Mercurial > hg > truffle
diff src/share/vm/opto/loopnode.hpp @ 3345:bad7ecd0b6ed
5091921: Sign flip issues in loop optimizer
Summary: Fix integer overflow problem in the code generated by loop optimizer.
Reviewed-by: never
author | kvn |
---|---|
date | Wed, 04 May 2011 13:12:42 -0700 |
parents | 3af54845df98 |
children | 38569792a45a |
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--- a/src/share/vm/opto/loopnode.hpp Wed May 04 03:42:58 2011 -0700 +++ b/src/share/vm/opto/loopnode.hpp Wed May 04 13:12:42 2011 -0700 @@ -289,6 +289,28 @@ inline Node *CountedLoopNode::incr() const { return loopexit() ? loopexit()->incr() : NULL; } inline Node *CountedLoopNode::phi() const { return loopexit() ? loopexit()->phi() : NULL; } +//------------------------------LoopLimitNode----------------------------- +// Counted Loop limit node which represents exact final iterator value: +// trip_count = (limit - init_trip + stride - 1)/stride +// final_value= trip_count * stride + init_trip. +// Use HW instructions to calculate it when it can overflow in integer. +// Note, final_value should fit into integer since counted loop has +// limit check: limit <= max_int-stride. +class LoopLimitNode : public Node { + enum { Init=1, Limit=2, Stride=3 }; + public: + LoopLimitNode( Compile* C, Node *init, Node *limit, Node *stride ) : Node(0,init,limit,stride) { + // Put it on the Macro nodes list to optimize during macro nodes expansion. + init_flags(Flag_is_macro); + C->add_macro_node(this); + } + virtual int Opcode() const; + virtual const Type *bottom_type() const { return TypeInt::INT; } + virtual uint ideal_reg() const { return Op_RegI; } + virtual const Type *Value( PhaseTransform *phase ) const; + virtual Node *Ideal(PhaseGVN *phase, bool can_reshape); + virtual Node *Identity( PhaseTransform *phase ); +}; // -----------------------------IdealLoopTree---------------------------------- class IdealLoopTree : public ResourceObj { @@ -775,6 +797,8 @@ bool is_counted_loop( Node *x, IdealLoopTree *loop ); + Node* exact_limit( IdealLoopTree *loop ); + // Return a post-walked LoopNode IdealLoopTree *get_loop( Node *n ) const { // Dead nodes have no loop, so return the top level loop instead @@ -837,7 +861,6 @@ bool is_scaled_iv_plus_offset(Node* exp, Node* iv, int* p_scale, Node** p_offset, int depth = 0); // Return true if proj is for "proj->[region->..]call_uct" - // Return true if proj is for "proj->[region->..]call_uct" static bool is_uncommon_trap_proj(ProjNode* proj, Deoptimization::DeoptReason reason); // Return true for "if(test)-> proj -> ... // | @@ -860,10 +883,11 @@ PhaseIterGVN* igvn); static Node* clone_loop_predicates(Node* old_entry, Node* new_entry, bool move_predicates, + bool clone_limit_check, PhaseIdealLoop* loop_phase, PhaseIterGVN* igvn); - Node* clone_loop_predicates(Node* old_entry, Node* new_entry); - Node* move_loop_predicates(Node* old_entry, Node* new_entry); + Node* clone_loop_predicates(Node* old_entry, Node* new_entry, bool clone_limit_check); + Node* move_loop_predicates(Node* old_entry, Node* new_entry, bool clone_limit_check); void eliminate_loop_predicates(Node* entry); static Node* skip_loop_predicates(Node* entry); @@ -873,7 +897,7 @@ // Find a predicate static Node* find_predicate(Node* entry); // Construct a range check for a predicate if - BoolNode* rc_predicate(Node* ctrl, + BoolNode* rc_predicate(IdealLoopTree *loop, Node* ctrl, int scale, Node* offset, Node* init, Node* limit, Node* stride, Node* range, bool upper); @@ -903,11 +927,11 @@ // Range Check Elimination uses this function! // Constrain the main loop iterations so the affine function: - // scale_con * I + offset < limit + // low_limit <= scale_con * I + offset < upper_limit // always holds true. That is, either increase the number of iterations in // the pre-loop or the post-loop until the condition holds true in the main // loop. Scale_con, offset and limit are all loop invariant. - void add_constraint( int stride_con, int scale_con, Node *offset, Node *limit, Node *pre_ctrl, Node **pre_limit, Node **main_limit ); + void add_constraint( int stride_con, int scale_con, Node *offset, Node *low_limit, Node *upper_limit, Node *pre_ctrl, Node **pre_limit, Node **main_limit ); // Partially peel loop up through last_peel node. bool partial_peel( IdealLoopTree *loop, Node_List &old_new );