Also removes redundant rule checks in emitType01().

BUG= https://bugs.chromium.org/p/nativeclient/issues/detail?id=4334
R=jpp@chromium.org

Review URL: https://codereview.chromium.org/1460523005 .

Pre-computes the max stack size outgoing arguments, and pre-allocates
it during prolog, deallocating during epilog.

With this CL, there are no more StackAdjustments needed for the ARM32,
which will simplify rematerializing alloca'd variables.

BUG= https://code.google.com/p/nativeclient/issues/detail?id=4076
R=sehr@chromium.org

Review URL: https://codereview.chromium.org/1467473003 .

This pass gives Targets the ability to pre-lower high-level
instructions that will later be lowered to a target-specific helper,
e.g., 64-bit division on targets that can't natively handle them.

This is a pre-requirement for correct outargs pre-allocation during
function prolog.

R=sehr@chromium.org

Review URL: https://codereview.chromium.org/1455033005 .

BUG=
R=stichnot@chromium.org

Review URL: https://codereview.chromium.org/1460003003 .

Also does some clean up on emitType01 methods (making optional argument
explicit, and moving rule checks to the lowest level).

BUG= https://bugs.chromium.org/p/nativeclient/issues/detail?id=4334
R=jpp@chromium.org

Review URL: https://codereview.chromium.org/1456783003 .

This CL removes two warts from the ARM32 backend:
1) during argument lowering, if a stack parameter is assigned a
register, the backend creates a new Variable that references the stack
location with the incoming argument, and _mov() it to the parameter.

2) During stack slot legalization, all _mov(Mem(), Reg) are converted to
stores; and all _mov(Reg, Mem()) are converted to loads.

BUG= https://code.google.com/p/nativeclient/issues/detail?id=4076
R=kschimpf@google.com

Review URL: https://codereview.chromium.org/1457683004 .

Adds BL and BLX to ARM integrated assembler.

BUG= https://bugs.chromium.org/p/nativeclient/issues/detail?id=4334
R=jpp@chromium.org

Review URL: https://codereview.chromium.org/1452293003 .

To see the main effect of this, look at the doxygen for file
IceGlobalContext.h to see the effect of turning this on.
Without it, the nested classes are not available because they
are private.

My guess is that often doxygen is used to generate API documents and for that reason, exporting of private info is excluded by default.

BUG=
R=stichnot@chromium.org

Review URL: https://codereview.chromium.org/1411123019 .

Creates a special OperandARM32 for representing imm5 used when
performing a shift operation.

BUG= https://code.google.com/p/nativeclient/issues/detail?id=4076
R=kschimpf@google.com

Review URL: https://codereview.chromium.org/1449263003 .

BUG= https://bugs.chromium.org/p/nativeclient/issues/detail?id=4334
R=stichnot@chromium.org

Review URL: https://codereview.chromium.org/1458523002 .

1. Include a test build (but no link) using g++, to identify errors and warnings before they hit the Windows bots.

2. Move "git diff --quiet" to the end so that the presubmit tests can easily be run before committing locally, if desired.

3. Add "make presubmit" as an alias for "make check-presubmit".

4. Document the individual steps.

BUG= none
R=jpp@chromium.org

Review URL: https://codereview.chromium.org/1453713002 .

BUG= https://code.google.com/p/nativeclient/issues/detail?id=4076
R=stichnot@chromium.org

Review URL: https://codereview.chromium.org/1438773004 .

BUG= none
TEST= make -j32 -f Makefile.standalone CXX=g++ LLVM_EXTRA_WARNINGS="-Wno-unknown-pragmas -Wno-unused-parameter -Wno-comment -Wno-enum-compare -Wno-strict-aliasing" STDLIB_FLAGS=
(this command will compile but fail to link)

R=jpp@chromium.org

Review URL: https://codereview.chromium.org/1452993002 .

The register allocator does not need to be considering rematerializable variables at all.  When it does, there tends to be a big performance cost because the live range of a rematerializable variable tends to be large, leading to lots of expensive overlap computations against register allocation candidates.

BUG= none
R=jpp@chromium.org, sehr@chromium.org

Review URL: https://codereview.chromium.org/1450233002 .

Rather than bumping the stack pointer around the scalar return sequence in
_fld, ensure the prolog allocates enough space.

BUG=
R=stichnot@chromium.org

Review URL: https://codereview.chromium.org/1442753008 .

Also removes reliance on lowerAlloca entirely for the fixed allocations.

BUG=
R=jpp@chromium.org, stichnot@chromium.org

Review URL: https://codereview.chromium.org/1435363002 .

No functional changes, as measured by identical spec2k asm output.

1. Use early "return" and "continue" to reduce "if" nesting.

2. Reflow comments to 80 columns (instead of presumably 79).

3. Add some BuildDefs::dump() tests to reduce translator code size.

BUG= none
R=kschimpf@google.com

Review URL: https://codereview.chromium.org/1448773002 .

BUG= none
R=jpp@chromium.org

Review URL: https://codereview.chromium.org/1452553002 .

Fixes case where the ARM integrated assembler for class InstARM32Mov
did not revert to using the stand-alone assembler (method emit) to
generate the corresponding assembly instructions(s).

This fixes last known problem with method emitIAS (other than
reverting to the stand-alone assembler if not implemented). Removes
use of workaround flag "-unsafe-ias".

BUG= https://bugs.chromium.org/p/nativeclient/issues/detail?id=4334
R=stichnot@chromium.org

Review URL: https://codereview.chromium.org/1448783004 .

Lots of definitions of Target outside of asserts.

BUG=

Review URL: https://codereview.chromium.org/1448673002 .

This involves changing AdjustStack to grow/shrink the stack, and to use that
operation exclusively to move the StackAdjustment variable in lowering, rather
than in call emission as before.

BUG=
R=stichnot@chromium.org

Review URL: https://codereview.chromium.org/1449523002 .

There are situations where a variable is assigned as the result of a rematerializable alloca instruction, and then another variable is assigned as essentially a known-offset interior pointer into the alloca space.  In this case, the secondary variable is also rematerializable.

We add a pass, after alloca analysis, to find these derived variables and mark them transitively as rematerializable.  Because we lack use-def chains (or in fact any map to variable use locations), we need to iterate over the CFG until convergence.  Fortunately, this is pretty cheap, and not even done unless the alloca analysis seeds it with an initial set of rematerializable variables.

This analysis is only really needed for arithmetic instructions, but we also need to apply it to assignments and pointer-type bitcasts that are added when the IceConverter directly parses a .ll file rather than a .pexe file.

BUG= none
R=jpp@chromium.org, sehr@chromium.org

Review URL: https://codereview.chromium.org/1441793002 .

BUG= none
R=jpp@chromium.org, sehr@chromium.org

Review URL: https://codereview.chromium.org/1439363002 .

Remove a bit of complex repeated template naming.

BUG=
R=jpp@chromium.org, stichnot@chromium.org

Review URL: https://codereview.chromium.org/1438933002 .

getOffset() was being dereferenced even when it was nullptr.

BUG= none
R=kschimpf@google.com

Review URL: https://codereview.chromium.org/1435283003 .

This just prints the function being translated, once per function.  This is useful if there is a crash or fatal error somewhere, and you want to quickly discover which function to set -verbose-focus on.

Also, fixes some warnings/errors in the MINIMAL build.

BUG= none
R=kschimpf@google.com

Review URL: https://codereview.chromium.org/1439983002 .

These two methods introduce multiple instructions. Between each
instruction a newline must be inserted, and a call to startNextInt().
This CL makes sure both cases are met.

BUG=None
R=stichnot@chromium.org

Review URL: https://codereview.chromium.org/1441023002 .

BUG= https://bugs.chromium.org/p/nativeclient/issues/detail?id=4334
R=stichnot@chromium.org

Review URL: https://codereview.chromium.org/1432413003 .

This CL passes in context from the ARM target lowering, so that
it can figure out what register (SP or FP) and offset to use
when loading/storing variables.

BUG= https://bugs.chromium.org/p/nativeclient/issues/detail?id=4334
R=stichnot@chromium.org

Review URL: https://codereview.chromium.org/1414043015 .

Partition allocas that occur in the entry block into two categories.  The first is those whose size is fixed and alignment are less than or equal to the stack alignment.  These are emitted relative to a pointer, either in increasing offset relative to the stack pointer or decreasing offset relative to the frame pointer.  (Actually, we are not enabling this optimization for frame pointer frames yet)  The second category is allocas whose size is dynamic or alignment is creater than the stack alignment.  These are emitted relative to a user variable in increasing offset order.  This optimization is only enabled for x86 at O2.

BUG=
R=stichnot@chromium.org

Review URL: https://codereview.chromium.org/1411583007 .

Extends assembler movw method to handle integer constants in addition
to relocatable constants, since (32-bit) integer constants are
frequently used in movw instructions.

BUG= https://bugs.chromium.org/p/nativeclient/issues/detail?id=4334
R=stichnot@chromium.org

Review URL: https://codereview.chromium.org/1440693002 .

Improves the bool folding logic so that branches are short circuited.

BUG= https://code.google.com/p/nativeclient/issues/detail?id=4076
R=stichnot@chromium.org

Review URL: https://codereview.chromium.org/1417393003 .

Removes blank line after push instructions.

BUG=None
R=stichnot@chromium.org

Review URL: https://codereview.chromium.org/1439683002 .

Fold and/or followed by branch to eliminate cmp.  Also, fold fcmp instructions into branches similarly to what was done for icmp instructions.

BUG=
R=jpp@chromium.org, stichnot@chromium.org

Review URL: https://codereview.chromium.org/1436623002 .

Originally, for each non-deleted instruction, CfgNode::emit() would call the virtual Inst::emit() and then print a newline (also printing end-of-live-range info as necessary).  This resulted in clumsy blank lines in the asm output, corresponding to non target specific pseudo instructions such as FakeDef, FakeUse, FakeKill.

We change this so that CfgNode::emit() only prints a newline for an InstTarget subclass, or if any end-of-live-range text was printed.

If a high-level instruction still wants to emit something in a comment, it's responsible for printing its own newline.

BUG= none
TEST= ./pydir/szbuild_spec2k.py -O2 --force -v --filetype=asm --sz=--asm-verbose=0
TEST= ./pydir/szbuild_spec2k.py -O2 --force -v --filetype=asm --sz=--asm-verbose=1
TEST= ./pydir/szbuild_spec2k.py -O2 --force -v --filetype=asm --target=arm32
R=kschimpf@google.com

Review URL: https://codereview.chromium.org/1431353003 .

BUG= https://bugs.chromium.org/p/nativeclient/issues/detail?id=4334
R=jpp@chromium.org, stichnot@chromium.org

Review URL: https://codereview.chromium.org/1433743002 .

This enables the following workflow:

1. Run "szbuild.py --filetype=asm ..." to generate a .s file.
2. Edit the .s file to mock up a Subzero change.
3. Run "szbuild.py --filetype=asm --no-sz ..." to restart the build post pnacl-sz.

This workflow is good for trying out localized changes to hot basic blocks, though it isn't really appropriate for global optimizations like register allocation.

BUG= none
R=kschimpf@google.com

Review URL: https://codereview.chromium.org/1417003005 .

BUG=
R=jpp@chromium.org, stichnot@chromium.org

Review URL: https://codereview.chromium.org/1430273004 .

Patch from Reed Kotler <rkotlerimgtec@gmail.com>.

BUG= https://code.google.com/p/nativeclient/issues/detail?id=4076
R=kschimpf@google.com, stichnot@chromium.org

Review URL: https://codereview.chromium.org/1422753010 .

Also formatted IceCfg.cpp, since it needed it.

BUG= https://bugs.chromium.org/p/nativeclient/issues/detail?id=4334
R=stichnot@chromium.org

Review URL: https://codereview.chromium.org/1422253003 .