llvm-svn: 34891

the order that instcombine processed instructions in the testcase.  The end
result is that instcombine finished with:

define i16 @test1(i16 %a) {
        %tmp = zext i16 %a to i32               ; <i32> [#uses=2]
        %tmp21 = lshr i32 %tmp, 8               ; <i32> [#uses=1]
        %tmp5 = shl i32 %tmp, 8         ; <i32> [#uses=1]
        %tmp.upgrd.32 = or i32 %tmp21, %tmp5            ; <i32> [#uses=1]
        %tmp.upgrd.3 = trunc i32 %tmp.upgrd.32 to i16           ; <i16> [#uses=1]
        ret i16 %tmp.upgrd.3
}

which can't get matched as a bswap.

This patch makes instcombine more sophisticated about removing truncating
casts, allowing it to turn this into:

define i16 @test2(i16 %a) {
        %tmp211 = lshr i16 %a, 8
        %tmp52 = shl i16 %a, 8
        %tmp.upgrd.323 = or i16 %tmp211, %tmp52
        ret i16 %tmp.upgrd.323
}

which then matches as bswap.  This fixes bswap.ll and implements
InstCombine/cast2.ll:test[12].  This also implements cast elimination of
add/sub.

llvm-svn: 34870

llvm-svn: 34868

finish without combining something it is capable of.

llvm-svn: 34865

llvm-svn: 34863

Replace expensive getZExtValue() == 0 calls with isZero() calls.

llvm-svn: 34861

llvm-svn: 34860

llvm-svn: 34859

llvm-svn: 34858

llvm-svn: 34856

2. Make sure debug output of APInt values is safe for all bit widths.

llvm-svn: 34855

llvm-svn: 34854

llvm-svn: 34853

a value from the worklist required scanning the entire worklist to remove all
entries.  We now use a combination map+vector to prevent duplicates from
happening and prevent the scan.  This speeds up instcombine on a large file
from the llvm-gcc bootstrap from 189.7s to 4.84s in a debug build and from
5.04s to 1.37s in a release build.

llvm-svn: 34848

llvm-svn: 34846

llvm-svn: 34832

llvm-svn: 34822

Constant::isNullValue() in situations where it is possible.

llvm-svn: 34821

using isNullValue() instead of getZExtValue() == 0.

llvm-svn: 34815

assert if the ConstantInt's value is large.

llvm-svn: 34814

bit width of the ConstantInt being converted.

llvm-svn: 34810

This caused a warning for construction with -1. Avoid the warning by using
-1ULL instead.

llvm-svn: 34796

are not needed as the results are the same with or without it.

Patch by Nicholas Lewycky.

llvm-svn: 34782

Adjust to changes in ConstantRange interface.

llvm-svn: 34762

Remove ConstantInt from ConstantRange interface and adjust its users to
compensate.

llvm-svn: 34758

First round of ConstantRange changes. This makes all CR constructors use
only APInt and not use ConstantInt. Clients are adjusted accordingly.

llvm-svn: 34756

llvm-svn: 34640

llvm-svn: 34638

llvm-svn: 34546

llvm-svn: 34531

llvm-svn: 34495

llvm-svn: 34480

llvm-svn: 34456

llvm-svn: 34439

llvm-svn: 34417

llvm-svn: 34395

llvm-svn: 34394

llvm-svn: 34333

by 5%.

llvm-svn: 34332

on 447.dealII

llvm-svn: 34323