Refactor construction of switch statements so it doesn't use class
HSubgraph.
There are also a few improvements. We do not use an auxiliary list of
comparisons because they're embedded as a linked list in the graph
under construction. We share a common break block for all breaks from
the same switch. We do not insert empty blocks unless necessary to
maintain edge-split form.
There is also a bug fix. The entry to a clause body is a potential
join and must have a join ID set, otherwise deoptimization within the
body can go to an unpredictable place in the unoptimized code.
Review URL: http://codereview.chromium.org/6650021
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7099 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Instead of allocating fresh temporary lists for every instruction, reuse
the same instance and reset it between instructions.
This reduces the amount of zone memory used for inserting the HChange
instructions roughly by half.
Review URL: http://codereview.chromium.org/6628079
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7094 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Change the way we construct the graph for polymorphic loads to match that of
polymorphic stores.
Introduce a stack-allocated helper for saving and restoring all the
function-specific graph builder state that needs to change when we begin
translating an inlined function. Make this class authoritative by moving
redundant state out of the builder and deferring to the current function's
state.
Ensure that we always print a tracing message when abandoning an inlining
attempt.
Review URL: http://codereview.chromium.org/6628012
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7074 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Before we would compute the flag by iterating over all uses. The truncating
flag is always determined at construction time since we already computed
the flag for all other instructions before inserting HChange instructions.
Review URL: http://codereview.chromium.org/6615012
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7047 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Do not use subgraphs to implement the translation of simple branching
control flow, for the function body entry, or for labeled blocks.
Combine all the loop construction functions into a single one.
Resolve a possible problem with duplicate AST IDs used both for joined loop
break blocks, the normal loop exit, and for their common successor, by never
introducing the extra (successor) block and instead making the normal loop
exit a predecessor of the break join block. There is a similar issue with
joined continue blocks.
Remove a (never needed) two-element zone list per each time we replace one
hydrogen value with another.
Review URL: http://codereview.chromium.org/6604002
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7027 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Change the interface to the Hydrogen graph builder to appear like it
directly holds a current basic block and a current environment.
Remove some direct accesses to the current subgraph, and remove
subgraph accessors that simply forwarded to the exit block.
Review URL: http://codereview.chromium.org/6532088
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@6887 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Before, the live ranges of the arguments extended to the call itself, and
they were pushed immediately before the call. Now, they are spilled eagerly
as soon as their value is available and they are spilled to the right place.
The inlined runtime calls in the optimized backend are changed to work as in
all the other backends: they get their arguments untranslated and can choose
their own custom evaluation order.
Review URL: http://codereview.chromium.org/6526047
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@6876 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
When deoptimizing to after an expression of the form (expr0 || expr1)
or (expr0 && expr1) in an effect context, the unoptimized code could
incorrectly see the value of the expression.
Handle the short-circuit binary operators specially in effect contexts.
This fixes the issue and will generate better code when the left
subexpression is boolean-valued.
BUG=v8:1166
Review URL: http://codereview.chromium.org/6519046
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@6831 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Rather than passing in a pair of unequal-length lists, pass the default
subgraph separately. Construct the typecase from the top down rather than
the bottom up, so it doesn't need an intermediate zone list.
Also, change a basic block's 'last' instruction field to really be its last
instruction by correctly updating it when inserting and removing
instructions.
Review URL: http://codereview.chromium.org/6516016
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@6783 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Before, Hydrogen call instructions had uses of the PushArgument instructions
for their arguments. These operands were unneeded, bloated the IR, and
caused calls to be the only Hydrogen instructions with an unpredictable
number of operands.
Now, PushArgument is a pure side-effecting instruction that has no uses.
Review URL: http://codereview.chromium.org/6480030
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@6749 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
1. The placement of checks for negative zero has to be computed after
all conversion instructions have been inserted. I separated the code
into its own phase.
2. GVN need to take instruction flags into account when comparing
instructions for redundancy.
Review URL: http://codereview.chromium.org/6260035
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@6534 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Before, we disabled code motion for check instructions on the final
optimization attempt. It is unsafe to prevent movement of check
instructions but to allow movement of instructions that assume the checks
were performed.
Review URL: http://codereview.chromium.org/6378012
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@6485 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This patch adds H- and L-variants of StringCharCodeAt and StringLength.
StringCharCodeAt is used to inline a constant function call of
String.prototype.charCodeAt and to implement the corresponding inline
runtime function. It does not yet use the recently introduced extra IC
state. (We can specialize on string encoding and avoid deopts because
of out of bounds accesses.)
StringLength needs more work because the stub version of it also
supports strings wrappers and it matters in some cases. (We have to
separate the string only case.)
Review URL: http://codereview.chromium.org/6243008
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@6408 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
The function HEnvironment::SetExpressionStackAt did not update the
environment's history. This function is used to patch the bailout
environment for count operations and global function calls.
Reorganize class HEnvironment to make it fit V8's style a bit better
and to try to add some sanity to which C++ functions are intended to
be inlined.
Remove the flag --trace-environment which merely duplicated data in
the hydrogen.cfg file except without enough context to be useful.
BUG=1004
Review URL: http://codereview.chromium.org/5992011
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@6137 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Before, when we deoptimized after a branch we jumped to before the branch
was taken in the unoptimized code with a token value that indicated when
edge to take. There was a lot of machinery to track this value through the
short-circuit logical operations and logical negation, and to handle it
properly at inline function return sites. There was also machinery to
prevent incorrectly seeing this environment with the extra value never
actually materialized in the unoptimized code.
Instead, now we deoptimize directly to one of the targets of the branch.
Much but not yet all of the extra machinery has been removed or simplified.
The cost is that branching control structures (the looping statements, if
statements, conditional expressions, and the short-circuit binary logical
operations) need extra AST IDs to identify the branch targets.
Review URL: http://codereview.chromium.org/5908001
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@6049 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
