Added optimization that narrow load / op / store and the 'op' is a bit twiddling instruction and its second operand is an immediate. If bits that are touched by 'op' can be done with a narrower instruction, reduce the width of the load and store as well. This happens a lot with bitfield manipulation code.
e.g.
orl     $65536, 8(%rax)
=>
orb     $1, 10(%rax)

Since narrowing is not always a win, e.g. i32 -> i16 is a loss on x86, dag combiner consults with the target before performing the optimization.

llvm-svn: 72507

llvm-svn: 72494

FP_TO_XINT.  Necessary for some cleanups I'm working on.  Updated 
from the previous version (r72431) to fix a bug and make some things a 
bit clearer.

llvm-svn: 72445

llvm-svn: 72436

FP_TO_XINT.  Necessary for some cleanups I'm working on. 

llvm-svn: 72431

moment.

llvm-svn: 72350

systems instead of attempting to promote them to a 64-bit SINT_TO_FP or 
FP_TO_SINT.  This is in preparation for removing the type legalization 
code from LegalizeDAG: once type legalization is gone from LegalizeDAG, 
it won't be able to handle the i64 operand/result correctly.

This isn't quite ideal, but I don't think any other operation for any 
target ends up in this situation, so treating this case specially seems 
reasonable.

llvm-svn: 72324

llvm-svn: 71726

need to work a bit to combine things like (x+c1+c2) into x+c3.

llvm-svn: 71232

llvm-svn: 70425

llvm-svn: 70372

PR2957

ISD::VECTOR_SHUFFLE now stores an array of integers representing the shuffle
mask internal to the node, rather than taking a BUILD_VECTOR of ConstantSDNodes
as the shuffle mask.  A value of -1 represents UNDEF.

In addition to eliminating the creation of illegal BUILD_VECTORS just to 
represent shuffle masks, we are better about canonicalizing the shuffle mask,
resulting in substantially better code for some classes of shuffles.

llvm-svn: 70225

very elegant, but neither is the tls specification :-(

llvm-svn: 69968

llvm-svn: 69967

ISD::VECTOR_SHUFFLE now stores an array of integers representing the shuffle
mask internal to the node, rather than taking a BUILD_VECTOR of ConstantSDNodes
as the shuffle mask.  A value of -1 represents UNDEF.

In addition to eliminating the creation of illegal BUILD_VECTORS just to 
represent shuffle masks, we are better about canonicalizing the shuffle mask,
resulting in substantially better code for some classes of shuffles.

A clean up of x86 shuffle code, and some canonicalizing in DAGCombiner is next.

llvm-svn: 69952

Spotted by gcc-4.5.

llvm-svn: 69673

in the MachineFunction class, renaming it to addLiveIn for consistency with
the same method in MachineBasicBlock.  Thanks for Anton for suggesting this.

llvm-svn: 69615

leaq	foo@TLSGD(%rip), %rdi

as part of the instruction sequence. Using a register other than %rdi and then
copying it to %rdi is not valid.

llvm-svn: 69350

llvm-svn: 68947

code that uses it by using SelectionDAG::getVTList instead.

llvm-svn: 68744

llvm-svn: 68666

Tested by bootstrapping llvm-gcc and using that to build llvm.

llvm-svn: 68645

llvm-svn: 68603

with SUBREG_TO_REG, teach SimpleRegisterCoalescing to coalesce
SUBREG_TO_REG instructions (which are similar to INSERT_SUBREG
instructions), and teach the DAGCombiner to take advantage of this on
targets which support it. This eliminates many redundant
zero-extension operations on x86-64.

This adds a new TargetLowering hook, isZExtFree. It's similar to
isTruncateFree, except it only applies to actual definitions, and not
no-op truncates which may not zero the high bits.

Also, this adds a new optimization to SimplifyDemandedBits: transform
operations like x+y into (zext (add (trunc x), (trunc y))) on targets
where all the casts are no-ops. In contexts where the high part of the
add is explicitly masked off, this allows the mask operation to be
eliminated. Fix the DAGCombiner to avoid undoing these transformations
to eliminate casts on targets where the casts are no-ops.

Also, this adds a new two-address lowering heuristic. Since
two-address lowering runs before coalescing, it helps to be able to
look through copies when deciding whether commuting and/or
three-address conversion are profitable.

Also, fix a bug in LiveInterval::MergeInClobberRanges. It didn't handle
the case that a clobber range extended both before and beyond an
existing live range. In that case, multiple live ranges need to be
added. This was exposed by the new subreg coalescing code.

Remove 2008-05-06-SpillerBug.ll. It was bugpoint-reduced, and the
spiller behavior it was looking for no longer occurrs with the new
instruction selection.

llvm-svn: 68576

builds.

--- Reverse-merging (from foreign repository) r68552 into '.':
U    test/CodeGen/X86/tls8.ll
U    test/CodeGen/X86/tls10.ll
U    test/CodeGen/X86/tls2.ll
U    test/CodeGen/X86/tls6.ll
U    lib/Target/X86/X86Instr64bit.td
U    lib/Target/X86/X86InstrSSE.td
U    lib/Target/X86/X86InstrInfo.td
U    lib/Target/X86/X86RegisterInfo.cpp
U    lib/Target/X86/X86ISelLowering.cpp
U    lib/Target/X86/X86CodeEmitter.cpp
U    lib/Target/X86/X86FastISel.cpp
U    lib/Target/X86/X86InstrInfo.h
U    lib/Target/X86/X86ISelDAGToDAG.cpp
U    lib/Target/X86/AsmPrinter/X86ATTAsmPrinter.cpp
U    lib/Target/X86/AsmPrinter/X86IntelAsmPrinter.cpp
U    lib/Target/X86/AsmPrinter/X86ATTAsmPrinter.h
U    lib/Target/X86/AsmPrinter/X86IntelAsmPrinter.h
U    lib/Target/X86/X86ISelLowering.h
U    lib/Target/X86/X86InstrInfo.cpp
U    lib/Target/X86/X86InstrBuilder.h
U    lib/Target/X86/X86RegisterInfo.td

llvm-svn: 68560

This introduces a small regression on the generated code
quality in the case we are just computing addresses, not
loading values.

Will work on it and on X86-64 support.

llvm-svn: 68552

movq for v2i64 on x86-32.

llvm-svn: 68368

llvm-svn: 68253

llvm-svn: 68133

When optimzing a mul by immediate into two, the resulting mul's should get a x86 specific node to avoid dag combiner from hacking on them further.

llvm-svn: 68066

llvm-svn: 67949

Optimize some 64-bit multiplication by constants into two lea's or one lea + shl since imulq is slow (latency 5). e.g.
x * 40
=>
shlq    $3, %rdi
leaq    (%rdi,%rdi,4), %rax

This has the added benefit of allowing more multiply to be folded into addressing mode. e.g.
a * 24 + b
=>
leaq    (%rdi,%rdi,2), %rax
leaq    (%rsi,%rax,8), %rax

llvm-svn: 67917

improve TLS support (see http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20090309/075220.html), but that code is VERY brittle.

This patch just makes it a bit more resistant.

llvm-svn: 67843

llvm-svn: 67784

llvm-svn: 67742

  %a = ...
  %b = and i32 %a, 2
  %c = srl i32 %b, 1
  %d = br i32 %c, 

into

  %a = ...
  %b = and %a, 2
  %c = X86ISD::CMP %b, 0
  %d = X86ISD::BRCOND %c ...

This applies only when the AND constant value has one bit set and the SRL
constant is equal to the log2 of the AND constant. The back-end is smart enough
to convert the result into a TEST/JMP sequence.

llvm-svn: 67728

instructions. Prevent that if we don't want implicit uses of SSE.

llvm-svn: 66877

Fix some significant problems with constant pools that resulted in unnecessary paddings between constant pool entries, larger than necessary alignments (e.g. 8 byte alignment for .literal4 sections), and potentially other issues.

1. ConstantPoolSDNode alignment field is log2 value of the alignment requirement. This is not consistent with other SDNode variants.
2. MachineConstantPool alignment field is also a log2 value.
3. However, some places are creating ConstantPoolSDNode with alignment value rather than log2 values. This creates entries with artificially large alignments, e.g. 256 for SSE vector values.
4. Constant pool entry offsets are computed when they are created. However, asm printer group them by sections. That means the offsets are no longer valid. However, asm printer uses them to determine size of padding between entries.
5. Asm printer uses expensive data structure multimap to track constant pool entries by sections.
6. Asm printer iterate over SmallPtrSet when it's emitting constant pool entries. This is non-deterministic.


Solutions:
1. ConstantPoolSDNode alignment field is changed to keep non-log2 value.
2. MachineConstantPool alignment field is also changed to keep non-log2 value.
3. Functions that create ConstantPool nodes are passing in non-log2 alignments.
4. MachineConstantPoolEntry no longer keeps an offset field. It's replaced with an alignment field. Offsets are not computed when constant pool entries are created. They are computed on the fly in asm printer and JIT.
5. Asm printer uses cheaper data structure to group constant pool entries.
6. Asm printer compute entry offsets after grouping is done.
7. Change JIT code to compute entry offsets on the fly.

llvm-svn: 66875

for i32/i64 expressions (we could also do i16 on cpus where
i16 lea is fast, but I didn't add this).  On the example, we now
generate:

_test:
	movl	4(%esp), %eax
	cmpl	$42, (%eax)
	setl	%al
	movzbl	%al, %eax
	leal	4(%eax,%eax,8), %eax
	ret

instead of:

_test:
	movl	4(%esp), %eax
	cmpl	$41, (%eax)
	movl	$4, %ecx
	movl	$13, %eax
	cmovg	%ecx, %eax
	ret

llvm-svn: 66869

example to:

_test:
	movl	4(%esp), %eax
	cmpl	$41, (%eax)
	setg	%al
	movzbl	%al, %eax
	orl	$4294967294, %eax
	ret

instead of:

        movl    4(%esp), %eax
        cmpl    $41, (%eax)
	movl	$4294967294, %ecx
	movl	$4294967295, %eax
	cmova	%ecx, %eax
	ret

which is smaller in code size and faster. rdar://6668608

llvm-svn: 66868