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| author | ZelinMa557 <72912470+ZelinMa557@users.noreply.github.com> | 2024-04-19 22:59:07 +0800 |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2024-04-19 22:59:07 +0800 |
| commit | 97c71247312c7e5261168283c13cd7e3ecd039a5 (patch) | |
| tree | 885c31fdb852b542d7e1b80b99b60bee615df1d7 | |
| parent | 3a4bc11b675c0511319c2843221133e986825b3b (diff) | |
| download | llvm-97c71247312c7e5261168283c13cd7e3ecd039a5.zip llvm-97c71247312c7e5261168283c13cd7e3ecd039a5.tar.gz llvm-97c71247312c7e5261168283c13cd7e3ecd039a5.tar.bz2 | |
[InstCombine] Regard zext nneg as sext when folding add(zext neg(add)) (#88887)
fixes #88348
proof:
https://alive2.llvm.org/ce/z/fJnM7t
test will be added later
---------
Signed-off-by: ZelinMa557 <3388706467@qq.com>
| -rw-r--r-- | llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp | 6 | ||||
| -rw-r--r-- | llvm/test/Transforms/InstCombine/add.ll | 37 |
2 files changed, 40 insertions, 3 deletions
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp b/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp index 9a16ca9..fc284bc 100644 --- a/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp @@ -828,9 +828,10 @@ static Instruction *foldNoWrapAdd(BinaryOperator &Add, // More general combining of constants in the wide type. // (sext (X +nsw NarrowC)) + C --> (sext X) + (sext(NarrowC) + C) + // or (zext nneg (X +nsw NarrowC)) + C --> (sext X) + (sext(NarrowC) + C) Constant *NarrowC; - if (match(Op0, - m_OneUse(m_SExt(m_NSWAddLike(m_Value(X), m_Constant(NarrowC)))))) { + if (match(Op0, m_OneUse(m_SExtLike( + m_NSWAddLike(m_Value(X), m_Constant(NarrowC)))))) { Value *WideC = Builder.CreateSExt(NarrowC, Ty); Value *NewC = Builder.CreateAdd(WideC, Op1C); Value *WideX = Builder.CreateSExt(X, Ty); @@ -844,7 +845,6 @@ static Instruction *foldNoWrapAdd(BinaryOperator &Add, Value *WideX = Builder.CreateZExt(X, Ty); return BinaryOperator::CreateAdd(WideX, NewC); } - return nullptr; } diff --git a/llvm/test/Transforms/InstCombine/add.ll b/llvm/test/Transforms/InstCombine/add.ll index 39b4ad8..56ee54d 100644 --- a/llvm/test/Transforms/InstCombine/add.ll +++ b/llvm/test/Transforms/InstCombine/add.ll @@ -4091,6 +4091,43 @@ define i32 @fold_zext_addition_fail2(i8 %x) { ret i32 %r } +define i32 @fold_zext_nneg_add_const(i8 %x) { +; CHECK-LABEL: @fold_zext_nneg_add_const( +; CHECK-NEXT: [[TMP1:%.*]] = sext i8 [[X:%.*]] to i32 +; CHECK-NEXT: [[R:%.*]] = add nsw i32 [[TMP1]], 98 +; CHECK-NEXT: ret i32 [[R]] +; + %xx = add nsw i8 %x, 123 + %ze = zext nneg i8 %xx to i32 + %r = add nsw i32 %ze, -25 + ret i32 %r +} + +define i32 @fold_zext_nneg_add_const_fail1(i8 %x) { +; CHECK-LABEL: @fold_zext_nneg_add_const_fail1( +; CHECK-NEXT: [[XX:%.*]] = add nsw i8 [[X:%.*]], 123 +; CHECK-NEXT: [[ZE:%.*]] = zext i8 [[XX]] to i32 +; CHECK-NEXT: [[R:%.*]] = add nsw i32 [[ZE]], -25 +; CHECK-NEXT: ret i32 [[R]] +; + %xx = add nsw i8 %x, 123 + %ze = zext i8 %xx to i32 + %r = add nsw i32 %ze, -25 + ret i32 %r +} + +define i32 @fold_zext_nneg_add_const_fail2(i8 %x) { +; CHECK-LABEL: @fold_zext_nneg_add_const_fail2( +; CHECK-NEXT: [[XX:%.*]] = add i8 [[X:%.*]], 123 +; CHECK-NEXT: [[ZE:%.*]] = zext nneg i8 [[XX]] to i32 +; CHECK-NEXT: [[R:%.*]] = add nsw i32 [[ZE]], -25 +; CHECK-NEXT: ret i32 [[R]] +; + %xx = add i8 %x, 123 + %ze = zext nneg i8 %xx to i32 + %r = add nsw i32 %ze, -25 + ret i32 %r +} declare void @llvm.assume(i1) declare void @fake_func(i32) |