|
1 | 1 | --- |
2 | | -title: "Breaking change: Arm64 SVE NonFaulting loads require mask parameter" |
3 | | -description: "Learn about the breaking change in .NET 10 where Arm64 SVE NonFaulting load APIs now require a mask parameter as the first argument." |
4 | | -ms.date: 01/31/2025 |
| 2 | +title: "Breaking change: Arm64 SVE nonfaulting loads require mask parameter" |
| 3 | +description: "Learn about the breaking change in .NET 10 where Arm64 SVE nonfaulting load APIs now require a mask parameter as the first argument." |
| 4 | +ms.date: 08/11/2025 |
5 | 5 | ai-usage: ai-assisted |
6 | 6 | ms.custom: https://github.com/dotnet/docs/issues/47439 |
7 | 7 | --- |
8 | 8 |
|
9 | | -# Arm64 SVE NonFaulting loads require mask parameter |
| 9 | +# Arm64 SVE nonfaulting loads require mask parameter |
10 | 10 |
|
11 | | -All Arm64 SVE NonFaulting load APIs have been updated to include a `mask` argument as the first position. This affects all methods with "NonFaulting" in their name in the <xref:System.Runtime.Intrinsics.Arm.Sve?displayProperty=fullName> class. |
| 11 | +All Arm64 SVE nonfaulting load APIs have been updated to include a `mask` parameter in the first position. This change affects all methods with `LoadVector*NonFaulting` in their name in the <xref:System.Runtime.Intrinsics.Arm.Sve?displayProperty=fullName> class. |
12 | 12 |
|
13 | 13 | ## Version introduced |
14 | 14 |
|
15 | | -.NET 10 |
| 15 | +.NET 10 Preview 7 |
16 | 16 |
|
17 | 17 | ## Previous behavior |
18 | 18 |
|
19 | | -NonFaulting load APIs took only an address parameter and would load a full vector: |
| 19 | +Previously, nonfaulting load APIs took only an address parameter and loaded a full vector: |
20 | 20 |
|
21 | 21 | ```csharp |
22 | | -// .NET 9 behavior |
23 | 22 | Vector<short> result = Sve.LoadVectorByteNonFaultingZeroExtendToInt16(address); |
| 23 | +``` |
| 24 | + |
| 25 | +To do nonfaulting load with masked-out elements, you had to use <xref:System.Runtime.Intrinsics.Arm.Sve.ConditionalSelect*>: |
24 | 26 |
|
25 | | -// To do masked loading, you had to use ConditionalSelect |
26 | | -Vector<short> maskedResult = Sve.ConditionalSelect(mask, |
27 | | - Sve.LoadVectorByteNonFaultingZeroExtendToInt16(address), |
| 27 | +```csharp |
| 28 | +Vector<short> maskedResult = Sve.ConditionalSelect( |
| 29 | + mask, |
| 30 | + Sve.LoadVectorByteNonFaultingZeroExtendToInt16(address), |
28 | 31 | zero); |
29 | 32 | ``` |
30 | 33 |
|
31 | 34 | ## New behavior |
32 | 35 |
|
33 | | -NonFaulting load APIs now require a mask parameter as the first argument: |
| 36 | +Starting in .NET 10, nonfaulting load APIs now require a mask parameter as the first argument. |
34 | 37 |
|
35 | | -```csharp |
36 | | -// .NET 10 behavior - mask parameter required |
37 | | -Vector<short> result = Sve.LoadVectorByteNonFaultingZeroExtendToInt16( |
38 | | - Sve.CreateTrueMaskInt16(), address); |
39 | | - |
40 | | -// Masked loading is now done directly |
41 | | -Vector<short> maskedResult = Sve.LoadVectorByteNonFaultingZeroExtendToInt16( |
42 | | - mask, address); |
43 | | -``` |
| 38 | +To do a nonfaulting load for all elements, use code similar to the following: `Sve.LoadVector*NonFaulting*(Sve.CreateTrueMask*(), addr);` |
44 | 39 |
|
45 | 40 | ## Type of breaking change |
46 | 41 |
|
47 | 42 | This change can affect [binary compatibility](../../categories.md#binary-compatibility) and [source compatibility](../../categories.md#source-compatibility). |
48 | 43 |
|
49 | 44 | ## Reason for change |
50 | 45 |
|
51 | | -This change was necessary because a non-faulting load updates the FFR (First Fault Register) depending on which vector lanes are loaded. The standard conversion of `ConditionalSelect(mask, LoadVectorNonFaulting(addr), zero)` to a masked load cannot be used because it doesn't properly handle the FFR register state. Therefore, the only valid way to implement a masked non-faulting load is by exposing it as a dedicated API with a mask parameter. |
| 46 | +This change was necessary because a nonfaulting load updates the first fault register (FFR) depending on which vector lanes are loaded. The standard conversion of `ConditionalSelect(mask, LoadVectorNonFaulting(addr), zero)` to a masked load can't be used because it doesn't properly handle the FFR register state. Therefore, the only valid way to implement a masked nonfaulting load is by exposing it as a dedicated API. |
52 | 47 |
|
53 | 48 | ## Recommended action |
54 | 49 |
|
55 | 50 | - For existing uses of `Sve.ConditionalSelect(mask, Sve.LoadVector*NonFaulting*(addr), zero)`, replace them with `Sve.LoadVector*NonFaulting*(mask, addr)`. |
56 | | -- For other uses of non-faulting loads that should load all elements, update them to include a true mask: `Sve.LoadVector*NonFaulting*(Sve.CreateTrueMask*(), addr)`. |
| 51 | +- Update other uses of nonfaulting loads to include a true mask: `Sve.LoadVector*NonFaulting*(Sve.CreateTrueMask*(), addr)`. |
57 | 52 |
|
58 | 53 | ## Affected APIs |
59 | 54 |
|
60 | | -- <xref:System.Runtime.Intrinsics.Arm.Sve.LoadVectorByteNonFaultingZeroExtendToInt16%2A?displayProperty=fullName> |
61 | | -- <xref:System.Runtime.Intrinsics.Arm.Sve.LoadVectorByteNonFaultingZeroExtendToInt32%2A?displayProperty=fullName> |
62 | | -- <xref:System.Runtime.Intrinsics.Arm.Sve.LoadVectorByteNonFaultingZeroExtendToInt64%2A?displayProperty=fullName> |
63 | | -- <xref:System.Runtime.Intrinsics.Arm.Sve.LoadVectorByteNonFaultingZeroExtendToUInt16%2A?displayProperty=fullName> |
64 | | -- <xref:System.Runtime.Intrinsics.Arm.Sve.LoadVectorByteNonFaultingZeroExtendToUInt32%2A?displayProperty=fullName> |
65 | | -- <xref:System.Runtime.Intrinsics.Arm.Sve.LoadVectorByteNonFaultingZeroExtendToUInt64%2A?displayProperty=fullName> |
66 | | -- <xref:System.Runtime.Intrinsics.Arm.Sve.LoadVectorInt16NonFaultingSignExtendToInt32%2A?displayProperty=fullName> |
67 | | -- <xref:System.Runtime.Intrinsics.Arm.Sve.LoadVectorInt16NonFaultingSignExtendToInt64%2A?displayProperty=fullName> |
68 | | -- <xref:System.Runtime.Intrinsics.Arm.Sve.LoadVectorInt16NonFaultingSignExtendToUInt32%2A?displayProperty=fullName> |
69 | | -- <xref:System.Runtime.Intrinsics.Arm.Sve.LoadVectorInt16NonFaultingSignExtendToUInt64%2A?displayProperty=fullName> |
70 | | -- <xref:System.Runtime.Intrinsics.Arm.Sve.LoadVectorInt32NonFaultingSignExtendToInt64%2A?displayProperty=fullName> |
71 | | -- <xref:System.Runtime.Intrinsics.Arm.Sve.LoadVectorInt32NonFaultingSignExtendToUInt64%2A?displayProperty=fullName> |
| 55 | +- <xref:System.Runtime.Intrinsics.Arm.Sve.LoadVectorByteNonFaultingZeroExtendToInt16(System.Byte*)?displayProperty=fullName> |
| 56 | +- <xref:System.Runtime.Intrinsics.Arm.Sve.LoadVectorByteNonFaultingZeroExtendToInt32(System.Byte*)?displayProperty=fullName> |
| 57 | +- <xref:System.Runtime.Intrinsics.Arm.Sve.LoadVectorByteNonFaultingZeroExtendToInt64(System.Byte*)?displayProperty=fullName> |
| 58 | +- <xref:System.Runtime.Intrinsics.Arm.Sve.LoadVectorByteNonFaultingZeroExtendToUInt16(System.Byte*)?displayProperty=fullName> |
| 59 | +- <xref:System.Runtime.Intrinsics.Arm.Sve.LoadVectorByteNonFaultingZeroExtendToUInt32(System.Byte*)?displayProperty=fullName> |
| 60 | +- <xref:System.Runtime.Intrinsics.Arm.Sve.LoadVectorByteNonFaultingZeroExtendToUInt64(System.Byte*)?displayProperty=fullName> |
| 61 | +- <xref:System.Runtime.Intrinsics.Arm.Sve.LoadVectorInt16NonFaultingSignExtendToInt32(System.Int16*)?displayProperty=fullName> |
| 62 | +- <xref:System.Runtime.Intrinsics.Arm.Sve.LoadVectorInt16NonFaultingSignExtendToInt64(System.Int16*)?displayProperty=fullName> |
| 63 | +- <xref:System.Runtime.Intrinsics.Arm.Sve.LoadVectorInt16NonFaultingSignExtendToUInt32(System.Int16*)?displayProperty=fullName> |
| 64 | +- <xref:System.Runtime.Intrinsics.Arm.Sve.LoadVectorInt16NonFaultingSignExtendToUInt64(System.Int16*)?displayProperty=fullName> |
| 65 | +- <xref:System.Runtime.Intrinsics.Arm.Sve.LoadVectorInt32NonFaultingSignExtendToInt64(System.Int32*)?displayProperty=fullName> |
| 66 | +- <xref:System.Runtime.Intrinsics.Arm.Sve.LoadVectorInt32NonFaultingSignExtendToUInt64(System.Int32*)?displayProperty=fullName> |
72 | 67 | - <xref:System.Runtime.Intrinsics.Arm.Sve.LoadVectorNonFaulting%2A?displayProperty=fullName> |
73 | | -- <xref:System.Runtime.Intrinsics.Arm.Sve.LoadVectorSByteNonFaultingSignExtendToInt16%2A?displayProperty=fullName> |
74 | | -- <xref:System.Runtime.Intrinsics.Arm.Sve.LoadVectorSByteNonFaultingSignExtendToInt32%2A?displayProperty=fullName> |
75 | | -- <xref:System.Runtime.Intrinsics.Arm.Sve.LoadVectorSByteNonFaultingSignExtendToInt64%2A?displayProperty=fullName> |
76 | | -- <xref:System.Runtime.Intrinsics.Arm.Sve.LoadVectorSByteNonFaultingSignExtendToUInt16%2A?displayProperty=fullName> |
77 | | -- <xref:System.Runtime.Intrinsics.Arm.Sve.LoadVectorSByteNonFaultingSignExtendToUInt32%2A?displayProperty=fullName> |
78 | | -- <xref:System.Runtime.Intrinsics.Arm.Sve.LoadVectorSByteNonFaultingSignExtendToUInt64%2A?displayProperty=fullName> |
79 | | -- <xref:System.Runtime.Intrinsics.Arm.Sve.LoadVectorUInt16NonFaultingZeroExtendToInt32%2A?displayProperty=fullName> |
80 | | -- <xref:System.Runtime.Intrinsics.Arm.Sve.LoadVectorUInt16NonFaultingZeroExtendToInt64%2A?displayProperty=fullName> |
81 | | -- <xref:System.Runtime.Intrinsics.Arm.Sve.LoadVectorUInt16NonFaultingZeroExtendToUInt32%2A?displayProperty=fullName> |
82 | | -- <xref:System.Runtime.Intrinsics.Arm.Sve.LoadVectorUInt16NonFaultingZeroExtendToUInt64%2A?displayProperty=fullName> |
83 | | -- <xref:System.Runtime.Intrinsics.Arm.Sve.LoadVectorUInt32NonFaultingZeroExtendToInt64%2A?displayProperty=fullName> |
84 | | -- <xref:System.Runtime.Intrinsics.Arm.Sve.LoadVectorUInt32NonFaultingZeroExtendToUInt64%2A?displayProperty=fullName> |
| 68 | +- <xref:System.Runtime.Intrinsics.Arm.Sve.LoadVectorSByteNonFaultingSignExtendToInt16(System.SByte*)?displayProperty=fullName> |
| 69 | +- <xref:System.Runtime.Intrinsics.Arm.Sve.LoadVectorSByteNonFaultingSignExtendToInt32(System.SByte*)?displayProperty=fullName> |
| 70 | +- <xref:System.Runtime.Intrinsics.Arm.Sve.LoadVectorSByteNonFaultingSignExtendToInt64(System.SByte*)?displayProperty=fullName> |
| 71 | +- <xref:System.Runtime.Intrinsics.Arm.Sve.LoadVectorSByteNonFaultingSignExtendToUInt16(System.SByte*)?displayProperty=fullName> |
| 72 | +- <xref:System.Runtime.Intrinsics.Arm.Sve.LoadVectorSByteNonFaultingSignExtendToUInt32(System.SByte*)?displayProperty=fullName> |
| 73 | +- <xref:System.Runtime.Intrinsics.Arm.Sve.LoadVectorSByteNonFaultingSignExtendToUInt64(System.SByte*)?displayProperty=fullName> |
| 74 | +- <xref:System.Runtime.Intrinsics.Arm.Sve.LoadVectorUInt16NonFaultingZeroExtendToInt32(System.UInt16*)?displayProperty=fullName> |
| 75 | +- <xref:System.Runtime.Intrinsics.Arm.Sve.LoadVectorUInt16NonFaultingZeroExtendToInt64(System.UInt16*)?displayProperty=fullName> |
| 76 | +- <xref:System.Runtime.Intrinsics.Arm.Sve.LoadVectorUInt16NonFaultingZeroExtendToUInt32(System.UInt16*)?displayProperty=fullName> |
| 77 | +- <xref:System.Runtime.Intrinsics.Arm.Sve.LoadVectorUInt16NonFaultingZeroExtendToUInt64(System.UInt16*)?displayProperty=fullName> |
| 78 | +- <xref:System.Runtime.Intrinsics.Arm.Sve.LoadVectorUInt32NonFaultingZeroExtendToInt64(System.UInt32*)?displayProperty=fullName> |
| 79 | +- <xref:System.Runtime.Intrinsics.Arm.Sve.LoadVectorUInt32NonFaultingZeroExtendToUInt64(System.UInt32*)?displayProperty=fullName> |
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