This is a workaround for issue that Subzero currently assumes all
global addresses have a name, but finalized pexe files leave most
global addresses unnamed.

It does this by allowing two optional command-line flag name prefixes
that are used to generate names for unnamed global addresses.

BUG= None
R=stichnot@chromium.org

Review URL: https://codereview.chromium.org/567703003

BUG=none
R=stichnot@chromium.org

Review URL: https://codereview.chromium.org/567553003

BUG= https://code.google.com/p/nativeclient/issues/detail?id=3892
R=jvoung@chromium.org, stichnot@chromium.org

Review URL: https://codereview.chromium.org/568473002

BUG= none
R=jfb@chromium.org

Review URL: https://codereview.chromium.org/565553002

Also fixes minor issues with branches in instructions (i.e. defining
entry node and computing predecessors).

BUG= https://code.google.com/p/nativeclient/issues/detail?id=3892
R=stichnot@chromium.org

Review URL: https://codereview.chromium.org/561823002

Fixes call to extractElement.

BUG= None
R=stichnot@chromium.org

Review URL: https://codereview.chromium.org/562783002

BUG= https://code.google.com/p/nativeclient/issues/detail?id=3892
R=jvoung@chromium.org, stichnot@chromium.org

Review URL: https://codereview.chromium.org/561883002

This addresses a TODO and fixes a code generation bug that was causing sprintf and _vfprintf_r to execute incorrectly.

BUG= none
R=jvoung@chromium.org

Review URL: https://codereview.chromium.org/560773002

Ended up needing to fix the InstX8632Lockable error that JF ran into
now that -O0 is really -O0:
https://codereview.chromium.org/512933006/

BUG=none
R=stichnot@chromium.org

Review URL: https://codereview.chromium.org/557933002

BUG= none
R=jvoung@chromium.org

Review URL: https://codereview.chromium.org/560493002

BUG= https://code.google.com/p/nativeclient/issues/detail?id=3894
R=jvoung@chromium.org, stichnot@chromium.org

Review URL: https://codereview.chromium.org/545623005

The script translates a pexe using both Subzero and llc, and then uses linker tricks to resolve each symbol into either its Subzero or llc version.  This enables quick bisection-based debugging of Subzero code generation.

BUG= none
R=jfb@chromium.org, jvoung@chromium.org

Review URL: https://codereview.chromium.org/551953002

1. Modify dump() to match LLVM.

2. If it weren't for minimum stack alignment, the alignment code would be broken, so add a test in case the alignment code changes.

BUG= none
R=jvoung@chromium.org, kschimpf@google.com

Review URL: https://codereview.chromium.org/557533003

BUG= https://code.google.com/p/nativeclient/issues/detail?id=3894
R=jvoung@chromium.org, stichnot@chromium.org

Review URL: https://codereview.chromium.org/548553002

This makes it much easier to run scripts from different working directories, as long as they are run somewhere under the native_client directory.

BUG= none
R=jvoung@chromium.org

Review URL: https://codereview.chromium.org/554013002

One issue is that the test_arith cross test defined functions on i1 but never actually invoked them.

Another issue is that the lowering was using 8-bit registers for i1 values, but was being sloppy about leaving stuff in the upper 7 bits, and then using all 8 bits for tests.

This takes the approach of explicitly masking the result whenever it's possible for the result to exceed one bit, such as trunc, fptosi, fptoui.

Another possibility might be to allow the upper 7 bits to stay sloppy, and explicitly only test the lower bit.

Additionally, some "CHECK: ret" lines were removed, since they aren't actually needed after the change to use CHECK-LABEL, and they are affected by an llvm-dump bug (which is fixed in LLVM 3.6).

BUG= none
R=jvoung@chromium.org

Review URL: https://codereview.chromium.org/547033002

This is the truncating cvt instruction instead of rounding.

A few interesting floating point inputs are added to the cross tests.

Also, the cross test error output is modified to be more clear.

BUG= none
R=jvoung@chromium.org

Review URL: https://codereview.chromium.org/550723002

BUG= https://code.google.com/p/nativeclient/issues/detail?id=3894
R=stichnot@chromium.org

Review URL: https://codereview.chromium.org/545603003

BUG= https://code.google.com/p/nativeclient/issues/detail?id=3894
R=jvoung@chromium.org, stichnot@chromium.org

Review URL: https://codereview.chromium.org/543793003

Also declare a few variables as Constant* instead of Operand* when they hold the result of Ctx->getConstantInt(), to be consistent with the rest of the code.

BUG= none
R=jvoung@chromium.org

Review URL: https://codereview.chromium.org/541093002

BUG=https: //code.google.com/p/nativeclient/issues/detail?id=3894
R=stichnot@chromium.org

Review URL: https://codereview.chromium.org/531123002

There's already a hack that emits asm like:
  lea eax, myglobal
instead of:
  mov eax, [myglobal]
because of an llvm-mc parser bug.  However, the lea hack still doesn't work if the symbol is a reserved word, e.g.:
  lea eax, flags

The extra hack is to drop into AT&T syntax temporarily:
.att_syntax
  leal flags, %eax
.intel_syntax

BUG= none
R=jvoung@chromium.org

Review URL: https://codereview.chromium.org/543803002

The bug was first spotted in the optimized gl_Color4ub() from spec2k's mesa.  The lowering sequences for fptosi and fptoui with i8 or i16 include "mov T_2, T_1" where T_1 and T_2 may have different integer types, and the statement:
      T_2->setPreferredRegister(T_1, true);

If T_2's type is i8 and T_1 is assigned a register that has no 8-bit version, then T_2 gets an unsuitable register.

The fix is to honor RegisterOverlap only when RegMask allows.

It's hard to construct a good test for this, since it depends heavily on register allocation decisions, which will change over time.

BUG= none
R=jvoung@chromium.org

Review URL: https://codereview.chromium.org/544713002

Integers are generally dumped as signed instead of unsigned values.
Integers of i1 type are dumped as 'false' and 'true'.  Floating point
values still don't match LLVM.

BUG= none
R=kschimpf@google.com

Review URL: https://codereview.chromium.org/539743002

BUG= //code.google.com/p/nativeclient/issues/detail?id=3894
R=jvoung@chromium.org

Review URL: https://codereview.chromium.org/529113002

BUG= none
R=jvoung@chromium.org

Review URL: https://codereview.chromium.org/535623002

Now it assumes tests are being run from within the Subzero portion of the native_client tree, and sets up PATH to find PNaCl tools relative to there.

It may be necessary to do a one-time setup to be able to build pexes:

    pnacl/build.sh sdk newlib

or the equivalent scons commands.

If the tool chain is updated, propagate the changes via:

    toolchain_build/toolchain_build_pnacl.py llvm_i686_linux --install=toolchain/linux_x86/pnacl_newlib

BUG= none
R=jvoung@chromium.org

Review URL: https://codereview.chromium.org/525603002

Also clean up other error cases (in function block) to simply return, since they have already generated an error message.

BUG= https://code.google.com/p/nativeclient/issues/detail?id=3894
R=jvoung@chromium.org, stichnot@chromium.org

Review URL: https://codereview.chromium.org/514273002

Then when we have an integrated assembler, we can check
its disassembly and the result should be the same.
This only touches the tests that invoke llvm-mc currently.
There are other tests which check for .s file output.

There are quite a bit of quirks with llvm-objdump,
which is unfortunate:

(*) The symbolizer doesn't pick up non-section-local
function calls. Some externals were converted to be
local functions. Workaround: where it counts, I just
left a check via .s files and a new --check-prefix.
It's a little better in 3.6.

(*) The symbolizer doesn't pick up global variable names.
I just checked for the relocation addend instead.
Didn't check if it was better in 3.6, but maybe.

(*) We have a bug in bundling lock + instructions.
See
BUG=https://code.google.com/p/nativeclient/issues/detail?id=3929

(*) There's no disassembly for branch lables.
Checks of jump instructions were converted to check
for positive or negative values, depending on whether
it is a forward or backward branch.

BUG=none
R=stichnot@chromium.org

Review URL: https://codereview.chromium.org/509233002

BUG=none
R=stichnot@chromium.org

Review URL: https://codereview.chromium.org/515993002

Otherwise, I don't have pnacl-freeze in my path, and
I think the lit tests have trouble finding it.

src/PNaClTranslator.cpp: In member function ‘uint32_t {anonymous}::FunctionParser::convertRelativeToAbsIndex(int32_t)’:
src/PNaClTranslator.cpp:882:55: error: comparison between signed and unsigned integer expressions [-Werror=sign-compare]
     if (Id > 0 && AbsNextId < static_cast<uint32_t>(Id)) {
                                                       ^
BUG=none
R=kschimpf@google.com, stichnot@chromium.org

Review URL: https://codereview.chromium.org/515003004

Handle binops and returns.

BUG= https://code.google.com/p/nativeclient/issues/detail?id=3894
R=jvoung@chromium.org, stichnot@chromium.org

Review URL: https://codereview.chromium.org/395193005

Also adds much-needed logging of the decision process that goes into the address mode optimization.

BUG= none
R=jvoung@chromium.org

Review URL: https://codereview.chromium.org/490333003

With the original link command, -lpthread comes before some other LLVM libraries, and this ends up causing undefined pthreads symbols.  The new link command makes sure the -lpthread part comes last.

BUG= none
R=jvoung@chromium.org

Review URL: https://codereview.chromium.org/514723004

Some lowering sequences were incorrectly allowing immediate operands in native instructions.  This includes 32-bit icmp, 64-bit icmp, select, switch, and 64-bit mul.

BUG= none
R=jvoung@chromium.org

Review URL: https://codereview.chromium.org/511543002

BUG= none
R=jvoung@chromium.org

Review URL: https://codereview.chromium.org/507813002

Add the llvm2ice -sandbox option (false by default) to select between
native and sandboxed code generation.  Currently, it controls whether
the llvm.nacl.read.tp intrinsic is lowered to gs:[0x0] or a call to
__nacl_read_tp.

Change the asm output slightly for -ffunction-sections so that objdump
is more willing to provide a disassembly.

BUG= none
R=jvoung@chromium.org

Review URL: https://codereview.chromium.org/504963002

This was committed as a test, not actually intended.

This reverts commit 420e8bf2.

BUG=
R=dschuff@chromium.org

Review URL: https://codereview.chromium.org/504073003

Patch from Jim Stichnoth <stichnot@chromium.org>.

Background: After lowering each high-level ICE instruction, Om1 calls
postLower() to do simple register allocation.  It only assigns
registers where absolutely necessary, specifically for infinite-weight
variables, while honoring pre-coloring decisions.  The original Om1
register allocation never tried to reuse registers within a lowered
sequence, which was generally OK except for very long lowering
sequences, such as call instructions or some intrinsics.  In these
cases, when it ran out of physical registers, it would just reset the
free list and hope for the best, but with no guarantee of correctness.

The fix involves keeping track of which instruction in the lowered
sequence holds the last use of each variable, and releasing each
register back to the free list after its last use.  This makes much
better use of registers.  It's not necessarily optimal, at least with
respect to pre-colored variables, since those registers are
black-listed even if they don't interfere with an infinite-weight
variable.

BUG= none
R=jvoung@chromium.org

Review URL: https://codereview.chromium.org/483453002