Author: djg Date: Mon Sep 17 12:31:57 2007 New Revision: 42035 URL: http://llvm.org/viewvc/llvm-project?rev=42035&view=rev Log: Instcombine x-((x/y)*y) into a remainder operator.
Added: llvm/trunk/test/Transforms/InstCombine/srem.ll llvm/trunk/test/Transforms/InstCombine/urem.ll Modified: llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp Modified: llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp?rev=42035&r1=42034&r2=42035&view=diff ============================================================================== --- llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp (original) +++ llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp Mon Sep 17 12:31:57 2007 @@ -2257,6 +2257,17 @@ Constant *CP1 = Subtract(ConstantInt::get(I.getType(), 1), C2); return BinaryOperator::createMul(Op0, CP1); } + + // X - ((X / Y) * Y) --> X % Y + if (Op1I->getOpcode() == Instruction::Mul) + if (Instruction *I = dyn_cast<Instruction>(Op1I->getOperand(0))) + if (Op0 == I->getOperand(0) && + Op1I->getOperand(1) == I->getOperand(1)) { + if (I->getOpcode() == Instruction::SDiv) + return BinaryOperator::createSRem(Op0, Op1I->getOperand(1)); + if (I->getOpcode() == Instruction::UDiv) + return BinaryOperator::createURem(Op0, Op1I->getOperand(1)); + } } } @@ -2902,7 +2913,7 @@ /// getICmpValue - This is the complement of getICmpCode, which turns an /// opcode and two operands into either a constant true or false, or a brand -/// new /// ICmp instruction. The sign is passed in to determine which kind +/// new ICmp instruction. The sign is passed in to determine which kind /// of predicate to use in new icmp instructions. static Value *getICmpValue(bool sign, unsigned code, Value *LHS, Value *RHS) { switch (code) { Added: llvm/trunk/test/Transforms/InstCombine/srem.ll URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/srem.ll?rev=42035&view=auto ============================================================================== --- llvm/trunk/test/Transforms/InstCombine/srem.ll (added) +++ llvm/trunk/test/Transforms/InstCombine/srem.ll Mon Sep 17 12:31:57 2007 @@ -0,0 +1,8 @@ +; RUN: llvm-as < %s | opt -instcombine | llvm-dis | grep srem + +define i64 @foo(i64 %x1, i64 %y2) { + %r = sdiv i64 %x1, %y2 + %r7 = mul i64 %r, %y2 + %r8 = sub i64 %x1, %r7 + ret i64 %r8 +} Added: llvm/trunk/test/Transforms/InstCombine/urem.ll URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/urem.ll?rev=42035&view=auto ============================================================================== --- llvm/trunk/test/Transforms/InstCombine/urem.ll (added) +++ llvm/trunk/test/Transforms/InstCombine/urem.ll Mon Sep 17 12:31:57 2007 @@ -0,0 +1,8 @@ +; RUN: llvm-as < %s | opt -instcombine | llvm-dis | grep urem + +define i64 @rem_unsigned(i64 %x1, i64 %y2) { + %r = udiv i64 %x1, %y2 + %r7 = mul i64 %r, %y2 + %r8 = sub i64 %x1, %r7 + ret i64 %r8 +} _______________________________________________ llvm-commits mailing list llvm-commits@cs.uiuc.edu http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits