Author: Nikita Popov Date: 2024-02-20T12:02:48Z New Revision: ebc589e44ffe7b77cc500f3d2dc1a7ba11dd82b1
URL: https://github.com/llvm/llvm-project/commit/ebc589e44ffe7b77cc500f3d2dc1a7ba11dd82b1 DIFF: https://github.com/llvm/llvm-project/commit/ebc589e44ffe7b77cc500f3d2dc1a7ba11dd82b1.diff LOG: [InstCombine] Fold gep of exact unsigned division (#82334) Extend the transform added in https://github.com/llvm/llvm-project/pull/76458 to also handle unsigned division. X exact/ Y * Y == X holds independently of whether the division is signed or unsigned. Proofs: https://alive2.llvm.org/ce/z/wFd5Ec (cherry picked from commit 26d4afc3de86ca5416c8e38000362c526b6808cd) Added: Modified: llvm/lib/Transforms/InstCombine/InstructionCombining.cpp llvm/test/Transforms/InstCombine/getelementptr.ll Removed: ################################################################################ diff --git a/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp b/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp index 249f4a7710e046..5d207dcfd18dd4 100644 --- a/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp +++ b/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp @@ -2594,10 +2594,10 @@ Instruction *InstCombinerImpl::visitGetElementPtrInst(GetElementPtrInst &GEP) { Value *V; if ((has_single_bit(TyAllocSize) && match(GEP.getOperand(1), - m_Exact(m_AShr(m_Value(V), - m_SpecificInt(countr_zero(TyAllocSize)))))) || + m_Exact(m_Shr(m_Value(V), + m_SpecificInt(countr_zero(TyAllocSize)))))) || match(GEP.getOperand(1), - m_Exact(m_SDiv(m_Value(V), m_SpecificInt(TyAllocSize))))) { + m_Exact(m_IDiv(m_Value(V), m_SpecificInt(TyAllocSize))))) { GetElementPtrInst *NewGEP = GetElementPtrInst::Create( Builder.getInt8Ty(), GEP.getPointerOperand(), V); NewGEP->setIsInBounds(GEP.isInBounds()); diff --git a/llvm/test/Transforms/InstCombine/getelementptr.ll b/llvm/test/Transforms/InstCombine/getelementptr.ll index e6a3b759cf78d6..c90b6c9fb29592 100644 --- a/llvm/test/Transforms/InstCombine/getelementptr.ll +++ b/llvm/test/Transforms/InstCombine/getelementptr.ll @@ -1476,8 +1476,7 @@ define ptr @gep_sdiv(ptr %p, i64 %off) { define ptr @gep_udiv(ptr %p, i64 %off) { ; CHECK-LABEL: @gep_udiv( -; CHECK-NEXT: [[INDEX:%.*]] = udiv exact i64 [[OFF:%.*]], 7 -; CHECK-NEXT: [[PTR:%.*]] = getelementptr [[STRUCT_C:%.*]], ptr [[P:%.*]], i64 [[INDEX]] +; CHECK-NEXT: [[PTR:%.*]] = getelementptr i8, ptr [[P:%.*]], i64 [[OFF:%.*]] ; CHECK-NEXT: ret ptr [[PTR]] ; %index = udiv exact i64 %off, 7 @@ -1517,8 +1516,7 @@ define ptr @gep_ashr(ptr %p, i64 %off) { define ptr @gep_lshr(ptr %p, i64 %off) { ; CHECK-LABEL: @gep_lshr( -; CHECK-NEXT: [[INDEX:%.*]] = lshr exact i64 [[OFF:%.*]], 2 -; CHECK-NEXT: [[PTR:%.*]] = getelementptr i32, ptr [[P:%.*]], i64 [[INDEX]] +; CHECK-NEXT: [[PTR:%.*]] = getelementptr i8, ptr [[P:%.*]], i64 [[OFF:%.*]] ; CHECK-NEXT: ret ptr [[PTR]] ; %index = lshr exact i64 %off, 2 _______________________________________________ llvm-branch-commits mailing list llvm-branch-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
