diff options
| -rw-r--r-- | lib/Transforms/Scalar/Reassociate.cpp | 18 | ||||
| -rw-r--r-- | test/Transforms/Reassociate/crash.ll | 14 |
2 files changed, 21 insertions, 11 deletions
diff --git a/lib/Transforms/Scalar/Reassociate.cpp b/lib/Transforms/Scalar/Reassociate.cpp index b572f4eb07..69cdc0f799 100644 --- a/lib/Transforms/Scalar/Reassociate.cpp +++ b/lib/Transforms/Scalar/Reassociate.cpp @@ -673,16 +673,10 @@ void Reassociate::RewriteExprTree(BinaryOperator *I, // original in some non-trivial way, requiring the clearing of optional flags. // Flags are cleared from the operator in ExpressionChanged up to I inclusive. BinaryOperator *ExpressionChanged = 0; - BinaryOperator *Previous; - BinaryOperator *Op = 0; - for (unsigned i = 0, e = Ops.size(); i != e; ++i) { + for (unsigned i = 0; ; ++i) { assert(!NodesToRewrite.empty() && "Optimized expressions has more nodes than original!"); - Previous = Op; Op = NodesToRewrite.pop_back_val(); - if (ExpressionChanged) - // Compactify the tree instructions together with each other to guarantee - // that the expression tree is dominated by all of Ops. - Op->moveBefore(Previous); + BinaryOperator *Op = NodesToRewrite.pop_back_val(); // The last operation (which comes earliest in the IR) is special as both // operands will come from Ops, rather than just one with the other being @@ -771,15 +765,17 @@ void Reassociate::RewriteExprTree(BinaryOperator *I, } // If the expression changed non-trivially then clear out all subclass data - // starting from the operator specified in ExpressionChanged. - if (ExpressionChanged) { + // starting from the operator specified in ExpressionChanged, and compactify + // the operators to just before the expression root to guarantee that the + // expression tree is dominated by all of Ops. + if (ExpressionChanged) do { ExpressionChanged->clearSubclassOptionalData(); if (ExpressionChanged == I) break; + ExpressionChanged->moveBefore(I); ExpressionChanged = cast<BinaryOperator>(*ExpressionChanged->use_begin()); } while (1); - } // Throw away any left over nodes from the original expression. for (unsigned i = 0, e = NodesToRewrite.size(); i != e; ++i) diff --git a/test/Transforms/Reassociate/crash.ll b/test/Transforms/Reassociate/crash.ll index e2ebcddf6b..a99c844f01 100644 --- a/test/Transforms/Reassociate/crash.ll +++ b/test/Transforms/Reassociate/crash.ll @@ -119,3 +119,17 @@ for.cond: ; preds = %for.cond, %entry %conv = zext i16 %p to i32 br label %for.cond } + +; PR12963 +@a = external global i8 +define i8 @f0(i8 %x) { + %t0 = load i8* @a + %t1 = mul i8 %x, %x + %t2 = mul i8 %t1, %t1 + %t3 = mul i8 %t2, %t2 + %t4 = mul i8 %t3, %x + %t5 = mul i8 %t4, %t4 + %t6 = mul i8 %t5, %x + %t7 = mul i8 %t6, %t0 + ret i8 %t7 +} |