may be called. If the entry block is empty, the insertion point iterator will be
the "end()" value. Calling ->getParent() on it (among others) causes problems.

Modify materializeFrameBaseRegister to take the machine basic block and insert
the frame base register at the beginning of that block. (It's very similar to
what the code does all ready. The only difference is that it will always insert
at the beginning of the entry block instead of after a previous materialization
of the frame base register. I doubt that that matters here.)

<rdar://problem/8782198>

llvm-svn: 122104

BUILD_VECTOR operands where the element type is not legal.  I had previously
changed this code to insert TRUNCATE operations, but that was just wrong.

llvm-svn: 122102

code for the case where 32-bit divide by constant is
turned into 64-bit multiply by constant.  8771012.

llvm-svn: 122090

the operand uses the same register as a tied operand:

  %r1 = add %r1, %r1

If add were a three-address instruction, kill flags would be required on at
least one of the uses. Since it is a two-address instruction, the tied use
operand must not have a kill flag.

This change makes the kill flag on the untied use operand optional.

llvm-svn: 122082

llvm-svn: 122073

This is a three-way interval list intersection between a virtual register, a
live interval union, and a loop. It will be used to identify interference-free
loops for live range splitting.

llvm-svn: 122034

Radar 8776599

llvm-svn: 122018

llvm-svn: 122016

 - Treaty talks on the non-proliferation of MC objects broke down.

llvm-svn: 121949

live range splitting around loops guided by register pressure.

So far, trySplit() simply prints a lot of debug output.

llvm-svn: 121918

A MachineLoopRange contains the intervals of slot indexes covered by the blocks
in a loop. This representation of the loop blocks is more efficient to compare
against interfering registers during register coalescing.

llvm-svn: 121917

llvm-svn: 121903

function so that it can live in Analysis instead of
VMCore.

llvm-svn: 121885

llvm-svn: 121872

Bypass loops have the current live range live through, but contain no uses or
defs. Splitting around a bypass loop can free registers for other uses inside
the loop by spilling the split range.

llvm-svn: 121871

This method returns the set of loops with uses that are candidates for
splitting.

llvm-svn: 121870

a wider mul if the wider mul is legal.

llvm-svn: 121848

result, the top bits are truncated off anyway, just use SRL.

llvm-svn: 121846

llvm-svn: 121807

llvm-svn: 121806

llvm-svn: 121805

llvm-svn: 121801

regB = move RCX
regA = op regB, regC
RAX  = move regA
where both regB and regC are killed. If regB is constrainted to non-compatible
physical registers but regC is not constrainted at all, then it's better to
commute the instruction.
       movl    %edi, %eax
       shlq    $32, %rcx
       leaq    (%rcx,%rax), %rax
=>
       movl    %edi, %eax
       shlq    $32, %rcx
       orq     %rcx, %rax
rdar://8762995

llvm-svn: 121793

warning in the opt build.

llvm-svn: 121791

llvm-svn: 121783

LiveIntervalUnions.

llvm-svn: 121781

llvm-svn: 121774

llvm-svn: 121741

spill weight. Filter out fixed registers instead.

Add support for reassigning an interference that was assigned to an alias.

llvm-svn: 121737

llvm-svn: 121736

when the wider type is legal.  This allows us to compile:

define zeroext i16 @test1(i16 zeroext %x) nounwind {
entry:
	%div = udiv i16 %x, 33
	ret i16 %div
}

into:

test1:                                  # @test1
	movzwl	4(%esp), %eax
	imull	$63551, %eax, %eax      # imm = 0xF83F
	shrl	$21, %eax
	ret

instead of:

test1:                                  # @test1
        movw    $-1985, %ax             # imm = 0xFFFFFFFFFFFFF83F
        mulw    4(%esp)
        andl    $65504, %edx            # imm = 0xFFE0
        movl    %edx, %eax
        shrl    $5, %eax
        ret

Implementing rdar://8760399 and example #4 from:
http://blog.regehr.org/archives/320

We should implement the same thing for [su]mul_hilo, but I don't
have immediate plans to do this.

llvm-svn: 121696

for each constant pool entry.  Using WriteTypeSymbolic here takes time
proportional to the size of the module, for each constant pool entry.

This speeds up -verbose-asm llc on 252.eon (a random testcase at my disposal)
from 4.4s to 2.137s.  llc takes 2.11s with asm-verbose off, so this is now a
pretty reasonable cost for verbose comments.

llvm-svn: 121691

llvm-svn: 121662

catch this here rather than later after accessing uninitialized memory
etc.  Fires when compiling the testcase in PR8237.

llvm-svn: 121635

llvm-svn: 121604

llvm-svn: 121599

Fix build breakage.

llvm-svn: 121596

lib/CodeGen/RegAllocGreedy.cpp:233: error: unused variable 'TRC' [-Wunused-variable]

llvm-svn: 121594

Soon, RegAllocGreedy will start splitting live ranges, and then deferred
spilling won't work anyway.

llvm-svn: 121591

The spiller should only spill. The register allocator will drive live range
splitting, it has the needed information about register pressure and
interferences.

llvm-svn: 121590