[llvm] LAA: fix logic for MaxTargetVectorWidth (PR #125487)

[Ramkumar Ramachandra via llvm-commits]

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@@ -10,38 +10,104 @@ target datalayout = "e-m:o-i64:64-i128:128-n32:64-S128"
 ; If the dependence distance is not a constant, whether it gets identified as backwards or unknown depends on the minimum distance and the target's vector length.
 
 define void @backward_min_distance_8(ptr %A, i64 %N) {
-; COMMON-LABEL: 'backward_min_distance_8'
-; COMMON-NEXT:    loop:
-; COMMON-NEXT:      Memory dependences are safe with run-time checks
-; COMMON-NEXT:      Dependences:
-; COMMON-NEXT:      Run-time memory checks:
-; COMMON-NEXT:      Check 0:
-; COMMON-NEXT:        Comparing group ([[GRP1:0x[0-9a-f]+]]):
-; COMMON-NEXT:          %gep.off.iv = getelementptr inbounds i8, ptr %gep.off, i64 %iv
-; COMMON-NEXT:        Against group ([[GRP2:0x[0-9a-f]+]]):
-; COMMON-NEXT:          %gep = getelementptr inbounds i8, ptr %A, i64 %iv
-; COMMON-NEXT:      Grouped accesses:
-; COMMON-NEXT:        Group [[GRP1]]:
-; COMMON-NEXT:          (Low: {(1 + %A)<nuw>,+,1}<nuw><%outer.header> High: {(257 + %A),+,1}<nw><%outer.header>)
-; COMMON-NEXT:            Member: {{\{\{}}(1 + %A)<nuw>,+,1}<nuw><%outer.header>,+,1}<nuw><%loop>
-; COMMON-NEXT:        Group [[GRP2]]:
-; COMMON-NEXT:          (Low: %A High: (256 + %A))
-; COMMON-NEXT:            Member: {%A,+,1}<nuw><%loop>
-; COMMON-EMPTY:
-; COMMON-NEXT:      Non vectorizable stores to invariant address were not found in loop.
-; COMMON-NEXT:      SCEV assumptions:
-; COMMON-EMPTY:
-; COMMON-NEXT:      Expressions re-written:
-; COMMON-NEXT:    outer.header:
-; COMMON-NEXT:      Report: loop is not the innermost loop
-; COMMON-NEXT:      Dependences:
-; COMMON-NEXT:      Run-time memory checks:
-; COMMON-NEXT:      Grouped accesses:
-; COMMON-EMPTY:
-; COMMON-NEXT:      Non vectorizable stores to invariant address were not found in loop.
-; COMMON-NEXT:      SCEV assumptions:
-; COMMON-EMPTY:
-; COMMON-NEXT:      Expressions re-written:
+; CHECK-LABEL: 'backward_min_distance_8'
+; CHECK-NEXT:    loop:
+; CHECK-NEXT:      Memory dependences are safe with run-time checks
+; CHECK-NEXT:      Dependences:
+; CHECK-NEXT:      Run-time memory checks:
+; CHECK-NEXT:      Check 0:
+; CHECK-NEXT:        Comparing group ([[GRP1:0x[0-9a-f]+]]):
+; CHECK-NEXT:          %gep.off.iv = getelementptr inbounds i8, ptr %gep.off, i64 %iv
+; CHECK-NEXT:        Against group ([[GRP2:0x[0-9a-f]+]]):
+; CHECK-NEXT:          %gep = getelementptr inbounds i8, ptr %A, i64 %iv
+; CHECK-NEXT:      Grouped accesses:
+; CHECK-NEXT:        Group [[GRP1]]:
+; CHECK-NEXT:          (Low: {(1 + %A)<nuw>,+,1}<nuw><%outer.header> High: {(257 + %A),+,1}<nw><%outer.header>)
+; CHECK-NEXT:            Member: {{\{\{}}(1 + %A)<nuw>,+,1}<nuw><%outer.header>,+,1}<nuw><%loop>
+; CHECK-NEXT:        Group [[GRP2]]:
+; CHECK-NEXT:          (Low: %A High: (256 + %A))
+; CHECK-NEXT:            Member: {%A,+,1}<nuw><%loop>
+; CHECK-EMPTY:
+; CHECK-NEXT:      Non vectorizable stores to invariant address were not found in loop.
+; CHECK-NEXT:      SCEV assumptions:
+; CHECK-EMPTY:
+; CHECK-NEXT:      Expressions re-written:
+; CHECK-NEXT:    outer.header:
+; CHECK-NEXT:      Report: loop is not the innermost loop
+; CHECK-NEXT:      Dependences:
+; CHECK-NEXT:      Run-time memory checks:
+; CHECK-NEXT:      Grouped accesses:
+; CHECK-EMPTY:
+; CHECK-NEXT:      Non vectorizable stores to invariant address were not found in loop.
+; CHECK-NEXT:      SCEV assumptions:
+; CHECK-EMPTY:
+; CHECK-NEXT:      Expressions re-written:
+;
+; VW128-LABEL: 'backward_min_distance_8'
----------------
artagnon wrote:

There seems to be a UTC bug, due to which COMMON lines seem to be conflicting. I've manually put back the COMMON lines in for this test for now.

https://github.com/llvm/llvm-project/pull/125487