The MC assembler doesn't like using the empty string as a private label
prefix because then it treats all labels as private. This commit reverts
back to the default prefix, which is .L, which is common in ELF targets
and consistent with the LLVM name mangler.
llvm-svn: 257083
The first instruction in a block is what the rend() iterator points to, so
if it moves, we need to re-evaluate rend() so that we continue to iterate
through the rest of the instructions.
llvm-svn: 256953
Move RegStackify after coalescing and teach it to use LiveIntervals instead
of depending on SSA form. This avoids a problem where a register in a COPY
instruction is stackified and then subsequently coalesced with a register
that is not stackified.
This also puts it after the scheduler, which allows us to simplify the
EXPR_STACK constraint, as we no longer have instructions being reordered
after stackification and before coloring.
llvm-svn: 256402
Implement a new BLOCK scope placement algorithm which better handles
early-return blocks and early exists from nested scopes.
Differential Revision: http://reviews.llvm.org/D15368
llvm-svn: 255564
This patch introduces a codegen-only instruction currently named br_unless,
which makes it convenient to implement ReverseBranchCondition and re-enable
the MachineBlockPlacement pass. Then in a late pass, it lowers br_unless
back into br_if.
Differential Revision: http://reviews.llvm.org/D14995
llvm-svn: 254826
This is just prototype for load/store for i32 types. I'll add them to
the rest of the types if we like this direction.
Differential Revision: http://reviews.llvm.org/D15197
llvm-svn: 254807
This distinguishes input operands from output operands. This is something of
a syntactic experiment to see whether the mild amount of clutter this adds is
outweighed by the extra information it conveys to the reader.
llvm-svn: 253922
WebAssembly is currently using labels to end scopes, so for example a
loop scope looks like this:
BB0_0:
loop BB0_1
...
BB0_1:
with BB0_0 being the label of the first block not in the loop. This
requires that the label be printed even when it's only reachable via
fallthrough. To arrange this, insert a no-op LOOP_END instruction in
such cases at the end of the loop.
llvm-svn: 253901
Always starting blocks at the top of their containing loops works, but creates
unnecessarily deep nesting because it makes all blocks in a loop overlap.
Refine the BLOCK placement algorithm to start blocks at nearest common
dominating points instead, which significantly shrinks them and reduces
overlapping.
llvm-svn: 253876
This also takes the push/pop syntax another step forward, introducing stack
slot numbers to make it easier to see how expressions are connected. For
example, the value pushed in $push7 is popped in $pop7.
And, this begins an experiment with making get_local and set_local implicit
when an operation directly uses or defines a register. This greatly reduces
clutter. If this experiment succeeds, it may make sense to do this for
const instructions as well.
And, this introduces more special code for ARGUMENTS; hopefully this code
will soon be obviated by proper support for live-in virtual registers.
llvm-svn: 253465
Summary: This is to match the new version in the spec
Reviewers: sunfish
Subscribers: jfb, llvm-commits, dschuff
Differential Revision: http://reviews.llvm.org/D14519
llvm-svn: 253249
Switch to MC for instruction printing.
This encompasses several changes which are all interconnected:
- Use the MC framework for printing almost all instructions.
- AsmStrings are now live.
- This introduces an indirection between LLVM vregs and WebAssembly registers,
and a new pass, WebAssemblyRegNumbering, for computing a basic the mapping.
This addresses some basic issues with argument registers and unused registers.
- The way ARGUMENT instructions are handled no longer generates redundant
get_local+set_local for every argument.
This also changes the assembly syntax somewhat; most notably, MC's printing
does not use sigils on label names, so those are no longer present, and
push/pop now have a sigil to keep them unambiguous.
The usage of set_local/get_local/$push/$pop will continue to evolve
significantly. This patch is just one step of a larger change.
llvm-svn: 252910
This encompasses several changes which are all interconnected:
- Use the MC framework for printing almost all instructions.
- AsmStrings are now live.
- This introduces an indirection between LLVM vregs and WebAssembly registers,
and a new pass, WebAssemblyRegNumbering, for computing a basic the mapping.
This addresses some basic issues with argument registers and unused registers.
- The way ARGUMENT instructions are handled no longer generates redundant
get_local+set_local for every argument.
This also changes the assembly syntax somewhat; most notably, MC's printing
use sigils on label names, so those are no longer present, and push/pop now
have a sigil to keep them unambiguous.
The usage of set_local/get_local/$push/$pop will continue to evolve
significantly. This patch is just one step of a larger change.
llvm-svn: 252858
Summary: The syntax has changed a bit recently.
Reviewers: binji
Subscribers: llvm-commits, jfb, sunfish, dschuff
Differential Revision: http://reviews.llvm.org/D13821
llvm-svn: 250535
Summary:
Follow the same syntax as for the spec repo. Both have evolved slightly
independently and need to converge again.
This, along with wasmate changes, allows me to do the following:
echo "int add(int a, int b) { return a + b; }" > add.c
./out/bin/clang -O2 -S --target=wasm32-unknown-unknown add.c -o add.wack
./experimental/prototype-wasmate/wasmate.py add.wack > add.wast
./sexpr-wasm-prototype/out/sexpr-wasm add.wast -o add.wasm
./sexpr-wasm-prototype/third_party/v8-native-prototype/v8/v8/out/Release/d8 -e "print(WASM.instantiateModule(readbuffer('add.wasm'), {print:print}).add(42, 1337));"
As you'd expect, the d8 shell prints out the right value.
Reviewers: sunfish
Subscribers: jfb, llvm-commits, dschuff
Differential Revision: http://reviews.llvm.org/D13712
llvm-svn: 250480
This new syntax is built around putting each instruction on its own line
in a "mnemonic op, op, op" like syntax. It also uses conventional data
section directives like ".byte" and so on rather than requiring everything
to be in hierarchical S-expression format. This is a more natural syntax
for a ".s" file format from the perspective of LLVM MC and related tools,
while remaining easy to translate into other forms as needed.
llvm-svn: 249364
This pass implements a simple algorithm for conversion from CFG to
wasm's structured control flow. It doesn't yet handle multiple-entry
loops; that will be added in a future patch.
It also adds initial support for switch statements.
Differential Revision: http://reviews.llvm.org/D12735
llvm-svn: 247818
Dan Gohman