[llvm] [InstCombine] Fold `getelementptr inbounds null, idx -> null` (PR #130742)

[Nikita Popov via llvm-commits]

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@@ -383,39 +383,68 @@ bb:
   ret <2 x half> %result
 }
 
-define <2 x half> @chain_hi_to_lo_flat() {
-; GCN-LABEL: chain_hi_to_lo_flat:
-; GCN:       ; %bb.0: ; %bb
-; GCN-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
-; GCN-NEXT:    v_mov_b32_e32 v0, 2
-; GCN-NEXT:    v_mov_b32_e32 v1, 0
-; GCN-NEXT:    flat_load_ushort v0, v[0:1]
-; GCN-NEXT:    v_mov_b32_e32 v1, 0
-; GCN-NEXT:    v_mov_b32_e32 v2, 0
-; GCN-NEXT:    s_waitcnt vmcnt(0) lgkmcnt(0)
-; GCN-NEXT:    flat_load_short_d16_hi v0, v[1:2]
-; GCN-NEXT:    s_waitcnt vmcnt(0) lgkmcnt(0)
-; GCN-NEXT:    s_setpc_b64 s[30:31]
+define <2 x half> @chain_hi_to_lo_flat(ptr inreg %ptr) {
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nikic wrote:

It would be good to land this separately to make it clear the diff is unrelated. (Possibly should also be done for some of the other tests you've marked with null_pointer_is_valid.)

https://github.com/llvm/llvm-project/pull/130742