JIT: Move remaining xarch floating->integral cast implementation to lowering - #117571

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JIT: Move remaining xarch floating->integral cast implementation to lowering#117571
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This changes the lowering of floating->integral casts to always replace the cast node with HWIntrinsics rather than doing fixups ahead of the cast and leaving the node in place as a self-cast or letting it be handled in codegen. Since the self-cast was not always eliminated in codegen, this results in some size and throughput improvements.

Because the cast is always replaced now, genFloatToIntCast is no longer necessary on xarch.

This is best viewed with whitespace ignored. Most of the changes are simply an extra level of indentation for the pre-AVX10.2 code in LowerCast.

Diffs

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Comment threadsrc/coreclr/jit/hwintrinsiccodegenxarch.cpp
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cc @tannergooding

This is more peeled from #116805, with feedback addressed

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CC. @dotnet/jit-contrib, @EgorBo for secondary sign-off

This has a couple correctness fixes in addition to the general codegen improvements, so if we're not comfortable taking the whole thing for .NET 10, we likely still need to peel off the fixes that were called out

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CC. @dotnet/jit-contrib for secondary review

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@jakobbotsch, PTAL.

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Pull Request Overview

This PR refactors the JIT's handling of floating-point to integral casts on xarch by moving all conversion logic to the lowering phase. Previously, some casts were handled in codegen via genFloatToIntCast, but now all floating->integral casts are replaced with HWIntrinsic nodes during lowering. This enables better optimization and eliminates the need for genFloatToIntCast on xarch.

Key changes:

  • Floating->integral casts are now always replaced with HWIntrinsic nodes in LowerCast
  • New AVX10v2 saturating conversion intrinsics are introduced for direct hardware support
  • Fallback paths for pre-AVX10v2 hardware use complex SIMD manipulation for saturation semantics
  • The genFloatToIntCast function is removed from xarch codegen

Reviewed Changes

Copilot reviewed 10 out of 10 changed files in this pull request and generated 3 comments.

Show a summary per file
FileDescription
src/coreclr/jit/lowerxarch.cppImplements complete lowering of floating->integral casts with AVX10v2, AVX512, and fallback paths; replaces cast node with HWIntrinsics
src/coreclr/jit/lower.cppReturns early from LowerNode after cast lowering since the node is now removed
src/coreclr/jit/instr.cppRemoves floating->integral conversion instruction selection since these are now lowered to HWIntrinsics
src/coreclr/jit/hwintrinsiclistxarch.hAdds new AVX10v2 scalar saturating conversion intrinsics and fixes naming consistency
src/coreclr/jit/hwintrinsiccodegenxarch.cppAdds codegen support for new AVX10v2 saturating conversion intrinsics
src/coreclr/jit/hwintrinsic.cppEnables AVX10v2_X64 ISA range for 64-bit intrinsics
src/coreclr/jit/gentree.cppFixes intrinsic naming from "Truncation" to "Truncated" for consistency
src/coreclr/jit/codegenxarch.cppRemoves obsolete genFloatToIntCast function that is no longer needed
src/coreclr/jit/codegenlinear.cppAdds xarch guard to make floating->integral casts unreachable on xarch
src/coreclr/jit/CMakeLists.txtEnables SIMD features for i386 Unix builds to support the new lowering approach

Comment threadsrc/coreclr/jit/lowerxarch.cpp
Comment threadsrc/coreclr/jit/lowerxarch.cpp Outdated
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Merged up to resolve conflicts with #121251

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@saucecontrol@tannergooding@iremyux
JIT: Move remaining xarch floating->integral cast implementation to l…
1bb6344
…owering (dotnet#117571)
This changes the lowering of floating->integral casts to always replace
the cast node with HWIntrinsics rather than doing fixups ahead of the
cast and leaving the node in place as a self-cast or letting it be
handled in codegen. Since the self-cast was not always eliminated in
codegen, this results in some size and throughput improvements.
Because the cast is always replaced now, `genFloatToIntCast` is no
longer necessary on xarch.
This is best viewed with whitespace ignored. Most of the changes are
simply an extra level of indentation for the pre-AVX10.2 code in
`LowerCast`.
[Diffs](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1235886&view=ms.vss-build-web.run-extensions-tab)
---------
Co-authored-by: Tanner Gooding <tagoo@microsoft.com>
@github-actionsgithub-actionsBot locked and limited conversation to collaborators Mar 5, 2026
Sign up for freeto subscribe to this conversation on GitHub. Already have an account? Sign in.

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JIT: Move remaining xarch floating->integral cast implementation to lowering - #117571
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Merged
JIT: Move remaining xarch floating->integral cast implementation to lowering#117571
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This changes the lowering of floating->integral casts to always replace the cast node with HWIntrinsics rather than doing fixups ahead of the cast and leaving the node in place as a self-cast or letting it be handled in codegen. Since the self-cast was not always eliminated in codegen, this results in some size and throughput improvements.
Because the cast is always replaced now, genFloatToIntCast is no longer necessary on xarch.
This is best viewed with whitespace ignored. Most of the changes are simply an extra level of indentation for the pre-AVX10.2 code in LowerCast.
Diffs
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Comment threadsrc/coreclr/jit/CMakeLists.txt
Comment threadsrc/coreclr/jit/hwintrinsiccodegenxarch.cpp
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cc @tannergooding
This is more peeled from #116805, with feedback addressed
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CC. @dotnet/jit-contrib, @EgorBo for secondary sign-off
This has a couple correctness fixes in addition to the general codegen improvements, so if we're not comfortable taking the whole thing for .NET 10, we likely still need to peel off the fixes that were called out
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CC. @dotnet/jit-contrib for secondary review
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@jakobbotsch, PTAL.
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Pull Request Overview
This PR refactors the JIT's handling of floating-point to integral casts on xarch by moving all conversion logic to the lowering phase. Previously, some casts were handled in codegen via genFloatToIntCast, but now all floating->integral casts are replaced with HWIntrinsic nodes during lowering. This enables better optimization and eliminates the need for genFloatToIntCast on xarch.
Key changes:
  • Floating->integral casts are now always replaced with HWIntrinsic nodes in LowerCast
  • New AVX10v2 saturating conversion intrinsics are introduced for direct hardware support
  • Fallback paths for pre-AVX10v2 hardware use complex SIMD manipulation for saturation semantics
  • The genFloatToIntCast function is removed from xarch codegen
Reviewed Changes
Copilot reviewed 10 out of 10 changed files in this pull request and generated 3 comments.
Show a summary per file
FileDescription
src/coreclr/jit/lowerxarch.cppImplements complete lowering of floating->integral casts with AVX10v2, AVX512, and fallback paths; replaces cast node with HWIntrinsics
src/coreclr/jit/lower.cppReturns early from LowerNode after cast lowering since the node is now removed
src/coreclr/jit/instr.cppRemoves floating->integral conversion instruction selection since these are now lowered to HWIntrinsics
src/coreclr/jit/hwintrinsiclistxarch.hAdds new AVX10v2 scalar saturating conversion intrinsics and fixes naming consistency
src/coreclr/jit/hwintrinsiccodegenxarch.cppAdds codegen support for new AVX10v2 saturating conversion intrinsics
src/coreclr/jit/hwintrinsic.cppEnables AVX10v2_X64 ISA range for 64-bit intrinsics
src/coreclr/jit/gentree.cppFixes intrinsic naming from "Truncation" to "Truncated" for consistency
src/coreclr/jit/codegenxarch.cppRemoves obsolete genFloatToIntCast function that is no longer needed
src/coreclr/jit/codegenlinear.cppAdds xarch guard to make floating->integral casts unreachable on xarch
src/coreclr/jit/CMakeLists.txtEnables SIMD features for i386 Unix builds to support the new lowering approach
Comment threadsrc/coreclr/jit/lowerxarch.cpp
Comment threadsrc/coreclr/jit/lowerxarch.cpp
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Comment threadsrc/coreclr/jit/hwintrinsic.cpp
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Comment threadsrc/coreclr/jit/lowerxarch.cpp
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Merged up to resolve conflicts with #121251

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@saucecontrol@tannergooding@iremyux
JIT: Move remaining xarch floating->integral cast implementation to l…
1bb6344
…owering (dotnet#117571)
This changes the lowering of floating->integral casts to always replace
the cast node with HWIntrinsics rather than doing fixups ahead of the
cast and leaving the node in place as a self-cast or letting it be
handled in codegen. Since the self-cast was not always eliminated in
codegen, this results in some size and throughput improvements.
Because the cast is always replaced now, `genFloatToIntCast` is no
longer necessary on xarch.
This is best viewed with whitespace ignored. Most of the changes are
simply an extra level of indentation for the pre-AVX10.2 code in
`LowerCast`.
[Diffs](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1235886&view=ms.vss-build-web.run-extensions-tab)
---------
Co-authored-by: Tanner Gooding <tagoo@microsoft.com>
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JIT: Move remaining xarch floating->integral cast implementation to lowering - #117571
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saucecontrol:lng2flt4
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Merged
JIT: Move remaining xarch floating->integral cast implementation to lowering#117571
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This changes the lowering of floating->integral casts to always replace the cast node with HWIntrinsics rather than doing fixups ahead of the cast and leaving the node in place as a self-cast or letting it be handled in codegen. Since the self-cast was not always eliminated in codegen, this results in some size and throughput improvements.
Because the cast is always replaced now, genFloatToIntCast is no longer necessary on xarch.
This is best viewed with whitespace ignored. Most of the changes are simply an extra level of indentation for the pre-AVX10.2 code in LowerCast.
Diffs
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CC. @dotnet/jit-contrib, @EgorBo for secondary sign-off
This has a couple correctness fixes in addition to the general codegen improvements, so if we're not comfortable taking the whole thing for .NET 10, we likely still need to peel off the fixes that were called out
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CC. @dotnet/jit-contrib for secondary review
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Pull Request Overview
This PR refactors the JIT's handling of floating-point to integral casts on xarch by moving all conversion logic to the lowering phase. Previously, some casts were handled in codegen via genFloatToIntCast, but now all floating->integral casts are replaced with HWIntrinsic nodes during lowering. This enables better optimization and eliminates the need for genFloatToIntCast on xarch.
Key changes:
  • Floating->integral casts are now always replaced with HWIntrinsic nodes in LowerCast
  • New AVX10v2 saturating conversion intrinsics are introduced for direct hardware support
  • Fallback paths for pre-AVX10v2 hardware use complex SIMD manipulation for saturation semantics
  • The genFloatToIntCast function is removed from xarch codegen
Reviewed Changes
Copilot reviewed 10 out of 10 changed files in this pull request and generated 3 comments.
Show a summary per file
FileDescription
src/coreclr/jit/lowerxarch.cppImplements complete lowering of floating->integral casts with AVX10v2, AVX512, and fallback paths; replaces cast node with HWIntrinsics
src/coreclr/jit/lower.cppReturns early from LowerNode after cast lowering since the node is now removed
src/coreclr/jit/instr.cppRemoves floating->integral conversion instruction selection since these are now lowered to HWIntrinsics
src/coreclr/jit/hwintrinsiclistxarch.hAdds new AVX10v2 scalar saturating conversion intrinsics and fixes naming consistency
src/coreclr/jit/hwintrinsiccodegenxarch.cppAdds codegen support for new AVX10v2 saturating conversion intrinsics
src/coreclr/jit/hwintrinsic.cppEnables AVX10v2_X64 ISA range for 64-bit intrinsics
src/coreclr/jit/gentree.cppFixes intrinsic naming from "Truncation" to "Truncated" for consistency
src/coreclr/jit/codegenxarch.cppRemoves obsolete genFloatToIntCast function that is no longer needed
src/coreclr/jit/codegenlinear.cppAdds xarch guard to make floating->integral casts unreachable on xarch
src/coreclr/jit/CMakeLists.txtEnables SIMD features for i386 Unix builds to support the new lowering approach
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Comment threadsrc/coreclr/jit/hwintrinsic.cpp
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JIT: Move remaining xarch floating->integral cast implementation to l…
1bb6344
…owering (dotnet#117571)
This changes the lowering of floating->integral casts to always replace
the cast node with HWIntrinsics rather than doing fixups ahead of the
cast and leaving the node in place as a self-cast or letting it be
handled in codegen. Since the self-cast was not always eliminated in
codegen, this results in some size and throughput improvements.
Because the cast is always replaced now, `genFloatToIntCast` is no
longer necessary on xarch.
This is best viewed with whitespace ignored. Most of the changes are
simply an extra level of indentation for the pre-AVX10.2 code in
`LowerCast`.
[Diffs](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1235886&view=ms.vss-build-web.run-extensions-tab)
---------
Co-authored-by: Tanner Gooding <tagoo@microsoft.com>
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JIT: Move remaining xarch floating->integral cast implementation to lowering - #117571
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This changes the lowering of floating->integral casts to always replace the cast node with HWIntrinsics rather than doing fixups ahead of the cast and leaving the node in place as a self-cast or letting it be handled in codegen. Since the self-cast was not always eliminated in codegen, this results in some size and throughput improvements.
Because the cast is always replaced now, genFloatToIntCast is no longer necessary on xarch.
This is best viewed with whitespace ignored. Most of the changes are simply an extra level of indentation for the pre-AVX10.2 code in LowerCast.
Diffs
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Comment threadsrc/coreclr/jit/CMakeLists.txt
Comment threadsrc/coreclr/jit/hwintrinsiccodegenxarch.cpp
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cc @tannergooding
This is more peeled from #116805, with feedback addressed
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CC. @dotnet/jit-contrib, @EgorBo for secondary sign-off
This has a couple correctness fixes in addition to the general codegen improvements, so if we're not comfortable taking the whole thing for .NET 10, we likely still need to peel off the fixes that were called out
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Pull Request Overview
This PR refactors the JIT's handling of floating-point to integral casts on xarch by moving all conversion logic to the lowering phase. Previously, some casts were handled in codegen via genFloatToIntCast, but now all floating->integral casts are replaced with HWIntrinsic nodes during lowering. This enables better optimization and eliminates the need for genFloatToIntCast on xarch.
Key changes:
  • Floating->integral casts are now always replaced with HWIntrinsic nodes in LowerCast
  • New AVX10v2 saturating conversion intrinsics are introduced for direct hardware support
  • Fallback paths for pre-AVX10v2 hardware use complex SIMD manipulation for saturation semantics
  • The genFloatToIntCast function is removed from xarch codegen
Reviewed Changes
Copilot reviewed 10 out of 10 changed files in this pull request and generated 3 comments.
Show a summary per file
FileDescription
src/coreclr/jit/lowerxarch.cppImplements complete lowering of floating->integral casts with AVX10v2, AVX512, and fallback paths; replaces cast node with HWIntrinsics
src/coreclr/jit/lower.cppReturns early from LowerNode after cast lowering since the node is now removed
src/coreclr/jit/instr.cppRemoves floating->integral conversion instruction selection since these are now lowered to HWIntrinsics
src/coreclr/jit/hwintrinsiclistxarch.hAdds new AVX10v2 scalar saturating conversion intrinsics and fixes naming consistency
src/coreclr/jit/hwintrinsiccodegenxarch.cppAdds codegen support for new AVX10v2 saturating conversion intrinsics
src/coreclr/jit/hwintrinsic.cppEnables AVX10v2_X64 ISA range for 64-bit intrinsics
src/coreclr/jit/gentree.cppFixes intrinsic naming from "Truncation" to "Truncated" for consistency
src/coreclr/jit/codegenxarch.cppRemoves obsolete genFloatToIntCast function that is no longer needed
src/coreclr/jit/codegenlinear.cppAdds xarch guard to make floating->integral casts unreachable on xarch
src/coreclr/jit/CMakeLists.txtEnables SIMD features for i386 Unix builds to support the new lowering approach
Comment threadsrc/coreclr/jit/lowerxarch.cpp
Comment threadsrc/coreclr/jit/lowerxarch.cpp
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Merged up to resolve conflicts with #121251

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JIT: Move remaining xarch floating->integral cast implementation to l…
1bb6344
…owering (dotnet#117571)
This changes the lowering of floating->integral casts to always replace
the cast node with HWIntrinsics rather than doing fixups ahead of the
cast and leaving the node in place as a self-cast or letting it be
handled in codegen. Since the self-cast was not always eliminated in
codegen, this results in some size and throughput improvements.
Because the cast is always replaced now, `genFloatToIntCast` is no
longer necessary on xarch.
This is best viewed with whitespace ignored. Most of the changes are
simply an extra level of indentation for the pre-AVX10.2 code in
`LowerCast`.
[Diffs](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1235886&view=ms.vss-build-web.run-extensions-tab)
---------
Co-authored-by: Tanner Gooding <tagoo@microsoft.com>
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JIT: Move remaining xarch floating->integral cast implementation to lowering - #117571
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This changes the lowering of floating->integral casts to always replace the cast node with HWIntrinsics rather than doing fixups ahead of the cast and leaving the node in place as a self-cast or letting it be handled in codegen. Since the self-cast was not always eliminated in codegen, this results in some size and throughput improvements.
Because the cast is always replaced now, genFloatToIntCast is no longer necessary on xarch.
This is best viewed with whitespace ignored. Most of the changes are simply an extra level of indentation for the pre-AVX10.2 code in LowerCast.
Diffs
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Comment threadsrc/coreclr/jit/CMakeLists.txt
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cc @tannergooding
This is more peeled from #116805, with feedback addressed
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CC. @dotnet/jit-contrib, @EgorBo for secondary sign-off
This has a couple correctness fixes in addition to the general codegen improvements, so if we're not comfortable taking the whole thing for .NET 10, we likely still need to peel off the fixes that were called out
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CC. @dotnet/jit-contrib for secondary review
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@jakobbotsch, PTAL.
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Pull Request Overview
This PR refactors the JIT's handling of floating-point to integral casts on xarch by moving all conversion logic to the lowering phase. Previously, some casts were handled in codegen via genFloatToIntCast, but now all floating->integral casts are replaced with HWIntrinsic nodes during lowering. This enables better optimization and eliminates the need for genFloatToIntCast on xarch.
Key changes:
  • Floating->integral casts are now always replaced with HWIntrinsic nodes in LowerCast
  • New AVX10v2 saturating conversion intrinsics are introduced for direct hardware support
  • Fallback paths for pre-AVX10v2 hardware use complex SIMD manipulation for saturation semantics
  • The genFloatToIntCast function is removed from xarch codegen
Reviewed Changes
Copilot reviewed 10 out of 10 changed files in this pull request and generated 3 comments.
Show a summary per file
FileDescription
src/coreclr/jit/lowerxarch.cppImplements complete lowering of floating->integral casts with AVX10v2, AVX512, and fallback paths; replaces cast node with HWIntrinsics
src/coreclr/jit/lower.cppReturns early from LowerNode after cast lowering since the node is now removed
src/coreclr/jit/instr.cppRemoves floating->integral conversion instruction selection since these are now lowered to HWIntrinsics
src/coreclr/jit/hwintrinsiclistxarch.hAdds new AVX10v2 scalar saturating conversion intrinsics and fixes naming consistency
src/coreclr/jit/hwintrinsiccodegenxarch.cppAdds codegen support for new AVX10v2 saturating conversion intrinsics
src/coreclr/jit/hwintrinsic.cppEnables AVX10v2_X64 ISA range for 64-bit intrinsics
src/coreclr/jit/gentree.cppFixes intrinsic naming from "Truncation" to "Truncated" for consistency
src/coreclr/jit/codegenxarch.cppRemoves obsolete genFloatToIntCast function that is no longer needed
src/coreclr/jit/codegenlinear.cppAdds xarch guard to make floating->integral casts unreachable on xarch
src/coreclr/jit/CMakeLists.txtEnables SIMD features for i386 Unix builds to support the new lowering approach
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Merged up to resolve conflicts with #121251

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@saucecontrol@tannergooding@iremyux
JIT: Move remaining xarch floating->integral cast implementation to l…
1bb6344
…owering (dotnet#117571)
This changes the lowering of floating->integral casts to always replace
the cast node with HWIntrinsics rather than doing fixups ahead of the
cast and leaving the node in place as a self-cast or letting it be
handled in codegen. Since the self-cast was not always eliminated in
codegen, this results in some size and throughput improvements.
Because the cast is always replaced now, `genFloatToIntCast` is no
longer necessary on xarch.
This is best viewed with whitespace ignored. Most of the changes are
simply an extra level of indentation for the pre-AVX10.2 code in
`LowerCast`.
[Diffs](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1235886&view=ms.vss-build-web.run-extensions-tab)
---------
Co-authored-by: Tanner Gooding <tagoo@microsoft.com>
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JIT: Move remaining xarch floating->integral cast implementation to lowering - #117571
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JIT: Move remaining xarch floating->integral cast implementation to lowering#117571
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This changes the lowering of floating->integral casts to always replace the cast node with HWIntrinsics rather than doing fixups ahead of the cast and leaving the node in place as a self-cast or letting it be handled in codegen. Since the self-cast was not always eliminated in codegen, this results in some size and throughput improvements.
Because the cast is always replaced now, genFloatToIntCast is no longer necessary on xarch.
This is best viewed with whitespace ignored. Most of the changes are simply an extra level of indentation for the pre-AVX10.2 code in LowerCast.
Diffs
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cc @tannergooding
This is more peeled from #116805, with feedback addressed
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CC. @dotnet/jit-contrib, @EgorBo for secondary sign-off
This has a couple correctness fixes in addition to the general codegen improvements, so if we're not comfortable taking the whole thing for .NET 10, we likely still need to peel off the fixes that were called out
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Pull Request Overview
This PR refactors the JIT's handling of floating-point to integral casts on xarch by moving all conversion logic to the lowering phase. Previously, some casts were handled in codegen via genFloatToIntCast, but now all floating->integral casts are replaced with HWIntrinsic nodes during lowering. This enables better optimization and eliminates the need for genFloatToIntCast on xarch.
Key changes:
  • Floating->integral casts are now always replaced with HWIntrinsic nodes in LowerCast
  • New AVX10v2 saturating conversion intrinsics are introduced for direct hardware support
  • Fallback paths for pre-AVX10v2 hardware use complex SIMD manipulation for saturation semantics
  • The genFloatToIntCast function is removed from xarch codegen
Reviewed Changes
Copilot reviewed 10 out of 10 changed files in this pull request and generated 3 comments.
Show a summary per file
FileDescription
src/coreclr/jit/lowerxarch.cppImplements complete lowering of floating->integral casts with AVX10v2, AVX512, and fallback paths; replaces cast node with HWIntrinsics
src/coreclr/jit/lower.cppReturns early from LowerNode after cast lowering since the node is now removed
src/coreclr/jit/instr.cppRemoves floating->integral conversion instruction selection since these are now lowered to HWIntrinsics
src/coreclr/jit/hwintrinsiclistxarch.hAdds new AVX10v2 scalar saturating conversion intrinsics and fixes naming consistency
src/coreclr/jit/hwintrinsiccodegenxarch.cppAdds codegen support for new AVX10v2 saturating conversion intrinsics
src/coreclr/jit/hwintrinsic.cppEnables AVX10v2_X64 ISA range for 64-bit intrinsics
src/coreclr/jit/gentree.cppFixes intrinsic naming from "Truncation" to "Truncated" for consistency
src/coreclr/jit/codegenxarch.cppRemoves obsolete genFloatToIntCast function that is no longer needed
src/coreclr/jit/codegenlinear.cppAdds xarch guard to make floating->integral casts unreachable on xarch
src/coreclr/jit/CMakeLists.txtEnables SIMD features for i386 Unix builds to support the new lowering approach
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Merged up to resolve conflicts with #121251

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JIT: Move remaining xarch floating->integral cast implementation to l…
1bb6344
…owering (dotnet#117571)
This changes the lowering of floating->integral casts to always replace
the cast node with HWIntrinsics rather than doing fixups ahead of the
cast and leaving the node in place as a self-cast or letting it be
handled in codegen. Since the self-cast was not always eliminated in
codegen, this results in some size and throughput improvements.
Because the cast is always replaced now, `genFloatToIntCast` is no
longer necessary on xarch.
This is best viewed with whitespace ignored. Most of the changes are
simply an extra level of indentation for the pre-AVX10.2 code in
`LowerCast`.
[Diffs](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1235886&view=ms.vss-build-web.run-extensions-tab)
---------
Co-authored-by: Tanner Gooding <tagoo@microsoft.com>
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JIT: Move remaining xarch floating->integral cast implementation to lowering - #117571
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saucecontrol:lng2flt4
Feb 2, 2026
Merged
JIT: Move remaining xarch floating->integral cast implementation to lowering#117571
kg merged 16 commits into
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This changes the lowering of floating->integral casts to always replace the cast node with HWIntrinsics rather than doing fixups ahead of the cast and leaving the node in place as a self-cast or letting it be handled in codegen. Since the self-cast was not always eliminated in codegen, this results in some size and throughput improvements.
Because the cast is always replaced now, genFloatToIntCast is no longer necessary on xarch.
This is best viewed with whitespace ignored. Most of the changes are simply an extra level of indentation for the pre-AVX10.2 code in LowerCast.
Diffs
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Comment threadsrc/coreclr/jit/CMakeLists.txt
Comment threadsrc/coreclr/jit/hwintrinsiccodegenxarch.cpp
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cc @tannergooding
This is more peeled from #116805, with feedback addressed
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CC. @dotnet/jit-contrib, @EgorBo for secondary sign-off
This has a couple correctness fixes in addition to the general codegen improvements, so if we're not comfortable taking the whole thing for .NET 10, we likely still need to peel off the fixes that were called out
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CC. @dotnet/jit-contrib for secondary review
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@jakobbotsch, PTAL.
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Pull Request Overview
This PR refactors the JIT's handling of floating-point to integral casts on xarch by moving all conversion logic to the lowering phase. Previously, some casts were handled in codegen via genFloatToIntCast, but now all floating->integral casts are replaced with HWIntrinsic nodes during lowering. This enables better optimization and eliminates the need for genFloatToIntCast on xarch.
Key changes:
  • Floating->integral casts are now always replaced with HWIntrinsic nodes in LowerCast
  • New AVX10v2 saturating conversion intrinsics are introduced for direct hardware support
  • Fallback paths for pre-AVX10v2 hardware use complex SIMD manipulation for saturation semantics
  • The genFloatToIntCast function is removed from xarch codegen
Reviewed Changes
Copilot reviewed 10 out of 10 changed files in this pull request and generated 3 comments.
Show a summary per file
FileDescription
src/coreclr/jit/lowerxarch.cppImplements complete lowering of floating->integral casts with AVX10v2, AVX512, and fallback paths; replaces cast node with HWIntrinsics
src/coreclr/jit/lower.cppReturns early from LowerNode after cast lowering since the node is now removed
src/coreclr/jit/instr.cppRemoves floating->integral conversion instruction selection since these are now lowered to HWIntrinsics
src/coreclr/jit/hwintrinsiclistxarch.hAdds new AVX10v2 scalar saturating conversion intrinsics and fixes naming consistency
src/coreclr/jit/hwintrinsiccodegenxarch.cppAdds codegen support for new AVX10v2 saturating conversion intrinsics
src/coreclr/jit/hwintrinsic.cppEnables AVX10v2_X64 ISA range for 64-bit intrinsics
src/coreclr/jit/gentree.cppFixes intrinsic naming from "Truncation" to "Truncated" for consistency
src/coreclr/jit/codegenxarch.cppRemoves obsolete genFloatToIntCast function that is no longer needed
src/coreclr/jit/codegenlinear.cppAdds xarch guard to make floating->integral casts unreachable on xarch
src/coreclr/jit/CMakeLists.txtEnables SIMD features for i386 Unix builds to support the new lowering approach
Comment threadsrc/coreclr/jit/lowerxarch.cpp
Comment threadsrc/coreclr/jit/lowerxarch.cpp
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Comment threadsrc/coreclr/jit/hwintrinsic.cpp
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Merged up to resolve conflicts with #121251

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@saucecontrol@tannergooding@iremyux
JIT: Move remaining xarch floating->integral cast implementation to l…
1bb6344
…owering (dotnet#117571)
This changes the lowering of floating->integral casts to always replace
the cast node with HWIntrinsics rather than doing fixups ahead of the
cast and leaving the node in place as a self-cast or letting it be
handled in codegen. Since the self-cast was not always eliminated in
codegen, this results in some size and throughput improvements.
Because the cast is always replaced now, `genFloatToIntCast` is no
longer necessary on xarch.
This is best viewed with whitespace ignored. Most of the changes are
simply an extra level of indentation for the pre-AVX10.2 code in
`LowerCast`.
[Diffs](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1235886&view=ms.vss-build-web.run-extensions-tab)
---------
Co-authored-by: Tanner Gooding <tagoo@microsoft.com>
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JIT: Move remaining xarch floating->integral cast implementation to lowering - #117571
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JIT: Move remaining xarch floating->integral cast implementation to lowering#117571
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This changes the lowering of floating->integral casts to always replace the cast node with HWIntrinsics rather than doing fixups ahead of the cast and leaving the node in place as a self-cast or letting it be handled in codegen. Since the self-cast was not always eliminated in codegen, this results in some size and throughput improvements.
Because the cast is always replaced now, genFloatToIntCast is no longer necessary on xarch.
This is best viewed with whitespace ignored. Most of the changes are simply an extra level of indentation for the pre-AVX10.2 code in LowerCast.
Diffs
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CC. @dotnet/jit-contrib, @EgorBo for secondary sign-off
This has a couple correctness fixes in addition to the general codegen improvements, so if we're not comfortable taking the whole thing for .NET 10, we likely still need to peel off the fixes that were called out
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Pull Request Overview
This PR refactors the JIT's handling of floating-point to integral casts on xarch by moving all conversion logic to the lowering phase. Previously, some casts were handled in codegen via genFloatToIntCast, but now all floating->integral casts are replaced with HWIntrinsic nodes during lowering. This enables better optimization and eliminates the need for genFloatToIntCast on xarch.
Key changes:
  • Floating->integral casts are now always replaced with HWIntrinsic nodes in LowerCast
  • New AVX10v2 saturating conversion intrinsics are introduced for direct hardware support
  • Fallback paths for pre-AVX10v2 hardware use complex SIMD manipulation for saturation semantics
  • The genFloatToIntCast function is removed from xarch codegen
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src/coreclr/jit/lowerxarch.cppImplements complete lowering of floating->integral casts with AVX10v2, AVX512, and fallback paths; replaces cast node with HWIntrinsics
src/coreclr/jit/lower.cppReturns early from LowerNode after cast lowering since the node is now removed
src/coreclr/jit/instr.cppRemoves floating->integral conversion instruction selection since these are now lowered to HWIntrinsics
src/coreclr/jit/hwintrinsiclistxarch.hAdds new AVX10v2 scalar saturating conversion intrinsics and fixes naming consistency
src/coreclr/jit/hwintrinsiccodegenxarch.cppAdds codegen support for new AVX10v2 saturating conversion intrinsics
src/coreclr/jit/hwintrinsic.cppEnables AVX10v2_X64 ISA range for 64-bit intrinsics
src/coreclr/jit/gentree.cppFixes intrinsic naming from "Truncation" to "Truncated" for consistency
src/coreclr/jit/codegenxarch.cppRemoves obsolete genFloatToIntCast function that is no longer needed
src/coreclr/jit/codegenlinear.cppAdds xarch guard to make floating->integral casts unreachable on xarch
src/coreclr/jit/CMakeLists.txtEnables SIMD features for i386 Unix builds to support the new lowering approach
Comment threadsrc/coreclr/jit/lowerxarch.cpp
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Merged up to resolve conflicts with #121251

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Thank you for the contribution! 👍
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@saucecontrol@tannergooding@iremyux
JIT: Move remaining xarch floating->integral cast implementation to l…
1bb6344
…owering (dotnet#117571)
This changes the lowering of floating->integral casts to always replace
the cast node with HWIntrinsics rather than doing fixups ahead of the
cast and leaving the node in place as a self-cast or letting it be
handled in codegen. Since the self-cast was not always eliminated in
codegen, this results in some size and throughput improvements.
Because the cast is always replaced now, `genFloatToIntCast` is no
longer necessary on xarch.
This is best viewed with whitespace ignored. Most of the changes are
simply an extra level of indentation for the pre-AVX10.2 code in
`LowerCast`.
[Diffs](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1235886&view=ms.vss-build-web.run-extensions-tab)
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Co-authored-by: Tanner Gooding <tagoo@microsoft.com>
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