diff --git a/llvm/lib/Analysis/InstructionSimplify.cpp b/llvm/lib/Analysis/InstructionSimplify.cpp --- a/llvm/lib/Analysis/InstructionSimplify.cpp +++ b/llvm/lib/Analysis/InstructionSimplify.cpp @@ -68,6 +68,8 @@ const SimplifyQuery &, unsigned); static Value *SimplifyGEPInst(Type *, ArrayRef, const SimplifyQuery &, unsigned); +static Value *SimplifySelectInst(Value *, Value *, Value *, + const SimplifyQuery &, unsigned); static Value *foldSelectWithBinaryOp(Value *Cond, Value *TrueVal, Value *FalseVal) { @@ -3992,6 +3994,17 @@ } } + // Same for Selects. + if (auto *SI = dyn_cast(I)) { + if (MaxRecurse) { + SmallVector NewOps(3); + transform(SI->operands(), NewOps.begin(), + [&](Value *V) { return V == Op ? RepOp : V; }); + return PreventSelfSimplify(SimplifySelectInst( + NewOps[0], NewOps[1], NewOps[2], Q, MaxRecurse - 1)); + } + } + // TODO: We could hand off more cases to instsimplify here. // If all operands are constant after substituting Op for RepOp then we can diff --git a/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp b/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp --- a/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp @@ -2600,34 +2600,50 @@ return BinaryOperator::CreateAnd(CondVal, TrueVal); } + auto *One = ConstantInt::getTrue(SelType); + auto *Zero = ConstantInt::getFalse(SelType); + // select a, false, b -> select !a, b, false if (match(TrueVal, m_Zero())) { Value *NotCond = Builder.CreateNot(CondVal, "not." + CondVal->getName()); - return SelectInst::Create(NotCond, FalseVal, - ConstantInt::getFalse(SelType)); + return SelectInst::Create(NotCond, FalseVal, Zero); } // select a, b, true -> select !a, true, b if (match(FalseVal, m_One())) { Value *NotCond = Builder.CreateNot(CondVal, "not." + CondVal->getName()); - return SelectInst::Create(NotCond, ConstantInt::getTrue(SelType), - TrueVal); + return SelectInst::Create(NotCond, One, TrueVal); } // select a, a, b -> select a, true, b if (CondVal == TrueVal) - return replaceOperand(SI, 1, ConstantInt::getTrue(SelType)); + return replaceOperand(SI, 1, One); // select a, b, a -> select a, b, false if (CondVal == FalseVal) - return replaceOperand(SI, 2, ConstantInt::getFalse(SelType)); + return replaceOperand(SI, 2, Zero); // select a, !a, b -> select !a, b, false if (match(TrueVal, m_Not(m_Specific(CondVal)))) - return SelectInst::Create(TrueVal, FalseVal, - ConstantInt::getFalse(SelType)); + return SelectInst::Create(TrueVal, FalseVal, Zero); // select a, b, !a -> select !a, true, b if (match(FalseVal, m_Not(m_Specific(CondVal)))) - return SelectInst::Create(FalseVal, ConstantInt::getTrue(SelType), - TrueVal); + return SelectInst::Create(FalseVal, One, TrueVal); + + Value *A, *B; + // select (select a, true, b), true, b -> select a, true, b + if (match(CondVal, m_Select(m_Value(A), m_One(), m_Value(B))) && + match(TrueVal, m_One()) && match(FalseVal, m_Specific(B))) + return replaceOperand(SI, 0, A); + // select (select a, b, false), b, false -> select a, b, false + if (match(CondVal, m_Select(m_Value(A), m_Value(B), m_Zero())) && + match(TrueVal, m_Specific(B)) && match(FalseVal, m_Zero())) + return replaceOperand(SI, 0, A); + + if (Value *S = SimplifyWithOpReplaced(TrueVal, CondVal, One, SQ, + /* AllowRefinement */ true)) + return replaceOperand(SI, 1, S); + if (Value *S = SimplifyWithOpReplaced(FalseVal, CondVal, Zero, SQ, + /* AllowRefinement */ true)) + return replaceOperand(SI, 2, S); } // Selecting between two integer or vector splat integer constants? diff --git a/llvm/test/Transforms/InstCombine/select-safe-bool-transforms.ll b/llvm/test/Transforms/InstCombine/select-safe-bool-transforms.ll --- a/llvm/test/Transforms/InstCombine/select-safe-bool-transforms.ll +++ b/llvm/test/Transforms/InstCombine/select-safe-bool-transforms.ll @@ -18,8 +18,7 @@ } define i1 @land_land_left2(i1 %A, i1 %B) { ; CHECK-LABEL: @land_land_left2( -; CHECK-NEXT: [[C:%.*]] = select i1 [[B:%.*]], i1 [[A:%.*]], i1 false -; CHECK-NEXT: [[RES:%.*]] = select i1 [[C]], i1 [[A]], i1 false +; CHECK-NEXT: [[RES:%.*]] = select i1 [[B:%.*]], i1 [[A:%.*]], i1 false ; CHECK-NEXT: ret i1 [[RES]] ; %c = select i1 %B, i1 %A, i1 false @@ -181,8 +180,7 @@ } define i1 @lor_lor_left2(i1 %A, i1 %B) { ; CHECK-LABEL: @lor_lor_left2( -; CHECK-NEXT: [[C:%.*]] = select i1 [[B:%.*]], i1 true, i1 [[A:%.*]] -; CHECK-NEXT: [[RES:%.*]] = select i1 [[C]], i1 true, i1 [[A]] +; CHECK-NEXT: [[RES:%.*]] = select i1 [[B:%.*]], i1 true, i1 [[A:%.*]] ; CHECK-NEXT: ret i1 [[RES]] ; %c = select i1 %B, i1 true, i1 %A @@ -262,8 +260,8 @@ } define i1 @land_land_right2(i1 %A, i1 %B) { ; CHECK-LABEL: @land_land_right2( -; CHECK-NEXT: [[TMP1:%.*]] = select i1 [[A:%.*]], i1 [[B:%.*]], i1 false -; CHECK-NEXT: ret i1 [[TMP1]] +; CHECK-NEXT: [[RES:%.*]] = select i1 [[A:%.*]], i1 [[B:%.*]], i1 false +; CHECK-NEXT: ret i1 [[RES]] ; %c = select i1 %B, i1 %A, i1 false %res = select i1 %A, i1 %c, i1 false @@ -301,9 +299,7 @@ } define i1 @land_lor_right2(i1 %A, i1 %B) { ; CHECK-LABEL: @land_lor_right2( -; CHECK-NEXT: [[C:%.*]] = select i1 [[B:%.*]], i1 [[A:%.*]], i1 false -; CHECK-NEXT: [[RES:%.*]] = select i1 [[A]], i1 true, i1 [[C]] -; CHECK-NEXT: ret i1 [[RES]] +; CHECK-NEXT: ret i1 [[A:%.*]] ; %c = select i1 %B, i1 %A, i1 false %res = select i1 %A, i1 true, i1 %c @@ -333,8 +329,7 @@ ; A land (A band B) define i1 @band_land_right1(i1 %A, i1 %B) { ; CHECK-LABEL: @band_land_right1( -; CHECK-NEXT: [[C:%.*]] = and i1 [[A:%.*]], [[B:%.*]] -; CHECK-NEXT: [[RES:%.*]] = select i1 [[A]], i1 [[C]], i1 false +; CHECK-NEXT: [[RES:%.*]] = select i1 [[A:%.*]], i1 [[B:%.*]], i1 false ; CHECK-NEXT: ret i1 [[RES]] ; %c = and i1 %A, %B @@ -343,8 +338,7 @@ } define i1 @band_land_right2(i1 %A, i1 %B) { ; CHECK-LABEL: @band_land_right2( -; CHECK-NEXT: [[C:%.*]] = and i1 [[B:%.*]], [[A:%.*]] -; CHECK-NEXT: [[RES:%.*]] = select i1 [[A]], i1 [[C]], i1 false +; CHECK-NEXT: [[RES:%.*]] = select i1 [[A:%.*]], i1 [[B:%.*]], i1 false ; CHECK-NEXT: ret i1 [[RES]] ; %c = and i1 %B, %A @@ -355,9 +349,7 @@ ; A lor (A band B) define i1 @band_lor_right1(i1 %A, i1 %B) { ; CHECK-LABEL: @band_lor_right1( -; CHECK-NEXT: [[C:%.*]] = and i1 [[A:%.*]], [[B:%.*]] -; CHECK-NEXT: [[RES:%.*]] = select i1 [[A]], i1 true, i1 [[C]] -; CHECK-NEXT: ret i1 [[RES]] +; CHECK-NEXT: ret i1 [[A:%.*]] ; %c = and i1 %A, %B %res = select i1 %A, i1 true, i1 %c @@ -365,9 +357,7 @@ } define i1 @band_lor_right2(i1 %A, i1 %B) { ; CHECK-LABEL: @band_lor_right2( -; CHECK-NEXT: [[C:%.*]] = and i1 [[B:%.*]], [[A:%.*]] -; CHECK-NEXT: [[RES:%.*]] = select i1 [[A]], i1 true, i1 [[C]] -; CHECK-NEXT: ret i1 [[RES]] +; CHECK-NEXT: ret i1 [[A:%.*]] ; %c = and i1 %B, %A %res = select i1 %A, i1 true, i1 %c @@ -385,9 +375,7 @@ } define i1 @lor_land_right2(i1 %A, i1 %B) { ; CHECK-LABEL: @lor_land_right2( -; CHECK-NEXT: [[C:%.*]] = select i1 [[B:%.*]], i1 true, i1 [[A:%.*]] -; CHECK-NEXT: [[RES:%.*]] = select i1 [[A]], i1 [[C]], i1 false -; CHECK-NEXT: ret i1 [[RES]] +; CHECK-NEXT: ret i1 [[A:%.*]] ; %c = select i1 %B, i1 true, i1 %A %res = select i1 %A, i1 %c, i1 false @@ -426,8 +414,8 @@ } define i1 @lor_lor_right2(i1 %A, i1 %B) { ; CHECK-LABEL: @lor_lor_right2( -; CHECK-NEXT: [[TMP1:%.*]] = select i1 [[A:%.*]], i1 true, i1 [[B:%.*]] -; CHECK-NEXT: ret i1 [[TMP1]] +; CHECK-NEXT: [[RES:%.*]] = select i1 [[A:%.*]], i1 true, i1 [[B:%.*]] +; CHECK-NEXT: ret i1 [[RES]] ; %c = select i1 %B, i1 true, i1 %A %res = select i1 %A, i1 true, i1 %c @@ -457,9 +445,7 @@ ; A land (A bor B) define i1 @bor_land_right1(i1 %A, i1 %B) { ; CHECK-LABEL: @bor_land_right1( -; CHECK-NEXT: [[C:%.*]] = or i1 [[A:%.*]], [[B:%.*]] -; CHECK-NEXT: [[RES:%.*]] = select i1 [[A]], i1 [[C]], i1 false -; CHECK-NEXT: ret i1 [[RES]] +; CHECK-NEXT: ret i1 [[A:%.*]] ; %c = or i1 %A, %B %res = select i1 %A, i1 %c, i1 false @@ -467,9 +453,7 @@ } define i1 @bor_land_right2(i1 %A, i1 %B) { ; CHECK-LABEL: @bor_land_right2( -; CHECK-NEXT: [[C:%.*]] = or i1 [[B:%.*]], [[A:%.*]] -; CHECK-NEXT: [[RES:%.*]] = select i1 [[A]], i1 [[C]], i1 false -; CHECK-NEXT: ret i1 [[RES]] +; CHECK-NEXT: ret i1 [[A:%.*]] ; %c = or i1 %B, %A %res = select i1 %A, i1 %c, i1 false @@ -479,8 +463,7 @@ ; A lor (A bor B) define i1 @bor_lor_right1(i1 %A, i1 %B) { ; CHECK-LABEL: @bor_lor_right1( -; CHECK-NEXT: [[C:%.*]] = or i1 [[A:%.*]], [[B:%.*]] -; CHECK-NEXT: [[RES:%.*]] = select i1 [[A]], i1 true, i1 [[C]] +; CHECK-NEXT: [[RES:%.*]] = select i1 [[A:%.*]], i1 true, i1 [[B:%.*]] ; CHECK-NEXT: ret i1 [[RES]] ; %c = or i1 %A, %B @@ -489,8 +472,7 @@ } define i1 @bor_lor_right2(i1 %A, i1 %B) { ; CHECK-LABEL: @bor_lor_right2( -; CHECK-NEXT: [[C:%.*]] = or i1 [[B:%.*]], [[A:%.*]] -; CHECK-NEXT: [[RES:%.*]] = select i1 [[A]], i1 true, i1 [[C]] +; CHECK-NEXT: [[RES:%.*]] = select i1 [[A:%.*]], i1 true, i1 [[B:%.*]] ; CHECK-NEXT: ret i1 [[RES]] ; %c = or i1 %B, %A diff --git a/llvm/test/Transforms/SimplifyCFG/merge-cond-stores.ll b/llvm/test/Transforms/SimplifyCFG/merge-cond-stores.ll --- a/llvm/test/Transforms/SimplifyCFG/merge-cond-stores.ll +++ b/llvm/test/Transforms/SimplifyCFG/merge-cond-stores.ll @@ -267,18 +267,17 @@ define i32 @test_diamond_simple(i32* %p, i32* %q, i32 %a, i32 %b) { ; CHECK-LABEL: @test_diamond_simple( ; CHECK-NEXT: entry: -; CHECK-NEXT: [[X1:%.*]] = icmp eq i32 [[A:%.*]], 0 -; CHECK-NEXT: [[Z2:%.*]] = select i1 [[X1]], i32 [[B:%.*]], i32 0 -; CHECK-NEXT: [[X2:%.*]] = icmp eq i32 [[B]], 0 -; CHECK-NEXT: [[TMP0:%.*]] = or i32 [[A]], [[B]] -; CHECK-NEXT: [[DOTNOT:%.*]] = icmp eq i32 [[TMP0]], 0 -; CHECK-NEXT: br i1 [[DOTNOT]], label [[TMP2:%.*]], label [[TMP1:%.*]] -; CHECK: 1: -; CHECK-NEXT: [[SIMPLIFYCFG_MERGE:%.*]] = select i1 [[X2]], i32 [[Z2]], i32 1 -; CHECK-NEXT: store i32 [[SIMPLIFYCFG_MERGE]], i32* [[P:%.*]], align 4 -; CHECK-NEXT: br label [[TMP2]] +; CHECK-NEXT: [[X2:%.*]] = icmp eq i32 [[B:%.*]], 0 +; CHECK-NEXT: [[TMP0:%.*]] = or i32 [[B]], [[A:%.*]] +; CHECK-NEXT: [[TMP1:%.*]] = icmp eq i32 [[TMP0]], 0 +; CHECK-NEXT: br i1 [[TMP1]], label [[TMP3:%.*]], label [[TMP2:%.*]] ; CHECK: 2: -; CHECK-NEXT: [[Z4:%.*]] = select i1 [[X2]], i32 [[Z2]], i32 3 +; CHECK-NEXT: [[NOT_X2:%.*]] = xor i1 [[X2]], true +; CHECK-NEXT: [[SIMPLIFYCFG_MERGE:%.*]] = zext i1 [[NOT_X2]] to i32 +; CHECK-NEXT: store i32 [[SIMPLIFYCFG_MERGE]], i32* [[P:%.*]], align 4 +; CHECK-NEXT: br label [[TMP3]] +; CHECK: 3: +; CHECK-NEXT: [[Z4:%.*]] = select i1 [[X2]], i32 0, i32 3 ; CHECK-NEXT: ret i32 [[Z4]] ; entry: