From 0d56b06f86d6e1707aec9c7e1fd13f6e5301c209 Mon Sep 17 00:00:00 2001 From: Dan Gohman Date: Fri, 22 May 2009 07:14:20 +0000 Subject: [PATCH] Fix a thinko in the code that adapted SCEVMulExpr operands for use in expanding SCEVAddExprs with GEPs. The operands of a SCEVMulExpr need to be multiplied together, not added. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72250 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Analysis/ScalarEvolutionExpander.cpp | 16 ++++- .../IndVarSimplify/gep-with-mul-base.ll | 58 +++++++++++++++++++ 2 files changed, 71 insertions(+), 3 deletions(-) create mode 100644 test/Transforms/IndVarSimplify/gep-with-mul-base.ll diff --git a/lib/Analysis/ScalarEvolutionExpander.cpp b/lib/Analysis/ScalarEvolutionExpander.cpp index d110385fb3e..507ced74fd1 100644 --- a/lib/Analysis/ScalarEvolutionExpander.cpp +++ b/lib/Analysis/ScalarEvolutionExpander.cpp @@ -168,6 +168,8 @@ Value *SCEVExpander::expandAddToGEP(const SCEVAddExpr *S, std::vector ScaledOps; for (unsigned i = 0, e = Ops.size(); i != e; ++i) { if (ElSize != 0) { + // For a Constant, check for a multiple of the pointer type's + // scale size. if (const SCEVConstant *C = dyn_cast(Ops[i])) if (!C->getValue()->getValue().srem(ElSize)) { ConstantInt *CI = @@ -176,13 +178,19 @@ Value *SCEVExpander::expandAddToGEP(const SCEVAddExpr *S, ScaledOps.push_back(Div); continue; } + // In a Mul, check if there is a constant operand which is a multiple + // of the pointer type's scale size. if (const SCEVMulExpr *M = dyn_cast(Ops[i])) if (const SCEVConstant *C = dyn_cast(M->getOperand(0))) - if (C->getValue()->getValue() == ElSize) { - for (unsigned j = 1, f = M->getNumOperands(); j != f; ++j) - ScaledOps.push_back(M->getOperand(j)); + if (!C->getValue()->getValue().srem(ElSize)) { + std::vector NewMulOps(M->getOperands()); + NewMulOps[0] = + SE.getConstant(C->getValue()->getValue().sdiv(ElSize)); + ScaledOps.push_back(SE.getMulExpr(NewMulOps)); continue; } + // In an Unknown, check if the underlying value is a Mul by a constant + // which is equal to the pointer type's scale size. if (const SCEVUnknown *U = dyn_cast(Ops[i])) if (BinaryOperator *BO = dyn_cast(U->getValue())) if (BO->getOpcode() == Instruction::Mul) @@ -191,6 +199,8 @@ Value *SCEVExpander::expandAddToGEP(const SCEVAddExpr *S, ScaledOps.push_back(SE.getUnknown(BO->getOperand(0))); continue; } + // If the pointer type's scale size is 1, no scaling is necessary + // and any value can be used. if (ElSize == 1) { ScaledOps.push_back(Ops[i]); continue; diff --git a/test/Transforms/IndVarSimplify/gep-with-mul-base.ll b/test/Transforms/IndVarSimplify/gep-with-mul-base.ll new file mode 100644 index 00000000000..0e5e1067177 --- /dev/null +++ b/test/Transforms/IndVarSimplify/gep-with-mul-base.ll @@ -0,0 +1,58 @@ +; RUN: llvm-as < %s | opt -indvars | llvm-dis > %t +; RUN: grep add %t | count 8 +; RUN: grep mul %t | count 9 + +define void @foo(i64 %n, i64 %m, i64 %o, double* nocapture %p) nounwind { +entry: + %tmp = icmp sgt i64 %n, 0 ; [#uses=1] + br i1 %tmp, label %bb.nph, label %return + +bb.nph: ; preds = %entry + %tmp1 = mul i64 %n, 37 ; [#uses=1] + %tmp2 = mul i64 %tmp1, %m ; [#uses=1] + %tmp3 = mul i64 %tmp2, %o ; [#uses=1] + br label %bb + +bb: ; preds = %bb, %bb.nph + %i.01 = phi i64 [ %tmp3, %bb.nph ], [ %tmp13, %bb ] ; [#uses=3] + %tmp9 = getelementptr double* %p, i64 %i.01 ; [#uses=1] + %tmp10 = load double* %tmp9, align 8 ; [#uses=1] + %tmp11 = fdiv double %tmp10, 2.100000e+00 ; [#uses=1] + store double %tmp11, double* %tmp9, align 8 + %tmp13 = add i64 %i.01, 1 ; [#uses=2] + %tmp14 = icmp slt i64 %tmp13, %n ; [#uses=1] + br i1 %tmp14, label %bb, label %return.loopexit + +return.loopexit: ; preds = %bb + br label %return + +return: ; preds = %return.loopexit, %entry + ret void +} +define void @bar(i64 %n, i64 %m, i64 %o, i64 %q, double* nocapture %p) nounwind { +entry: + %tmp = icmp sgt i64 %n, 0 ; [#uses=1] + br i1 %tmp, label %bb.nph, label %return + +bb.nph: ; preds = %entry + %tmp1 = mul i64 %n, %q ; [#uses=1] + %tmp2 = mul i64 %tmp1, %m ; [#uses=1] + %tmp3 = mul i64 %tmp2, %o ; [#uses=1] + br label %bb + +bb: ; preds = %bb, %bb.nph + %i.01 = phi i64 [ %tmp3, %bb.nph ], [ %tmp13, %bb ] ; [#uses=3] + %tmp9 = getelementptr double* %p, i64 %i.01 ; [#uses=1] + %tmp10 = load double* %tmp9, align 8 ; [#uses=1] + %tmp11 = fdiv double %tmp10, 2.100000e+00 ; [#uses=1] + store double %tmp11, double* %tmp9, align 8 + %tmp13 = add i64 %i.01, 1 ; [#uses=2] + %tmp14 = icmp slt i64 %tmp13, %n ; [#uses=1] + br i1 %tmp14, label %bb, label %return.loopexit + +return.loopexit: ; preds = %bb + br label %return + +return: ; preds = %return.loopexit, %entry + ret void +}