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-rw-r--r--vendor/github.com/tetratelabs/wazero/internal/moremath/moremath.go271
1 files changed, 271 insertions, 0 deletions
diff --git a/vendor/github.com/tetratelabs/wazero/internal/moremath/moremath.go b/vendor/github.com/tetratelabs/wazero/internal/moremath/moremath.go
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index 000000000..4741f07bb
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+++ b/vendor/github.com/tetratelabs/wazero/internal/moremath/moremath.go
@@ -0,0 +1,271 @@
+package moremath
+
+import (
+ "math"
+)
+
+// https://www.w3.org/TR/2022/WD-wasm-core-2-20220419/syntax/values.html#floating-point
+const (
+ // F32CanonicalNaNBits is the 32-bit float where payload's MSB equals 1 and others are all zero.
+ F32CanonicalNaNBits = uint32(0x7fc0_0000)
+ // F32CanonicalNaNBitsMask can be used to judge the value `v` is canonical nan as "v&F32CanonicalNaNBitsMask == F32CanonicalNaNBits"
+ F32CanonicalNaNBitsMask = uint32(0x7fff_ffff)
+ // F64CanonicalNaNBits is the 64-bit float where payload's MSB equals 1 and others are all zero.
+ F64CanonicalNaNBits = uint64(0x7ff8_0000_0000_0000)
+ // F64CanonicalNaNBitsMask can be used to judge the value `v` is canonical nan as "v&F64CanonicalNaNBitsMask == F64CanonicalNaNBits"
+ F64CanonicalNaNBitsMask = uint64(0x7fff_ffff_ffff_ffff)
+ // F32ArithmeticNaNPayloadMSB is used to extract the most significant bit of payload of 32-bit arithmetic NaN values
+ F32ArithmeticNaNPayloadMSB = uint32(0x0040_0000)
+ // F32ExponentMask is used to extract the exponent of 32-bit floating point.
+ F32ExponentMask = uint32(0x7f80_0000)
+ // F32ArithmeticNaNBits is an example 32-bit arithmetic NaN.
+ F32ArithmeticNaNBits = F32CanonicalNaNBits | 0b1 // Set first bit to make this different from the canonical NaN.
+ // F64ArithmeticNaNPayloadMSB is used to extract the most significant bit of payload of 64-bit arithmetic NaN values
+ F64ArithmeticNaNPayloadMSB = uint64(0x0008_0000_0000_0000)
+ // F64ExponentMask is used to extract the exponent of 64-bit floating point.
+ F64ExponentMask = uint64(0x7ff0_0000_0000_0000)
+ // F64ArithmeticNaNBits is an example 64-bit arithmetic NaN.
+ F64ArithmeticNaNBits = F64CanonicalNaNBits | 0b1 // Set first bit to make this different from the canonical NaN.
+)
+
+// WasmCompatMin64 is the Wasm spec compatible variant of math.Min for 64-bit floating points.
+func WasmCompatMin64(x, y float64) float64 {
+ switch {
+ case math.IsNaN(x) || math.IsNaN(y):
+ return returnF64NaNBinOp(x, y)
+ case math.IsInf(x, -1) || math.IsInf(y, -1):
+ return math.Inf(-1)
+ case x == 0 && x == y:
+ if math.Signbit(x) {
+ return x
+ }
+ return y
+ }
+ if x < y {
+ return x
+ }
+ return y
+}
+
+// WasmCompatMin32 is the Wasm spec compatible variant of math.Min for 32-bit floating points.
+func WasmCompatMin32(x, y float32) float32 {
+ x64, y64 := float64(x), float64(y)
+ switch {
+ case math.IsNaN(x64) || math.IsNaN(y64):
+ return returnF32NaNBinOp(x, y)
+ case math.IsInf(x64, -1) || math.IsInf(y64, -1):
+ return float32(math.Inf(-1))
+ case x == 0 && x == y:
+ if math.Signbit(x64) {
+ return x
+ }
+ return y
+ }
+ if x < y {
+ return x
+ }
+ return y
+}
+
+// WasmCompatMax64 is the Wasm spec compatible variant of math.Max for 64-bit floating points.
+func WasmCompatMax64(x, y float64) float64 {
+ switch {
+ case math.IsNaN(x) || math.IsNaN(y):
+ return returnF64NaNBinOp(x, y)
+ case math.IsInf(x, 1) || math.IsInf(y, 1):
+ return math.Inf(1)
+ case x == 0 && x == y:
+ if math.Signbit(x) {
+ return y
+ }
+ return x
+ }
+ if x > y {
+ return x
+ }
+ return y
+}
+
+// WasmCompatMax32 is the Wasm spec compatible variant of math.Max for 32-bit floating points.
+func WasmCompatMax32(x, y float32) float32 {
+ x64, y64 := float64(x), float64(y)
+ switch {
+ case math.IsNaN(x64) || math.IsNaN(y64):
+ return returnF32NaNBinOp(x, y)
+ case math.IsInf(x64, 1) || math.IsInf(y64, 1):
+ return float32(math.Inf(1))
+ case x == 0 && x == y:
+ if math.Signbit(x64) {
+ return y
+ }
+ return x
+ }
+ if x > y {
+ return x
+ }
+ return y
+}
+
+// WasmCompatNearestF32 is the Wasm spec compatible variant of math.Round, used for Nearest instruction.
+// For example, this converts 1.9 to 2.0, and this has the semantics of LLVM's rint intrinsic.
+//
+// e.g. math.Round(-4.5) results in -5 while this results in -4.
+//
+// See https://llvm.org/docs/LangRef.html#llvm-rint-intrinsic.
+func WasmCompatNearestF32(f float32) float32 {
+ var res float32
+ // TODO: look at https://github.com/bytecodealliance/wasmtime/pull/2171 and reconsider this algorithm
+ if f != 0 {
+ ceil := float32(math.Ceil(float64(f)))
+ floor := float32(math.Floor(float64(f)))
+ distToCeil := math.Abs(float64(f - ceil))
+ distToFloor := math.Abs(float64(f - floor))
+ h := ceil / 2.0
+ if distToCeil < distToFloor {
+ res = ceil
+ } else if distToCeil == distToFloor && float32(math.Floor(float64(h))) == h {
+ res = ceil
+ } else {
+ res = floor
+ }
+ } else {
+ res = f
+ }
+ return returnF32UniOp(f, res)
+}
+
+// WasmCompatNearestF64 is the Wasm spec compatible variant of math.Round, used for Nearest instruction.
+// For example, this converts 1.9 to 2.0, and this has the semantics of LLVM's rint intrinsic.
+//
+// e.g. math.Round(-4.5) results in -5 while this results in -4.
+//
+// See https://llvm.org/docs/LangRef.html#llvm-rint-intrinsic.
+func WasmCompatNearestF64(f float64) float64 {
+ // TODO: look at https://github.com/bytecodealliance/wasmtime/pull/2171 and reconsider this algorithm
+ var res float64
+ if f != 0 {
+ ceil := math.Ceil(f)
+ floor := math.Floor(f)
+ distToCeil := math.Abs(f - ceil)
+ distToFloor := math.Abs(f - floor)
+ h := ceil / 2.0
+ if distToCeil < distToFloor {
+ res = ceil
+ } else if distToCeil == distToFloor && math.Floor(h) == h {
+ res = ceil
+ } else {
+ res = floor
+ }
+ } else {
+ res = f
+ }
+ return returnF64UniOp(f, res)
+}
+
+// WasmCompatCeilF32 is the same as math.Ceil on 32-bit except that
+// the returned NaN value follows the Wasm specification on NaN
+// propagation.
+// https://www.w3.org/TR/2022/WD-wasm-core-2-20220419/exec/numerics.html#nan-propagation
+func WasmCompatCeilF32(f float32) float32 {
+ return returnF32UniOp(f, float32(math.Ceil(float64(f))))
+}
+
+// WasmCompatCeilF64 is the same as math.Ceil on 64-bit except that
+// the returned NaN value follows the Wasm specification on NaN
+// propagation.
+// https://www.w3.org/TR/2022/WD-wasm-core-2-20220419/exec/numerics.html#nan-propagation
+func WasmCompatCeilF64(f float64) float64 {
+ return returnF64UniOp(f, math.Ceil(f))
+}
+
+// WasmCompatFloorF32 is the same as math.Floor on 32-bit except that
+// the returned NaN value follows the Wasm specification on NaN
+// propagation.
+// https://www.w3.org/TR/2022/WD-wasm-core-2-20220419/exec/numerics.html#nan-propagation
+func WasmCompatFloorF32(f float32) float32 {
+ return returnF32UniOp(f, float32(math.Floor(float64(f))))
+}
+
+// WasmCompatFloorF64 is the same as math.Floor on 64-bit except that
+// the returned NaN value follows the Wasm specification on NaN
+// propagation.
+// https://www.w3.org/TR/2022/WD-wasm-core-2-20220419/exec/numerics.html#nan-propagation
+func WasmCompatFloorF64(f float64) float64 {
+ return returnF64UniOp(f, math.Floor(f))
+}
+
+// WasmCompatTruncF32 is the same as math.Trunc on 32-bit except that
+// the returned NaN value follows the Wasm specification on NaN
+// propagation.
+// https://www.w3.org/TR/2022/WD-wasm-core-2-20220419/exec/numerics.html#nan-propagation
+func WasmCompatTruncF32(f float32) float32 {
+ return returnF32UniOp(f, float32(math.Trunc(float64(f))))
+}
+
+// WasmCompatTruncF64 is the same as math.Trunc on 64-bit except that
+// the returned NaN value follows the Wasm specification on NaN
+// propagation.
+// https://www.w3.org/TR/2022/WD-wasm-core-2-20220419/exec/numerics.html#nan-propagation
+func WasmCompatTruncF64(f float64) float64 {
+ return returnF64UniOp(f, math.Trunc(f))
+}
+
+func f32IsNaN(v float32) bool {
+ return v != v // this is how NaN is defined.
+}
+
+func f64IsNaN(v float64) bool {
+ return v != v // this is how NaN is defined.
+}
+
+// returnF32UniOp returns the result of 32-bit unary operation. This accepts `original` which is the operand,
+// and `result` which is its result. This returns the `result` as-is if the result is not NaN. Otherwise, this follows
+// the same logic as in the reference interpreter as well as the amd64 and arm64 floating point handling.
+func returnF32UniOp(original, result float32) float32 {
+ // Following the same logic as in the reference interpreter:
+ // https://github.com/WebAssembly/spec/blob/d48af683f5e6d00c13f775ab07d29a15daf92203/interpreter/exec/fxx.ml#L115-L122
+ if !f32IsNaN(result) {
+ return result
+ }
+ if !f32IsNaN(original) {
+ return math.Float32frombits(F32CanonicalNaNBits)
+ }
+ return math.Float32frombits(math.Float32bits(original) | F32CanonicalNaNBits)
+}
+
+// returnF32UniOp returns the result of 64-bit unary operation. This accepts `original` which is the operand,
+// and `result` which is its result. This returns the `result` as-is if the result is not NaN. Otherwise, this follows
+// the same logic as in the reference interpreter as well as the amd64 and arm64 floating point handling.
+func returnF64UniOp(original, result float64) float64 {
+ // Following the same logic as in the reference interpreter (== amd64 and arm64's behavior):
+ // https://github.com/WebAssembly/spec/blob/d48af683f5e6d00c13f775ab07d29a15daf92203/interpreter/exec/fxx.ml#L115-L122
+ if !f64IsNaN(result) {
+ return result
+ }
+ if !f64IsNaN(original) {
+ return math.Float64frombits(F64CanonicalNaNBits)
+ }
+ return math.Float64frombits(math.Float64bits(original) | F64CanonicalNaNBits)
+}
+
+// returnF64NaNBinOp returns a NaN for 64-bit binary operations. `x` and `y` are original floats
+// and at least one of them is NaN. The returned NaN is guaranteed to comply with the NaN propagation
+// procedure: https://www.w3.org/TR/2022/WD-wasm-core-2-20220419/exec/numerics.html#nan-propagation
+func returnF64NaNBinOp(x, y float64) float64 {
+ if f64IsNaN(x) {
+ return math.Float64frombits(math.Float64bits(x) | F64CanonicalNaNBits)
+ } else {
+ return math.Float64frombits(math.Float64bits(y) | F64CanonicalNaNBits)
+ }
+}
+
+// returnF64NaNBinOp returns a NaN for 32-bit binary operations. `x` and `y` are original floats
+// and at least one of them is NaN. The returned NaN is guaranteed to comply with the NaN propagation
+// procedure: https://www.w3.org/TR/2022/WD-wasm-core-2-20220419/exec/numerics.html#nan-propagation
+func returnF32NaNBinOp(x, y float32) float32 {
+ if f32IsNaN(x) {
+ return math.Float32frombits(math.Float32bits(x) | F32CanonicalNaNBits)
+ } else {
+ return math.Float32frombits(math.Float32bits(y) | F32CanonicalNaNBits)
+ }
+}