[llvm-branch-commits] [llvm] [AtomicExpand] Add bitcasts when expanding load atomic vector (PR #120716)

[Matt Arsenault via llvm-branch-commits]

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@@ -151,3 +151,17 @@ define void @pointer_cmpxchg_expand6(ptr addrspace(1) %ptr,
   ret void
 }
 
+define <2 x ptr> @atomic_vec2_ptr_align(ptr %x) nounwind {
+; CHECK-LABEL: @atomic_vec2_ptr_align(
+; CHECK-NEXT:    [[TMP1:%.*]] = call i128 @__atomic_load_16(ptr [[X:%.*]], i32 2)
+; CHECK-NEXT:    [[TMP2:%.*]] = trunc i128 [[TMP1]] to i64
+; CHECK-NEXT:    [[TMP3:%.*]] = lshr i128 [[TMP1]], 64
+; CHECK-NEXT:    [[TMP4:%.*]] = trunc i128 [[TMP3]] to i64
+; CHECK-NEXT:    [[TMP5:%.*]] = insertelement <2 x i64> poison, i64 [[TMP2]], i32 0
+; CHECK-NEXT:    [[TMP6:%.*]] = insertelement <2 x i64> [[TMP5]], i64 [[TMP4]], i32 1
+; CHECK-NEXT:    [[TMP7:%.*]] = inttoptr <2 x i64> [[TMP6]] to <2 x ptr>
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arsenm wrote:

I don't understand why you need to do all this work to decompose the integer into pieces. You can just do bitcast i128 to `<2 x ptr>` and then `inttoptr <2 x i64> to <2 x ptr>`?

https://github.com/llvm/llvm-project/pull/120716