[AArch64][GlobalISel] Clamp <n x p0> vecs when legalizing G_EXTRACT_VECTOR_ELT

[paquette]

Summary

This case was missing from G_EXTRACT_VECTOR_ELT. It's the same as for s64.

https://godbolt.org/z/Tnq4acY8z

[arsenm]

llvm/test/CodeGen/AArch64/GlobalISel/legalize-extract-vector-elt.mir

264

Also need to be careful of other address space pointer vectors

[paquette]

llvm/test/CodeGen/AArch64/GlobalISel/legalize-extract-vector-elt.mir

264

Yeah, I'll add a testcase.

llvm/lib/Target/AArch64/GISel/AArch64LegalizerInfo.cpp

getActionDefinitionsBuilder(G_EXTRACT_VECTOR_ELT)
       .minScalarOrEltIf(
           [=](const LegalityQuery &Query) {
             return Query.Types[1].getNumElements() <= 16;
           },
           0, s8)
       .minScalarOrElt(0, s8) // Worst case, we need at least s8.
       .clampMaxNumElements(1, s64, 2)
       .clampMaxNumElements(1, s32, 4)
-      .clampMaxNumElements(1, s16, 8);
+      .clampMaxNumElements(1, s16, 8)
+      .clampMaxNumElements(1, p0, 2);
 
   getActionDefinitionsBuilder(G_INSERT_VECTOR_ELT)
       .legalIf(typeInSet(0, {v8s16, v2s32, v4s32, v2s64}));
 
   getActionDefinitionsBuilder(G_BUILD_VECTOR)
       .legalFor({{v8s8, s8},
                  {v16s8, s8},
                  {v2s16, s16},

llvm/test/CodeGen/AArch64/GlobalISel/legalize-extract-vector-elt.mir

bb.0:
     %concat:_(<16 x s16>) = G_CONCAT_VECTORS %0(<8 x s16>), %1(<8 x s16>)
     %idx:_(s32) = G_CONSTANT i32 9
     %idxprom:_(s64) = G_SEXT %idx(s32)
     %3:_(s16) = G_EXTRACT_VECTOR_ELT %concat:_(<16 x s16>), %idxprom:_(s64)
     %ext:_(s32) = G_ANYEXT %3
     $w0 = COPY %ext(s32)
     RET_ReallyLR
 ...
+---
+name:            test_eve_v4p0
+body: |
+  bb.0:
+    liveins: $x0
+    ; CHECK-LABEL: name: test_eve_v4p0
+    ; CHECK: [[DEF:%[0-9]+]]:_(p0) = G_IMPLICIT_DEF
+    ; CHECK: %idx:_(s64) = G_CONSTANT i64 1
+    ; CHECK: [[BUILD_VECTOR:%[0-9]+]]:_(<2 x p0>) = G_BUILD_VECTOR [[DEF]](p0), [[DEF]](p0)
+    ; CHECK: %eve:_(p0) = G_EXTRACT_VECTOR_ELT [[BUILD_VECTOR]](<2 x p0>), %idx(s64)
+    ; CHECK: $x0 = COPY %eve(p0)
+    ; CHECK: RET_ReallyLR
+    %vec:_(<4 x p0>) = G_IMPLICIT_DEF
+    %idx:_(s64) = G_CONSTANT i64 1
+    %eve:_(p0) = G_EXTRACT_VECTOR_ELT %vec:_(<4 x p0>), %idx:_(s64)
+    $x0 = COPY %eve(p0)
+    RET_ReallyLR