[llvm] [AArch64][GISel] Support SVE with 128-bit min-size for G_LOAD and G_STORE (PR #92130)

[via llvm-commits]

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@@ -61,6 +61,79 @@ AArch64LegalizerInfo::AArch64LegalizerInfo(const AArch64Subtarget &ST)
   const LLT v2s64 = LLT::fixed_vector(2, 64);
   const LLT v2p0 = LLT::fixed_vector(2, p0);
 
+  // Scalable vector sizes range from 128 to 2048
+  // Note that subtargets may not support the full range.
+  // See [ScalableVecTypes] below.
+  const LLT nxv16s8 = LLT::scalable_vector(16, s8);
+  const LLT nxv32s8 = LLT::scalable_vector(32, s8);
+  const LLT nxv64s8 = LLT::scalable_vector(64, s8);
+  const LLT nxv128s8 = LLT::scalable_vector(128, s8);
+  const LLT nxv256s8 = LLT::scalable_vector(256, s8);
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Him188 wrote:

To make it simpler for now, I would remove all these except for base sizes of 128-bit:
- `nxv8s16`, `nxv4s32`, and `nxv2s64` as listed in the original patch
- `nxv16s8` since SelectionDAG supports it
- `nxv2p0` since it has the same effective size as `nxv2s64`.


https://github.com/llvm/llvm-project/pull/92130