intersection of the LHS and RHS ConstantRanges and return "false" when
the range is empty.

This simplifies some code and catches some extra cases.

llvm-svn: 126744

llvm-svn: 126720

llvm-svn: 126715

llvm-svn: 126694

llvm-svn: 126671

only existed as the result of a misunderstanding.

llvm-svn: 126669

Based on a patch by Alistair Lynn.

llvm-svn: 126647

also have a zero when numerator = denominator. Reverts parts of r126635 and
r126637.

llvm-svn: 126644

PR9343.

llvm-svn: 126643

argument), regardless of the divisor. Teach instcombine about this and fix
test7 in PR9343!

llvm-svn: 126635

Yes, there are other types than i8* and GEPs on them can produce an add+multiply.
We don't consider that cheap enough to be speculatively executed.

llvm-svn: 126481

llvm-svn: 126452

llvm-svn: 126445

llvm-svn: 126398

trivial places.  This pass needs a lot of work.

llvm-svn: 126367

to reduce nesting.  This needs to be turned into a table.

llvm-svn: 126366

function prototype into a call to a varargs prototype.  We do
allow the xform if we have a definition, but otherwise we don't
want to risk that we're changing the abi in a subtle way.  On
X86-64, for example, varargs require passing stuff in %al.

llvm-svn: 126363

values from all of the loop's exiting blocks are equal. Patch by Andrew Clinton.

llvm-svn: 126253

itself without going via a phi node then we could return false here in
spite of making a change.  Also, tweak the comment because this method
can (and always could) return true without deleting the original phi node.
For example, if the phi node was used by a read-only invoke instruction
which is used by another phi node phi2 which is only used by and only uses
the invoke, then phi2 would be deleted but not the invoke instruction and
not the original phi node.

llvm-svn: 126129

llvm-svn: 126125

should be that if the phi is used by a side-effect free instruction with
no uses then the phi and the instruction now get zapped (checked by the
unittest).

llvm-svn: 126124

llvm-svn: 126102

test for that. With this change, test/CodeGen/X86/codegen-dce.ll no longer finds
any instructions to DCE, so delete the test.

Also renamed J and JP to I and IP in RecursivelyDeleteDeadPHINode.

llvm-svn: 126088

llvm-svn: 126082

We usually catch this kind of optimization through InstSimplify's distributive
magic, but or doesn't distribute over xor in general.

"A | ~(A | B) -> A | ~B" hits 24 times on gcc.c.

llvm-svn: 126081

by Andrew Clinton!

llvm-svn: 126077

one Value set. This is faster because we only need to use the set when there
isn't already an entry in the map. No functionality change!

llvm-svn: 126076

the instruction passed in.  Make sure to account for this correctly, instead
of looping infinitely.

llvm-svn: 126058

constant, including globals.  This makes us generate much more "pretty" pattern
globals as well because it doesn't break it down to an array of bytes all the
time.

This enables us to handle stores of relocatable globals.  This kicks in about
48 times in 254.gap, giving us stuff like this:

@.memset_pattern40 = internal constant [2 x %struct.TypHeader* (%struct.TypHeader*, %struct.TypHeader*)*] [%struct.TypHeader* (%struct.TypHeader*, %struct
.TypHeader*)* @IsFalse, %struct.TypHeader* (%struct.TypHeader*, %struct.TypHeader*)* @IsFalse], align 16

...
  call void @memset_pattern16(i8* %scevgep5859, i8* bitcast ([2 x %struct.TypHeader* (%struct.TypHeader*, %struct.TypHeader*)*]* @.memset_pattern40 to i8*
), i64 %tmp75) nounwind

llvm-svn: 126044

unsplatable values into memset_pattern16 when it is available
(recent darwins).  This transforms lots of strided loop stores
of ints for example, like 5 in vpr:

  Formed memset:   call void @memset_pattern16(i8* %4, i8* getelementptr inbounds ([16 x i8]* @.memset_pattern9, i32 0, i32 0), i64 %tmp25)
    from store to: {%3,+,4}<%11> at:   store i32 3, i32* %scevgep, align 4, !tbaa !4

llvm-svn: 126040

to hack on memset, memcpy etc.

llvm-svn: 125974

llvm-svn: 125968

overflow.  These subsume some existing equality transforms, so zap those.

llvm-svn: 125843

taken (and used!).  This prevents merging the blocks (invalidating
the block addresses) in a case like this:

#define _THIS_IP_  ({ __label__ __here; __here: (unsigned long)&&__here; })

void foo() {
  printf("%p\n", _THIS_IP_);
  printf("%p\n", _THIS_IP_);
  printf("%p\n", _THIS_IP_);
}

which fixes PR4151.

llvm-svn: 125829

This is part of a futile attempt to not "break" bizzaro
code like this:

 l1:
  printf("l1: %p\n", &&l1);
  ++x;

  if( x < 3 ) goto l1;


Previously we'd fold &&l1 to 1, which is fine per our semantics
but not helpful to the user.

llvm-svn: 125827

common operations through a phi. 

llvm-svn: 125790

llvm-svn: 125787

result inbounds if all of the inputs are inbounds.

llvm-svn: 125785

llvm-svn: 125774

variations (some of these were already present so I unified the code).  Spotted by my
auto-simplifier as occurring a lot.

llvm-svn: 125734