[llvm] [LV][VPlan] Implement VPlan-based cost for exit condition. (PR #125640)

[Florian Hahn via llvm-commits]

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@@ -27,23 +27,30 @@ define i64 @test_value_in_exit_compare_chain_used_outside(ptr %src, i64 %x, i64
 ; CHECK-NEXT:    br label %[[VECTOR_BODY:.*]]
 ; CHECK:       [[VECTOR_BODY]]:
 ; CHECK-NEXT:    [[TMP10:%.*]] = phi i64 [ 0, %[[VECTOR_PH]] ], [ [[INDEX_NEXT:%.*]], %[[VECTOR_BODY]] ]
-; CHECK-NEXT:    [[VEC_PHI:%.*]] = phi <8 x i8> [ zeroinitializer, %[[VECTOR_PH]] ], [ [[TMP29:%.*]], %[[VECTOR_BODY]] ]
+; CHECK-NEXT:    [[VEC_PHI:%.*]] = phi <4 x i8> [ zeroinitializer, %[[VECTOR_PH]] ], [ [[TMP17:%.*]], %[[VECTOR_BODY]] ]
+; CHECK-NEXT:    [[VEC_PHI3:%.*]] = phi <4 x i8> [ zeroinitializer, %[[VECTOR_PH]] ], [ [[TMP19:%.*]], %[[VECTOR_BODY]] ]
 ; CHECK-NEXT:    [[TMP18:%.*]] = and i64 [[TMP10]], 1
 ; CHECK-NEXT:    [[TMP26:%.*]] = getelementptr i8, ptr [[SRC]], i64 [[TMP18]]
 ; CHECK-NEXT:    [[TMP27:%.*]] = getelementptr i8, ptr [[TMP26]], i32 0
-; CHECK-NEXT:    [[TMP28:%.*]] = getelementptr i8, ptr [[TMP27]], i32 -7
-; CHECK-NEXT:    [[WIDE_LOAD:%.*]] = load <8 x i8>, ptr [[TMP28]], align 1
-; CHECK-NEXT:    [[REVERSE:%.*]] = shufflevector <8 x i8> [[WIDE_LOAD]], <8 x i8> poison, <8 x i32> <i32 7, i32 6, i32 5, i32 4, i32 3, i32 2, i32 1, i32 0>
-; CHECK-NEXT:    [[TMP29]] = xor <8 x i8> [[REVERSE]], [[VEC_PHI]]
+; CHECK-NEXT:    [[TMP13:%.*]] = getelementptr i8, ptr [[TMP27]], i32 -3
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fhahn wrote:

this looks like a possible regression, we now use narrower vector width but interleave. This should probably just use the wider vector width?

https://github.com/llvm/llvm-project/pull/125640