Skip to content

[LAA] Support assumptions with non-constant deref sizes. #156529

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Closed
fhahn wants to merge 1 commit into from
Closed

[LAA] Support assumptions with non-constant deref sizes. #156529

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
9 changes: 6 additions & 3 deletions llvm/lib/Analysis/LoopAccessAnalysis.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -194,7 +194,10 @@ RuntimeCheckingPtrGroup::RuntimeCheckingPtrGroup(
/// return nullptr. \p A and \p B must have the same type.
static const SCEV *addSCEVNoOverflow(const SCEV *A, const SCEV *B,
ScalarEvolution &SE) {
if (!SE.willNotOverflow(Instruction::Add, /*IsSigned=*/false, A, B))
const SCEV *X;
if (!SE.willNotOverflow(Instruction::Add, /*IsSigned=*/false, A, B) &&
(!match(A, m_scev_Add(m_SCEV(X), m_SCEV())) ||
X != SE.getNegativeSCEV(B)))
return nullptr;
return SE.getAddExpr(A, B);
}
Expand Down Expand Up @@ -238,8 +241,8 @@ static bool evaluatePtrAddRecAtMaxBTCWillNotWrap(
StartPtrV, {Attribute::Dereferenceable}, *AC,
L->getLoopPredecessor()->getTerminator(), DT);
if (DerefRK) {
DerefBytesSCEV = SE.getUMaxExpr(
DerefBytesSCEV, SE.getConstant(WiderTy, DerefRK.ArgValue));
DerefBytesSCEV =
SE.getUMaxExpr(DerefBytesSCEV, SE.getSCEV(DerefRK.IRArgValue));
}
}

Expand Down
46 changes: 38 additions & 8 deletions llvm/test/Transforms/LoopVectorize/single-early-exit-deref-assumptions.ll
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -126,21 +126,51 @@ define i64 @early_exit_alignment_and_deref_known_via_assumption(ptr noalias %p1,
; CHECK-NEXT: entry:
; CHECK-NEXT: call void @llvm.assume(i1 true) [ "align"(ptr [[P1]], i64 4), "dereferenceable"(ptr [[P1]], i64 [[N]]) ]
; CHECK-NEXT: call void @llvm.assume(i1 true) [ "align"(ptr [[P2]], i64 4), "dereferenceable"(ptr [[P2]], i64 [[N]]) ]
; CHECK-NEXT: [[MIN_ITERS_CHECK:%.*]] = icmp ult i64 [[N]], 4
; CHECK-NEXT: br i1 [[MIN_ITERS_CHECK]], label [[SCALAR_PH:%.*]], label [[VECTOR_PH:%.*]]
; CHECK: vector.ph:
; CHECK-NEXT: [[N_MOD_VF:%.*]] = urem i64 [[N]], 4
; CHECK-NEXT: [[INDEX_NEXT:%.*]] = sub i64 [[N]], [[N_MOD_VF]]
; CHECK-NEXT: br label [[LOOP:%.*]]
; CHECK: vector.body:
; CHECK-NEXT: [[INDEX1:%.*]] = phi i64 [ 0, [[VECTOR_PH]] ], [ [[INDEX_NEXT3:%.*]], [[LOOP]] ]
; CHECK-NEXT: [[TMP0:%.*]] = getelementptr inbounds i8, ptr [[P1]], i64 [[INDEX1]]
; CHECK-NEXT: [[WIDE_LOAD:%.*]] = load <4 x i8>, ptr [[TMP0]], align 1
; CHECK-NEXT: [[TMP1:%.*]] = getelementptr inbounds i8, ptr [[P2]], i64 [[INDEX1]]
; CHECK-NEXT: [[WIDE_LOAD2:%.*]] = load <4 x i8>, ptr [[TMP1]], align 1
; CHECK-NEXT: [[TMP2:%.*]] = icmp ne <4 x i8> [[WIDE_LOAD]], [[WIDE_LOAD2]]
; CHECK-NEXT: [[INDEX_NEXT3]] = add nuw i64 [[INDEX1]], 4
; CHECK-NEXT: [[TMP3:%.*]] = freeze <4 x i1> [[TMP2]]
; CHECK-NEXT: [[TMP4:%.*]] = call i1 @llvm.vector.reduce.or.v4i1(<4 x i1> [[TMP3]])
; CHECK-NEXT: [[TMP5:%.*]] = icmp eq i64 [[INDEX_NEXT3]], [[INDEX_NEXT]]
; CHECK-NEXT: [[TMP6:%.*]] = or i1 [[TMP4]], [[TMP5]]
; CHECK-NEXT: br i1 [[TMP6]], label [[MIDDLE_SPLIT:%.*]], label [[LOOP]], !llvm.loop [[LOOP4:![0-9]+]]
; CHECK: middle.split:
; CHECK-NEXT: br i1 [[TMP4]], label [[VECTOR_EARLY_EXIT:%.*]], label [[LOOP_INC:%.*]]
; CHECK: middle.block:
; CHECK-NEXT: [[CMP_N:%.*]] = icmp eq i64 [[N]], [[INDEX_NEXT]]
; CHECK-NEXT: br i1 [[CMP_N]], label [[LOOP_END:%.*]], label [[SCALAR_PH]]
; CHECK: vector.early.exit:
; CHECK-NEXT: [[TMP7:%.*]] = call i64 @llvm.experimental.cttz.elts.i64.v4i1(<4 x i1> [[TMP2]], i1 true)
; CHECK-NEXT: [[TMP8:%.*]] = add i64 [[INDEX1]], [[TMP7]]
; CHECK-NEXT: br label [[LOOP_END]]
; CHECK: scalar.ph:
; CHECK-NEXT: [[INDEX:%.*]] = phi i64 [ [[INDEX_NEXT]], [[LOOP_INC]] ], [ 0, [[ENTRY:%.*]] ]
; CHECK-NEXT: br label [[LOOP1:%.*]]
; CHECK: loop:
; CHECK-NEXT: [[INDEX:%.*]] = phi i64 [ [[INDEX_NEXT:%.*]], [[LOOP_INC:%.*]] ], [ 0, [[ENTRY:%.*]] ]
; CHECK-NEXT: [[ARRAYIDX:%.*]] = getelementptr inbounds i8, ptr [[P1]], i64 [[INDEX]]
; CHECK-NEXT: [[INDEX2:%.*]] = phi i64 [ [[INDEX_NEXT1:%.*]], [[LOOP_INC1:%.*]] ], [ [[INDEX]], [[SCALAR_PH]] ]
; CHECK-NEXT: [[ARRAYIDX:%.*]] = getelementptr inbounds i8, ptr [[P1]], i64 [[INDEX2]]
; CHECK-NEXT: [[LD1:%.*]] = load i8, ptr [[ARRAYIDX]], align 1
; CHECK-NEXT: [[ARRAYIDX1:%.*]] = getelementptr inbounds i8, ptr [[P2]], i64 [[INDEX]]
; CHECK-NEXT: [[ARRAYIDX1:%.*]] = getelementptr inbounds i8, ptr [[P2]], i64 [[INDEX2]]
; CHECK-NEXT: [[LD2:%.*]] = load i8, ptr [[ARRAYIDX1]], align 1
; CHECK-NEXT: [[CMP3:%.*]] = icmp eq i8 [[LD1]], [[LD2]]
; CHECK-NEXT: br i1 [[CMP3]], label [[LOOP_INC]], label [[LOOP_END:%.*]]
; CHECK-NEXT: br i1 [[CMP3]], label [[LOOP_INC1]], label [[LOOP_END]]
; CHECK: loop.inc:
; CHECK-NEXT: [[INDEX_NEXT]] = add i64 [[INDEX]], 1
; CHECK-NEXT: [[EXITCOND:%.*]] = icmp ne i64 [[INDEX_NEXT]], [[N]]
; CHECK-NEXT: br i1 [[EXITCOND]], label [[LOOP]], label [[LOOP_END]]
; CHECK-NEXT: [[INDEX_NEXT1]] = add i64 [[INDEX2]], 1
; CHECK-NEXT: [[EXITCOND:%.*]] = icmp ne i64 [[INDEX_NEXT1]], [[N]]
; CHECK-NEXT: br i1 [[EXITCOND]], label [[LOOP1]], label [[LOOP_END]], !llvm.loop [[LOOP5:![0-9]+]]
; CHECK: loop.end:
; CHECK-NEXT: [[RETVAL:%.*]] = phi i64 [ [[INDEX]], [[LOOP]] ], [ -1, [[LOOP_INC]] ]
; CHECK-NEXT: [[RETVAL:%.*]] = phi i64 [ [[INDEX2]], [[LOOP1]] ], [ -1, [[LOOP_INC1]] ], [ -1, [[LOOP_INC]] ], [ [[TMP8]], [[VECTOR_EARLY_EXIT]] ]
; CHECK-NEXT: ret i64 [[RETVAL]]
;
entry:
Expand Down
Loading