[llvm] r221171 - [Reassociate] Canonicalize negative constants out of expressions.
Reid Kleckner
rnk at google.com
Tue Nov 4 15:21:28 PST 2014
I don't have a reduction, but I can confirm that reverting this change
causes the test to pass.
On Tue, Nov 4, 2014 at 2:55 PM, Reid Kleckner <rnk at google.com> wrote:
> I suspect that this change has broken some random number generation tests
> in Chromium:
>
> http://build.chromium.org/p/chromium.fyi/builders/Cr%20Win%20Clang%20tester/builds/755
>
> The LLVM revision window was 221173 to 221166, and this looks like the
> most culpable commit. The LLVM changes in that revision window were an R600
> change, yours, my noexcept change, an optnone change, and an MDNode=>Value
> change.
>
> I'll try to get a reduction.
>
> On Mon, Nov 3, 2014 at 11:11 AM, Chad Rosier <mcrosier at codeaurora.org>
> wrote:
>
>> Author: mcrosier
>> Date: Mon Nov 3 13:11:30 2014
>> New Revision: 221171
>>
>> URL: http://llvm.org/viewvc/llvm-project?rev=221171&view=rev
>> Log:
>> [Reassociate] Canonicalize negative constants out of expressions.
>>
>> This gives CSE/GVN more options to eliminate duplicate expressions.
>> This is a follow up patch to http://reviews.llvm.org/D4904.
>>
>> http://reviews.llvm.org/D5363
>>
>> Added:
>> llvm/trunk/test/Transforms/Reassociate/canonicalize-neg-const.ll
>> Removed:
>> llvm/trunk/test/Transforms/Reassociate/liftsign.ll
>> Modified:
>> llvm/trunk/lib/Transforms/Scalar/Reassociate.cpp
>> llvm/trunk/test/Transforms/Reassociate/basictest.ll
>>
>> Modified: llvm/trunk/lib/Transforms/Scalar/Reassociate.cpp
>> URL:
>> http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/Reassociate.cpp?rev=221171&r1=221170&r2=221171&view=diff
>>
>> ==============================================================================
>> --- llvm/trunk/lib/Transforms/Scalar/Reassociate.cpp (original)
>> +++ llvm/trunk/lib/Transforms/Scalar/Reassociate.cpp Mon Nov 3 13:11:30
>> 2014
>> @@ -193,9 +193,8 @@ namespace {
>> Value *OptimizeMul(BinaryOperator *I, SmallVectorImpl<ValueEntry>
>> &Ops);
>> Value *RemoveFactorFromExpression(Value *V, Value *Factor);
>> void EraseInst(Instruction *I);
>> - void optimizeFAddNegExpr(ConstantFP *ConstOperand, Instruction *I,
>> - int OperandNr);
>> void OptimizeInst(Instruction *I);
>> + Instruction *canonicalizeNegConstExpr(Instruction *I);
>> };
>> }
>>
>> @@ -1930,31 +1929,105 @@ void Reassociate::EraseInst(Instruction
>> }
>> }
>>
>> -void Reassociate::optimizeFAddNegExpr(ConstantFP *ConstOperand,
>> Instruction *I,
>> - int OperandNr) {
>> +// Canonicalize expressions of the following form:
>> +// x + (-Constant * y) -> x - (Constant * y)
>> +// x - (-Constant * y) -> x + (Constant * y)
>> +Instruction *Reassociate::canonicalizeNegConstExpr(Instruction *I) {
>> + if (!I->hasOneUse() || I->getType()->isVectorTy())
>> + return nullptr;
>> +
>> + // Must have at least one constant operand.
>> + Constant *C0 = dyn_cast<Constant>(I->getOperand(0));
>> + Constant *C1 = dyn_cast<Constant>(I->getOperand(1));
>> + if (!C0 && !C1)
>> + return nullptr;
>> +
>> + // Must be a negative ConstantInt or ConstantFP.
>> + Constant *C = C0 ? C0 : C1;
>> + unsigned ConstIdx = C0 ? 0 : 1;
>> + if (auto *CI = dyn_cast<ConstantInt>(C)) {
>> + if (!CI->isNegative())
>> + return nullptr;
>> + } else if (auto *CF = dyn_cast<ConstantFP>(C)) {
>> + if (!CF->isNegative())
>> + return nullptr;
>> + } else
>> + return nullptr;
>> +
>> + // User must be a binary operator with one or more uses.
>> + Instruction *User = I->user_back();
>> + if (!isa<BinaryOperator>(User) || !User->getNumUses())
>> + return nullptr;
>> +
>> + // Must be a binary operator with higher precedence that add/sub.
>> + switch(I->getOpcode()) {
>> + default:
>> + return nullptr;
>> + case Instruction::Mul:
>> + case Instruction::FMul:
>> + case Instruction::UDiv:
>> + case Instruction::SDiv:
>> + case Instruction::FDiv:
>> + case Instruction::URem:
>> + case Instruction::SRem:
>> + case Instruction::FRem:
>> + break;
>> + }
>> +
>> + unsigned UserOpcode = User->getOpcode();
>> + if (UserOpcode != Instruction::Add && UserOpcode != Instruction::FAdd
>> &&
>> + UserOpcode != Instruction::Sub && UserOpcode != Instruction::FSub)
>> + return nullptr;
>> +
>> + // Subtraction is not commutative. Explicitly, the following transform
>> is
>> + // not valid: (-Constant * y) - x -> x + (Constant * y)
>> + if (!User->isCommutative() && User->getOperand(1) != I)
>> + return nullptr;
>> +
>> // Change the sign of the constant.
>> - APFloat Val = ConstOperand->getValueAPF();
>> - Val.changeSign();
>> - I->setOperand(0, ConstantFP::get(ConstOperand->getContext(), Val));
>> -
>> - assert(I->hasOneUse() && "Only a single use can be replaced.");
>> - Instruction *Parent = I->user_back();
>> -
>> - Value *OtherOperand = Parent->getOperand(1 - OperandNr);
>> -
>> - unsigned Opcode = Parent->getOpcode();
>> - assert(Opcode == Instruction::FAdd ||
>> - (Opcode == Instruction::FSub && Parent->getOperand(1) == I));
>> -
>> - BinaryOperator *NI = Opcode == Instruction::FAdd
>> - ? BinaryOperator::CreateFSub(OtherOperand, I)
>> - : BinaryOperator::CreateFAdd(OtherOperand, I);
>> - NI->setFastMathFlags(cast<FPMathOperator>(Parent)->getFastMathFlags());
>> - NI->insertBefore(Parent);
>> - NI->setName(Parent->getName() + ".repl");
>> - Parent->replaceAllUsesWith(NI);
>> + if (ConstantInt *CI = dyn_cast<ConstantInt>(C))
>> + I->setOperand(ConstIdx, ConstantInt::get(CI->getContext(),
>> -CI->getValue()));
>> + else {
>> + ConstantFP *CF = cast<ConstantFP>(C);
>> + APFloat Val = CF->getValueAPF();
>> + Val.changeSign();
>> + I->setOperand(ConstIdx, ConstantFP::get(CF->getContext(), Val));
>> + }
>> +
>> + // Canonicalize I to RHS to simplify the next bit of logic. E.g.,
>> + // ((-Const*y) + x) -> (x + (-Const*y)).
>> + if (User->getOperand(0) == I && User->isCommutative())
>> + cast<BinaryOperator>(User)->swapOperands();
>> +
>> + Value *Op0 = User->getOperand(0);
>> + Value *Op1 = User->getOperand(1);
>> + BinaryOperator *NI;
>> + switch(UserOpcode) {
>> + default:
>> + llvm_unreachable("Unexpected Opcode!");
>> + case Instruction::Add:
>> + NI = BinaryOperator::CreateSub(Op0, Op1);
>> + break;
>> + case Instruction::Sub:
>> + NI = BinaryOperator::CreateAdd(Op0, Op1);
>> + break;
>> + case Instruction::FAdd:
>> + NI = BinaryOperator::CreateFSub(Op0, Op1);
>> + NI->setFastMathFlags(cast<FPMathOperator>(User)->getFastMathFlags());
>> + break;
>> + case Instruction::FSub:
>> + NI = BinaryOperator::CreateFAdd(Op0, Op1);
>> + NI->setFastMathFlags(cast<FPMathOperator>(User)->getFastMathFlags());
>> + break;
>> + }
>> +
>> + NI->insertBefore(User);
>> + NI->setName(User->getName());
>> + User->replaceAllUsesWith(NI);
>> NI->setDebugLoc(I->getDebugLoc());
>> + RedoInsts.insert(I);
>> MadeChange = true;
>> + return NI;
>> }
>>
>> /// OptimizeInst - Inspect and optimize the given instruction. Note that
>> erasing
>> @@ -1977,6 +2050,10 @@ void Reassociate::OptimizeInst(Instructi
>> I = NI;
>> }
>>
>> + // Canonicalize negative constants out of expressions.
>> + if (Instruction *Res = canonicalizeNegConstExpr(I))
>> + I = Res;
>> +
>> // Commute floating point binary operators, to canonicalize the order
>> of their
>> // operands. This can potentially expose more CSE opportunities, and
>> makes
>> // writing other transformations simpler.
>> @@ -1997,24 +2074,6 @@ void Reassociate::OptimizeInst(Instructi
>> }
>> }
>>
>> - // Reassociate: x + -ConstantFP * y -> x - ConstantFP * y
>> - // The FMul can also be an FDiv, and FAdd can be a FSub.
>> - if (Opcode == Instruction::FMul || Opcode == Instruction::FDiv) {
>> - if (ConstantFP *LHSConst = dyn_cast<ConstantFP>(I->getOperand(0)))
>> {
>> - if (LHSConst->isNegative() && I->hasOneUse()) {
>> - Instruction *Parent = I->user_back();
>> - if (Parent->getOpcode() == Instruction::FAdd) {
>> - if (Parent->getOperand(0) == I)
>> - optimizeFAddNegExpr(LHSConst, I, 0);
>> - else if (Parent->getOperand(1) == I)
>> - optimizeFAddNegExpr(LHSConst, I, 1);
>> - } else if (Parent->getOpcode() == Instruction::FSub)
>> - if (Parent->getOperand(1) == I)
>> - optimizeFAddNegExpr(LHSConst, I, 1);
>> - }
>> - }
>> - }
>> -
>> // FIXME: We should commute vector instructions as well. However,
>> this
>> // requires further analysis to determine the effect on later passes.
>>
>>
>> Modified: llvm/trunk/test/Transforms/Reassociate/basictest.ll
>> URL:
>> http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/Reassociate/basictest.ll?rev=221171&r1=221170&r2=221171&view=diff
>>
>> ==============================================================================
>> --- llvm/trunk/test/Transforms/Reassociate/basictest.ll (original)
>> +++ llvm/trunk/test/Transforms/Reassociate/basictest.ll Mon Nov 3
>> 13:11:30 2014
>> @@ -203,7 +203,7 @@ define i32 @test14(i32 %X1, i32 %X2) {
>>
>> ; CHECK-LABEL: @test14
>> ; CHECK-NEXT: sub i32 %X1, %X2
>> -; CHECK-NEXT: mul i32 %tmp, 47
>> +; CHECK-NEXT: mul i32 %B2, 47
>> ; CHECK-NEXT: ret i32
>> }
>>
>>
>> Added: llvm/trunk/test/Transforms/Reassociate/canonicalize-neg-const.ll
>> URL:
>> http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/Reassociate/canonicalize-neg-const.ll?rev=221171&view=auto
>>
>> ==============================================================================
>> --- llvm/trunk/test/Transforms/Reassociate/canonicalize-neg-const.ll
>> (added)
>> +++ llvm/trunk/test/Transforms/Reassociate/canonicalize-neg-const.ll Mon
>> Nov 3 13:11:30 2014
>> @@ -0,0 +1,235 @@
>> +; RUN: opt -reassociate -gvn -S < %s | FileCheck %s
>> +
>> +; (x + 0.1234 * y) * (x + -0.1234 * y) -> (x + 0.1234 * y) * (x - 0.1234
>> * y)
>> +define double @test1(double %x, double %y) {
>> +; CHECK-LABEL: @test1
>> +; CHECK-NEXT: fmul double 1.234000e-01, %y
>> +; CHECK-NEXT: fadd double %x, %mul
>> +; CHECK-NEXT: fsub double %x, %mul
>> +; CHECK-NEXT: fmul double %add{{.*}}, %add{{.*}}
>> +; CHECK-NEXT: ret double %mul
>> +
>> + %mul = fmul double 1.234000e-01, %y
>> + %add = fadd double %mul, %x
>> + %mul1 = fmul double -1.234000e-01, %y
>> + %add2 = fadd double %mul1, %x
>> + %mul3 = fmul double %add, %add2
>> + ret double %mul3
>> +}
>> +
>> +; (x + -0.1234 * y) * (x + -0.1234 * y) -> (x - 0.1234 * y) * (x -
>> 0.1234 * y)
>> +define double @test2(double %x, double %y) {
>> +; CHECK-LABEL: @test2
>> +; CHECK-NEXT: fmul double 1.234000e-01, %y
>> +; CHECK-NEXT: fsub double %x, %mul
>> +; CHECK-NEXT: fmul double %add{{.*}}, %add{{.*}}
>> +; CHECK-NEXT: ret double %mul
>> +
>> + %mul = fmul double %y, -1.234000e-01
>> + %add = fadd double %mul, %x
>> + %mul1 = fmul double %y, -1.234000e-01
>> + %add2 = fadd double %mul1, %x
>> + %mul3 = fmul double %add, %add2
>> + ret double %mul3
>> +}
>> +
>> +; (x + 0.1234 / y) * (x + -0.1234 / y) -> (x + 0.1234 / y) * (x - 0.1234
>> / y)
>> +define double @test3(double %x, double %y) {
>> +; CHECK-LABEL: @test3
>> +; CHECK-NEXT: fdiv double 1.234000e-01, %y
>> +; CHECK-NEXT: fadd double %x, %div
>> +; CHECK-NEXT: fsub double %x, %div
>> +; CHECK-NEXT: fmul double %add{{.*}}, %add{{.*}}
>> +; CHECK-NEXT: ret double
>> +
>> + %div = fdiv double 1.234000e-01, %y
>> + %add = fadd double %div, %x
>> + %div1 = fdiv double -1.234000e-01, %y
>> + %add2 = fadd double %div1, %x
>> + %mul3 = fmul double %add, %add2
>> + ret double %mul3
>> +}
>> +
>> +; (x + 0.1234 * y) * (x - -0.1234 * y) -> (x + 0.1234 * y) * (x + 0.1234
>> * y)
>> +define double @test4(double %x, double %y) {
>> +; CHECK-LABEL: @test4
>> +; CHECK-NEXT: fmul double 1.234000e-01, %y
>> +; CHECK-NEXT: fadd double %x, %mul
>> +; CHECK-NEXT: fmul double %add{{.*}}, %add{{.*}}
>> +; CHECK-NEXT: ret double
>> +
>> + %mul = fmul double %y, 1.234000e-01
>> + %add = fadd double %mul, %x
>> + %mul1 = fmul double %y, -1.234000e-01
>> + %add2 = fsub double %x, %mul1
>> + %mul3 = fmul double %add, %add2
>> + ret double %mul3
>> +}
>> +
>> +; Canonicalize (x - -1234 * y)
>> +define i64 @test5(i64 %x, i64 %y) {
>> +; CHECK-LABEL: @test5
>> +; CHECK-NEXT: mul i64 %y, 1234
>> +; CHECK-NEXT: add i64 %mul, %x
>> +; CHECK-NEXT: ret i64 %sub
>> +
>> + %mul = mul i64 %y, -1234
>> + %sub = sub i64 %x, %mul
>> + ret i64 %sub
>> +}
>> +
>> +; Canonicalize (x - -0.1234 * y)
>> +define double @test6(double %x, double %y) {
>> +; CHECK-LABEL: @test6
>> +; CHECK-NEXT: fmul double 1.234000e-01, %y
>> +; CHECK-NEXT: fadd double %x, %mul
>> +; CHECK-NEXT: ret double
>> +
>> + %mul = fmul double -1.234000e-01, %y
>> + %sub = fsub double %x, %mul
>> + ret double %sub
>> +}
>> +
>> +; Don't modify (-0.1234 * y - x)
>> +define double @test7(double %x, double %y) {
>> +; CHECK-LABEL: @test7
>> +; CHECK-NEXT: fmul double -1.234000e-01, %y
>> +; CHECK-NEXT: fsub double %mul, %x
>> +; CHECK-NEXT: ret double %sub
>> +
>> + %mul = fmul double -1.234000e-01, %y
>> + %sub = fsub double %mul, %x
>> + ret double %sub
>> +}
>> +
>> +; Canonicalize (-0.1234 * y + x) -> (x - 0.1234 * y)
>> +define double @test8(double %x, double %y) {
>> +; CHECK-LABEL: @test8
>> +; CHECK-NEXT: fmul double 1.234000e-01, %y
>> +; CHECK-NEXT: fsub double %x, %mul
>> +; CHECK-NEXT: ret double %add
>> +
>> + %mul = fmul double -1.234000e-01, %y
>> + %add = fadd double %mul, %x
>> + ret double %add
>> +}
>> +
>> +; Canonicalize (y * -0.1234 + x) -> (x - 0.1234 * y)
>> +define double @test9(double %x, double %y) {
>> +; CHECK-LABEL: @test9
>> +; CHECK-NEXT: fmul double 1.234000e-01, %y
>> +; CHECK-NEXT: fsub double %x, %mul
>> +; CHECK-NEXT: ret double %add
>> +
>> + %mul = fmul double %y, -1.234000e-01
>> + %add = fadd double %mul, %x
>> + ret double %add
>> +}
>> +
>> +; Canonicalize (x - -1234 udiv y)
>> +define i64 @test10(i64 %x, i64 %y) {
>> +; CHECK-LABEL: @test10
>> +; CHECK-NEXT: udiv i64 1234, %y
>> +; CHECK-NEXT: add i64 %div, %x
>> +; CHECK-NEXT: ret i64 %sub
>> +
>> + %div = udiv i64 -1234, %y
>> + %sub = sub i64 %x, %div
>> + ret i64 %sub
>> +}
>> +
>> +; Canonicalize (x - -1234 sdiv y)
>> +define i64 @test11(i64 %x, i64 %y) {
>> +; CHECK-LABEL: @test11
>> +; CHECK-NEXT: sdiv i64 1234, %y
>> +; CHECK-NEXT: add i64 %div, %x
>> +; CHECK-NEXT: ret i64 %sub
>> +
>> + %div = sdiv i64 -1234, %y
>> + %sub = sub i64 %x, %div
>> + ret i64 %sub
>> +}
>> +
>> +; Canonicalize (x - -0.1234 / y)
>> +define double @test12(double %x, double %y) {
>> +; CHECK-LABEL: @test12
>> +; CHECK-NEXT: fdiv double 1.234000e-01, %y
>> +; CHECK-NEXT: fadd double %x, %div
>> +; CHECK-NEXT: ret double %sub
>> +
>> + %div = fdiv double -1.234000e-01, %y
>> + %sub = fsub double %x, %div
>> + ret double %sub
>> +}
>> +
>> +; Canonicalize (x - -0.1234 urem y)
>> +define i64 @test13(i64 %x, i64 %y) {
>> +; CHECK-LABEL: @test13
>> +; CHECK-NEXT: urem i64 1234, %y
>> +; CHECK-NEXT: add i64 %urem, %x
>> +; CHECK-NEXT: ret i64 %sub
>> +
>> + %urem = urem i64 -1234, %y
>> + %sub = sub i64 %x, %urem
>> + ret i64 %sub
>> +}
>> +
>> +; Canonicalize (x + -0.1234 srem y)
>> +define i64 @test14(i64 %x, i64 %y) {
>> +; CHECK-LABEL: @test14
>> +; CHECK-NEXT: srem i64 1234, %y
>> +; CHECK-NEXT: sub i64 %x, %srem
>> +; CHECK-NEXT: ret i64 %add
>> +
>> + %srem = srem i64 -1234, %y
>> + %add = add i64 %x, %srem
>> + ret i64 %add
>> +}
>> +
>> +; Don't modify (-0.1234 srem y - x)
>> +define i64 @test15(i64 %x, i64 %y) {
>> +; CHECK-LABEL: @test15
>> +; CHECK-NEXT: %srem = srem i64 -1234, %y
>> +; CHECK-NEXT: %sub = sub i64 %srem, %x
>> +; CHECK-NEXT: ret i64 %sub
>> +
>> + %srem = srem i64 -1234, %y
>> + %sub = sub i64 %srem, %x
>> + ret i64 %sub
>> +}
>> +
>> +; Canonicalize (x - -0.1234 frem y)
>> +define double @test16(double %x, double %y) {
>> +; CHECK-LABEL: @test16
>> +; CHECK-NEXT: frem double 1.234000e-01, %y
>> +; CHECK-NEXT: fadd double %x, %rem
>> +; CHECK-NEXT: ret double %sub
>> +
>> + %rem = frem double -1.234000e-01, %y
>> + %sub = fsub double %x, %rem
>> + ret double %sub
>> +}
>> +
>> +; Canonicalize (x + -0.1234 frem y)
>> +define double @test17(double %x, double %y) {
>> +; CHECK-LABEL: @test17
>> +; CHECK-NEXT: frem double 1.234000e-01, %y
>> +; CHECK-NEXT: fsub double %x, %rem
>> +; CHECK-NEXT: ret double %add
>> +
>> + %rem = frem double -1.234000e-01, %y
>> + %add = fadd double %x, %rem
>> + ret double %add
>> +}
>> +
>> +; Canonicalize (-0.1234 frem y + x) -> (x - 0.1234 frem y)
>> +define double @test18(double %x, double %y) {
>> +; CHECK-LABEL: @test18
>> +; CHECK-NEXT: frem double 1.234000e-01, %y
>> +; CHECK-NEXT: fsub double %x, %rem
>> +; CHECK-NEXT: ret double %add
>> +
>> + %rem = frem double -1.234000e-01, %y
>> + %add = fadd double %x, %rem
>> + ret double %add
>> +}
>>
>> Removed: llvm/trunk/test/Transforms/Reassociate/liftsign.ll
>> URL:
>> http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/Reassociate/liftsign.ll?rev=221170&view=auto
>>
>> ==============================================================================
>> --- llvm/trunk/test/Transforms/Reassociate/liftsign.ll (original)
>> +++ llvm/trunk/test/Transforms/Reassociate/liftsign.ll (removed)
>> @@ -1,69 +0,0 @@
>> -; RUN: opt -reassociate -gvn -S < %s | FileCheck %s
>> -
>> -; (x + 0.1234 * y) * (x + -0.1234 * y) -> (x + 0.1234 * y) * (x - 0.1234
>> * y)
>> -; so CSE can simplify it further
>> -define double @lift_sign1(double %x, double %y) nounwind readnone ssp
>> uwtable {
>> -; CHECK-LABEL: @lift_sign1(
>> - %mul = fmul double 1.234000e-01, %y
>> - %add = fadd double %mul, %x
>> - %mul1 = fmul double -1.234000e-01, %y
>> - %add2 = fadd double %mul1, %x
>> - %mul3 = fmul double %add, %add2
>> -; CHECK-NOT: %mul1 = fmul double -1.234000e-01, %y
>> -; CHECK-NOT: %add2 = fadd %mul1, %x
>> -; CHECK: %add2.repl = fsub double %x, %mul
>> -; CHECK: %mul3 = fmul double %add, %add2
>> -ret double %mul3
>> -}
>> -
>> -; (x + -0.1234 * y) * (x + -0.1234 * y) -> (x - 0.1234 * y) * (x -
>> 0.1234 * y)
>> -; GVN can then rewrite it even further
>> -define double @lift_sign2(double %x, double %y) nounwind readnone ssp
>> uwtable {
>> -; CHECK-LABEL: @lift_sign2(
>> - %mul = fmul double %y, -1.234000e-01
>> - %add = fadd double %mul, %x
>> - %mul1 = fmul double %y, -1.234000e-01
>> - %add2 = fadd double %mul1, %x
>> - %mul3 = fmul double %add, %add2
>> -; CHECK-NOT: %mul = fmul double %y, -1.234000e-01
>> -; CHECK-NOT: %add = fadd double %mul, %x
>> -; CHECK-NOT: %mul1 = fmul double %y, -1.234000e-01
>> -; CHECK-NOT: %add2 = fadd double %mul1, %x
>> -; CHECK-NOT: %mul3 = fmul double %add, %add2
>> -; CHECK: %mul = fmul double 1.234000e-01, %y
>> -; CHECK: %add.repl = fsub double %x, %mul
>> -; CHECK: %mul3 = fmul double %add.repl, %add.repl
>> - ret double %mul3
>> -}
>> -
>> -; (x + 0.1234 * y) * (x - -0.1234 * y) -> (x + 0.1234 * y) * (x + 0.1234
>> * y)
>> -define double @lift_sign3(double %x, double %y) nounwind readnone ssp
>> uwtable {
>> -; CHECK-LABEL: @lift_sign3(
>> - %mul = fmul double %y, 1.234000e-01
>> - %add = fadd double %mul, %x
>> - %mul1 = fmul double %y, -1.234000e-01
>> - %add2 = fsub double %x, %mul1
>> - %mul3 = fmul double %add, %add2
>> -; CHECK-NOT: %mul1 = fmul double %y, -1.234000e-01
>> -; CHECK-NOT: %add2 = fsub double %x, %mul1
>> -; CHECK-NOT: %mul3 = fmul double %add, %add2
>> -; CHECK: %mul3 = fmul double %add, %add
>> - ret double %mul3
>> -}
>> -
>> -; (x + 0.1234 / y) * (x + -0.1234 / y) -> (x + 0.1234 / y) * (x - 0.1234
>> / y)
>> -; so CSE can simplify it further
>> -define double @lift_sign4(double %x, double %y) nounwind readnone ssp
>> uwtable {
>> -; CHECK-LABEL: @lift_sign4(
>> - %div = fdiv double 1.234000e-01, %y
>> - %add = fadd double %div, %x
>> - %div1 = fdiv double -1.234000e-01, %y
>> - %add2 = fadd double %div1, %x
>> - %mul3 = fmul double %add, %add2
>> -; CHECK-NOT: %div1 = fdiv double -1.234000e-01, %y
>> -; CHECK-NOT: %add2 = fadd double %div1, %x
>> -; CHECK-NOT: %mul3 = fmul double %add, %add2
>> -; CHECK: %add2.repl = fsub double %x, %div
>> -; CHECK: %mul3 = fmul double %add, %add2.repl
>> - ret double %mul3
>> -}
>>
>>
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