void; it doesn't need to have a void type.

llvm-svn: 128212

llvm-svn: 128211

void return type. This fixes PR9487.

llvm-svn: 128197

llvm-svn: 128196

use it later. I couldn't make a test that hits this with the current code.

llvm-svn: 128195

llvm-svn: 128194

that were hit in practice.

llvm-svn: 128146

llvm-svn: 128068

llvm-svn: 128030

llvm-svn: 127997

As suggested by Nick Lewycky, ignore debugging intrinsics when trying to decide whether a destructor is empty or not.

llvm-svn: 127985

llvm-svn: 127984

Re-apply r127953 with fixes: eliminate empty return block if it has no predecessors; update dominator tree if cfg is modified.

llvm-svn: 127981

llvm-svn: 127976

llvm-svn: 127975

llvm-svn: 127974

Add an optimization to GlobalOpt that eliminates calls to __cxa_atexit, if the function passed is empty.

llvm-svn: 127970

to canonicalize IR", it broke a lot of things.

llvm-svn: 127954

to have single return block (at least getting there) for optimizations. This
is general goodness but it would prevent some tailcall optimizations.
One specific case is code like this:
int f1(void);
int f2(void);
int f3(void);
int f4(void);
int f5(void);
int f6(void);
int foo(int x) {
  switch(x) {
  case 1: return f1();
  case 2: return f2();
  case 3: return f3();
  case 4: return f4();
  case 5: return f5();
  case 6: return f6();
  }
}

=>
LBB0_2:                                 ## %sw.bb
  callq   _f1
  popq    %rbp
  ret
LBB0_3:                                 ## %sw.bb1
  callq   _f2
  popq    %rbp
  ret
LBB0_4:                                 ## %sw.bb3
  callq   _f3
  popq    %rbp
  ret

This patch teaches codegenprep to duplicate returns when the return value
is a phi and where the phi operands are produced by tail calls followed by
an unconditional branch:

sw.bb7:                                           ; preds = %entry
  %call8 = tail call i32 @f5() nounwind
  br label %return
sw.bb9:                                           ; preds = %entry
  %call10 = tail call i32 @f6() nounwind
  br label %return
return:
  %retval.0 = phi i32 [ %call10, %sw.bb9 ], [ %call8, %sw.bb7 ], ... [ 0, %entry ]
  ret i32 %retval.0

This allows codegen to generate better code like this:

LBB0_2:                                 ## %sw.bb
        jmp     _f1                     ## TAILCALL
LBB0_3:                                 ## %sw.bb1
        jmp     _f2                     ## TAILCALL
LBB0_4:                                 ## %sw.bb3
        jmp     _f3                     ## TAILCALL

rdar://9147433

llvm-svn: 127953

If an AllocaInst referred by DbgDeclareInst is used by a LoadInst then the LoadInst should also get a corresponding llvm.dbg.value intrinsic.

llvm-svn: 127924

llvm-svn: 127923

llvm-svn: 127922

llvm-svn: 127842

SCEV may generate expressions composed of multiple pointers, which can
lead to invalid GEP expansion. Until we can teach SCEV to follow strict
pointer rules, make sure no bad GEPs creep into IR.
Fixes rdar://problem/9038671.

llvm-svn: 127839

llvm-svn: 127837

This is done by lowering dbg.declare intrinsic into dbg.value intrinsic.
Radar 9143931.

llvm-svn: 127834

llvm-svn: 127832

llvm-svn: 127728

chose is having a non-memcpy/memset use and being larger than any native integer
type. Originally I chose having an access of a size smaller than the total size
of the alloca, but this caused some minor issues on the spirit benchmark where
SRoA runs again after some inlining.

This fixes <rdar://problem/8613163>.

llvm-svn: 127718

llvm-svn: 127716

llvm-svn: 127715

llvm-svn: 127684

llvm-svn: 127674

of pointers in an std::map.

llvm-svn: 127650

normal version.

Fixes rdar://9123638

llvm-svn: 127636

properties.
Added the self-wrap flag for SCEV::AddRecExpr.
A slew of temporary FIXMEs indicate the intention of the no-self-wrap flag
without changing behavior in this revision.

llvm-svn: 127590

llvm-svn: 127589

Early CSE pass so this patch reverts it to original source code.

llvm-svn: 127574

load and store reference same memory location, the memory location
is represented by getelementptr with two uses (load and store) and
the getelementptr's base is alloca with single use. At this point,
instructions from alloca to store can be removed.
(this pattern is generated when bitfield is accessed.)
For example,
%u = alloca %struct.test, align 4               ; [#uses=1]
%0 = getelementptr inbounds %struct.test* %u, i32 0, i32 0;[#uses=2]
%1 = load i8* %0, align 4                       ; [#uses=1]
%2 = and i8 %1, -16                             ; [#uses=1]
%3 = or i8 %2, 5                                ; [#uses=1]
store i8 %3, i8* %0, align 4

llvm-svn: 127565

llvm-svn: 127539