llvm-svn: 21839

suitable for tail calls.

llvm-svn: 21836

llvm-svn: 21809

llvm-svn: 21788

llvm-svn: 21786

llvm-svn: 21785

This makes reassociate realize that loads should be treated as unmovable, and
gives distinct ranks to distinct values defined in the same basic block, allowing
reassociate to do its thing.

llvm-svn: 21783

llvm-svn: 21781

llvm-svn: 21780

llvm-svn: 21778

llvm-svn: 21776

in.  This tends to get cases like this:

  X = cast ubyte to int
  Y = shr int X, ...

Tested by: shift.ll:test24

llvm-svn: 21775

llvm-svn: 21772

llvm-svn: 21771

llvm-svn: 21770

of trying to do local reassociation tweaks at each level, only process an expression
tree once (at its root).  This does not improve the reassociation pass in any real way.

llvm-svn: 21768

Reassociate/shifttest.ll

llvm-svn: 21761

llvm-svn: 21759

llvm-svn: 21737

and.ll:test31

llvm-svn: 21717

the result, turn signed shift rights into unsigned shift rights if possible.

This leads to later simplification and happens *often* in 176.gcc.  For example,
this testcase:

struct xxx { unsigned int code : 8; };
enum codes { A, B, C, D, E, F };
int foo(struct xxx *P) {
  if ((enum codes)P->code == A)
     bar();
}

used to be compiled to:

int %foo(%struct.xxx* %P) {
        %tmp.1 = getelementptr %struct.xxx* %P, int 0, uint 0           ; <uint*> [#uses=1]
        %tmp.2 = load uint* %tmp.1              ; <uint> [#uses=1]
        %tmp.3 = cast uint %tmp.2 to int                ; <int> [#uses=1]
        %tmp.4 = shl int %tmp.3, ubyte 24               ; <int> [#uses=1]
        %tmp.5 = shr int %tmp.4, ubyte 24               ; <int> [#uses=1]
        %tmp.6 = cast int %tmp.5 to sbyte               ; <sbyte> [#uses=1]
        %tmp.8 = seteq sbyte %tmp.6, 0          ; <bool> [#uses=1]
        br bool %tmp.8, label %then, label %UnifiedReturnBlock

Now it is compiled to:

        %tmp.1 = getelementptr %struct.xxx* %P, int 0, uint 0           ; <uint*> [#uses=1]
        %tmp.2 = load uint* %tmp.1              ; <uint> [#uses=1]
        %tmp.2 = cast uint %tmp.2 to sbyte              ; <sbyte> [#uses=1]
        %tmp.8 = seteq sbyte %tmp.2, 0          ; <bool> [#uses=1]
        br bool %tmp.8, label %then, label %UnifiedReturnBlock

which is the difference between this:

foo:
        subl $4, %esp
        movl 8(%esp), %eax
        movl (%eax), %eax
        shll $24, %eax
        sarl $24, %eax
        testb %al, %al
        jne .LBBfoo_2

and this:

foo:
        subl $4, %esp
        movl 8(%esp), %eax
        movl (%eax), %eax
        testb %al, %al
        jne .LBBfoo_2

This occurs 3243 times total in the External tests, 215x in povray,
6x in each f2c'd program, 1451x in 176.gcc, 7x in crafty, 20x in perl,
25x in gap, 3x in m88ksim, 25x in ijpeg.

Maybe this will cause a little jump on gcc tommorow :)

llvm-svn: 21715

llvm-svn: 21713

llvm-svn: 21712

llvm-svn: 21709

This implements set.ll:test20.

This triggers 2x on povray, 9x on mesa, 11x on gcc, 2x on crafty, 1x on eon,
6x on perlbmk and 11x on m88ksim.

It allows us to compile these two functions into the same code:

struct s { unsigned int bit : 1; };
unsigned foo(struct s *p) {
  if (p->bit)
    return 1;
  else
    return 0;
}
unsigned bar(struct s *p) { return p->bit; }

llvm-svn: 21690

llvm-svn: 21653

llvm-svn: 21647

Implement load.ll:test7

llvm-svn: 21645

llvm-svn: 21565

llvm-svn: 21541

llvm-svn: 21500

llvm-svn: 21495

Completely rework the 'setcc (cast x to larger), y' code.  This code has
the advantage of implementing setcc.ll:test19 (being more general than
the previous code) and being correct in all cases.

This allows us to unxfail 2004-11-27-SetCCForCastLargerAndConstant.ll,
and close PR454.

llvm-svn: 21491

llvm-svn: 21480

any constant RHS, not just a constant integer RHS.  This implements
select.ll:test17

llvm-svn: 21470

llvm-svn: 21427

        %shortcirc_val = select bool %tmp.1, bool true, bool %tmp.4             ; <bool> [#uses=1]
        %tmp.6 = cast bool %shortcirc_val to int                ; <int> [#uses=1]

into this:

        %shortcirc_val = or bool %tmp.1, %tmp.4         ; <bool> [#uses=1]
        %tmp.6 = cast bool %shortcirc_val to int                ; <int> [#uses=1]

not this:

        %tmp.4.cast = cast bool %tmp.4 to int           ; <int> [#uses=1]
        %tmp.6 = select bool %tmp.1, int 1, int %tmp.4.cast             ; <int> [#uses=1]

llvm-svn: 21389

Make IPSCCP strip off dead constant exprs that are using functions, making
them appear as though their address is taken.  This allows us to propagate
some more pool descriptors, lowering the overhead of pool alloc.

llvm-svn: 21363

llvm-svn: 21354

llvm-svn: 21320