Refactor some code to expose an interface to constant fold and instruction given it's opcode, typeand operands.

llvm-svn: 28517

llvm-svn: 28512

llvm-svn: 28507

there's still a lot of work to be done on it.

llvm-svn: 28506

llvm-svn: 28503

and documentation updates soo.

llvm-svn: 28495

llvm-svn: 28490

No functionality change.

llvm-svn: 28489

the program.  This exposes more opportunities for the instcombiner, and implements
vec_shuffle.ll:test6

llvm-svn: 28487

extractelement from the SV's source.  This implement vec_shuffle.ll:test[45]

llvm-svn: 28485

array scopes possibly accessing valid memory in outer subscripts.

llvm-svn: 28478

This implements Transforms/InstCombine/2006-05-10-InvalidIndexUndef.ll

llvm-svn: 28450

by Anton Korobeynikov!  This is a step towards closing PR786.

llvm-svn: 28447

llvm-svn: 28422

llvm-svn: 28395

Patch written by Domagoj Babic!

llvm-svn: 28367

to the new module.  Patch provided by Nick Lewycky!

llvm-svn: 28349

llvm-svn: 28289

llvm-svn: 28286

llvm-svn: 28284

bitfield now gives this code:

_plus:
        lwz r2, 0(r3)
        rlwimi r2, r2, 0, 1, 31
        xoris r2, r2, 32768
        stw r2, 0(r3)
        blr

instead of this:

_plus:
        lwz r2, 0(r3)
        srwi r4, r2, 31
        slwi r4, r4, 31
        addis r4, r4, -32768
        rlwimi r2, r4, 0, 0, 0
        stw r2, 0(r3)
        blr

this can obviously still be improved.

llvm-svn: 28275

currently very limited, but can be extended in the future.  For example,
we now compile:

uint %test30(uint %c1) {
        %c2 = cast uint %c1 to ubyte
        %c3 = xor ubyte %c2, 1
        %c4 = cast ubyte %c3 to uint
        ret uint %c4
}

to:

_xor:
        movzbl 4(%esp), %eax
        xorl $1, %eax
        ret

instead of:

_xor:
        movb $1, %al
        xorb 4(%esp), %al
        movzbl %al, %eax
        ret

More impressively, we now compile:

struct B { unsigned bit : 1; };
void xor(struct B *b) { b->bit = b->bit ^ 1; }

To (X86/PPC):

_xor:
        movl 4(%esp), %eax
        xorl $-2147483648, (%eax)
        ret
_xor:
        lwz r2, 0(r3)
        xoris r2, r2, 32768
        stw r2, 0(r3)
        blr

instead of (X86/PPC):

_xor:
        movl 4(%esp), %eax
        movl (%eax), %ecx
        movl %ecx, %edx
        shrl $31, %edx
        # TRUNCATE movb %dl, %dl
        xorb $1, %dl
        movzbl %dl, %edx
        andl $2147483647, %ecx
        shll $31, %edx
        orl %ecx, %edx
        movl %edx, (%eax)
        ret

_xor:
        lwz r2, 0(r3)
        srwi r4, r2, 31
        xori r4, r4, 1
        rlwimi r2, r4, 31, 0, 0
        stw r2, 0(r3)
        blr

This implements InstCombine/cast.ll:test30.

llvm-svn: 28273

Fix a nasty bug in the memcmp optimizer where we used the wrong variable!

llvm-svn: 28269

llvm-svn: 28268

When doing the initial pass of constant folding, if we get a constantexpr,
simplify the constant expr like we would do if the constant is folded in the
normal loop.

This fixes the missed-optimization regression in
Transforms/InstCombine/getelementptr.ll last night.

llvm-svn: 28224

1. Implement InstCombine/deadcode.ll by not adding instructions in unreachable
   blocks (due to constants in conditional branches/switches) to the worklist.
   This causes them to be deleted before instcombine starts up, leading to
   better optimization.

2. In the prepass over instructions, do trivial constprop/dce as we go.  This
   has the effect of improving the effectiveness of #1.  In addition, it
   *significantly* speeds up instcombine on test cases with large amounts of
   constant folding code (for example, that produced by code specialization
   or partial evaluation).  In one example, it speeds up instcombine from
   0.0589s to 0.0224s with a release build (a 2.6x speedup).

llvm-svn: 28215

Domagoj Babic!

llvm-svn: 28181

Make the "fold (and (cast A), (cast B)) -> (cast (and A, B))" transformation
only apply when both casts really will cause code to be generated.  If one or
both doesn't, then this xform doesn't remove a cast.

This fixes Transforms/InstCombine/2006-05-06-Infloop.ll

llvm-svn: 28141

llvm-svn: 28128

llvm-svn: 28126

llvm-svn: 28101

Domagoj Babic!

llvm-svn: 28048

llvm-svn: 28019

llvm-svn: 28007

Transforms/InstCombine/vec_insert_to_shuffle.ll

llvm-svn: 27997

nondeterminism being bad) could cause some trivial missed optimizations (dead
phi nodes being left around for later passes to clean up).

With this, llvm-gcc4 now bootstraps and correctly compares.  I don't know
why I never tried to do it before... :)

llvm-svn: 27984

llvm-svn: 27912

llvm-svn: 27881

can be converted to losslessly, we can continue the conversion to a direct call.

llvm-svn: 27880

if the pointer is known aligned.

llvm-svn: 27781