>
if (calculateLeft.exists(Z80ExpressionCompiler.changesBC)) {
if (calculateLeft.exists(Z80ExpressionCompiler.changesDE)) {
calculateRight ++ List(ZLine.register(ZOpcode.PUSH, ZRegister.HL)) ++ Z80ExpressionCompiler.fixTsx(ctx, calculateLeft) ++ List(ZLine.register(ZOpcode.POP, ZRegister.BC)) -> true
} else {
calculateRight ++ List(ZLine.ld8(ZRegister.D, ZRegister.H), ZLine.ld8(ZRegister.E, ZRegister.L)) ++ calculateLeft -> false
}
} else {
calculateRight ++ List(ZLine.ld8(ZRegister.B, ZRegister.H), ZLine.ld8(ZRegister.C, ZRegister.L)) ++ calculateLeft -> true
}
}
val (effectiveCompType, label) = branches match {
case BranchIfFalse(la) => ComparisonType.negate(compType) -> la

48
src/test/scala/millfork/test/ComparisonSuite.scala
View File

@ -581,4 +581,52 @@ class ComparisonSuite extends FunSuite with Matchers {
}
}
test("Complex word comparisons") {
val code =
"""
| byte output @$c000
| struct st { word x }
| st obj
| noinline word f() = 400
| void main() {
| pointer.st p
| p = obj.pointer
| p->x = 400
| output = 0
|
| if p->x == 400 { output += 1 } // ↑
| if p->x != 400 { output -= 1 }
| if p->x >= 400 { output += 1 } // ↑
| if p->x <= 400 { output += 1 } // ↑
| if p->x > 400 { output -= 1 }
| if p->x < 400 { output -= 1 }
|
| if 400 == p->x { output += 1 } // ↑
| if 400 != p->x { output -= 1 }
| if 400 <= p->x { output += 1 } // ↑
| if 400 >= p->x { output += 1 } // ↑
| if 400 < p->x { output -= 1 }
| if 400 > p->x { output -= 1 }
|
| if f() == 400 { output += 1 } // ↑
| if f() != 400 { output -= 1 }
| if f() >= 400 { output += 1 } // ↑
| if f() <= 400 { output += 1 } // ↑
| if f() > 400 { output -= 1 }
| if f() < 400 { output -= 1 }
|
| if 400 == f() { output += 1 } // ↑
| if 400 != f() { output -= 1 }
| if 400 <= f() { output += 1 } // ↑
| if 400 >= f() { output += 1 } // ↑
| if 400 < f() { output -= 1 }
| if 400 > f() { output -= 1 }
|
| }
|""".stripMargin
EmuUnoptimizedCrossPlatformRun(Cpu.Mos, Cpu.Z80)(code) { m =>
m.readByte(0xc000) should equal(code.count(_ == '↑'))
}
}
}