llvm-svn: 127952

not have native support for this operation (such as X86).
The legalized code uses two vector INT_TO_FP operations and is faster
than scalarizing.

llvm-svn: 127951

llvm-svn: 127944

llvm-svn: 127943

llvm-svn: 127939

Proof-of-concept code that code-gens a module to an in-memory MachO object.
This will be hooked up to a run-time dynamic linker library (see: llvm-rtdyld
for similarly conceptual work for that part) which will take the compiled
object and link it together with the rest of the system, providing back to the
JIT a table of available symbols which will be used to respond to the
getPointerTo*() queries.

llvm-svn: 127916

The llvm.dbg.value intrinsic refers to SSA values, not virtual registers, so we
should be able to extend the range of a value by tracking that value through
register copies. This greatly improves the debug value tracking for function
arguments that for some reason are copied to a second virtual register at the
end of the entry block.

We only extend the debug value range where its register is killed. All original
llvm.dbg.value locations are still respected.

Copies from physical registers are ignored. That should not be a problem since
the entry block already adds DBG_VALUE instructions for the virtual registers
holding the function arguments.

llvm-svn: 127912

Stack slot real estate is virtually free compared to registers, so it is
advantageous to spill earlier even though the same value is now kept in both a
register and a stack slot.

Also eliminate redundant spills by extending the stack slot live range
underneath reloaded registers.

This can trigger a dead code elimination, removing copies and even reloads that
were only feeding spills.

llvm-svn: 127868

This is not supposed to happen, but I have seen the x86 rematter getting
confused when rematerializing partial redefs.

llvm-svn: 127857

and early clobbers.

Assert when trying to find an undefined value.

llvm-svn: 127856

BuildUDIV: If the divisor is even we can simplify the fixup of the multiplied value by introducing an early shift.

This allows us to compile "unsigned foo(unsigned x) { return x/28; }" into
	shrl	$2, %edi
	imulq	$613566757, %rdi, %rax
	shrq	$32, %rax
	ret

instead of
	movl    %edi, %eax
	imulq   $613566757, %rax, %rcx
	shrq    $32, %rcx
	subl    %ecx, %eax
	shrl    %eax
	addl    %ecx, %eax
	shrl    $4, %eax

on x86_64

llvm-svn: 127829

I have convinced myself that it can only happen when a phi value dies. When it
happens, allocate new virtual registers for the components.

llvm-svn: 127827

llvm-svn: 127809

llvm-svn: 127807

llvm-svn: 127779

The register allocator needs to adjust its live interval unions when that happens.

llvm-svn: 127774

llvm-svn: 127773

The live range of a virtual register may change which invalidates the cached
interference information.

llvm-svn: 127772

llvm-svn: 127771

rather than an int. Thankfully, this only causes LLVM to miss optimizations, not
generate incorrect code.

This just fixes the zext at the return. We still insert an i32 ZextAssert when
reading a function's arguments, but it is followed by a truncate and another i8
ZextAssert so it is not optimized.

llvm-svn: 127766

llvm-svn: 127764

plus the test where it used to break.", which broke Clang self-host of a
Debug+Asserts compiler, on OS X.

llvm-svn: 127763

llvm-svn: 127757

After live range splitting, an original value may be available in multiple
registers. Tracing back through the registers containing the same value, find
the best place to insert a spill, determine if the value has already been
spilled, or discover a reaching def that may be rematerialized.

This is only the analysis part. The information is not used for anything yet.

llvm-svn: 127698

llvm-svn: 127697

v2 = bitcast v1
...
v3 = bitcast v2
...
   = v3
=>
v2 = bitcast v1
...
   = v1
if v1 and v3 are of in the same register class.

bitcast between i32 and fp (and others) are often not nops since they
are in different register classes. These bitcast instructions are often
left because they are in different basic blocks and cannot be
eliminated by dag combine.

rdar://9104514

llvm-svn: 127668

zext(undef) = 0, because the top bits will be zero.

llvm-svn: 127649

and then go kablooie. The problem was that it was tracking the PHI nodes anew
each time into this function. But it didn't need to. And because the recursion
didn't know that a PHINode was visited before, it would go ahead and call
itself.

There is a testcase, but unfortunately it's too big to add. This problem will go
away with the EH rewrite.
<rdar://problem/8856298>

llvm-svn: 127640

Use the opportunity to get rid of the trailing underscore variable names.

llvm-svn: 127618

Remove the unused reserved_ bit vector, no functional change intended.

This doesn't break 'svn blame', this file really is all my fault.

llvm-svn: 127607

llvm-svn: 127600

llvm-svn: 127598

Use the virtual register number as a cache tag instead. They are not reused.

llvm-svn: 127561

This allows the allocator to free any resources used by the virtual register,
including physical register assignments.

llvm-svn: 127560

llvm-gcc-i386-linux-selfhost and llvm-x86_64-linux-checks buildbots.
The original log entry:
Remove optimization emitting a reference insted of label difference, since
it can create more relocations. Removed isBaseAddressKnownZero method,
because it is no longer used.

llvm-svn: 127540

llvm-svn: 127530

Live range splitting can create a number of small live ranges containing only a
single real use. Spill these small live ranges along with the large range they
are connected to with copies. This enables memory operand folding and maximizes
the spill to fill distance.

Work in progress with known bugs.

llvm-svn: 127529

There are too many compatibility problems with using mixed types in
std::upper_bound, and I don't want to spend 110 lines of boilerplate setting up
a call to a 10-line function. Binary search is not /that/ hard to implement
correctly.

I tried terminating the binary search with a linear search, but that actually
made the algorithm slower against my expectation. Most live intervals have less
than 4 segments. The early test against endIndex() does pay, and this version is
25% faster than plain std::upper_bound().

llvm-svn: 127522

protector insertion not working correctly with unreachable code. Since that
revision was rolled out, this test doesn't actual fail before this fix.

llvm-svn: 127497

llvm-svn: 127496