[llvm] [LV] Support generating masks for switch terminators. (PR #99808)

[via llvm-commits]

================
@@ -391,9 +635,68 @@ define void @switch_under_br_default_common_dest_with_case(ptr %start, ptr %end,
 ; FORCED-LABEL: define void @switch_under_br_default_common_dest_with_case(
 ; FORCED-SAME: ptr [[START:%.*]], ptr [[END:%.*]], i64 [[X:%.*]]) #[[ATTR0]] {
 ; FORCED-NEXT:  [[ENTRY:.*]]:
+; FORCED-NEXT:    [[START2:%.*]] = ptrtoint ptr [[START]] to i64
+; FORCED-NEXT:    [[END1:%.*]] = ptrtoint ptr [[END]] to i64
+; FORCED-NEXT:    [[TMP0:%.*]] = add i64 [[END1]], -8
+; FORCED-NEXT:    [[TMP1:%.*]] = sub i64 [[TMP0]], [[START2]]
+; FORCED-NEXT:    [[TMP2:%.*]] = lshr i64 [[TMP1]], 3
+; FORCED-NEXT:    [[TMP3:%.*]] = add nuw nsw i64 [[TMP2]], 1
+; FORCED-NEXT:    [[MIN_ITERS_CHECK:%.*]] = icmp ult i64 [[TMP3]], 8
+; FORCED-NEXT:    br i1 [[MIN_ITERS_CHECK]], label %[[SCALAR_PH:.*]], label %[[VECTOR_PH:.*]]
+; FORCED:       [[VECTOR_PH]]:
+; FORCED-NEXT:    [[N_MOD_VF:%.*]] = urem i64 [[TMP3]], 8
+; FORCED-NEXT:    [[N_VEC:%.*]] = sub i64 [[TMP3]], [[N_MOD_VF]]
+; FORCED-NEXT:    [[TMP4:%.*]] = mul i64 [[N_VEC]], 8
+; FORCED-NEXT:    [[IND_END:%.*]] = getelementptr i8, ptr [[START]], i64 [[TMP4]]
+; FORCED-NEXT:    [[BROADCAST_SPLATINSERT:%.*]] = insertelement <4 x i64> poison, i64 [[X]], i64 0
+; FORCED-NEXT:    [[BROADCAST_SPLAT:%.*]] = shufflevector <4 x i64> [[BROADCAST_SPLATINSERT]], <4 x i64> poison, <4 x i32> zeroinitializer
+; FORCED-NEXT:    br label %[[VECTOR_BODY:.*]]
+; FORCED:       [[VECTOR_BODY]]:
+; FORCED-NEXT:    [[INDEX:%.*]] = phi i64 [ 0, %[[VECTOR_PH]] ], [ [[INDEX_NEXT:%.*]], %[[VECTOR_BODY]] ]
+; FORCED-NEXT:    [[OFFSET_IDX:%.*]] = mul i64 [[INDEX]], 8
+; FORCED-NEXT:    [[TMP5:%.*]] = add i64 [[OFFSET_IDX]], 0
+; FORCED-NEXT:    [[TMP6:%.*]] = add i64 [[OFFSET_IDX]], 32
+; FORCED-NEXT:    [[NEXT_GEP:%.*]] = getelementptr i8, ptr [[START]], i64 [[TMP5]]
+; FORCED-NEXT:    [[NEXT_GEP3:%.*]] = getelementptr i8, ptr [[START]], i64 [[TMP6]]
+; FORCED-NEXT:    [[TMP7:%.*]] = getelementptr i64, ptr [[NEXT_GEP]], i32 0
+; FORCED-NEXT:    [[TMP8:%.*]] = getelementptr i64, ptr [[NEXT_GEP]], i32 4
+; FORCED-NEXT:    [[WIDE_LOAD:%.*]] = load <4 x i64>, ptr [[TMP7]], align 1
+; FORCED-NEXT:    [[WIDE_LOAD4:%.*]] = load <4 x i64>, ptr [[TMP8]], align 1
+; FORCED-NEXT:    [[TMP9:%.*]] = icmp ule <4 x i64> [[WIDE_LOAD]], [[BROADCAST_SPLAT]]
+; FORCED-NEXT:    [[TMP10:%.*]] = icmp ule <4 x i64> [[WIDE_LOAD4]], [[BROADCAST_SPLAT]]
+; FORCED-NEXT:    [[TMP11:%.*]] = icmp eq <4 x i64> [[WIDE_LOAD]], <i64 -12, i64 -12, i64 -12, i64 -12>
+; FORCED-NEXT:    [[TMP12:%.*]] = icmp eq <4 x i64> [[WIDE_LOAD4]], <i64 -12, i64 -12, i64 -12, i64 -12>
+; FORCED-NEXT:    [[TMP13:%.*]] = icmp eq <4 x i64> [[WIDE_LOAD]], <i64 13, i64 13, i64 13, i64 13>
+; FORCED-NEXT:    [[TMP14:%.*]] = icmp eq <4 x i64> [[WIDE_LOAD4]], <i64 13, i64 13, i64 13, i64 13>
+; FORCED-NEXT:    [[TMP15:%.*]] = select <4 x i1> [[TMP9]], <4 x i1> [[TMP11]], <4 x i1> zeroinitializer
+; FORCED-NEXT:    [[TMP16:%.*]] = select <4 x i1> [[TMP10]], <4 x i1> [[TMP12]], <4 x i1> zeroinitializer
+; FORCED-NEXT:    [[TMP25:%.*]] = select <4 x i1> [[TMP9]], <4 x i1> [[TMP13]], <4 x i1> zeroinitializer
+; FORCED-NEXT:    [[TMP26:%.*]] = select <4 x i1> [[TMP10]], <4 x i1> [[TMP14]], <4 x i1> zeroinitializer
+; FORCED-NEXT:    [[TMP27:%.*]] = or <4 x i1> [[TMP15]], [[TMP25]]
+; FORCED-NEXT:    [[TMP20:%.*]] = or <4 x i1> [[TMP16]], [[TMP26]]
+; FORCED-NEXT:    [[TMP21:%.*]] = xor <4 x i1> [[TMP27]], <i1 true, i1 true, i1 true, i1 true>
+; FORCED-NEXT:    [[TMP22:%.*]] = xor <4 x i1> [[TMP20]], <i1 true, i1 true, i1 true, i1 true>
+; FORCED-NEXT:    [[TMP23:%.*]] = select <4 x i1> [[TMP9]], <4 x i1> [[TMP21]], <4 x i1> zeroinitializer
+; FORCED-NEXT:    [[TMP24:%.*]] = select <4 x i1> [[TMP10]], <4 x i1> [[TMP22]], <4 x i1> zeroinitializer
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ayalz wrote:

(Above selects are the logical-AND's with block in-mask.)

https://github.com/llvm/llvm-project/pull/99808