[llvm] [AMDGPU][SDAG] Legalise v2i32 or/xor/and instructions to make use of 64-bit wide instructions (PR #140694)

[Chris Jackson via llvm-commits]

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@@ -18,11 +18,11 @@ define <2 x i32> @test_add2x32(ptr %a_ptr, ptr %b_ptr) {
 ; CHECK-LABEL: test_add2x32:
 ; CHECK:       ; %bb.0:
 ; CHECK-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
-; CHECK-NEXT:    flat_load_dword v4, v[2:3]
-; CHECK-NEXT:    flat_load_dword v5, v[0:1]
-; CHECK-NEXT:    v_mov_b32_e32 v1, 48
+; CHECK-NEXT:    flat_load_dwordx2 v[4:5], v[0:1]
+; CHECK-NEXT:    flat_load_dwordx2 v[6:7], v[2:3]
 ; CHECK-NEXT:    s_waitcnt vmcnt(0) lgkmcnt(0)
-; CHECK-NEXT:    v_or_b32_e32 v0, v5, v4
+; CHECK-NEXT:    v_or_b32_e32 v1, v5, v7
+; CHECK-NEXT:    v_or_b32_e32 v0, v4, v6
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chrisjbris wrote:

Yep, the expansion of a non-legal v2i32 disjoint or gets reduced down to a constant through various legalisation and combines, but now that the v2i32 disjoint or instruction is legal that doesn't happen and instead ISel breaks the v2i32 disjoint or into two i32 or instructions instead.

https://github.com/llvm/llvm-project/pull/140694