[llvm] [AArch64][GlobalISel] Don't crash when legalising vector G_SHL (PR #168848)

[Matt Arsenault via llvm-commits]

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@@ -216,15 +216,15 @@ AArch64LegalizerInfo::AArch64LegalizerInfo(const AArch64Subtarget &ST)
       .widenScalarToNextPow2(0)
       .clampScalar(1, s32, s64)
       .clampScalar(0, s32, s64)
+      .minScalarSameAs(1, 0)
+      .minScalarEltSameAsIf(isVector(0), 1, 0)
+      .maxScalarEltSameAsIf(isVector(0), 1, 0)
       .clampNumElements(0, v8s8, v16s8)
       .clampNumElements(0, v4s16, v8s16)
       .clampNumElements(0, v2s32, v4s32)
       .clampNumElements(0, v2s64, v2s64)
       .moreElementsToNextPow2(0)
-      .minScalarSameAs(1, 0)
-      .scalarizeIf(scalarOrEltWiderThan(0, 64), 0)
-      .minScalarEltSameAsIf(isVector(0), 1, 0)
-      .maxScalarEltSameAsIf(isVector(0), 1, 0);
+      .scalarizeIf(scalarOrEltWiderThan(0, 64), 0);
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arsenm wrote:

We probably should have validation that the reported rule makes sense for the given operation as part of the rule parsing. The failure ideally wouldn't be deferred all the way to the application 

https://github.com/llvm/llvm-project/pull/168848