Alexey Bataev 78777a204a
[LV]Split store-load forward distance analysis from other checks, NFC (#121156)
The patch splits the store-load forwarding distance analysis from other
dependency analysis in LAA. Currently it supports only power-of-2
distances, required to support non-power-of-2 distances in future.

Part of #100755
2025-03-31 07:28:44 -04:00

38 lines
1.1 KiB
LLVM

; RUN: opt -passes='print<access-info>' -disable-output < %s 2>&1 | FileCheck %s
; Analyze this loop:
; for (i = 0; i < n; i++)
; A[i + 4] = A[i] * 2;
; CHECK: Memory dependences are safe with a maximum safe vector width of 64 bits, with a maximum safe store-load forward width of 64 bits
target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-apple-macosx10.10.0"
@A = common global ptr null, align 8
define void @f() {
entry:
%a = load ptr, ptr @A, align 8
br label %for.body
for.body: ; preds = %for.body, %entry
%ind = phi i64 [ 0, %entry ], [ %add, %for.body ]
%arrayidxA = getelementptr inbounds i16, ptr %a, i64 %ind
%loadA = load i16, ptr %arrayidxA, align 2
%mul = mul i16 %loadA, 2
%next = add nuw nsw i64 %ind, 4
%arrayidxA_next = getelementptr inbounds i16, ptr %a, i64 %next
store i16 %mul, ptr %arrayidxA_next, align 2
%add = add nuw nsw i64 %ind, 1
%exitcond = icmp eq i64 %add, 20
br i1 %exitcond, label %for.end, label %for.body
for.end: ; preds = %for.body
ret void
}