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llvm-project/llvm/test/Analysis/LoopAccessAnalysis/resort-to-memchecks-only.ll

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[LoopAccesses] If shouldRetryWithRuntimeCheck, reset InterestingDependences When dependence analysis encounters a non-constant distance between memory accesses it aborts the analysis and falls back to run-time checks only. In this case we weren't resetting the array of dependences. llvm-svn: 237574
2015-05-18 23:37:03 +08:00
; RUN: opt -loop-accesses -analyze < %s | FileCheck %s
[PM] Avoid getResult on a higher level in LoopAccessAnalysis Note that require<domtree> and require<loops> aren't needed because they come in implicitly via the loop pass manager. llvm-svn: 274712
2016-07-07 09:01:53 +08:00
; RUN: opt -passes='require<scalar-evolution>,require<aa>,loop(print-access-info)' -disable-output < %s 2>&1 | FileCheck %s
[LoopAccesses] If shouldRetryWithRuntimeCheck, reset InterestingDependences When dependence analysis encounters a non-constant distance between memory accesses it aborts the analysis and falls back to run-time checks only. In this case we weren't resetting the array of dependences. llvm-svn: 237574
2015-05-18 23:37:03 +08:00
; We give up analyzing the dependences in this loop due to non-constant
; distance between A[i+offset] and A[i] and add memchecks to prove
[LAA] LLE 3/6: Rename InterestingDependence to Dependences, NFC Summary: We now collect all types of dependences including lexically forward deps not just "interesting" ones. Reviewers: hfinkel Subscribers: rengolin, llvm-commits Differential Revision: http://reviews.llvm.org/D13256 llvm-svn: 251985
2015-11-04 05:39:52 +08:00
; independence. Make sure that no dependences are reported in
[LoopAccesses] If shouldRetryWithRuntimeCheck, reset InterestingDependences When dependence analysis encounters a non-constant distance between memory accesses it aborts the analysis and falls back to run-time checks only. In this case we weren't resetting the array of dependences. llvm-svn: 237574
2015-05-18 23:37:03 +08:00
; this case.
;
; for (i = 0; i < n; i++)
; A[i + offset] = A[i] * B[i] * C[i];
target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-apple-macosx10.10.0"
; CHECK: Memory dependences are safe with run-time checks
[LAA] LLE 3/6: Rename InterestingDependence to Dependences, NFC Summary: We now collect all types of dependences including lexically forward deps not just "interesting" ones. Reviewers: hfinkel Subscribers: rengolin, llvm-commits Differential Revision: http://reviews.llvm.org/D13256 llvm-svn: 251985
2015-11-04 05:39:52 +08:00
; CHECK-NEXT: Dependences:
[LoopAccesses] If shouldRetryWithRuntimeCheck, reset InterestingDependences When dependence analysis encounters a non-constant distance between memory accesses it aborts the analysis and falls back to run-time checks only. In this case we weren't resetting the array of dependences. llvm-svn: 237574
2015-05-18 23:37:03 +08:00
; CHECK-NEXT: Run-time memory checks:
; CHECK-NEXT: 0:
[LAA] Merge memchecks for accesses separated by a constant offset Summary: Often filter-like loops will do memory accesses that are separated by constant offsets. In these cases it is common that we will exceed the threshold for the allowable number of checks. However, it should be possible to merge such checks, sice a check of any interval againt two other intervals separated by a constant offset (a,b), (a+c, b+c) will be equivalent with a check againt (a, b+c), as long as (a,b) and (a+c, b+c) overlap. Assuming the loop will be executed for a sufficient number of iterations, this will be true. If not true, checking against (a, b+c) is still safe (although not equivalent). As long as there are no dependencies between two accesses, we can merge their checks into a single one. We use this technique to construct groups of accesses, and then check the intervals associated with the groups instead of checking the accesses directly. Reviewers: anemet Subscribers: llvm-commits Differential Revision: http://reviews.llvm.org/D10386 llvm-svn: 241673
2015-07-08 17:16:33 +08:00
; CHECK-NEXT: Comparing group
[LoopAccesses] If shouldRetryWithRuntimeCheck, reset InterestingDependences When dependence analysis encounters a non-constant distance between memory accesses it aborts the analysis and falls back to run-time checks only. In this case we weren't resetting the array of dependences. llvm-svn: 237574
2015-05-18 23:37:03 +08:00
; CHECK-NEXT: %arrayidxA2 = getelementptr inbounds i16, i16* %a, i64 %idx
[LAA] Merge memchecks for accesses separated by a constant offset Summary: Often filter-like loops will do memory accesses that are separated by constant offsets. In these cases it is common that we will exceed the threshold for the allowable number of checks. However, it should be possible to merge such checks, sice a check of any interval againt two other intervals separated by a constant offset (a,b), (a+c, b+c) will be equivalent with a check againt (a, b+c), as long as (a,b) and (a+c, b+c) overlap. Assuming the loop will be executed for a sufficient number of iterations, this will be true. If not true, checking against (a, b+c) is still safe (although not equivalent). As long as there are no dependencies between two accesses, we can merge their checks into a single one. We use this technique to construct groups of accesses, and then check the intervals associated with the groups instead of checking the accesses directly. Reviewers: anemet Subscribers: llvm-commits Differential Revision: http://reviews.llvm.org/D10386 llvm-svn: 241673
2015-07-08 17:16:33 +08:00
; CHECK-NEXT: Against group
[LoopAccesses] If shouldRetryWithRuntimeCheck, reset InterestingDependences When dependence analysis encounters a non-constant distance between memory accesses it aborts the analysis and falls back to run-time checks only. In this case we weren't resetting the array of dependences. llvm-svn: 237574
2015-05-18 23:37:03 +08:00
; CHECK-NEXT: %arrayidxA = getelementptr inbounds i16, i16* %a, i64 %indvar
@B = common global i16* null, align 8
@A = common global i16* null, align 8
@C = common global i16* null, align 8
define void @f(i64 %offset) {
entry:
%a = load i16*, i16** @A, align 8
%b = load i16*, i16** @B, align 8
%c = load i16*, i16** @C, align 8
br label %for.body
for.body: ; preds = %for.body, %entry
%indvar = phi i64 [ 0, %entry ], [ %add, %for.body ]
%arrayidxA = getelementptr inbounds i16, i16* %a, i64 %indvar
%loadA = load i16, i16* %arrayidxA, align 2
%arrayidxB = getelementptr inbounds i16, i16* %b, i64 %indvar
%loadB = load i16, i16* %arrayidxB, align 2
%arrayidxC = getelementptr inbounds i16, i16* %c, i64 %indvar
%loadC = load i16, i16* %arrayidxC, align 2
%mul = mul i16 %loadB, %loadA
%mul1 = mul i16 %mul, %loadC
%idx = add i64 %indvar, %offset
%arrayidxA2 = getelementptr inbounds i16, i16* %a, i64 %idx
store i16 %mul1, i16* %arrayidxA2, align 2
%add = add nuw nsw i64 %indvar, 1
%exitcond = icmp eq i64 %add, 20
br i1 %exitcond, label %for.end, label %for.body
for.end: ; preds = %for.body
ret void
}