[llvm] Use MaxStride instead of CommonStride to calculate MaxVF (PR #98142)

[Florian Hahn via llvm-commits]

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@@ -0,0 +1,80 @@
+; NOTE: Assertions have been autogenerated by utils/update_analyze_test_checks.py UTC_ARGS: --version 5
+; RUN: opt --disable-output -mtriple=x86_64 --passes="print<access-info>" %s 2>&1 | FileCheck %s
+
+ at a = dso_local local_unnamed_addr global [65536 x float] zeroinitializer, align 16
+
+; Equivalent C code for the test case:
+; #define LEN 256 * 256
+; float a[LEN];
+
+; void different_strides() {
+;   for (int i = 0; i < LEN - 1024 - 255; i++) {
+;   #pragma clang loop interleave(disable)
+;   #pragma clang loop unroll(disable)
+;     for (int j = 0; j < 256; j++)
+;       a[i + j + 1024] += a[j * 4 + i];
+;   }
+; }
+define dso_local void @different_strides() local_unnamed_addr {
+; CHECK-LABEL: 'different_strides'
+; CHECK-NEXT:    for.body4:
+; CHECK-NEXT:      Memory dependences are safe with a maximum safe vector width of 2048 bits
+; CHECK-NEXT:      Dependences:
+; CHECK-NEXT:        BackwardVectorizable:
+; CHECK-NEXT:            %3 = load float, ptr %arrayidx, align 4 ->
+; CHECK-NEXT:            store float %add9, ptr %arrayidx8, align 4
+; CHECK-EMPTY:
+; CHECK-NEXT:        Forward:
+; CHECK-NEXT:            %5 = load float, ptr %arrayidx8, align 4 ->
+; CHECK-NEXT:            store float %add9, ptr %arrayidx8, align 4
+; CHECK-EMPTY:
+; 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:
+; CHECK-NEXT:    for.cond1.preheader:
+; 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:
+;
+entry:
+  br label %for.cond1.preheader
+
+for.cond1.preheader:
+  %indvars.iv25 = phi i64 [ 0, %entry ], [ %indvars.iv.next26, %for.cond.cleanup3 ]
+  %0 = add nuw nsw i64 %indvars.iv25, 1024
+  br label %for.body4
+
+for.cond.cleanup:
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fhahn wrote:

move to the end, and rename `exit`?

https://github.com/llvm/llvm-project/pull/98142