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| author | Nikita Popov <npopov@redhat.com> | 2023-12-22 11:17:39 +0100 |
|---|---|---|
| committer | Nikita Popov <npopov@redhat.com> | 2023-12-22 11:30:17 +0100 |
| commit | c16559137cd1ad08ef5934558829d2ff5d227d70 (patch) | |
| tree | 6cf8df473de9ff48acff8984a60e9e5575db987d | |
| parent | 24e80d4cc5778fe4869badd34acbe1e7ded811d6 (diff) | |
| download | llvm-c16559137cd1ad08ef5934558829d2ff5d227d70.zip llvm-c16559137cd1ad08ef5934558829d2ff5d227d70.tar.gz llvm-c16559137cd1ad08ef5934558829d2ff5d227d70.tar.bz2 | |
[IndVars] Avoid unnecessary truncate for zext nneg use
When performing sext IV widening, if one of the narrow uses is in
a zext nneg, we can treat it like an sext and avoid the insertion
of a trunc.
| -rw-r--r-- | llvm/lib/Transforms/Utils/SimplifyIndVar.cpp | 2 | ||||
| -rw-r--r-- | llvm/test/Transforms/IndVarSimplify/widen-nonnegative.ll | 8 |
2 files changed, 3 insertions, 7 deletions
diff --git a/llvm/lib/Transforms/Utils/SimplifyIndVar.cpp b/llvm/lib/Transforms/Utils/SimplifyIndVar.cpp index 2f2fa37..42e7c40 100644 --- a/llvm/lib/Transforms/Utils/SimplifyIndVar.cpp +++ b/llvm/lib/Transforms/Utils/SimplifyIndVar.cpp @@ -1762,7 +1762,7 @@ Instruction *WidenIV::widenIVUse(WidenIV::NarrowIVDefUse DU, SCEVExpander &Rewri }; // Our raison d'etre! Eliminate sign and zero extension. - if ((isa<SExtInst>(DU.NarrowUse) && canWidenBySExt()) || + if ((match(DU.NarrowUse, m_SExtLike(m_Value())) && canWidenBySExt()) || (isa<ZExtInst>(DU.NarrowUse) && canWidenByZExt())) { Value *NewDef = DU.WideDef; if (DU.NarrowUse->getType() != WideType) { diff --git a/llvm/test/Transforms/IndVarSimplify/widen-nonnegative.ll b/llvm/test/Transforms/IndVarSimplify/widen-nonnegative.ll index 612e945..739db26 100644 --- a/llvm/test/Transforms/IndVarSimplify/widen-nonnegative.ll +++ b/llvm/test/Transforms/IndVarSimplify/widen-nonnegative.ll @@ -331,9 +331,7 @@ define void @zext_nneg_add_nsw(ptr %A, i32 %offset, i32 %M) { ; CHECK: for.body: ; CHECK-NEXT: [[INDVARS_IV:%.*]] = phi i64 [ [[INDVARS_IV_NEXT:%.*]], [[FOR_BODY]] ], [ 0, [[ENTRY:%.*]] ] ; CHECK-NEXT: [[TMP1:%.*]] = add nsw i64 [[INDVARS_IV]], [[TMP0]] -; CHECK-NEXT: [[TMP2:%.*]] = trunc i64 [[TMP1]] to i32 -; CHECK-NEXT: [[IDXPROM_US:%.*]] = zext nneg i32 [[TMP2]] to i64 -; CHECK-NEXT: [[ARRAYIDX_US:%.*]] = getelementptr inbounds i32, ptr [[A:%.*]], i64 [[IDXPROM_US]] +; CHECK-NEXT: [[ARRAYIDX_US:%.*]] = getelementptr inbounds i32, ptr [[A:%.*]], i64 [[TMP1]] ; CHECK-NEXT: tail call void @use_ptr(ptr [[ARRAYIDX_US]]) ; CHECK-NEXT: [[INDVARS_IV_NEXT]] = add nuw nsw i64 [[INDVARS_IV]], 1 ; CHECK-NEXT: [[EXITCOND:%.*]] = icmp ne i64 [[INDVARS_IV_NEXT]], [[WIDE_TRIP_COUNT]] @@ -658,9 +656,7 @@ define void @zext_nneg_mul_nsw(ptr %A, i32 %multiple, i32 %M) { ; CHECK: for.body: ; CHECK-NEXT: [[INDVARS_IV:%.*]] = phi i64 [ [[INDVARS_IV_NEXT:%.*]], [[FOR_BODY]] ], [ 0, [[ENTRY:%.*]] ] ; CHECK-NEXT: [[TMP1:%.*]] = mul nsw i64 [[INDVARS_IV]], [[TMP0]] -; CHECK-NEXT: [[TMP2:%.*]] = trunc i64 [[TMP1]] to i32 -; CHECK-NEXT: [[IDXPROM_US:%.*]] = zext nneg i32 [[TMP2]] to i64 -; CHECK-NEXT: [[ARRAYIDX_US:%.*]] = getelementptr inbounds i32, ptr [[A:%.*]], i64 [[IDXPROM_US]] +; CHECK-NEXT: [[ARRAYIDX_US:%.*]] = getelementptr inbounds i32, ptr [[A:%.*]], i64 [[TMP1]] ; CHECK-NEXT: tail call void @use_ptr(ptr [[ARRAYIDX_US]]) ; CHECK-NEXT: [[INDVARS_IV_NEXT]] = add nuw nsw i64 [[INDVARS_IV]], 1 ; CHECK-NEXT: [[EXITCOND:%.*]] = icmp ne i64 [[INDVARS_IV_NEXT]], [[WIDE_TRIP_COUNT]] |