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8080: Fix byte division and simplify byte multiplication

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This commit is contained in:
Karol Stasiak 2019-08-03 20:32:15 +02:00
parent 9d78385cba
commit 48220f739d
3 changed files with 37 additions and 3 deletions
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8
src/main/scala/millfork/compiler/z80/Z80Multiply.scala
View File

@ -47,7 +47,11 @@ object Z80Multiply {
false
}
}
val productOfConstants = CompoundConstant(MathOperator.Times, otherConst, NumericConstant(numericConst & 0xff, 1)).quickSimplify
val productOfConstants = numericConst match {
case 0 => Constant.Zero
case 1 => otherConst
case _ => CompoundConstant(MathOperator.Times, otherConst, NumericConstant(numericConst & 0xff, 1)).quickSimplify
}
(filteredParams, otherConst) match {
case (Nil, NumericConstant(n, _)) => List(ZLine.ldImm8(ZRegister.A, (numericConst * n).toInt))
case (Nil, _) => List(ZLine.ldImm8(ZRegister.A, productOfConstants))
@ -156,7 +160,7 @@ object Z80Multiply {
}
val qb = Z80ExpressionCompiler.compileToA(ctx, q)
val load = if (qb.exists(Z80ExpressionCompiler.changesHL)) {
pb ++ Z80ExpressionCompiler.stashHLIfChanged(ctx, qb)
pb ++ Z80ExpressionCompiler.stashHLIfChanged(ctx, qb) ++ List(ZLine.ld8(ZRegister.D, ZRegister.A))
} else if (pb.exists(Z80ExpressionCompiler.changesDE)) {
qb ++ List(ZLine.ld8(ZRegister.D, ZRegister.A)) ++ Z80ExpressionCompiler.stashDEIfChanged(ctx, pb)
} else {

10
src/main/scala/millfork/env/Constant.scala vendored
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@ -434,6 +434,16 @@ case class CompoundConstant(operator: MathOperator.Value, lhs: Constant, rhs: Co
case MathOperator.And => Constant.Zero
case _ => CompoundConstant(operator, l, r)
}
case (c, NumericConstant(1, 1)) =>
operator match {
case MathOperator.Times => c
case _ => CompoundConstant(operator, l, r)
}
case (NumericConstant(1, 1), c) =>
operator match {
case MathOperator.Times => c
case _ => CompoundConstant(operator, l, r)
}
case (NumericConstant(lv, ls), NumericConstant(rv, rs)) =>
var size = ls max rs
val bitmask = (1L << (8*size)) - 1

22
src/test/scala/millfork/test/ByteMathSuite.scala
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@ -1,7 +1,7 @@
package millfork.test
import millfork.Cpu
import millfork.test.emu.{EmuBenchmarkRun, EmuCrossPlatformBenchmarkRun, EmuUltraBenchmarkRun}
import millfork.test.emu.{EmuBenchmarkRun, EmuCrossPlatformBenchmarkRun, EmuUltraBenchmarkRun, EmuUnoptimizedCrossPlatformRun}
import org.scalatest.{AppendedClues, FunSuite, Matchers}
/**
@ -422,4 +422,24 @@ class ByteMathSuite extends FunSuite with Matchers with AppendedClues {
m.readByte(0xc003) should equal(x % y) withClue s"= $x %% $y"
}
}
test("Division bug repro"){
EmuUnoptimizedCrossPlatformRun(Cpu.Mos, Cpu.Z80)(
s"""
| import zp_reg
| byte output_q1 @$$c000, output_m1 @$$c001
| array zeroes[256] = [for i,0,until,256 [0]]
| void main () {
| byte a
| byte b
| a = 186
| memory_barrier()
| a /= zeroes[b] | 2
| output_q1 = a
| }
""".
stripMargin) { m =>
m.readByte(0xc000) should equal(93)
}
}
}