[llvm] [AArch64][GlobalISel] Add legalisation for G_INSERT_SUBVECTOR (PR #205349)

[David Green via llvm-commits]

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@@ -761,32 +759,56 @@ entry:
 }
 
 define i32 @extract_v4i32_vector_insert(<4 x i32> %a, <2 x i32> %b, i32 %c) {
-; CHECK-LABEL: extract_v4i32_vector_insert:
-; CHECK:       // %bb.0: // %entry
-; CHECK-NEXT:    sub sp, sp, #16
-; CHECK-NEXT:    .cfi_def_cfa_offset 16
-; CHECK-NEXT:    mov d0, v0.d[1]
-; CHECK-NEXT:    // kill: def $d1 killed $d1 def $q1
-; CHECK-NEXT:    mov x8, sp
-; CHECK-NEXT:    // kill: def $w0 killed $w0 def $x0
-; CHECK-NEXT:    bfi x8, x0, #2, #2
-; CHECK-NEXT:    mov v1.d[1], v0.d[0]
-; CHECK-NEXT:    str q1, [sp]
-; CHECK-NEXT:    ldr w0, [x8]
-; CHECK-NEXT:    add sp, sp, #16
-; CHECK-NEXT:    ret
+; CHECK-SD-LABEL: extract_v4i32_vector_insert:
+; CHECK-SD:       // %bb.0: // %entry
+; CHECK-SD-NEXT:    sub sp, sp, #16
+; CHECK-SD-NEXT:    .cfi_def_cfa_offset 16
+; CHECK-SD-NEXT:    mov d0, v0.d[1]
+; CHECK-SD-NEXT:    // kill: def $d1 killed $d1 def $q1
+; CHECK-SD-NEXT:    mov x8, sp
+; CHECK-SD-NEXT:    // kill: def $w0 killed $w0 def $x0
+; CHECK-SD-NEXT:    bfi x8, x0, #2, #2
+; CHECK-SD-NEXT:    mov v1.d[1], v0.d[0]
+; CHECK-SD-NEXT:    str q1, [sp]
+; CHECK-SD-NEXT:    ldr w0, [x8]
+; CHECK-SD-NEXT:    add sp, sp, #16
+; CHECK-SD-NEXT:    ret
+;
+; CHECK-GI-LABEL: extract_v4i32_vector_insert:
+; CHECK-GI:       // %bb.0: // %entry
+; CHECK-GI-NEXT:    sub sp, sp, #16
+; CHECK-GI-NEXT:    .cfi_def_cfa_offset 16
+; CHECK-GI-NEXT:    mov d0, v0.d[1]
+; CHECK-GI-NEXT:    // kill: def $d1 killed $d1 def $q1
+; CHECK-GI-NEXT:    mov w8, w0
+; CHECK-GI-NEXT:    mov x9, sp
+; CHECK-GI-NEXT:    and x8, x8, #0x3
+; CHECK-GI-NEXT:    mov v1.d[1], v0.d[0]
+; CHECK-GI-NEXT:    str q1, [sp]
+; CHECK-GI-NEXT:    ldr w0, [x9, x8, lsl #2]
+; CHECK-GI-NEXT:    add sp, sp, #16
+; CHECK-GI-NEXT:    ret
 entry:
   %vector = call <4 x i32> @llvm.vector.insert.v4i32.v2i32(<4 x i32> %a, <2 x i32> %b, i64 0)
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davemgreen wrote:

The extractelement might make them unreliable for testing llvm.vector.insert as we add more optimizations in the future. Can you create a new file, named something like insertsubvector.ll, and add the new tests to it but return the vector result directly. Some "v4i16/v2i16 inserted into v8i16" tests might be useful too, as the v8i16 is a legal type.

https://github.com/llvm/llvm-project/pull/205349