this fixes problems where codegenprepare would sink expressions into load/stores
that are not valid, and fixes cases where it would miss important valid ones.

This fixes several serious codesize and perf issues, particularly on targets
with complex addressing modes like arm and x86.  For example, now we compile
CodeGen/X86/isel-sink.ll to:

_test:
        movl 8(%esp), %eax
        movl 4(%esp), %ecx
        cmpl $1233, %eax
        ja LBB1_2       #F
LBB1_1: #T
        movl $4, (%ecx,%eax,4)
        movl $141, %eax
        ret
LBB1_2: #F
        movl (%ecx,%eax,4), %eax
        ret

instead of:

_test:
        movl 8(%esp), %eax
        leal (,%eax,4), %ecx
        addl 4(%esp), %ecx
        cmpl $1233, %eax
        ja LBB1_2       #F
LBB1_1: #T
        movl $4, (%ecx)
        movl $141, %eax
        ret
LBB1_2: #F
        movl (%ecx), %eax
        ret

llvm-svn: 35970

llvm-svn: 35906

        icmp slt i32 %X, 0              ; <i1>:0 [#uses=1]
        sext i1 %0 to i32               ; <i32>:1 [#uses=1]

into:

        %X.lobit = ashr i32 %X, 31              ; <i32> [#uses=1]

This implements InstCombine/icmp.ll:test[34]

llvm-svn: 35891

Transforms/InstCombine/icmp.ll

llvm-svn: 35890

llvm-svn: 35886

define i32 @test(i32 %X) {
entry:
        %Y = and i32 %X, 4              ; <i32> [#uses=1]
        icmp eq i32 %Y, 0               ; <i1>:0 [#uses=1]
        sext i1 %0 to i32               ; <i32>:1 [#uses=1]
        ret i32 %1
}

by moving code out of commonIntCastTransforms into visitZExt.  Simplify the
APInt gymnastics in it etc.

llvm-svn: 35885

llvm-svn: 35879

We now tolerate small amounts of undefined behavior, better emulating what
would happen if the transaction actually occurred in memory.  This fixes
SingleSource/UnitTests/2007-04-10-BitfieldTest.c on PPC, at least until
Devang gets a chance to fix the CFE from doing undefined things with bitfields :)

llvm-svn: 35875

InstCombine/set.ll:test25

llvm-svn: 35852

llvm-svn: 35844

llvm-svn: 35837

llvm-svn: 35836

happen to be an entry, in such case, it is not a good idea to
insert new block before entry.

Also fix typo in assertion check.

llvm-svn: 35833

llvm-svn: 35829

llvm-svn: 35825

llvm-svn: 35822

Handle Argument or Undef as an incoming PHI value.

llvm-svn: 35821

llvm-svn: 35820

llvm-svn: 35819

llvm-svn: 35792

Transforms/InstCombine/vec_insertelt.ll and fixes PR1286.

We now compile the code from that bug into:

_foo:
        movl 4(%esp), %eax
        movdqa (%eax), %xmm0
        movl 8(%esp), %ecx
        psllw (%ecx), %xmm0
        movdqa %xmm0, (%eax)
        ret

instead of:

_foo:
        subl $4, %esp
        movl %ebp, (%esp)
        movl %esp, %ebp
        movl 12(%ebp), %eax
        movdqa (%eax), %xmm0
        #IMPLICIT_DEF %eax
        pinsrw $2, %eax, %xmm0
        xorl %ecx, %ecx
        pinsrw $3, %ecx, %xmm0
        pinsrw $4, %eax, %xmm0
        pinsrw $5, %ecx, %xmm0
        pinsrw $6, %eax, %xmm0
        pinsrw $7, %ecx, %xmm0
        movl 8(%ebp), %eax
        movdqa (%eax), %xmm1
        psllw %xmm0, %xmm1
        movdqa %xmm1, (%eax)
        movl %ebp, %esp
        popl %ebp
        ret

woo :)

llvm-svn: 35788

llvm-svn: 35765

llvm-svn: 35763

Add a new xform to simplify (A&B)|(~A&C).  THis implements InstCombine/or2.ll:test1

llvm-svn: 35760

llvm-svn: 35734

llvm-svn: 35731

llvm-svn: 35724

llvm-svn: 35719

llvm-svn: 35718

first and then range testing second.

llvm-svn: 35715

llvm-svn: 35714

llvm-svn: 35700

llvm-svn: 35680

elsewhere.

llvm-svn: 35668

llvm-svn: 35665

llvm-svn: 35655

some constant exprs to apints).

Thanks to Anton for tracking down a small testcase that triggered this!

llvm-svn: 35633

ldecod now passes.

llvm-svn: 35626

llvm-svn: 35620

llvm-svn: 35615