CodeGen: Drop inert -fp-contract flags from tests
-fp-contract is nearly dead, but referenced in tests. These have
no output change with or without the flag now.
Co-authored-by: Claude (Claude-Opus-4.8) <noreply at anthropic.com>
[AArch64] Combine scalar_to_vector(C) -> buildvector (#220948)
This helps keep a single canonical form of a constant vector, helping a
number of the existing buildvector combines trigger.
[CoroSplit] Don't go sub-word for suspend index (#221374)
Currently, `CoroFrame` selects the coroutine suspend index type
(`SwitchIndexType`) using `Type::getIntNTy(Context, IndexBits)`. For
coroutines with fewer than 256 suspend points, this produces
sub-byte/sub-word integer types (such as `i1`, `i2`, or `i8`) in the
coroutine frame struct.
On targets whose `DataLayout` specifies `-n32` (no legal sub-32-bit
integer types), storing and loading sub-word integer fields in memory
forces the backend to emit read-modify-write sequences on every
coroutine suspend and zero-extension masks on every resume.
Use `DataLayout::getSmallestLegalIntType(Context, IndexBits)` when
selecting `SwitchIndexType` so that targets respect their legal native
integer width.
[X86] X86CompressEVEX - Fold AVX-512 sign-mask compares to MOVMSK (#216884)
## Summary
Fold AVX-512 complementary signed sign-test masks to the corresponding
MOVMSK instructions in `X86CompressEVEX`.
AVX-512 lowers comparisons such as:
- `X >= 0`
- `X > -1`
to `VPCMP*` producing a k-mask followed by `KMOV`.
For 128-bit and 256-bit B/D/Q forms, these masks can instead be obtained
from the source sign bits using:
- `VPCMPB` -> `VPMOVMSKB`
- `VPCMPD` -> `VMOVMSKPS`
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