This ensures that symbolic relocations are generated for stack
pointer manipulations.
These relocations are of type R_WEBASSEMBLY_GLOBAL_INDEX_LEB.
This change also adds support for reading relocations of this
type in WasmObjectFile.cpp.
Since its a globally imported symbol this does mean that
the get_global/set_global instruction won't be valid until
the objects are linked that global used in no longer an
imported global.
Differential Revision: https://reviews.llvm.org/D34172
llvm-svn: 305616
To facilitate this, add a new hidden command-line option to disable
the explicit-locals pass. That causes llc to emit invalid code that doesn't
have all locals converted to get_local/set_local, however it simplifies
testwriting in many cases.
llvm-svn: 296540
Per spec changes, store instructions in WebAssembly no longer have a return
value. Update the instruction descriptions.
Differential Revision: https://reviews.llvm.org/D25122
llvm-svn: 283501
The WebAssemly spec removing the return value from store instructions, so
remove the associated optimization from LLVM.
This patch leaves the store instruction operands in place for now, so stores
now always write to "$drop"; these will be removed in a seperate patch.
llvm-svn: 279100
Instead of this:
i32.const $push10=, __stack_pointer
i32.load $push11=, 0($pop10)
Emit this:
i32.const $push10=, 0
i32.load $push11=, __stack_pointer($pop10)
It's not currently clear which is better, though there's a chance the second
form may be better at overall compression. We can revisit this when we have
more data; for now it makes sense to make PEI consistent with isel.
Differential Revision: http://reviews.llvm.org/D20411
llvm-svn: 270635
This saves a small amount of code size, and is a first small step toward
passing values on the stack across block boundaries.
Differential Review: http://reviews.llvm.org/D20450
llvm-svn: 270294
Move the register stackification and coloring passes to run very late, after
PEI, tail duplication, and most other passes. This means that all code emitted
and expanded by those passes is now exposed to these passes. This also
eliminates the need for prologue/epilogue code to be manually stackified,
which significantly simplifies the code.
This does require running LiveIntervals a second time. It's useful to think
of these late passes not as late optimization passes, but as a domain-specific
compression algorithm based on knowledge of liveness information. It's used to
compress the code after all conventional optimizations are complete, which is
why it uses LiveIntervals at a phase when actual optimization passes don't
typically need it.
Differential Revision: http://reviews.llvm.org/D20075
llvm-svn: 269012
Summary:
MRI::eliminateFrameIndex can emit several instructions to do address
calculations; these can usually be stackified. Because instructions with
FI operands can have subsequent operands which may be expression trees,
find the top of the leftmost tree and insert the code before it, to keep
the LIFO property.
Also use stackified registers when writing back the SP value to memory
in the epilog; it's unnecessary because SP will not be used after the
epilog, and it results in better code.
Differential Revision: http://reviews.llvm.org/D18234
llvm-svn: 263725
This fixes very slow compilation on
test/CodeGen/Generic/2010-11-04-BigByval.ll . Note that MaxStoresPerMemcpy
and friends are not yet carefully tuned so the cutoff point is currently
somewhat arbitrary. However, it's important that there be a cutoff point
so that we don't emit unbounded quantities of loads and stores.
llvm-svn: 261050
Summary:
Just does the simple allocation of a stack object and passes
a pointer to the callee.
Differential Revision: http://reviews.llvm.org/D16610
llvm-svn: 258989
Sam Clegg