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Merged
sjrd merged 2 commits into from
Apr 6, 2025
Merged

Wasm: Implement fmod on the Scala side. #5149

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01ee94a
Wasm: Better codegen for Long shifts with constant right-hand-side.
sjrd Mar 26, 2025
b5e2700
Wasm: Implement fmod on the Scala side.
sjrd Mar 26, 2025
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455 changes: 455 additions & 0 deletions linker-private-library/src/main/scala/org/scalajs/linker/runtime/WasmRuntime.scala
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2 changes: 2 additions & 0 deletions linker/jvm/src/main/scala/org/scalajs/linker/backend/emitter/PrivateLibHolder.scala
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Original file line number Diff line number Diff line change
Expand Up @@ -27,6 +27,8 @@ object PrivateLibHolder {
"org/scalajs/linker/runtime/RuntimeLong.sjsir",
"org/scalajs/linker/runtime/RuntimeLong$.sjsir",
"org/scalajs/linker/runtime/UndefinedBehaviorError.sjsir",
"org/scalajs/linker/runtime/WasmRuntime.sjsir",
"org/scalajs/linker/runtime/WasmRuntime$.sjsir",
"scala/scalajs/js/JavaScriptException.sjsir"
)

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2 changes: 0 additions & 2 deletions linker/shared/src/main/scala/org/scalajs/linker/backend/wasmemitter/CoreWasmLib.scala
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Expand Up @@ -377,8 +377,6 @@ final class CoreWasmLib(coreSpec: CoreSpec, globalInfo: LinkedGlobalInfo) {
addHelperImport(genFunctionID.uIFallback, List(anyref), List(Int32))
addHelperImport(genFunctionID.typeTest(IntRef), List(anyref), List(Int32))

addHelperImport(genFunctionID.fmod, List(Float64, Float64), List(Float64))

addHelperImport(genFunctionID.jsValueToString, List(RefType.any), List(RefType.extern))
addHelperImport(genFunctionID.jsValueToStringForConcat, List(anyref), List(RefType.extern))
addHelperImport(genFunctionID.booleanToString, List(Int32), List(RefType.extern))
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6 changes: 5 additions & 1 deletion linker/shared/src/main/scala/org/scalajs/linker/backend/wasmemitter/Emitter.scala
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Expand Up @@ -446,7 +446,11 @@ object Emitter {

// See genIdentityHashCode in HelperFunctions
callMethodStatically(BoxedDoubleClass, hashCodeMethodName),
callMethodStatically(BoxedStringClass, hashCodeMethodName)
callMethodStatically(BoxedStringClass, hashCodeMethodName),

// Implementation of Float_% and Double_%
callStaticMethod(WasmRuntimeClass, fmodfMethodName),
callStaticMethod(WasmRuntimeClass, fmoddMethodName)
)
}

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45 changes: 17 additions & 28 deletions linker/shared/src/main/scala/org/scalajs/linker/backend/wasmemitter/FunctionEmitter.scala
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Expand Up @@ -1648,9 +1648,18 @@ private class FunctionEmitter private (

def genLongShiftOp(shiftInstr: wa.Instr): Type = {
genTree(lhs, LongType)
genTree(rhs, IntType)
markPosition(tree)
fb += wa.I64ExtendI32S
rhs match {
case IntLiteral(r) =>
// common case: fold the extension to 64 bits into the literal
markPosition(rhs)
fb += wa.I64Const(r.toLong)
markPosition(tree)
case _ =>
// otherwise, extend at run-time
genTree(rhs, IntType)
markPosition(tree)
fb += wa.I64ExtendI32S
}
fb += shiftInstr
LongType
}
Expand Down Expand Up @@ -1712,31 +1721,6 @@ private class FunctionEmitter private (
case Long_>> =>
genLongShiftOp(wa.I64ShrS)

/* Floating point remainders are specified by
* https://262.ecma-international.org/#sec-numeric-types-number-remainder
* which says that it is equivalent to the C library function `fmod`.
* For `Float`s, we promote and demote to `Double`s.
* `fmod` seems quite hard to correctly implement, so we delegate to a
* JavaScript Helper.
* (The naive function `x - trunc(x / y) * y` that we can find on the
* Web does not work.)
*/
case Float_% =>
genTree(lhs, FloatType)
fb += wa.F64PromoteF32
genTree(rhs, FloatType)
fb += wa.F64PromoteF32
markPosition(tree)
fb += wa.Call(genFunctionID.fmod)
fb += wa.F32DemoteF64
FloatType
case Double_% =>
genTree(lhs, DoubleType)
genTree(rhs, DoubleType)
markPosition(tree)
fb += wa.Call(genFunctionID.fmod)
DoubleType

case String_charAt =>
genTree(lhs, StringType)
genTree(rhs, IntType)
Expand Down Expand Up @@ -1875,6 +1859,9 @@ private class FunctionEmitter private (
private def getElementaryBinaryOpInstr(op: BinaryOp.Code): wa.Instr = {
import BinaryOp._

def fmodFunctionID(methodName: MethodName): wanme.FunctionID =
genFunctionID.forMethod(MemberNamespace.PublicStatic, SpecialNames.WasmRuntimeClass, methodName)

(op: @switch) match {
case Boolean_== => wa.I32Eq
case Boolean_!= => wa.I32Ne
Expand Down Expand Up @@ -1915,11 +1902,13 @@ private class FunctionEmitter private (
case Float_- => wa.F32Sub
case Float_* => wa.F32Mul
case Float_/ => wa.F32Div
case Float_% => wa.Call(fmodFunctionID(SpecialNames.fmodfMethodName))

case Double_+ => wa.F64Add
case Double_- => wa.F64Sub
case Double_* => wa.F64Mul
case Double_/ => wa.F64Div
case Double_% => wa.Call(fmodFunctionID(SpecialNames.fmoddMethodName))

case Double_== => wa.F64Eq
case Double_!= => wa.F64Ne
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3 changes: 0 additions & 3 deletions linker/shared/src/main/scala/org/scalajs/linker/backend/wasmemitter/LoaderContent.scala
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Expand Up @@ -100,9 +100,6 @@ const scalaJSHelpers = {
tF: (x) => typeof x === 'number' && (Math.fround(x) === x || x !== x),
tD: (x) => typeof x === 'number',

// fmod, to implement Float_% and Double_% (it is apparently quite hard to implement fmod otherwise)
fmod: (x, y) => x % y,

// Strings
emptyString: "",
jsValueToString: (x) => (x === void 0) ? "undefined" : x.toString(),
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6 changes: 6 additions & 0 deletions linker/shared/src/main/scala/org/scalajs/linker/backend/wasmemitter/SpecialNames.scala
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Expand Up @@ -37,6 +37,9 @@ object SpecialNames {
val UndefinedBehaviorErrorClass =
ClassName("org.scalajs.linker.runtime.UndefinedBehaviorError")

val WasmRuntimeClass =
ClassName("org.scalajs.linker.runtime.WasmRuntime")

// Field names

val valueFieldSimpleName = SimpleFieldName("value")
Expand All @@ -52,6 +55,9 @@ object SpecialNames {

val hashCodeMethodName = MethodName("hashCode", Nil, IntRef)

val fmodfMethodName = MethodName("fmodf", List(FloatRef, FloatRef), FloatRef)
val fmoddMethodName = MethodName("fmodd", List(DoubleRef, DoubleRef), DoubleRef)

/** A unique simple method name to map all method *signatures* into `MethodName`s. */
val normalizedSimpleMethodName = SimpleMethodName("m")
}
2 changes: 0 additions & 2 deletions linker/shared/src/main/scala/org/scalajs/linker/backend/wasmemitter/VarGen.scala
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Expand Up @@ -130,8 +130,6 @@ object VarGen {
case object bIFallback extends JSHelperFunctionID
case object uIFallback extends JSHelperFunctionID

case object fmod extends JSHelperFunctionID

case object jsValueToString extends JSHelperFunctionID // for actual toString() call
case object jsValueToStringForConcat extends JSHelperFunctionID
case object booleanToString extends JSHelperFunctionID
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39 changes: 38 additions & 1 deletion test-suite/shared/src/test/scala/org/scalajs/testsuite/compiler/DoubleTest.scala
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Expand Up @@ -221,6 +221,8 @@ class DoubleTest {
test(Double.NaN, Double.NaN, 2.1)
test(Double.NaN, Double.NaN, 5.5)
test(Double.NaN, Double.NaN, -151.189)
test(Double.NaN, Double.NaN, 3.123e-320)
test(Double.NaN, Double.NaN, 2.253547e-318)
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@gzm0 gzm0 Apr 6, 2025

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Could you add an explanation to the commit message what these additional values are?

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@sjrd sjrd Apr 6, 2025

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Done. They're subnormals.


// If d is NaN, return NaN
test(Double.NaN, Double.NaN, Double.NaN)
Expand All @@ -231,6 +233,8 @@ class DoubleTest {
test(Double.NaN, 2.1, Double.NaN)
test(Double.NaN, 5.5, Double.NaN)
test(Double.NaN, -151.189, Double.NaN)
test(Double.NaN, 3.123e-320, Double.NaN)
test(Double.NaN, 2.253547e-318, Double.NaN)

// If n is PositiveInfinity, return NaN
test(Double.NaN, Double.PositiveInfinity, Double.PositiveInfinity)
Expand All @@ -240,6 +244,8 @@ class DoubleTest {
test(Double.NaN, Double.PositiveInfinity, 2.1)
test(Double.NaN, Double.PositiveInfinity, 5.5)
test(Double.NaN, Double.PositiveInfinity, -151.189)
test(Double.NaN, Double.PositiveInfinity, 3.123e-320)
test(Double.NaN, Double.PositiveInfinity, 2.253547e-318)

// If n is NegativeInfinity, return NaN
test(Double.NaN, Double.NegativeInfinity, Double.PositiveInfinity)
Expand All @@ -249,56 +255,87 @@ class DoubleTest {
test(Double.NaN, Double.NegativeInfinity, 2.1)
test(Double.NaN, Double.NegativeInfinity, 5.5)
test(Double.NaN, Double.NegativeInfinity, -151.189)
test(Double.NaN, Double.NegativeInfinity, 3.123e-320)
test(Double.NaN, Double.NegativeInfinity, 2.253547e-318)

// If d is PositiveInfinity, return n
test(+0.0, +0.0, Double.PositiveInfinity)
test(-0.0, -0.0, Double.PositiveInfinity)
test(2.1, 2.1, Double.PositiveInfinity)
test(5.5, 5.5, Double.PositiveInfinity)
test(-151.189, -151.189, Double.PositiveInfinity)
test(3.123e-320, 3.123e-320, Double.PositiveInfinity)
test(2.253547e-318, 2.253547e-318, Double.PositiveInfinity)

// If d is NegativeInfinity, return n
test(+0.0, +0.0, Double.NegativeInfinity)
test(-0.0, -0.0, Double.NegativeInfinity)
test(2.1, 2.1, Double.NegativeInfinity)
test(5.5, 5.5, Double.NegativeInfinity)
test(-151.189, -151.189, Double.NegativeInfinity)
test(3.123e-320, 3.123e-320, Double.NegativeInfinity)
test(2.253547e-318, 2.253547e-318, Double.NegativeInfinity)

// If d is +0.0, return NaN
test(Double.NaN, +0.0, +0.0)
test(Double.NaN, -0.0, +0.0)
test(Double.NaN, 2.1, +0.0)
test(Double.NaN, 5.5, +0.0)
test(Double.NaN, -151.189, +0.0)
test(Double.NaN, 3.123e-320, +0.0)
test(Double.NaN, 2.253547e-318, +0.0)

// If d is -0.0, return NaN
test(Double.NaN, +0.0, -0.0)
test(Double.NaN, -0.0, -0.0)
test(Double.NaN, 2.1, -0.0)
test(Double.NaN, 5.5, -0.0)
test(Double.NaN, -151.189, -0.0)
test(Double.NaN, 3.123e-320, -0.0)
test(Double.NaN, 2.253547e-318, -0.0)

// If n is +0.0, return n
test(+0.0, +0.0, 2.1)
test(+0.0, +0.0, 5.5)
test(+0.0, +0.0, -151.189)
test(+0.0, +0.0, 3.123e-320)
test(+0.0, +0.0, 2.253547e-318)

// If n is -0.0, return n
test(-0.0, -0.0, 2.1)
test(-0.0, -0.0, 5.5)
test(-0.0, -0.0, -151.189)
test(-0.0, -0.0, 3.123e-320)
test(-0.0, -0.0, 2.253547e-318)

// Non-special values
// { val l = List(2.1, 5.5, -151.189); for (n <- l; d <- l) println(s" test(${n % d}, $n, $d)") }
// { val l = List(2.1, 5.5, -151.189, 3.123e-320, 2.253547e-318);
// for (n <- l; d <- l) println(s" test(${n % d}, $n, $d)".toLowerCase()) }
test(0.0, 2.1, 2.1)
test(2.1, 2.1, 5.5)
test(2.1, 2.1, -151.189)
test(2.0696e-320, 2.1, 3.123e-320)
test(1.772535e-318, 2.1, 2.253547e-318)
test(1.2999999999999998, 5.5, 2.1)
test(0.0, 5.5, 5.5)
test(5.5, 5.5, -151.189)
test(3.607e-321, 5.5, 3.123e-320)
test(6.8103e-319, 5.5, 2.253547e-318)
test(-2.0889999999999866, -151.189, 2.1)
test(-2.688999999999993, -151.189, 5.5)
test(-0.0, -151.189, -151.189)
test(-1.94e-320, -151.189, 3.123e-320)
test(-4.1349e-319, -151.189, 2.253547e-318)
test(3.123e-320, 3.123e-320, 2.1)
test(3.123e-320, 3.123e-320, 5.5)
test(3.123e-320, 3.123e-320, -151.189)
test(0.0, 3.123e-320, 3.123e-320)
test(3.123e-320, 3.123e-320, 2.253547e-318)
test(2.253547e-318, 2.253547e-318, 2.1)
test(2.253547e-318, 2.253547e-318, 5.5)
test(2.253547e-318, 2.253547e-318, -151.189)
test(4.995e-321, 2.253547e-318, 3.123e-320)
test(0.0, 2.253547e-318, 2.253547e-318)
}

@Test
Expand Down
39 changes: 38 additions & 1 deletion test-suite/shared/src/test/scala/org/scalajs/testsuite/compiler/FloatTest.scala
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Expand Up @@ -73,6 +73,8 @@ class FloatTest {
test(Float.NaN, Float.NaN, 2.1f)
test(Float.NaN, Float.NaN, 5.5f)
test(Float.NaN, Float.NaN, -151.189f)
test(Float.NaN, Float.NaN, 8.858e-42f)
test(Float.NaN, Float.NaN, 6.39164e-40f)

// If d is NaN, return NaN
test(Float.NaN, Float.NaN, Float.NaN)
Expand All @@ -83,6 +85,8 @@ class FloatTest {
test(Float.NaN, 2.1f, Float.NaN)
test(Float.NaN, 5.5f, Float.NaN)
test(Float.NaN, -151.189f, Float.NaN)
test(Float.NaN, 8.858e-42f, Float.NaN)
test(Float.NaN, 6.39164e-40f, Float.NaN)

// If n is PositiveInfinity, return NaN
test(Float.NaN, Float.PositiveInfinity, Float.PositiveInfinity)
Expand All @@ -92,6 +96,8 @@ class FloatTest {
test(Float.NaN, Float.PositiveInfinity, 2.1f)
test(Float.NaN, Float.PositiveInfinity, 5.5f)
test(Float.NaN, Float.PositiveInfinity, -151.189f)
test(Float.NaN, Float.PositiveInfinity, 8.858e-42f)
test(Float.NaN, Float.PositiveInfinity, 6.39164e-40f)

// If n is NegativeInfinity, return NaN
test(Float.NaN, Float.NegativeInfinity, Float.PositiveInfinity)
Expand All @@ -101,56 +107,87 @@ class FloatTest {
test(Float.NaN, Float.NegativeInfinity, 2.1f)
test(Float.NaN, Float.NegativeInfinity, 5.5f)
test(Float.NaN, Float.NegativeInfinity, -151.189f)
test(Float.NaN, Float.NegativeInfinity, 8.858e-42f)
test(Float.NaN, Float.NegativeInfinity, 6.39164e-40f)

// If d is PositiveInfinity, return n
test(+0.0f, +0.0f, Float.PositiveInfinity)
test(-0.0f, -0.0f, Float.PositiveInfinity)
test(2.1f, 2.1f, Float.PositiveInfinity)
test(5.5f, 5.5f, Float.PositiveInfinity)
test(-151.189f, -151.189f, Float.PositiveInfinity)
test(8.858e-42f, 8.858e-42f, Float.PositiveInfinity)
test(6.39164e-40f, 6.39164e-40f, Float.PositiveInfinity)

// If d is NegativeInfinity, return n
test(+0.0f, +0.0f, Float.NegativeInfinity)
test(-0.0f, -0.0f, Float.NegativeInfinity)
test(2.1f, 2.1f, Float.NegativeInfinity)
test(5.5f, 5.5f, Float.NegativeInfinity)
test(-151.189f, -151.189f, Float.NegativeInfinity)
test(8.858e-42f, 8.858e-42f, Float.NegativeInfinity)
test(6.39164e-40f, 6.39164e-40f, Float.NegativeInfinity)

// If d is +0.0, return NaN
test(Float.NaN, +0.0f, +0.0f)
test(Float.NaN, -0.0f, +0.0f)
test(Float.NaN, 2.1f, +0.0f)
test(Float.NaN, 5.5f, +0.0f)
test(Float.NaN, -151.189f, +0.0f)
test(Float.NaN, 8.858e-42f, +0.0f)
test(Float.NaN, 6.39164e-40f, +0.0f)

// If d is -0.0, return NaN
test(Float.NaN, +0.0f, -0.0f)
test(Float.NaN, -0.0f, -0.0f)
test(Float.NaN, 2.1f, -0.0f)
test(Float.NaN, 5.5f, -0.0f)
test(Float.NaN, -151.189f, -0.0f)
test(Float.NaN, 8.858e-42f, -0.0f)
test(Float.NaN, 6.39164e-40f, -0.0f)

// If n is +0.0, return n
test(+0.0f, +0.0f, 2.1f)
test(+0.0f, +0.0f, 5.5f)
test(+0.0f, +0.0f, -151.189f)
test(+0.0f, +0.0f, 8.858e-42f)
test(+0.0f, +0.0f, 6.39164e-40f)

// If n is -0.0, return n
test(-0.0f, -0.0f, 2.1f)
test(-0.0f, -0.0f, 5.5f)
test(-0.0f, -0.0f, -151.189f)
test(-0.0f, -0.0f, 8.858e-42f)
test(-0.0f, -0.0f, 6.39164e-40f)

// Non-special values
// { val l = List(2.1f, 5.5f, -151.189f); for (n <- l; d <- l) println(s" test(${n % d}f, ${n}f, ${d}f)") }
// { val l = List(2.1f, 5.5f, -151.189f, 8.858e-42f, 6.39164e-40f);
// for (n <- l; d <- l) println(s" test(${n % d}f, ${n}f, ${d}f)".toLowerCase()) }
test(0.0f, 2.1f, 2.1f)
test(2.1f, 2.1f, 5.5f)
test(2.1f, 2.1f, -151.189f)
test(8.085e-42f, 2.1f, 8.858e-42f)
test(6.1636e-40f, 2.1f, 6.39164e-40f)
test(1.3000002f, 5.5f, 2.1f)
test(0.0f, 5.5f, 5.5f)
test(5.5f, 5.5f, -151.189f)
test(5.11e-43f, 5.5f, 8.858e-42f)
test(4.77036e-40f, 5.5f, 6.39164e-40f)
test(-2.0890021f, -151.189f, 2.1f)
test(-2.6889954f, -151.189f, 5.5f)
test(-0.0f, -151.189f, -151.189f)
test(-1.139e-42f, -151.189f, 8.858e-42f)
test(-5.64734e-40f, -151.189f, 6.39164e-40f)
test(8.858e-42f, 8.858e-42f, 2.1f)
test(8.858e-42f, 8.858e-42f, 5.5f)
test(8.858e-42f, 8.858e-42f, -151.189f)
test(0.0f, 8.858e-42f, 8.858e-42f)
test(8.858e-42f, 8.858e-42f, 6.39164e-40f)
test(6.39164e-40f, 6.39164e-40f, 2.1f)
test(6.39164e-40f, 6.39164e-40f, 5.5f)
test(6.39164e-40f, 6.39164e-40f, -151.189f)
test(1.417e-42f, 6.39164e-40f, 8.858e-42f)
test(0.0f, 6.39164e-40f, 6.39164e-40f)
}

@Test
Expand Down