Move the getConstantExpr function towards the end of the file so we don't
need a dozen forward declarations.

llvm-svn: 34877

   ensure they are cleaned up when the stack frame exits.
2. Move a function to the Execution.cpp file where it belongs.

llvm-svn: 34876

llvm-svn: 34875

llvm-svn: 34874

llvm-svn: 34871

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

entry (0x8b056f0, LLVM BB @0x8b01b30, ID#0):
Live Ins: %r0 %r1 %r2 %r3
        %reg1032 = tMOVrr %r3<kill>
        %reg1033 = tMOVri8 1
        %reg1034 = tMOVri8 0
        tCMPi8 %reg1029<kill>, 0
        tBcc mbb<entry,0x8b06a10>, 0
    Successors according to CFG: 0x8b06980 0x8b06a10

entry (0x8b06980, LLVM BB @0x8b01b30, ID#12):
    Predecessors according to CFG: 0x8b056f0
        %reg1036 = tMOVrr %reg1034<kill>
    Successors according to CFG: 0x8b06a10

entry (0x8b06a10, LLVM BB @0x8b01b30, ID#13):
    Predecessors according to CFG: 0x8b056f0 0x8b06980
        %reg1024<dead> = tMOVrr %reg1030<kill>
        ...

reg1030 and r1 have already been joined. When reg1024 and reg1030 are joined,
r1 live range from function entry to the tMOVrr instruction are dead. Eliminate
r1 from the livein set of the entry BB, not the BB where the copy is.

llvm-svn: 34866

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: 34857

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

llvm-svn: 34852

llvm-svn: 34849

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: 34844

llvm-svn: 34843

- Available value use may be deleted (e.g. noop move).

llvm-svn: 34841

llvm-svn: 34839

passed in registers, not directly from the pregs themselves.

llvm-svn: 34838

llvm-svn: 34837

this to a NOTE: because pari/gp results start to get rounded incorrectly
after 192 bits of precision. APInt and pari/gp never differ by more than
1, but APInt is more accurate because it does not lose precision after 192
bits as does pari/gp.

llvm-svn: 34834

llvm-svn: 34833

llvm-svn: 34832

llvm-svn: 34831

llvm-svn: 34828

but not on X86 becuase shift by word size is "undefined".

llvm-svn: 34825

llvm-svn: 34824

llvm-svn: 34822

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

llvm-svn: 34821

llvm-svn: 34818

llvm-svn: 34816