positive and negative forms of constants together.  This 
allows us to compile:

int foo(int x, int y) {
    return (x-y) + (x-y) + (x-y);
}

into:

_foo:                                                       ## @foo
	subl	%esi, %edi
	leal	(%rdi,%rdi,2), %eax
	ret

instead of (where the 3 and -3 were not factored):

_foo:
        imull   $-3, 8(%esp), %ecx
        imull   $3, 4(%esp), %eax
        addl    %ecx, %eax
        ret

this started out as:
    movl    12(%ebp), %ecx
    imull   $3, 8(%ebp), %eax
    subl    %ecx, %eax
    subl    %ecx, %eax
    subl    %ecx, %eax
    ret

This comes from PR5359.

llvm-svn: 92381

llvm-svn: 92377

llvm-svn: 92375

This allows us to optimize test12 into:

define i32 @test12(i32 %X) {
  %factor = mul i32 %X, -3                        ; <i32> [#uses=1]
  %Z = add i32 %factor, 6                         ; <i32> [#uses=1]
  ret i32 %Z
}

instead of:

define i32 @test12(i32 %X) {
  %Y = sub i32 6, %X                              ; <i32> [#uses=1]
  %C = sub i32 %Y, %X                             ; <i32> [#uses=1]
  %Z = sub i32 %C, %X                             ; <i32> [#uses=1]
  ret i32 %Z
}

llvm-svn: 92373

sorted, so we can just do a linear scan.

llvm-svn: 92372

llvm-svn: 92370

llvm-svn: 92369

fix RemoveDeadBinaryOp to actually do something.

llvm-svn: 92368

instead of std::vector.

llvm-svn: 92366

llvm-svn: 92364

improve some comments, simplify a bit of code.

llvm-svn: 92363

llvm-svn: 92362

miscompilation, PR5458.

llvm-svn: 92354

llvm-svn: 92347

llvm-svn: 92346

llvm-svn: 92344

llvm-svn: 92343

by moving one method out of line and eliminating redundant checks
from other methods.

llvm-svn: 92337

things that occur in types.  "operands" are things that occur
in values.

llvm-svn: 92322

llvm-svn: 92264

llvm-svn: 92260

getMDKindID/getMDKindNames methods to LLVMContext (and add
convenience methods to Module), eliminating MetadataContext.
Move the state that it maintains out to LLVMContext.

llvm-svn: 92259

llvm-svn: 92256

I asked Devang to do back on Sep 27.  Instead of going through the
MetadataContext class with methods like getMD() and getMDs(), just
ask the instruction directly for its metadata with getMetadata()
and getAllMetadata().

This includes a variety of other fixes and improvements: previously
all Value*'s were bloated because the HasMetadata bit was thrown into
value, adding a 9th bit to a byte.  Now this is properly sunk down to
the Instruction class (the only place where it makes sense) and it
will be folded away somewhere soon.

This also fixes some confusion in getMDs and its clients about 
whether the returned list is indexed by the MDID or densely packed.
This is now returned sorted and densely packed and the comments make
this clear.

This introduces a number of fixme's which I'll follow up on.

llvm-svn: 92235

non-templated IRBuilderBase class.  Move that large CreateGlobalString
out of line, eliminating the need to #include GlobalVariable.h in IRBuilder.h

llvm-svn: 92227

doesn't exist already, eliminate registerMDKind.  Tidy up a bunch
of random stuff.

llvm-svn: 92225

llvm-svn: 92211

SDISel.  This optimization was causing simplifylibcalls to 
introduce type-unsafe nastiness.  This is the first step, I'll be 
expanding the memcmp optimizations shortly, covering things that
we really really wouldn't want simplifylibcalls to do.

llvm-svn: 92098

llvm-svn: 92084

Remove dump routine and the associated Debug.h from a header.  Patch up
other files to compensate.

llvm-svn: 92075

lowering code and update testcases.

llvm-svn: 91979

load is needed when we have a small store into a large alloca (at which 
point we get a load/insert/store sequence), but when you do a full-sized
store, this load ends up being dead.

This dead load is bad in really large nasty testcases where the load ends
up causing mem2reg to insert large chains of dependent phi nodes which only
ADCE can delete.  Instead of doing this, just don't insert the dead load.

This fixes rdar://6864035

llvm-svn: 91917

llvm-svn: 91916

missing check that an array reference doesn't go past the end of the array,
and remove some redundant checks for in-bound array and vector references
that are no longer needed.

llvm-svn: 91897

by merging all returns in a function into a single one, but simplifycfg 
currently likes to duplicate the return (an unfortunate choice!)

llvm-svn: 91890

instead of stored.  This reduces memdep memory usage, and also eliminates a bunch of
weakvh's.  This speeds up gvn on gcc.c-torture/20001226-1.c from 23.9s to 8.45s (2.8x)
on a different machine than earlier.

llvm-svn: 91885

llvm-svn: 91875

llvm-svn: 91853

load to avoid even messing around with SSAUpdate at all.  In this case (which
is very common, we can just use the input value directly).

This speeds up GVN time on gcc.c-torture/20001226-1.c from 36.4s to 16.3s,
which still isn't great, but substantially better and this is a simple speedup
that applies to lots of different cases.

llvm-svn: 91851

llvm-svn: 91849