llvm-svn: 61028

CFG when there is exactly one predecessor where the load is not available.
This is designed to not increase code size but still eliminate partially
redundant loads.  This fires 1765 times on 403.gcc even though it doesn't
do critical edge splitting yet (the most common reason for it to fail).

llvm-svn: 61027

return *just* a clobber of the start block, not other 
random stuff as well.

llvm-svn: 61026

unbreaking it after r61024.

llvm-svn: 61025

llvm-svn: 61024

cleans up the generated code a bit.  This should have the added benefit of
not randomly renaming functions/globals like my previous patch did. :)

llvm-svn: 61023

memdep keeps track of how PHIs affect the pointer in dep queries, which 
allows it to eliminate the load in cases like rle-phi-translate.ll, which
basically end up being:

BB1:
   X = load P
   br BB3
BB2:
   Y = load Q
   br BB3
BB3:
   R = phi [P] [Q]
   load R

turning "load R" into a phi of X/Y.  In addition to additional exposed
opportunities, this makes memdep safe in many cases that it wasn't before
(which is required for load PRE) and also makes it substantially more 
efficient.  For example, consider:


bb1:  // has many predecessors.
   P = some_operator()
   load P

In this example, previously memdep would scan all the predecessors of BB1
to see if they had something that would mustalias P.  In some cases (e.g.
test/Transforms/GVN/rle-must-alias.ll) it would actually find them and end
up eliminating something.  In many other cases though, it would scan and not
find anything useful.  MemDep now stops at a block if the pointer is defined
in that block and cannot be phi translated to predecessors.  This causes it
to miss the (rare) cases like rle-must-alias.ll, but makes it faster by not
scanning tons of stuff that is unlikely to be useful.  For example, this
speeds up GVN as a whole from 3.928s to 2.448s (60%)!.  IMO, scalar GVN 
should be enhanced to simplify the rle-must-alias pointer base anyway, which
would allow the loads to be eliminated.

In the future, this should be enhanced to phi translate through geps and 
bitcasts as well (as indicated by FIXMEs) making memdep even more powerful.

llvm-svn: 61022

Add support for slow-path GVN with full phi construction for scalars.  This is disabled for now, as it actually pessimizes code in the abscence
of phi translation for load elimination.  This slow down GVN a bit, by about 2% on 403.gcc.

llvm-svn: 61021

Remove TODO; icmp isn't a binary operator, so this function will never deal
with them.

llvm-svn: 61020

callee will not introduce any new aliases of that pointer.

The attributes had all bits allocated already, so I decided to collapse
alignment. Alignment was previously stored as a 16-bit integer from bits 16 to
32 of the attribute, but it was required to be a power of 2. Now it's stored in
log2 encoded form in five bits from 16 to 21. That gives us 11 more bits of
space.

You may have already noticed that you only need four bits to encode a 16-bit
power of two, so why five bits? Because the AsmParser accepted 32-bit
alignments, even though we couldn't store them (they were silently discarded).
Now we can store them in memory, but not in the bitcode.

The bitcode format was already storing these as 64-bit VBR integers. So, the
bitcode format stays the same, keeping the alignment values stored as 16 bit
raw values. There's some hideous code in the reader and writer that deals with
this, waiting to be ripped out the moment we run out of bits again and have to
replace the parameter attributes table encoding.

llvm-svn: 61019

llvm-svn: 61014

llvm-svn: 61013

llvm-svn: 61012

good for coverage with future changes.

llvm-svn: 61011

a future version of LangRef.

llvm-svn: 61010

llvm-svn: 61009

target constants are allowed to have an illegal
type.

llvm-svn: 61006

llvm-svn: 61005

* Lowercased all HTML element names
* Standardized spacing around { and }
* removed class "doc_table_nw": grep finds no uses

llvm-svn: 61004

Running /Users/void/llvm/llvm.src/test/CodeGen/Generic/dg.exp ...
FAIL: /Users/void/llvm/llvm.src/test/CodeGen/Generic/asm-large-immediate.ll
Failed with exit(1) at line 1
while running:  llvm-as < /Users/void/llvm/llvm.src/test/CodeGen/Generic/asm-large-immediate.ll |  llc | /usr/bin/grep 68719476738
Assertion failed: ((TypesNeedLegalizing || getTypeAction(VT) == Legal) && "Illegal type introduced after type legalization?"), function HandleOp, file /Users/void/llvm/llvm.src/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp, line 493.
0   llc               0x0085392e char const* std::find<char const*, char>(char const*, char const*, char const&) + 98
1   llc               0x00853e63 llvm::sys::PrintStackTraceOnErrorSignal() + 593
2   libSystem.B.dylib 0x96cac09b _sigtramp + 43
3   libSystem.B.dylib 0xffffffff _sigtramp + 1765097359
4   libSystem.B.dylib 0x96d24ec2 raise + 26
5   libSystem.B.dylib 0x96d3447f abort + 73
6   libSystem.B.dylib 0x96d26063 __assert_rtn + 101
7   llc               0x004f9018 llvm::cast_retty<llvm::SubprogramDesc, llvm::DebugInfoDesc*>::ret_type llvm::cast<llvm::Sub
...

llvm-svn: 61001

types into the DAG if they were not already there.
Check this with an assertion.

llvm-svn: 60997

llvm-svn: 60994

llvm-svn: 60988

llvm-svn: 60987

NDEBUG is unset and -debug is passed.

llvm-svn: 60986

llvm-svn: 60985

llvm-svn: 60984

These call are probably dependent but VS with /Za don't seems to think so. We need to help him.

llvm-svn: 60978

llvm[2]: Linking Release executable opt (without symbols)
...
Undefined symbols:
  "llvm::APFloat::IEEEsingle", referenced from:
      __ZN4llvm7APFloat10IEEEsingleE$non_lazy_ptr in libLLVMCore.a(Constants.o)
      __ZN4llvm7APFloat10IEEEsingleE$non_lazy_ptr in libLLVMCore.a(AsmWriter.o)
      __ZN4llvm7APFloat10IEEEsingleE$non_lazy_ptr in libLLVMCore.a(ConstantFold.o)
  "llvm::APFloat::IEEEdouble", referenced from:
      __ZN4llvm7APFloat10IEEEdoubleE$non_lazy_ptr in libLLVMCore.a(Constants.o)
      __ZN4llvm7APFloat10IEEEdoubleE$non_lazy_ptr in libLLVMCore.a(AsmWriter.o)
      __ZN4llvm7APFloat10IEEEdoubleE$non_lazy_ptr in libLLVMCore.a(ConstantFold.o)
ld: symbol(s) not found

This is in release mode. To replicate, compile llvm and llvm-gcc in optimized
mode. Then build llvm, in optimized mode, with the newly created compiler.

llvm-svn: 60977

Add missing DIType constructor, needed by DIVariable::getType().

llvm-svn: 60976

llvm-svn: 60975

llvm-svn: 60974

a pretification of the IR.

llvm-svn: 60973

width register load followed by a truncating
store for the copy, since the load will not place
the value in the lower bits.  Probably partial
loads/stores can never happen here, but fix it
anyway.

llvm-svn: 60972

llvm-svn: 60971

llvm-svn: 60970

llvm-svn: 60969

llvm-svn: 60968

llvm-svn: 60965

use of illegal integer types: instead, use a stack slot
and copying via integer registers.  The existing code
is still used if the bitconvert is to a legal integer
type.

This fires on the PPC testcases 2007-09-08-unaligned.ll
and vec_misaligned.ll.  It looks like equivalent code
is generated with these changes, just permuted, but
it's hard to tell.

With these changes, nothing in LegalizeDAG produces
illegal integer types anymore.  This is a prerequisite
for removing the LegalizeDAG type legalization code.

While there I noticed that the existing code doesn't
handle trunc store of f64 to f32: it turns this into
an i64 store, which represents a 4 byte stack smash.
I added a FIXME about this.  Hopefully someone more
motivated than I am will take care of it.

llvm-svn: 60964