diff options
| -rw-r--r-- | lib/Transforms/Scalar/LoopStrengthReduce.cpp | 15 | ||||
| -rw-r--r-- | test/Transforms/LoopStrengthReduce/change-compare-stride-trickiness-2.ll | 25 |
2 files changed, 33 insertions, 7 deletions
diff --git a/lib/Transforms/Scalar/LoopStrengthReduce.cpp b/lib/Transforms/Scalar/LoopStrengthReduce.cpp index 834a95d..92270b5 100644 --- a/lib/Transforms/Scalar/LoopStrengthReduce.cpp +++ b/lib/Transforms/Scalar/LoopStrengthReduce.cpp @@ -1993,6 +1993,12 @@ ICmpInst *LoopStrengthReduce::ChangeCompareStride(Loop *L, ICmpInst *Cond, ValidScale(!CommonExprs->isZero(), Scale, UsersToProcess)) continue; + // Avoid rewriting the compare instruction with an iv which has + // implicit extension or truncation built into it. + // TODO: This is over-conservative. + if (SE->getTypeSizeInBits(CondUse->getOffset()->getType()) != TyBits) + continue; + // If scale is negative, use swapped predicate unless it's testing // for equality. if (Scale < 0 && !Cond->isEquality()) @@ -2005,16 +2011,11 @@ ICmpInst *LoopStrengthReduce::ChangeCompareStride(Loop *L, ICmpInst *Cond, ConstantInt *CI = ConstantInt::get(NewCmpIntTy, NewCmpVal); NewCmpRHS = ConstantExpr::getIntToPtr(CI, NewCmpTy); } - NewOffset = CondUse->getOffset(); - if (CondUse->isSigned()) - NewOffset = SE->getNoopOrSignExtend(CondUse->getOffset(), NewCmpTy); - else - NewOffset = SE->getNoopOrZeroExtend(CondUse->getOffset(), NewCmpTy); NewOffset = TyBits == NewTyBits - ? SE->getMulExpr(NewOffset, + ? SE->getMulExpr(CondUse->getOffset(), SE->getConstant(ConstantInt::get(CmpTy, Scale))) : SE->getConstant(ConstantInt::get(NewCmpIntTy, - cast<SCEVConstant>(NewOffset)->getValue() + cast<SCEVConstant>(CondUse->getOffset())->getValue() ->getSExtValue()*Scale)); break; } diff --git a/test/Transforms/LoopStrengthReduce/change-compare-stride-trickiness-2.ll b/test/Transforms/LoopStrengthReduce/change-compare-stride-trickiness-2.ll index e3cb3a5..f77aea3 100644 --- a/test/Transforms/LoopStrengthReduce/change-compare-stride-trickiness-2.ll +++ b/test/Transforms/LoopStrengthReduce/change-compare-stride-trickiness-2.ll @@ -31,3 +31,28 @@ if.end52: ; preds = %for.cond.i.preheader %indvar.next689 = add i64 %indvar688, 1 ; <i64> [#uses=1] br i1 %phitmp654, label %for.cond.i.preheader, label %if.end } + +define void @promote(%struct.dumperinfo* %di) nounwind { +entry: + br label %if.end + +if.end: ; preds = %if.end52, %entry + br label %for.cond.i.preheader + +for.cond.i.preheader: ; preds = %if.end52, %if.end + %indvar688 = phi i32 [ 0, %if.end ], [ %indvar.next689, %if.end52 ] ; <i64> [#uses=3] + %tmp690 = shl i32 %indvar688, 12 ; <i64> [#uses=1] + %pa.0642 = add i32 %tmp690, 0 ; <i64> [#uses=1] + %tmp692693 = add i32 %indvar688, 1 ; <i32> [#uses=1] + %phitmp = sext i32 %tmp692693 to i64 ; <i64> [#uses=1] + br i1 false, label %if.end52, label %land.lhs.true.i + +land.lhs.true.i: ; preds = %for.cond.i.preheader + %shr2.i = lshr i32 %pa.0642, 18 ; <i64> [#uses=0] + unreachable + +if.end52: ; preds = %for.cond.i.preheader + %phitmp654 = icmp ult i64 %phitmp, 512 ; <i1> [#uses=1] + %indvar.next689 = add i32 %indvar688, 1 ; <i64> [#uses=1] + br i1 %phitmp654, label %for.cond.i.preheader, label %if.end +} |