From ac70b37a00dc02bd8923e0a4602d26be4581c570 Mon Sep 17 00:00:00 2001 From: Roman Lebedev Date: Wed, 5 Aug 2020 03:19:38 +0300 Subject: [PATCH] Revert "[InstCombine] Negator: -(X << C) --> X * (-1 << C)" Breaks codegen tests, will recommit later. This reverts commit 8aeb2fe13a4100b4c2e78d6ef75119304100cb1f. --- .../InstCombine/InstCombineNegator.cpp | 12 ++---- llvm/test/Transforms/InstCombine/icmp.ll | 3 +- llvm/test/Transforms/InstCombine/sub-gep.ll | 10 ++--- .../InstCombine/sub-of-negatible.ll | 4 +- llvm/test/Transforms/InstCombine/sub.ll | 43 +++++++++---------- 5 files changed, 32 insertions(+), 40 deletions(-) diff --git a/llvm/lib/Transforms/InstCombine/InstCombineNegator.cpp b/llvm/lib/Transforms/InstCombine/InstCombineNegator.cpp index b684016b6a29..1c7f00b0edee 100644 --- a/llvm/lib/Transforms/InstCombine/InstCombineNegator.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineNegator.cpp @@ -324,16 +324,10 @@ LLVM_NODISCARD Value *Negator::visitImpl(Value *V, unsigned Depth) { } case Instruction::Shl: { // `shl` is negatible if the first operand is negatible. - if (Value *NegOp0 = negate(I->getOperand(0), Depth + 1)) - return Builder.CreateShl(NegOp0, I->getOperand(1), I->getName() + ".neg"); - // Otherwise, `shl %x, C` can be interpreted as `mul %x, 1<(I->getOperand(1)); - if (!Op1C) // Early return. + Value *NegOp0 = negate(I->getOperand(0), Depth + 1); + if (!NegOp0) // Early return. return nullptr; - return Builder.CreateMul( - I->getOperand(0), - ConstantExpr::getShl(Constant::getAllOnesValue(Op1C->getType()), Op1C), - I->getName() + ".neg"); + return Builder.CreateShl(NegOp0, I->getOperand(1), I->getName() + ".neg"); } case Instruction::Or: if (!haveNoCommonBitsSet(I->getOperand(0), I->getOperand(1), DL, &AC, I, diff --git a/llvm/test/Transforms/InstCombine/icmp.ll b/llvm/test/Transforms/InstCombine/icmp.ll index 7addc85c4c8b..e3050aa1bac2 100644 --- a/llvm/test/Transforms/InstCombine/icmp.ll +++ b/llvm/test/Transforms/InstCombine/icmp.ll @@ -512,8 +512,7 @@ define i1 @test24(i64 %i) { ; unsigned overflow does not happen during offset computation define i1 @test24_neg_offs(i32* %p, i64 %offs) { ; CHECK-LABEL: @test24_neg_offs( -; CHECK-NEXT: [[P1_IDX_NEG:%.*]] = mul i64 [[OFFS:%.*]], -4 -; CHECK-NEXT: [[CMP:%.*]] = icmp eq i64 [[P1_IDX_NEG]], 8 +; CHECK-NEXT: [[CMP:%.*]] = icmp eq i64 [[OFFS:%.*]], -2 ; CHECK-NEXT: ret i1 [[CMP]] ; %p1 = getelementptr inbounds i32, i32* %p, i64 %offs diff --git a/llvm/test/Transforms/InstCombine/sub-gep.ll b/llvm/test/Transforms/InstCombine/sub-gep.ll index cf9604223f6c..51eb994bf345 100644 --- a/llvm/test/Transforms/InstCombine/sub-gep.ll +++ b/llvm/test/Transforms/InstCombine/sub-gep.ll @@ -58,8 +58,9 @@ define i32 @test_inbounds_nuw_trunc([0 x i32]* %base, i64 %idx) { define i64 @test_inbounds_nuw_swapped([0 x i32]* %base, i64 %idx) { ; CHECK-LABEL: @test_inbounds_nuw_swapped( -; CHECK-NEXT: [[P2_IDX_NEG:%.*]] = mul i64 [[IDX:%.*]], -4 -; CHECK-NEXT: ret i64 [[P2_IDX_NEG]] +; CHECK-NEXT: [[P2_IDX:%.*]] = shl nsw i64 [[IDX:%.*]], 2 +; CHECK-NEXT: [[DIFF_NEG:%.*]] = sub i64 0, [[P2_IDX]] +; CHECK-NEXT: ret i64 [[DIFF_NEG]] ; %p1 = getelementptr inbounds [0 x i32], [0 x i32]* %base, i64 0, i64 0 %p2 = getelementptr inbounds [0 x i32], [0 x i32]* %base, i64 0, i64 %idx @@ -72,9 +73,8 @@ define i64 @test_inbounds_nuw_swapped([0 x i32]* %base, i64 %idx) { ; The sub and shl here could be nuw, but this is harder to handle. define i64 @test_inbounds_nuw_two_gep([0 x i32]* %base, i64 %idx, i64 %idx2) { ; CHECK-LABEL: @test_inbounds_nuw_two_gep( -; CHECK-NEXT: [[P1_IDX_NEG:%.*]] = mul i64 [[IDX:%.*]], -4 -; CHECK-NEXT: [[P2_IDX_NEG_NEG:%.*]] = shl i64 [[IDX2:%.*]], 2 -; CHECK-NEXT: [[DOTNEG:%.*]] = add i64 [[P2_IDX_NEG_NEG]], [[P1_IDX_NEG]] +; CHECK-NEXT: [[P1_IDX1_NEG:%.*]] = sub i64 [[IDX2:%.*]], [[IDX:%.*]] +; CHECK-NEXT: [[DOTNEG:%.*]] = shl i64 [[P1_IDX1_NEG]], 2 ; CHECK-NEXT: ret i64 [[DOTNEG]] ; %p1 = getelementptr inbounds [0 x i32], [0 x i32]* %base, i64 0, i64 %idx diff --git a/llvm/test/Transforms/InstCombine/sub-of-negatible.ll b/llvm/test/Transforms/InstCombine/sub-of-negatible.ll index 4a3c56337c22..caa6e25ccf69 100644 --- a/llvm/test/Transforms/InstCombine/sub-of-negatible.ll +++ b/llvm/test/Transforms/InstCombine/sub-of-negatible.ll @@ -1076,8 +1076,8 @@ define i8 @negate_left_shift_by_constant(i8 %x, i8 %y, i8 %z, i8 %k) { ; CHECK-LABEL: @negate_left_shift_by_constant( ; CHECK-NEXT: [[T0:%.*]] = sub i8 [[K:%.*]], [[Z:%.*]] ; CHECK-NEXT: call void @use8(i8 [[T0]]) -; CHECK-NEXT: [[T1_NEG:%.*]] = mul i8 [[T0]], -16 -; CHECK-NEXT: [[T2:%.*]] = add i8 [[T1_NEG]], [[X:%.*]] +; CHECK-NEXT: [[T1:%.*]] = shl i8 [[T0]], 4 +; CHECK-NEXT: [[T2:%.*]] = sub i8 [[X:%.*]], [[T1]] ; CHECK-NEXT: ret i8 [[T2]] ; %t0 = sub i8 %k, %z diff --git a/llvm/test/Transforms/InstCombine/sub.ll b/llvm/test/Transforms/InstCombine/sub.ll index 4116a79d66d9..3bc8b67649fc 100644 --- a/llvm/test/Transforms/InstCombine/sub.ll +++ b/llvm/test/Transforms/InstCombine/sub.ll @@ -506,8 +506,8 @@ define i64 @test24b(i8* %P, i64 %A){ define i64 @test25(i8* %P, i64 %A){ ; CHECK-LABEL: @test25( -; CHECK-NEXT: [[B_IDX_NEG_NEG:%.*]] = shl i64 [[A:%.*]], 1 -; CHECK-NEXT: [[DOTNEG:%.*]] = add i64 [[B_IDX_NEG_NEG]], -84 +; CHECK-NEXT: [[B_IDX:%.*]] = shl nsw i64 [[A:%.*]], 1 +; CHECK-NEXT: [[DOTNEG:%.*]] = add i64 [[B_IDX]], -84 ; CHECK-NEXT: ret i64 [[DOTNEG]] ; %B = getelementptr inbounds [42 x i16], [42 x i16]* @Arr, i64 0, i64 %A @@ -521,8 +521,8 @@ define i64 @test25(i8* %P, i64 %A){ define i16 @test25_as1(i8 addrspace(1)* %P, i64 %A) { ; CHECK-LABEL: @test25_as1( ; CHECK-NEXT: [[TMP1:%.*]] = trunc i64 [[A:%.*]] to i16 -; CHECK-NEXT: [[B_IDX_NEG_NEG:%.*]] = shl i16 [[TMP1]], 1 -; CHECK-NEXT: [[DOTNEG:%.*]] = add i16 [[B_IDX_NEG_NEG]], -84 +; CHECK-NEXT: [[B_IDX:%.*]] = shl nsw i16 [[TMP1]], 1 +; CHECK-NEXT: [[DOTNEG:%.*]] = add i16 [[B_IDX]], -84 ; CHECK-NEXT: ret i16 [[DOTNEG]] ; %B = getelementptr inbounds [42 x i16], [42 x i16] addrspace(1)* @Arr_as1, i64 0, i64 %A @@ -557,8 +557,9 @@ define i64 @test_neg_shl_sub_extra_use1(i64 %a, i64 %b, i64* %p) { ; CHECK-LABEL: @test_neg_shl_sub_extra_use1( ; CHECK-NEXT: [[SUB:%.*]] = sub i64 [[A:%.*]], [[B:%.*]] ; CHECK-NEXT: store i64 [[SUB]], i64* [[P:%.*]], align 8 -; CHECK-NEXT: [[MUL_NEG:%.*]] = mul i64 [[SUB]], -4 -; CHECK-NEXT: ret i64 [[MUL_NEG]] +; CHECK-NEXT: [[MUL:%.*]] = shl i64 [[SUB]], 2 +; CHECK-NEXT: [[NEG:%.*]] = sub i64 0, [[MUL]] +; CHECK-NEXT: ret i64 [[NEG]] ; %sub = sub i64 %a, %b store i64 %sub, i64* %p @@ -839,10 +840,9 @@ define i64 @test29(i8* %foo, i64 %i, i64 %j) { define i64 @test30(i8* %foo, i64 %i, i64 %j) { ; CHECK-LABEL: @test30( -; CHECK-NEXT: [[GEP1_IDX_NEG:%.*]] = mul i64 [[I:%.*]], -4 -; CHECK-NEXT: [[TMP1:%.*]] = add i64 [[GEP1_IDX_NEG]], [[J:%.*]] -; CHECK-NEXT: [[DIFF_NEG:%.*]] = sub i64 0, [[TMP1]] -; CHECK-NEXT: ret i64 [[DIFF_NEG]] +; CHECK-NEXT: [[GEP1_IDX:%.*]] = shl nsw i64 [[I:%.*]], 2 +; CHECK-NEXT: [[DOTNEG:%.*]] = sub i64 [[GEP1_IDX]], [[J:%.*]] +; CHECK-NEXT: ret i64 [[DOTNEG]] ; %bit = bitcast i8* %foo to i32* %gep1 = getelementptr inbounds i32, i32* %bit, i64 %i @@ -855,10 +855,9 @@ define i64 @test30(i8* %foo, i64 %i, i64 %j) { define i16 @test30_as1(i8 addrspace(1)* %foo, i16 %i, i16 %j) { ; CHECK-LABEL: @test30_as1( -; CHECK-NEXT: [[GEP1_IDX_NEG:%.*]] = mul i16 [[I:%.*]], -4 -; CHECK-NEXT: [[TMP1:%.*]] = add i16 [[GEP1_IDX_NEG]], [[J:%.*]] -; CHECK-NEXT: [[DIFF_NEG:%.*]] = sub i16 0, [[TMP1]] -; CHECK-NEXT: ret i16 [[DIFF_NEG]] +; CHECK-NEXT: [[GEP1_IDX:%.*]] = shl nsw i16 [[I:%.*]], 2 +; CHECK-NEXT: [[DOTNEG:%.*]] = sub i16 [[GEP1_IDX]], [[J:%.*]] +; CHECK-NEXT: ret i16 [[DOTNEG]] ; %bit = bitcast i8 addrspace(1)* %foo to i32 addrspace(1)* %gep1 = getelementptr inbounds i32, i32 addrspace(1)* %bit, i16 %i @@ -1311,8 +1310,8 @@ define i64 @test61([100 x [100 x i8]]* %foo, i64 %i, i64 %j) { define i32 @test62(i32 %A) { ; CHECK-LABEL: @test62( -; CHECK-NEXT: [[B_NEG:%.*]] = mul i32 [[A:%.*]], -2 -; CHECK-NEXT: [[C:%.*]] = add i32 [[B_NEG]], 2 +; CHECK-NEXT: [[B:%.*]] = shl i32 [[A:%.*]], 1 +; CHECK-NEXT: [[C:%.*]] = sub i32 2, [[B]] ; CHECK-NEXT: ret i32 [[C]] ; %B = sub i32 1, %A @@ -1322,8 +1321,8 @@ define i32 @test62(i32 %A) { define <2 x i32> @test62vec(<2 x i32> %A) { ; CHECK-LABEL: @test62vec( -; CHECK-NEXT: [[B_NEG:%.*]] = mul <2 x i32> [[A:%.*]], -; CHECK-NEXT: [[C:%.*]] = add <2 x i32> [[B_NEG]], +; CHECK-NEXT: [[B:%.*]] = shl <2 x i32> [[A:%.*]], +; CHECK-NEXT: [[C:%.*]] = sub <2 x i32> , [[B]] ; CHECK-NEXT: ret <2 x i32> [[C]] ; %B = sub <2 x i32> , %A @@ -1333,8 +1332,8 @@ define <2 x i32> @test62vec(<2 x i32> %A) { define i32 @test63(i32 %A) { ; CHECK-LABEL: @test63( -; CHECK-NEXT: [[B_NEG_NEG:%.*]] = shl i32 [[A:%.*]], 1 -; CHECK-NEXT: ret i32 [[B_NEG_NEG]] +; CHECK-NEXT: [[B:%.*]] = shl i32 [[A:%.*]], 1 +; CHECK-NEXT: ret i32 [[B]] ; %B = sub i32 1, %A %C = shl i32 %B, 1 @@ -1344,8 +1343,8 @@ define i32 @test63(i32 %A) { define <2 x i32> @test63vec(<2 x i32> %A) { ; CHECK-LABEL: @test63vec( -; CHECK-NEXT: [[B_NEG_NEG:%.*]] = shl <2 x i32> [[A:%.*]], -; CHECK-NEXT: ret <2 x i32> [[B_NEG_NEG]] +; CHECK-NEXT: [[B:%.*]] = shl <2 x i32> [[A:%.*]], +; CHECK-NEXT: ret <2 x i32> [[B]] ; %B = sub <2 x i32> , %A %C = shl <2 x i32> %B,