llvm-svn: 112332

Add a prototype of a new peephole optimizing pass that uses LazyValue info to simplify PHIs and select's.
This pass addresses the missed optimizations from PR2581 and PR4420.

llvm-svn: 112325

A = shl x, 42
...
B = lshr ..., 38

which can be transformed into:
A = shl x, 4
...

iff we can prove that the would-be-shifted-in bits
are already zero.  This eliminates two shifts in the testcase
and allows eliminate of the whole i128 chain in the real example.

llvm-svn: 112314

framework, which is good at ripping through bitfield
operations.  This generalize a bunch of the existing
xforms that instcombine does, such as 
  (x << c) >> c -> and
to handle intermediate logical nodes.  This is useful for
ripping up the "promote to large integer" code produced by
SRoA.

llvm-svn: 112304

more general simplify demanded bits logic.

llvm-svn: 112291

llvm-svn: 112286

computation can be truncated if it is fed by a sext/zext that doesn't
have to be exactly equal to the truncation result type.

llvm-svn: 112285

by the SRoA "promote to large integer" code, eliminating
some type conversions like this:

   %94 = zext i16 %93 to i32                       ; <i32> [#uses=2]
   %96 = lshr i32 %94, 8                           ; <i32> [#uses=1]
   %101 = trunc i32 %96 to i8                      ; <i8> [#uses=1]

This also unblocks other xforms from happening, now clang is able to compile:

struct S { float A, B, C, D; };
float foo(struct S A) { return A.A + A.B+A.C+A.D; }

into:

_foo:                                   ## @foo
## BB#0:                                ## %entry
	pshufd	$1, %xmm0, %xmm2
	addss	%xmm0, %xmm2
	movdqa	%xmm1, %xmm3
	addss	%xmm2, %xmm3
	pshufd	$1, %xmm1, %xmm0
	addss	%xmm3, %xmm0
	ret

on x86-64, instead of:

_foo:                                   ## @foo
## BB#0:                                ## %entry
	movd	%xmm0, %rax
	shrq	$32, %rax
	movd	%eax, %xmm2
	addss	%xmm0, %xmm2
	movapd	%xmm1, %xmm3
	addss	%xmm2, %xmm3
	movd	%xmm1, %rax
	shrq	$32, %rax
	movd	%eax, %xmm0
	addss	%xmm3, %xmm0
	ret

This seems pretty close to optimal to me, at least without
using horizontal adds.  This also triggers in lots of other
code, including SPEC.

llvm-svn: 112278

Use LVI to eliminate conditional branches where we've tested a related condition previously.  Update tests for this change.
This fixes PR5652.

llvm-svn: 112270

by SRoA.  This is part of rdar://7892780, but needs another xform to
expose this.

llvm-svn: 112232

is a vector to be a vector element extraction.  This allows clang to
compile:

struct S { float A, B, C, D; };
float foo(struct S A) { return A.A + A.B+A.C+A.D; }

into:

_foo:                                   ## @foo
## BB#0:                                ## %entry
	movd	%xmm0, %rax
	shrq	$32, %rax
	movd	%eax, %xmm2
	addss	%xmm0, %xmm2
	movapd	%xmm1, %xmm3
	addss	%xmm2, %xmm3
	movd	%xmm1, %rax
	shrq	$32, %rax
	movd	%eax, %xmm0
	addss	%xmm3, %xmm0
	ret

instead of:

_foo:                                   ## @foo
## BB#0:                                ## %entry
	movd	%xmm0, %rax
	movd	%eax, %xmm0
	shrq	$32, %rax
	movd	%eax, %xmm2
	addss	%xmm0, %xmm2
	movd	%xmm1, %rax
	movd	%eax, %xmm1
	addss	%xmm2, %xmm1
	shrq	$32, %rax
	movd	%eax, %xmm0
	addss	%xmm1, %xmm0
	ret

... eliminating half of the horribleness.

llvm-svn: 112227

llvm-svn: 112198

fix: add a flag to MapValue and friends which indicates whether
any module-level mappings are being made. In the common case of
inlining, no module-level mappings are needed, so MapValue doesn't
need to examine non-function-local metadata, which can be very
expensive in the case of a large module with really deep metadata
(e.g. a large C++ program compiled with -g).

This flag is a little awkward; perhaps eventually it can be moved
into the ClonedCodeInfo class.

llvm-svn: 112190

except ...", it is causing *massive* performance regressions when building Clang
with itself (-O3 -g).

llvm-svn: 112158

individual ...", which depends on r111922, which I am reverting.

llvm-svn: 112157

llvm-svn: 112130

and was over-complicated, and replacing it with a simple implementation.

llvm-svn: 112120

llvm-svn: 112104

instructions, not when remapping modules.

llvm-svn: 112091

DIGlobalVariable can be used to encode debug info for  globals that are directly folded into a constant by FE.

llvm-svn: 112072

which does the same thing. This eliminates redundant code and
handles MDNodes better. MDNode linking still doesn't fully
work yet though.

llvm-svn: 111941

llvm-svn: 111923

that it avoids a lot of unnecessary cloning by avoiding remapping
MDNode cycles when none of the nodes in the cycle actually need to
be remapped. Also it uses the new temporary MDNode mechanism.

llvm-svn: 111922

llvm-svn: 111834

llvm-svn: 111816

Now that PassInfo and Pass::ID have been separated, move the rest of the passes over to the new registration API.

llvm-svn: 111815

llvm-svn: 111665

llvm-svn: 111571

When a set of bitmask operations, typically from a bitfield initialization, only modifies the low bytes of a value,
we can narrow the store to only over-write the affected bytes.

llvm-svn: 111568

llvm-svn: 111551

llvm-svn: 111543

of the two.

llvm-svn: 111495

llvm-svn: 111382

from the LHS should disable reconsidering that pred on the
RHS.  However, knowing something about the pred on the RHS
shouldn't disable subsequent additions on the RHS from
happening.

llvm-svn: 111349

llvm-svn: 111348

llvm-svn: 111344

llvm-svn: 111342

vector heavy code.  I'll re-enable when we've tracked down the problem.

llvm-svn: 111318

loop, making the resulting loop significantly less ugly.  Also, zap
its trivial PHI nodes, since it's easy.

llvm-svn: 111255

what it does manually.

llvm-svn: 111248