to rewrite with the wrong value.

llvm-svn: 26311

llvm-svn: 26289

llvm-svn: 26287

llvm-svn: 26285

Thanks to nate for pointing this out :)

llvm-svn: 26280

llvm-svn: 26279

the right loop.

llvm-svn: 26277

llvm-svn: 26258

risk :)

llvm-svn: 26248

and ComputeMaskedBits to match the new improved versions in instcombine.
Tested against all of multisource/benchmarks on ppc.

llvm-svn: 26238

Change SplitBlock to increment a BasicBlock::iterator, not an Instruction*.  Apparently they do different things :)

This fixes a testcase that nate reduced from spass.

Also included are a couple minor code changes that don't affect the generated
code at all.

llvm-svn: 26235

llvm-svn: 26228

llvm-svn: 26225

unswitch this loop on 2 before sweating to unswitch on 1/3.

void test4(int N, int i, int C, int*P, int*Q) {
  int j;
  for (j = 0; j < N; ++j) {
    switch (C) {                // general unswitching.
    default: P[i+j] = 0; break;
    case 1: Q[i+j] = 0; break;
    case 3: P[i+j] = Q[i+j]; break;
    case 2: break;              //  TRIVIAL UNSWITCH on C==2
    }
  }
}

llvm-svn: 26223

this for example:

  for (j = 0; j < N; ++j) {     // trivial unswitch
    if (C)
      P[i+j] = 0;
  }

turning it into the obvious code without bothering to duplicate an empty loop.

llvm-svn: 26220

Y = seteq bool X, true
instead of just using X :)

llvm-svn: 26215

llvm-svn: 26194

llvm-svn: 26191

llvm-svn: 26157

llvm-svn: 26155

for a sign extension.

This fixes InstCombine/2006-02-13-DemandedMiscompile.ll and Ptrdist/bc.

llvm-svn: 26152

of the input.  This fixes the mediabench/gsm/toast failure last night.

llvm-svn: 26138

llvm-svn: 26135

llvm-svn: 26134

1. Teach GetConstantInType to handle boolean constants.
2. Teach instcombine to fold (compare X, CST) when X has known 0/1 bits.
   Testcase here: set.ll:test22
3. Improve the "(X >> c1) & C2 == 0" folding code to allow a noop cast
   between the shift and and.  More aggressive bitfolding for other reasons
   was turning signed shr's into unsigned shr's, leaving the noop cast in
   the way.

llvm-svn: 26131

This allows us to simplify on conditions where bits are not known, but they
are not demanded either!  This also fixes a couple of bugs in
ComputeMaskedBits that were exposed during this work.

In the future, swaths of instcombine should be removed, as this code
subsumes a bunch of ad-hockery.

llvm-svn: 26122

llvm-svn: 26114

llvm-svn: 26113

llvm-svn: 26112

phi's in the successors

llvm-svn: 26108

with branches on partially invariant computations.

llvm-svn: 26104

llvm-svn: 26103

llvm-svn: 26102

branches in their entry block that control whether or not the loop is a noop or not.

llvm-svn: 26101

llvm-svn: 26098

llvm-svn: 26093

uses of loop values outside the loop.  We need loop-closed SSA form to do
this right, or to use SSA rewriting if we really care.

llvm-svn: 26089

llvm-svn: 26088

1. Teach it new tricks: in particular how to propagate through signed shr and sexts.
2. Teach it to return a bitset of known-1 and known-0 bits, instead of just zero.
3. Teach instcombine (AND X, C) to fold when we know all C bits of X.

This implements Regression/Transforms/InstCombine/bittest.ll, and allows
future things to be simplified.

llvm-svn: 26087

optimization where we reduce the number of bits in AND masks when possible.

llvm-svn: 26056