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: 92380

llvm-svn: 92378

llvm-svn: 92377

llvm-svn: 92375

llvm-svn: 92374

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

warning: comparison between signed and unsigned integer expressions
llvm-svn: 92359

miscompilation, PR5458.

llvm-svn: 92354

llvm-svn: 92353

llvm-svn: 92352

llvm-svn: 92349

llvm-svn: 92347

llvm-svn: 92346

llvm-svn: 92344

llvm-svn: 92343

to SmallVector, and add a unit test.

llvm-svn: 92340

llvm-svn: 92338

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

llvm-svn: 92337

llvm-svn: 92336

llvm-svn: 92335

one that remains.

llvm-svn: 92334

llvm-svn: 92333

llvm-svn: 92332

llvm-svn: 92331

llvm-svn: 92330

dumps one node instead of all of them.

llvm-svn: 92329

llvm-svn: 92328

llvm-svn: 92327

mdnode, not just operand 0 over and over.

llvm-svn: 92326

llvm-svn: 92325

llvm-svn: 92324